1Laboratory of Viral Immunopathology, Unit of Infectious Diseases and Hepatology, Azienda Ospedaliero-Universitaria di Parma, Parma 43126, Italy.
2Toxicology and Advanced Diagnostics, Ospedale Civile S. Agostino-Estense, Modena 41126, Italy.
Correspondence Address: Dr. Gabriele Missale, Laboratory of Viral Immunopathology, Unit of Infectious Diseases and Hepatology, Azienda Ospedaliero-Universitaria di Parma, Parma 43126, Italy. E-mail: firstname.lastname@example.org
© The Author(s) 2018. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, sharing, adaptation, distribution and reproduction in any medium or format, for any purpose, even commercially, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
The multiplicity and phenotype of intratumoral immune infiltrate have been shown to influence the clinical outcome of hepatocellular carcinoma (HCC), thus providing a strong rationale to therapeutic interventions aimed at restoring the dysfunctional immune response against the tumor. Improving the knowledge of the complex interactions between transformed hepatocytes, nonparenchymal resident cells, and infiltrating immune cells (characterizing the HCC microenvironment) will be instrumental to increase the success rate of existing immunotherapeutic strategies and to identify new potential targets for intervention or biomarkers to optimize the selection of candidate patients.
Hepatocellular carcinoma, immune checkpoint inhibitors, T lymphocytes, cytotoxic T lymphocytes, natural killer cells, macrophages, cytokines
The liver immune landscape fosters tolerance towards foreign antigens driven by portal blood. Liver sinusoidal endothelial cells (LSECs) that separate liver parenchyma from sinusoidal blood, liver resident macrophages (Kupffer cells), hepatic stellate cells (HSCs), and dendritic cells (DCs) exert antigen presenting cell (APC) function and participate in the tolerogenic liver environment. Innate immune cells such as natural killer (NK), NKT and γ/δ T cells are found at higher frequency in the liver, as Foxp3+ regulatory T cells (Tregs). The liver environment is also characterized by increased expression of immunosuppressive cytokines such as interleukin (IL)-10 and transforming growth factor (TGF)-β.
Hepatocellular carcinoma (HCC) initiation and progression are multi-step processes profoundly influenced by the interplay between hepatocytes and immune cells. Immunotolerance is disrupted in chronic liver disease where persistent infections with hepatitis B virus (HBV) or hepatitis C virus (HCV), accumulation of fat, exogenous toxic substances (alcohol) or iron overload (haemochromatosis) enhance inflammatory signals triggering a cycle of cell death/regeneration and compensatory fibrosis, leading to liver cirrhosis, that represents a pre-neoplastic state. Chronic inflammation induces the accumulation of reactive oxygen species, generating epigenetic changes and chromosomal instability that contribute to tumor initiation, with expression of neo-antigens and/or deregulation of the expression of oncofetal and cancer testis antigens such as alpha-fetoprotein (AFP), glypican-3 (GPC-3), melanoma-antigen gene (MAGE) family, NY-ESO.1.
Cytotoxic T cells (CTLs) recognizing tumor-associated antigen (TAAs) have been detected in HCC patients and their abundance is associated with patient survival[3-5]. CD8+ and CD4+ T cells were shown to accumulate in early HCC with a progressive decrease in late stages, that represents a negative predictor for disease outcome[3,6]. TAA-specific CD8+ T cells from peripheral blood produce interferon (IFN)-γ upon stimulation, but tumour-infiltrating lymphocytes fail to do so, indicating the progressive exhaustion of intratumour CD8+ T cells. Exhausted T cells are characterized by impaired effector function and sustained expression of co-inhibitory receptors, and cannot mature into memory T cells.
NK cells account for 25%-50% of the total number of liver lymphocytes and are strongly implicated in the anti-tumor response. Impaired effector function of NK cells was reported in HCC and related to disease outcome[7,8]. Several mechanisms have been implicated in NK cell dysfunction: the genetic make-up of KIR NK cell receptors[9-11], a higher percentage of NK-cells co-expressing inhibitory NKG2A and activating NKp30-NKp46 receptors[12,13], myeloid-derived suppressor cells (MDSCs)-mediated suppression[14-16], increased prevalence of a dysfunctional CD11bnegCD27neg NK-cell subset.
Among factors contributing to the immune suppressive microenvironment of HCC are cell-mediated mechanisms, the secretion of cytokines and chemokines by tumor, stromal, and infiltrating cells, and the immunoediting of TAAs[18,19]. In this context, adaptive immune response exerts a dual role with seemingly opposite functions, being part of the inflammatory environment that likely plays a major role in tumor promotion, but hampering tumor dissemination through cytotoxic function against transformed cells.
The development and progression of HCC evolve through a dynamic interaction between tumor cells, nonparenchymal resident cells such as Kupffer cells (KCs), HSCs, LSECs, infiltrating immune cells and immune mediators. All these elements participate in the tumor microenvironment that exerts a profound influence on the evolution of disease. The many factors that co-operate to the immune landscape of HCC represent potential targets for therapeutic intervention.
Immune checkpoints are coinhibitory molecules that control the duration and the strength of immune response to prevent over-activation of T cells. This class of molecules includes CTLA-4, PD-1, TIM-3, lymphocyte activation gene 3 protein (LAG-3) and B and T lymphocyte attenuator (BTLA). Immune checkpoints are exploited by tumors as mechanisms of immune evasion and may therefore become major targets of immune therapeutic strategies.
PD-1 is expressed by activated T and B lymphocytes, NK cells, Treg cells, MDSCs, monocytes and DCs[24,25]. The expression of PD-1 is induced by several cytokines including IFN-γ[26,27]. Under hypoxic conditions, production of hypoxia-inducible factor (HIF)-1 induces the expression of PD-L1, the PD-1 ligand, in MDSCs and tumor cells[22,27,28]. The interaction between PD-1 and PD-L1 inhibits T cell effector function and leads to T cell exhaustion. The immune infiltrate of HCC is enriched in PD1+ CD8+ cells and their abundance is associated with disease prognosis. The expression of PD-L1 in HCC has also been reported as a prognostic factor of shorter disease-free and overall survival[31-34].
TIM-3 is a transmembrane protein expressed on various immune cells and interacting with multiple ligands among which galectin-9, a soluble protein expressed by several tissues including liver that negatively regulates Th1 cell function. In addition, TIM-3+ Treg cells exhibit enhanced suppressor activity. A role of the TIM-3/galectin-9 pathway in the determination of HCC-infiltrating T cell dysfunction has been reported.
LAG-3 binds MHC class II molecules with high affinity[25,39] thus reducing co-stimulatory function of DCs. LAG-3 is upregulated upon activation of T cells and is a marker of exhausted T cells. Its activation and, as a consequence, its blockade are synergistic with PD-1[42,43]. BTLA is upregulated on activated lymphocytes and on tumour-specific CD8+ T cells in patients with cancer. High expression of the BTLA ligand HVEM (herpesvirus entry mediator) has been reported in patients with HCC and is associated with reduced lymphocyte infiltration and poorer prognosis.
Cytokines are membrane-bound or secreted proteins involved in the regulation of immune cell function, inflammation and angiogenesis. Their pleiotropic roles include pro- and anti-inflammatory functions. CD4+ T helper cells produce either Th1 cytokines [e.g., interleukin (IL)-1, IL-2, IL-12, IL-15, tumor necrosis factor (TNF)-α and IFN-γ] usually defined pro-inflammatory, or Th2 cytokines (e.g., IL-4, IL-8, IL-10 and IL-5) mainly exerting anti-inflammatory functions.
Increased levels of IL-10 and TGF-β and reduced levels of IFN-γ have been detected in plasma from HCC patients. In liver tissue IL-10 is produced by DCs, KCs, HSCs, LSECs, MDSCs and T cells, inducing tolerance[48,49]. Tolerogenic effect of IL-10 is linked to inhibition of CD4+ T cell activation and, as a consequence, of cytotoxic CD8+ T-cell function. In addition IL-10 further interferes with T cell activation by downregulating the expression of MHC-II and CD80/CD86 on APCs and of NF-kB, a transcription factor strongly implicated in inflammatory responses. Despite its immunosuppressive activity in the context of inflammation, several studies report an immune-stimulatory role of IL-10 on CD8+ T-cell and NK-cell cytotoxic activity in experimental tumor models[54-56].
TGF-β, produced by parenchymal and non-parenchymal liver cells, is implicated in the maintenance of liver immune homeostasis and may exert a suppressive function towards anti-tumor immune reaction. TGF-β inhibits the expression of the transcription factors T-bet and GATA3, essential for the conversion of naive CD4+ T cells into Th1 and Th2 CD4+ T cells, respectively[58,59]. Conversely, TGF-β induces the differentiation of naive CD4+ T-cells into Tregs, inhibits the differentiation of naive CD8+ T cells to effector cells[60,61] and decreases perforin and IFN-γ expression, further impairing cytotoxic CD8+ T-cell activity.
Immune evasion of tumor cells may be linked to altered antigen processing and presentation, deriving from HLA class I downregulation or from 2 microglobulin mutation/deletion. HLA class I expression is essential for antigen presentation to CTLs and for tumor cell recognition by NK cells. Tumor cell elimination by NK cells may be also impaired by decreased expression of the NKG2D ligand ULBP1 that correlates with early recurrence of HCC. Another mechanism of HCC immune evasion from NK cell killing has been ascribed to the impaired interaction between NKG2D and its stress-induced ligands MIC-A and -B, that are upregulated on tumor cells. In advanced HCC, tumor cells escape from NK-mediated immunosurveillance through shedding of MIC-A that induces downregulation of NKG2D thus affecting NK cell effector function.
Together with shared oncofetal and cancer-testis antigens, driver and passenger mutations occurring in the tumor cell genome can generate tumor-specific neoantigens that can contribute to tumor immunogenicity and represent potential immunotherapeutic targets. Like viral antigens, TAAs undergo immune selective pressure that triggers the selection of resistant variants with survival advantage due to lower immunogenicity or immunosuppressive activity. The genetic instability of transformed cells favors this phenomenon of antigenic immunoediting. Immune escape may also result from the secretion by HCC cells of immunosuppressive molecules as TGF-β, IL-10, indoleamine 2,3-dioxygenase (IDO), arginase, or from decreased co-stimulatory/increased inhibitory checkpoint signaling.
MDSCs represent a heterogeneous population of immature myeloid cells that share suppressive functions[71,72] through different mechanisms: depletion of arginine and cysteine that are essential for T cell function, and release of reactive oxygen and nitrogen species that disrupt TCR signaling. In addition, MDSCs promote tumor progression through neo-angiogenesis due to vascular endothelial growth factor (VEGF) production, and through enhanced tumor cell survival and dissemination.
In HCC MDSCs have been shown to inhibit NK cell function via NKp30 receptor or through membrane-bound TGF-β and to induce Tregs by IL-10 and TGF-β production. A specific CD14pos HLA-DRneg/low MDSC subset increased in tumor tissue and peripheral blood of patients with HCC was implicated the induction of Tregs. The multiplicity of this MDSC subset was reported as a negative prognostic factor for HCC recurrence after resection, radiation therapy, hepatic arterial infusion chemotherapy, as well as for tumor progression.
MDSCs are recruited by cytokines and chemokines secreted by tumor cells[72,82]. Senescent hepatocytes were shown to recruit immature MDSCs able to differentiate into macrophages through C-C motif chemokine ligand 2 (CCL2)-CCR2 signaling, thus preventing HCC initiation. However, in the presence of HCC, immature MDSCs do not differentiate thus contributing to the immunotolerant environment through NK-cell inhibition.
Kupffer cells (KCs), the liver resident macrophages, represent about 80% of the macrophages in the body and contribute to the maintenance of liver immune tolerance through their anti-inflammatory function exerted by upregulation of PDL-1 expression, downregulation of costimulatory molecules, secretion of IDO and IL-10. In human HCC, Kupffer cells in the peritumoral margin express higher levels of PD-L1 compared to non-tumorous liver, thus inhibiting CD8+ T cell effector function. Blockade of PD-1/PDL-1 interaction in vitro was able to restore T cell killing in vitro.
The HCC immune microenvironment induces the polarization of macrophages towards the M2 phenotype typical of the tumour-associated macrophages (TAMs). M2 macrophages are characterized by producing high levels of IL-10 that induce Treg expansion and impairs NK cell activation. In addition, TAM promote tumor angiogenesis and dissemination[91,92]. A distinct subset of monocytes expressing TIE2 with enhanced pro-angiogenic properties has been described in peripheral blood and in tumor infiltrate[93-95]. In human HCV-related HCC this monocyte subpopulation was related to neo-angiogenesis and to prognosis.
Tregs are CD4+ T cells expressing CD25, CTLA-4, CD62L and FoxP3. Tregs exert inhibitory functions through multiple mechanisms, among which IL-2 depletion by CD25 (IL-2 receptor), competition with CD28 by CTLA-4, CTLA-4-mediated downregulation of CD80 and CD86, expression of TGF-β and IL-10. The recruitment of Tregs in HCC occurs via the CCR6-CCL20 axis and CCL22 induction by tumor cell-secreted IL-1α. In addition, FoxP3 upregulation and conversion of CD4+ T cells into Tregs may be fostered by poor stimulation of naive CD4+ T cells combined with TGF-b signalling by tumor cells.
In patients with HCC, FoxP3+ Tregs are increased both in peripheral blood[102,103] and in tumor tissue[31,103], and the abundance of tumour-infiltrating Tregs is associated with intra-tumoral macrophages. Several studies support a negative correlation between Treg infiltrate and effector function of intra-tumoral CD8+ T cells[47,103] and a direct role of Treg infiltration over disease progression and overall survival[99,103-105].
HSCs play a role in HCC progression through release of hepatocyte growth factor and induction of both MDSC[107,108] and Treg accumulation. In addition, HSCs can also directly induce T cell apoptosis through PD-L1 expression. Activated HSCs interact with monocytes inducing an immunosuppressive environment and contributing to poor prognosis in HCC.
NKT cells are a heterogeneous group of T lymphocytes sharing properties of both T cells and NK cells. NKT cells recognize glycolipid antigens via an invariant TCR α chain. The CD4+ iNKT-cells have been found to be enriched in intrahepatic malignant tumors. Intra-tumoral CD4+ iNKT-cells produce Th2 cytokines that can inhibit expansion of tumor antigen-specific CD8+T-cells. Consistent with this view, we observed that enrichment of iNKT cells in HCC infiltrate was predictive of shorter TTR.
Several other infiltrating or stromal cell types co-operate to the generation of immunosuppressive tumor microenvironment. A population of PD-1-positive B cells has been identified in HCC. This cell subset was shown to suppress anti-tumor T cell response through PD-1-PDL-1 interaction and to promote disease progression.
LSECs express PDL-1 and contribute to the immunosuppressive environment by TGF-β-dependent induction of Tregs. A subset of CD14+ DCs with suppressor function has been detected in patients with HCC. These DCs expressing high levels of CTLA-4 and PD-1 inhibit T-cell response through production of IL-10 and indoleamine-2,3-dioxygenase (IDO). Th17 cells are a IL-17-producing CD4+ T cell subset that plays an important role in the maintenance of mucosal barriers. Increased frequency of CCR4+CCR6+, but not CCR4-CCR6+ Th17+ cells was reported in peripheral blood from patients with HCC. The CCR4+CCR6+Th17+ cell subset was shown to impair CD8+ T cell effector functions. Neutrophils release cytokines that contribute to the tumor microenvironment either promoting or inhibiting tumor progression. In HCC, neutrophils have been shown to recruit macrophages and Tregs fostering tumor progression and resistance to sorafenib. Tumor-associated fibroblasts (TAFs) are essential components of the HCC microenvironment and support tumor progression through the secretion of various cytokines and growth factors. HCC-associated TAFs inhibit NK-cell function by secreting prostaglandin E2 and IDO. In addition, TAFs have been shown to release IL-6 and SDF-1a (CXCL-12), which induce MDSC generation and activation thus impairing anti-tumor immune response.
The scenario of the immune mechanisms operative in HCC is quite complex with liver intrinsic immunosuppressive environment associated with several mechanisms common to solid tumors. Physiologically, with the exception on anecdotal cases the tumor will escape, avoid, adapt to or overcome the immune mediated mechanism aimed at rejection of transformed cells. From the therapeutic perspective the problem has been approached by several strategies focusing on potentiation of different effector immune cells, tumor antigens made immunogenic, block of negative costimulatory pathways or immunosuppressive cells or soluble mediators.
Adoptive transfer of autologous cytokine activated killer cells (CIK) has been one of the first immunotherapeutic approaches. Anti-CD3 antibodies in the presence of IL-2, IL-1 and IFN-γ expand and activate ex vivo NKT-cells that are reinfused in the patient. This approach has been performed as adjuvant treatment in patients undergoing liver resection for HCC or percutaneous ablative treatments like percutaneous ethanol injection (PEI) or transarterial chemo-embolization (TACE). A systematic review of phase II and III studies conducted in patients undergoing CIK infusion either alone or associated with resection, PEI or TACE, showed a significant effect on overall and progression free survival. More recently a randomized controlled trial of adjuvant CIK was conducted in patients undergoing curative liver resection showing a significant effect on TTR but no effect on DFS and OS. Another randomized phase 3 study from Korea could demonstrate that patients receiving CIK post-resection, PEI or radiofrequency thermal ablation (RFA) had a significantly increased recurrence-free and overall survival. Several other studies with similar methodological approach are ongoing in patients with HCC and other solid tumors.
More than 15 years ago, discovery of TAAs raised enthusiasm on their possible use for vaccination strategies. Several different approaches have been employed from tumor lysates to individual epitopes associated with different adjuvants by parenteral route (subcutaneous, intradermal or intravenous), or intratumoral injection. Alternatively DCs pulsed with synthetic peptides or transfected with RNA vectors have been used to expand tumor-specific T-cell response. Target antigens for HCC have been cancer testis TAAs like MAGE, synovial sarcoma X breakpoint 2 (SSX-2) and NY-ESO-1, beside GPC-3, human telomerase reverse transcriptase (TERT), carcinoembryonic antigen (CEA) and AFP. Clinical trials have been conducted in patients with advanced or non-resectable HCC or as an adjuvant treatment in patients undergoing resection or RFA or TACE. Efficacy in these studies has been limited. Phase II studies with antigen-pulsed DCs, intradermal GPC-3 peptide, or intravenous tumor (HepG2 cell line) lysate-pulsed DCs have been conducted showing partial response associated with antigen-specific T-cells responses in PBMCs in some patients. In particular, antigen-pulsed DCs vaccination showed no tumor recurrence up to 24 weeks in 9 out of 12 treated patients. Phase I GPC-3 studies achieved their aims: safety, immunogenicity and dose finding, however phase II studies with GPC-3 aimed at relapse prevention after curative treatments (surgery or RFA) failed to achieve clinically relevant results[129,130]. Infusion of autologous DCs pulsed with lysate of HepG2 cell line was performed in a phase II trial in patients with advanced HCC. Clinical response (either stable disease or partial response) was shown in 28% of patients performing at least three infusions. Treatment was safe and antigen-specific immune response could be demonstrated in some patients.
A particular vaccination strategy has been conducted with an oncolytic, genetically modified vaccinia virus (JX-594) that has been injected in the tumor lesions of advanced HCC patients. The rational of this approach is the release of tumor antigens from oncolytic tumor cells destruction associated with local expression of granulocyte-macrophage colony stimulating factor (GM-CSF), an inserted gene of the genetically modified vaccinia. JX-594 has been tested in a dose finding study showing improved overall survival in patients receiving a higher infectious dose compared to lower dose. A phase II trial failed to achieve survival advantage. In this trial however HCC patients were very advanced having progressed to sorafenib treatment. A phase III randomized clinical trial (NCT02562755) is now ongoing, comparing patients on sorafenib to patients undergoing three vaccination rounds followed by sorafenib treatment.
Table 1 represents a summary of completed clinical trials based on adoptive cell transfer and vaccines.
Adoptive cell transfer and vaccines for HCC immunotherapy
|Therapeutic approach||Target||Phase||Study population||No. of patients||Results||Ref.|
|CIK||na||II||Post-resection||76 + 74 controls||Improved RFS|||
|CIK||na||III||Post-resection||100 + 100 controls||Improved TTR|||
|CIK||na||III||Post-resection or RFA or PEI||114 + 112 controls||Improved RFS and OS|||
|Peptide vaccine||GPC-3||I||Advanced HCC||11||Improved CTL response|||
|Peptide vaccine||GPC-3||II||Post-resection or RFA||41||Improved RFS for patients with GPC-3 positive |
|DC pulsed HepG2 protein lysate||tumor antigens||II||Advanced HCC||35||PR 4%, SD 24%|||
|DC pulsed AFP, MAGE-1 and GPC-3||tumor antigens||I/II||Post-resection or RFA or PEI or TACE||12||Improved TTP vs. historical results|||
|Oncolytic virus JX-594||tumor antigens||II||Advanced HCC||30||Dose realated improved OS|||
More efficient adoptive cell transfer immunotherapeutic approaches, are represented by the CAR T-cell therapy which until now has been primarily used in hematologic malignancies. T cells are genetically engineered to express chimeric antigen receptors (CARs). Autologous engineered T cells are expanded ex vivo into the hundreds of millions and finally are infused in the patient. Third generation CARs are constituted of an immunoglobulin variable heavy chain (VH), a variable light chain (VL) connected to a transmembrane domain by a spacer and the transmembrane domain to 2 costimulatory molecules (e.g., CD27, CD28, 4-1BB, OX40) and CD3. This receptor when engaged can activate the effector cytotoxic T-cell, specifically redirected to the tumor antigen recognized by the VH and VL chains. As far as HCC, CAR-T have been designed with different specificities and phase I and phase I/II clinical trials are recruiting for patients with HCC or HCC and other solid tumors, targeting GPC-3, CEA and Mucin 1, cell surface associated (MUC-1).
A different approach that engages T and NK-cells in vivo to direct them against tumor cells is represented by bispecific antibodies (BsAb). BsAb against HCC and other solid tumors have been generated with different specificities. One arm of antibody binds a tumor antigen [GPC-3, epithelial cell adhesion molecule (EpCAM), osteopontin, VEGF] and the second can activate cytotoxic T or NK cells binding CD3 or CD16. A phase 1 dose escalation trial with BsAb specific for GPC-3 and CD3 is ongoing (NCT02748837).
Another approach to generate tumor-specific immune cells is cloning and TCR transfection of T and NK cells that are in vitro expanded and reinfused in the patients. These redirected effector cells, differently from CAR-T or BsAb, recognize tumor epitopes in the context of specific HLA-class I molecules, but have advantage to recognize endogenously processed antigens, that is the case of many known epitopes from tumor associated antigens or neo-antigens from somatic mutations of the tumor-cell. In fact, cell therapies based on CARs and antibodies can only recognize conformational antigens expressed on the surface of transformed cancer cells. Redirect T-cells have been clinically tested in a patient that developed extra-hepatic metastasis after liver transplantation for HCC in HBV-related liver disease. The tumor, but not the transplanted liver, expressed HBV antigens and autologous T-cells transfected with a TCR specific for HBsAg could expand in vivo and determine reduction of HBsAg serum levels.
The first clinical study on immune checkpoint inhibitors (ICIs) in HCC has been a phase II clinical trial targeting CTLA-4 in patients with advanced tumors in HCV chronic liver disease. The study showed partial response in 17.6% of patients and a good safety profile. Transaminase flares were observed in some of the patients after the first anti-CTLA-4 administrations that however did not require any immunosuppressive intervention. Interestingly in this study an enhanced HCV-specific T-cell response associated with significant drop of HCV viremia was observed. Several other studies have started. The main target has been PD-1 and its ligand PD-L1 and recently FDA has granted accelerated approval for anti-PD-1 in patients that had been previously treated with sorafenib, based on the phase I/II Checkmate-040 study (that showed an overall response rate of 18.2% and acceptable safety profile). There was concern on possible immune mediated liver toxicity in patients with liver cirrhosis and chronic HBV or HCV infection. However, until now safety profile of ICIs has not shown to be different from what observed for melanoma and non-small cell lung cancer (NSCLC) and even if substantial transaminase flares have been described, patients coming off therapy for adverse events are in line with what observed for other cancers treated with anti-PD-1 or anti-PD-L1.
First line studies comparing ICIs to sorafenib treatment are ongoing in patients with advanced HCC: two studies from different companies, CheckMate-459 and NCT03412773 with anti-PD-1 and the HIMALAYA study testing the combined activity of an anti-PD-L1 and anti-CTLA-4. The adjuvant role of ICIs is also tested with anti-PD-1 versus placebo in patients with early stage HCC undergoing surgery or ablation evaluating relapse free survival as primary endpoint (NCT03383458). A study combining RFA, cryablation or TACE and-CTLA-4 in advanced HCC has been recently published. Subtotal ablative treatments were given after the second anti-CTLA4 infusion. The study demonstrated feasibility and no dose-limiting toxicity of this therapeutic approach. Moreover 5/19 evaluable patients presented partial response. Interestingly pre and post-treatment biopsy showed an enrichment of CD3 and CD8 positive T-cells infiltrating the tumor after treatment that positively correlated with clinical response. Table 2 represents a more comprehensive list of completed and ongoing clinical trials with ICIs.
Immuno check points inhibitors for HCC immunotherapy
|Target||Number of patients||Trial||First line/Second line||Status||Results||Ref or study number|
|CTLA-4||20||Phase II||Adjuvant TACE and ablation||Completed||PR 17.6 %||134|
|CTLA-4||32||Pilot||Second||Completed||PR 15.6 %||137|
|PD-1||576||Phase I/II||FIirst and Second||Completed||PR 20 % (expansion) 15% (dose excalating)||135|
|PD-1||723||Phase III||First vs. sorafenib||Not recruiting active||NA||NCT02576509|
|PD-1||660||Phase III||First vs. sorafenib||Recruiting||NA||NCT03412773|
|PD-1||104||Phase II||Second||Not recruiting active||PR 15.4 %, CR 1%||NCT02702414|
|PD-1||408||Phase III||Second||Not recruiting active||NA||NCT02702401|
|PD-1||530||Phase III||Adjuvant SR and ablation||Recruiting active||NA||NCT03383458|
|PD-L1||114||Phase I||Second||Recruiting active||NA||NCT02519348|
|PD-L1 ± CTLA-4||440||Phase II||Second||Recruiting active||NA||NCT02519348|
|PD-L1 ± CTLA-4||1200||Phase III||First||Recruiting active||NA||NCT03298451|
Until now it is not possible to understand which immune checkpoint is the most promising for HCC patients. Experience from other solid malignancies suggests that combining different ICIs may improve clinical response, given the increased risk of severe toxicities. Vaccination protocols combined with ICIs are tested in clinical trials, representing an alternative treatment strategy expanding tumor-specific T-cell populations in vivo.
Another immunotherapeutic approach that cannot be strictly considered an ICI is represented by an anti-TGFbRI (Galunisertib) that is expected to block the immunosuppressive and pro-tumorogenic effect of TGF-β. It has been tested in association with sorafenib in a phase II clinical trial (NCT01246986) showing a median overall survival of 17.9 months that represents an improved survival compared to sorafenib historical results.
Although promising, the results of immunotherapy for HCC are far from optimal. Recent trials suggest that combined regimens with different ICIs would lead to higher rates of clinical response, but with increased risk of immune-related adverse events. The development of biomarkers with acceptable predictive value will be instrumental to maximize the benefit of immunotherapy.
As previously described, the anti-cancer immune response is the results of multiple factors deriving from the antigenic characteristics of the tumor, the multiplicity and the phenotype of TAA-specific immune cells, the latter mainly dictated by the tumor microenvironment. From this perspective the use of a single analyte biomarker might not be sufficient to recapitulate the complex interplay between tumor biology and immune response. Immunostaining with anti-PD-L1 antibodies has been the first approach evaluated to predict the response to anti-PD-1 treatments. However, this marker was shown to be unreliable especially for its poor negative predictive value[139,140]. In addition, the intrinsic variability of immunohistochemistry together with the heterogeneity and dynamic nature of PD-L1 expression in tumor and immune cells raise concern about its adequacy to clinical standards.
Multianalyte profiles may represent promising tools for the accurate prediction of immunotherapy outcome. The response to PD-1 blockade has been related to the presence of immunogenic neoantigens arising from the active expression of viral genes or from increased tumor mutational burden[140,142]. According to this view, pembrolizumab (anti-PD-1) was approved by FDA in 2017 for the treatment of unresectable or metastatic solid tumors with mutations in genes for DNA mismatch repair (dMMR) or microsatellite instability (MSI), independently from the tissue of origin. However, dMMR or MSI are infrequent in HCC.
The multiplicity, composition, activity and location of tumor-infiltrating immune cells have been shown to represent prognostic markers in HCC[4-6,104]. A subset of HCCs characterized by an inflammatory gene signature has been detected in several studies[144-148]. A recent study identified in about 25% of patients an immune-specific molecular class of HCC including two distinct subtypes, characterized by a prevalent adaptive T-cell response and an exhausted immune response, respectively. Interestingly, immune gene profiles suggesting active anti-tumoral response have been associated with longer time to recurrence[149,150].
Gene signatures may provide a global picture of the complex tumor immune landscape. This approach represents a tool for the discrimination of tumors with pre-existing immune infiltrate, more likely to respond to interventions aimed at overcoming inhibitory factors. In a recent paper a so-called “T cell-inflamed gene expression profile”, containing IFN-γ-responsive genes related to antigen presentation, chemokine expression, cytotoxic activity, and adaptive immune resistance, was shown to be necessary, but not always sufficient, for clinical response to pembrolizumab in 10 tumor types.
The lack or low abundance of cellular infiltrate may indicate a defect in innate immunity or in immune cell trafficking and suggest alternative therapeutic approaches. Consistent with observations made in other tumors, a molecular profile of “immune exclusion” is associated with activated Wnt/β-catenin pathway signaling in HCC. This suggests the potential of Wnt/β-catenin activation as a biomarker predictive of resistance to checkpoint inhibitors. As a future perspective, gene signatures integrating information about tumor cell mutational burden, presence and nature of the immune infiltrate, possibly at different investigational levels (genetic, genomic, epigenetic) would provide information for a comprehensive therapeutic stratification of HCC patients.
The authors contributed equally to the conception, design, writing, and revision of this review article.Availability of data and materials
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1. Thomson AW, Knolle PA. Antigen-presenting cell function in the tolerogenic liver environment. Nat Rev Immunol 2010;10:753-66.DOIPubMed
2. Moris D, Lu L, Qian S. Mechanisms of liver-induced tolerance. Curr Opin Organ Transplant 2016;22:71-8.DOI
3. Flecken T, Schmidt N, Hild S, Gostick E, Drognitz O, Zeiser R, Schemmer P, Bruns H, Eiermann T, Price DA, Blum HE, Neumann-Haefelin C, Thimme R. Immunodominance and functional alterations of tumor-associated antigen-specific CD8+ T-cell responses in hepatocellular carcinoma. Hepatology 2014;59:1415-26.DOIPubMedPMC
4. Unitt E, Marshall A, Gelson W, Rushbrook SM, Davies S, Vowler SL, Morris LS, Coleman N, Alexander GJ. Tumour lymphocytic infiltrate and recurrence of hepatocellular carcinoma following liver transplantation. J Hepatol 2006;45:246-53.DOIPubMed
5. Wada Y, Nakashima O, Kutami R, Yamamoto O, Kojiro M. Clinicopathological study on hepatocellular carcinoma with lymphocytic infiltration. Hepatology 1998;27:407-14.DOIPubMed
6. Fu J, Zhang Z, Zhou L, Qi Z, Xing S, Lv J, Shi J, Fu B, Liu Z, Zhang JY, Jin L, Zhao Y, Lau GK, Zhao J, Wang FS. Impairment of CD4+ cytotoxic T cells predicts poor survival and high recurrence rates in patients with hepatocellular carcinoma. Hepatology 2013;58:139-49.DOIPubMed
7. Cai L, Zhang Z, Zhou L, Wang H, Fu J, Zhang S, Shi M, Zhang H, Yang Y, Wu H, Tien P, Wang FS. Functional impairment in circulating and intrahepatic NK cells and relative mechanism in hepatocellular carcinoma patients. Clin Immunol 2008;129:428-37.DOIPubMed
8. Taketomi A, Shimada M, Shirabe K, Kajiyama K, Gion T, Sugimachi K. Natural killer cell activity in patients with hepatocellular carcinoma: a new prognostic indicator after hepatectomy. Cancer 1998;83:58-63.DOI
9. López-Vázquez A, Rodrigo L, Martínez-Borra J, Pérez R, Rodríguez M, Fdez-Morera JL, Fuentes D, Rodríguez-Rodero S, Gonzáez S, López-Larrea C. Protective effect of theHLA-Bw4I80 epitope and the killer cell immunoglobulin-like receptor 3DS1 gene against the development of hepatocellular carcinoma in patients with hepatitis C virus infection. J Infect Dis 2005;192:162-5.DOIPubMed
10. Cariani E, Pilli M, Zerbini A, Rota C, Olivani A, Zanelli P, Zanetti A, Trenti T, Ferrari C, Missale G. HLA and killer immunoglobulin-like receptor genes as outcome predictors of hepatitis C virus-related hepatocellular carcinoma. Clin Cancer Res 2013;19:5465-73.DOIPubMed
11. Cariani E, Missale G. KIR/HLA immunogenetic background influences the evolution of hepatocellular carcinoma. Oncoimmunology 2013;2:e26622.DOIPubMedPMC
12. Cariani E, Pilli M, Barili V, Porro E, Biasini E, Olivani A, Dalla Valle R, Trenti T, Ferrari C, Missale G. Natural killer cells phenotypic characterization as an outcome predictor of HCV-linked HCC after curative treatments. Oncoimmunology 2016;5:e1154249.DOIPubMedPMC
13. El Costa H, Casemayou A, Aguerre-Girr M, Rabot M, Berrebi A, Parant O, Clouet-Delannoy M, Lombardelli L, Jabrane-Ferrat N, Rukavina D, Bensussan A, Piccinni MP, Le Bouteiller P, Tabiasco J. Critical and differential roles of NKp46- and NKp30-activating receptors expressed by uterine NK cells in early pregnancy. J Immunol 2008;181:3009-17.DOIPubMed
14. Hoechst B, Voigtlaender T, Ormandy L, Gamrekelashvili J, Zhao F, Wedemeyer H, Lehner F, Manns MP, Greten TF, Korangy F. Myeloid derived suppressor cells inhibit natural killer cells in patients with hepatocellular carcinoma via the NKp30 receptor. Hepatology 2009;50:799-807.DOIPubMed
15. Li H, Han Y, Guo Q, Zhang M, Cao X. Cancer-expanded myeloid-derived suppressor cells induce anergy of NK cells through membrane-bound TGF-β1. J Immunol 2009;182:240-9.DOIPubMed
16. Wu Y, Kuang DM, Pan WD, Wan YL, Lao XM, Wang D, Li XF, Zheng L. Monocyte/macrophage elicited natural killer cell dysfunction in hepatocellular carcinoma is mediated by CD48/2B4 interactions. Hepatology 2013;57:1107-16.DOIPubMed
17. Zhang QF, Yin WW, Xia Y, Yi YY, He QF, Wang X, Ren H, Zhang DZ. Liver-infiltrating CD11b(-)CD27(-) NK subsets account for NK-cell dysfunction in patients with hepatocellular carcinoma and are associated with tumor progression. Cell Mol Immunol 2017;14:819-29.DOIPubMedPMC
18. Prieto J, Melero I, Sangro B. Immunological landscape and immunotherapy of hepatocellular carcinoma. Nat Rev Gastroenterol Hepatol 2015;12:681-700.DOIPubMed
19. Dunn GP, Bruce AT, Ikeda H, Old LJ, Schreiber RD. Cancer immunoediting: from immunosurveillance to tumor escape. Nat Immunol 2002;3:991-8.DOIPubMed
20. Ringelhan M, Pfister D, O'Connor T, Pikarsky E, Heikenwalder M. The immunology of hepatocellular carcinoma. Nat Immunol 2018;19:222-32.DOIPubMed
21. Krummel MF, Allison JP. CD28 and CTLA-4 have opposing effects on the response of T cells to stimulation. J Exp Med 1995;182:459-65.DOI
22. Hato T, Goyal L, Greten TF, Duda DG, Zhu AX. Immune checkpoint blockade in hepatocellular carcinoma: current progress and future directions. Hepatology 2014;60:1776-82.DOIPubMedPMC
23. Peggs KS, Quezada SA, Chambers CA, Korman AJ, Allison JP. Blockade of CTLA-4 on both effector and regulatory T cell compartments contributes to the antitumor activity of anti-CTLA-4 antibodies. J Exp Med 2009;206:1717-25.DOIPubMedPMC
24. Francisco LM, Salinas VH, Brown KE, Vanguri VK, Freeman GJ, Kuchroo VK, Sharpe AH. PD-L1 regulates the development, maintenance, and function of induced regulatory T cells. J Exp Med 2009;206:3015-29.DOIPubMedPMC
25. Nguyen LT, Ohashi PS. Clinical blockade of PD1 and LAG3—potential mechanisms of action. Nat Rev Immunol 2015;15:45-56.DOIPubMed
26. Quezada SA, Peggs KS. Exploiting CTLA-4, PD-1 and PD-L1 to reactivate the host immune response against cancer. Br J Cancer 2013;108:1560-5.DOIPubMedPMC
27. Zou W, Chen L. Inhibitory B7-family molecules in the tumour microenvironment. Nat Rev Immunol 2008;8:467-77.DOIPubMed
28. Noman MZ, Desantis G, Janji B, Hasmim M, Karray S, Dessen P, Bronte V, Chouaib S. PD-L1 is a novel direct target of HIF-1α, and its blockade under hypoxia enhanced MDSC-mediated T cell activation. J Exp Med 2014;211:781-90.DOIPubMedPMC
29. Barber DL, Wherry EJ, Masopust D, Zhu B, Allison JP, Sharpe AH, Freeman GJ, Ahmed R. Restoring function in exhausted CD8 T cells during chronic viral infection. Nature 2006;439:682-7.DOIPubMed
30. Shi F, Shi M, Zeng Z, Qi RZ, Liu ZW, Zhang JY, Yang YP, Tien P, Wang FS. PD-1 and PD-L1 upregulation promotes CD8(+) T-cell apoptosis and postoperative recurrence in hepatocellular carcinoma patients. Int J Cancer 2011;128:887-96.DOIPubMed
31. Cariani E, Pilli M, Zerbini A, Rota C, Olivani A, Pelosi G, Schianchi C, Soliani P, Silini EM, Trenti T, Ferrari C, Missale G. Immunological and molecular correlates of disease recurrence after liver resection for hepatocellular carcinoma. PLoS One 2012;7:e32493.DOIPubMedPMC
32. Zeng Z, Shi F, Zhou L, Zhang MN, Chen Y, Chang XJ, Lu YY, Bai WL, Qu JH, Wang CP, Wang H, Lou M, Wang FS, Lv JY, Yang YP. Upregulation of circulating PD-L1/PD-1 is associated with poor post-cryoablation prognosis in patients with HBV-related hepatocellular carcinoma. PLoS ONE 2011;6:e23621.DOIPubMedPMC
33. Wang BJ. Immunostaining of PD-1/PD-ls in liver tissues of patients with hepatitis and hepatocellular carcinoma. World J Gastroenterol 2011;17:3322-8.DOIPubMedPMC
34. Gao Q, Wang XY, Qiu SJ, Yamato I, Sho M, Nakajima Y, Zhou J, Li BZ, Shi YH, Xiao YS, Xu Y, Fan J. Overexpression of PD-L1 significantly associates with tumor aggressiveness and postoperative recurrence in human hepatocellular carcinoma. Clin Cancer Res 2009;15:971-9.DOIPubMed
35. Wada J, Ota K, Kumar A, Wallner EI, Kanwar YS. Developmental regulation, expression, and apoptotic potential of galectin-9, a β-galactoside binding lectin. J Clin Invest 1997;99:2452-61.DOIPubMedPMC
36. Zhu C, Anderson AC, Schubart A, Xiong H, Imitola J, Khoury SJ, Zheng XX, Strom TB, Kuchroo VK. The Tim-3 ligand galectin-9 negatively regulates T helper type 1 immunity. Nat Immunol 2005;6:1245-52.DOIPubMed
37. Gautron AS, Dominguez-Villar M, de Marcken M, Hafler DA. Enhanced suppressor function of TIM-3+FoxP3+ regulatory T cells. Eur J Immunol 2014;44:2703-11.DOIPubMedPMC
38. Li H, Wu K, Tao K, Chen L, Zheng Q, Lu X, Liu J, Shi L, Liu C, Wang G, Zou W. Tim-3/galectin-9 signaling pathway mediates T-cell dysfunction and predicts poor prognosis in patients with hepatitis B virus-associated hepatocellular carcinoma. Hepatology 2012;56:1342-51.DOIPubMed
39. Triebel F, Jitsukawa S, Baixeras E, Roman-Roman S, Genevee C, Viegas-Pequignot E, Hercend T. LAG-3, a novel lymphocyte activation gene closely related to CD4. J Exp Med 1990;171:1393-405.DOIPubMed
40. Workman CJ, Rice DS, Dugger KJ, Kurschner C, Vignali DA. Phenotypic analysis of the murine CD4-related glycoprotein, CD223 (LAG-3). Eur J Immunol 2002;32:2255-63.DOI
41. Wherry EJ, Ha SJ, Kaech SM, Haining WN, Sarkar S, Kalia V, Subramaniam S, Blattman JN, Barber DL, Ahmed R. Molecular signature of CD8+ T cell exhaustion during chronic viral infection. Immunity 2007;27:670-84.DOIPubMed
42. Woo SR, Turnis ME, Goldberg MV, Bankoti J, Selby M, Nirschl CJ, Bettini ML, Gravano DM, Vogel P, Liu CL, Tangsombatvisit S, Grosso JF, Netto G, Smeltzer MP, Chaux A, Utz PJ, Workman CJ, Pardoll DM, Korman AJ, Drake CG, Vignali DA. Immune inhibitory molecules LAG-3 and PD-1 synergistically regulate T-cell function to promote tumoral immune escape. Cancer Res 2012;72:917-27.DOIPubMedPMC
43. Matsuzaki J, Gnjatic S, Mhawech-Fauceglia P, Beck A, Miller A, Tsuji T, Eppolito C, Qian F, Lele S, Shrikant P, Old LJ, Odunsi K. Tumor-infiltrating NY-ESO-1-specific CD8+ T cells are negatively regulated by LAG-3 and PD-1 in human ovarian cancer. Proc Natl Acad Sci U S A 2010;107:7875-80.DOIPubMedPMC
44. Pasero C, Olive D. Interfering with coinhibitory molecules: BTLA/HVEM as new targets to enhance anti-tumor immunity. Immunol Lett 2013;151:71-5.DOIPubMed
45. Hokuto D, Sho M, Yamato I, Yasuda S, Obara S, Nomi T, Nakajima Y. Clinical impact of herpesvirus entry mediator expression in human hepatocellular carcinoma. Eur J Cancer 2015;51:157-65.DOIPubMed
46. Budhu A, Wang XW. The role of cytokines in hepatocellular carcinoma. J Leukoc Biol 2006;80:1197-213.DOIPubMed
47. Kalathil S, Lugade AA, Miller A, Iyer R, Thanavala Y. Higher frequencies of GARP+CTLA-4+Foxp3+ T regulatory cells and myeloid-derived suppressor cells in hepatocellular carcinoma patients are associated with impaired T-cell functionality. Cancer Res 2013;73:2435-44.DOIPubMedPMC
48. Hammerich L, Tacke F. Interleukins in chronic liver disease: lessons learned from experimental mouse models. Clin Exp Gastroenterol 2014;7:297-306.PubMedPMC
49. Erhardt A, Biburger M, Papadopoulos T, Tiegs G. IL-10, regulatory T cells, and Kupffer cells mediate tolerance in concanavalin A-induced liver injury in mice. Hepatology 2007;45:475-85.DOIPubMed
50. Taga K, Mostowski H, Tosato G. Human interleukin-10 can directly inhibit T-cell growth. Blood 1993;81:2964-71.PubMed
51. Greyer M, Whitney PG, Stock AT, Davey GM, Tebartz C, Bachem A, Mintern JD, Strugnell RA, Turner SJ, Gebhardt T, O'Keeffe M, Heath WR, Bedoui S. T cell help amplifies innate signals in CD8+DCs for optimal CD8+ T cell priming. Cell Rep 2016;14:586-97.DOIPubMed
52. Knolle PA, Uhrig A, Hegenbarth S, Loser E, Schmitt E, Gerken G, Lohse AW. IL-10 downregulates T cell activation by antigen-presenting liver sinusoidal endothelial cells through decreased antigen uptake via the mannose receptor and lowered surface expression of accessory molecules. Clin Exp Immunol 1998;114:427-33.DOIPubMedPMC
53. Asadullah K, Sterry W, Volk HD. Interleukin-10 therapy-review of a new approach. Pharmacol Rev 2003;55:241-69.DOIPubMed
54. Zheng LM, Ojcius DM, Garaud F, Roth C, Maxwell E, Li Z, Rong H, Chen J, Wang XY, Catino JJ, King I. Interleukin-10 inhibits tumor metastasis through an NK cell-dependent mechanism. J Exp Med 1996;184:579-84.DOIPubMed
55. Fujii S, Shimizu K, Shimizu T, Lotze MT. Interleukin-10 promotes the maintenance of antitumor CD8(t) T-cell effector function in situ. Blood 2001;98:2143-51.DOIPubMed
56. Mumm JB, Emmerich J, Zhang X, Chan I, Wu L, Mauze S, Blaisdell S, Basham B, Dai J, Grein J, Sheppard C, Hong K, Cutler C, Turner S, LaFace D, Kleinschek M, Judo M, Ayanoglu G, Langowski J, Gu D, Paporello B, Murphy E, Sriram V, Naravula S, Desai B, Medicherla S, Seghezzi W, McClanahan T, Cannon-Carlson S, Beebe AM, Oft M. IL-10 elicits IFNγ-dependent tumor immune surveillance. Cancer Cell 2011;20:781-96.DOIPubMed
57. Schon HT, Weiskirchen R. Immunomodulatory effects of transforming growth factor beta in the liver. Hepatobiliary Surg Nutr 2014;3:386-406.PubMedPMC
58. Gorelik L, Fields PE, Flavell RA. Cutting edge: TGF-beta inhibits Th type 2 development through inhibition of GATA-3 expression. J Immunol 2000;165:4773-7.DOIPubMed
59. Gorelik L, Constant S, Flavell RA. Mechanism of transforming growth factor beta-induced inhibition of T helper type 1 differentiation. J Exp Med 2002;195:1499-505.DOIPubMedPMC
60. Filippi CM, Juedes AE, Oldham JE, Ling E, Togher L, Peng Y, Flavell RA, von Herrath MG. Transforming growth factor-beta suppresses the activation of CD8+ T-cells when naive but promotes their survival and function once antigen experienced: a two-faced impact on autoimmunity. Diabetes 2008;57:2684-92.DOIPubMedPMC
61. McKarns SC, Schwartz RH. Distinct effects of TGF-beta 1 on CD4+ and CD8+ T cell survival, division, and IL-2 production: a role for T cell intrinsic Smad3. J Immunol 2005;174:2071-83.DOI
62. Thomas DA, Massague J. TGF-beta directly targets cytotoxic T cell functions during tumor evasion of immune surveillance. Cancer Cell 2005;8:369-80.DOIPubMed
63. Khong HT, Restifo NP. Natural selection of tumor variants in the generation of 'tumor escape' phenotypes. Nat Immunol 2002;3:999-1005.DOIPubMedPMC
64. Bauer S, Groh V, Wu J, Steinle A, Phillips JH, Lanier LL, Spies T. Activation of NK cells and T cells by NKG2D, a receptor for stress-inducible MICA. Science 1999;285:727-9.DOIPubMed
65. Kamimura H, Yamagiwa S, Tsuchiya A, Takamura M, Matsuda Y, Ohkoshi S, Inoue M, Wakai T, Shirai Y, Nomoto M, Aoyagi Y. Reduced NKG2D ligand expression in hepatocellular carcinoma correlates with early recurrence. J Hepatol 2012;56:381-8.DOIPubMed
66. Jinushi M, Takehara T, Tatsumi T, Hiramatsu N, Sakamori R, Yamaguchi S, Hayashi N. Impairment of natural killer cell and dendritic cell functions by the soluble form of MHC class I-related chain A in advanced human hepatocellular carcinomas. J Hepatol 2005;43:1013-20.DOIPubMed
67. Vogelstein B, Papadopoulos N, Velculescu VE, Zhou S, Diaz LA Jr, Kinzler KW. Cancer genome landscapes. Science 2013;339:1546-58.DOIPubMedPMC
68. Mittal D, Gubin MM, Schreiber RD, Smyth MJ. New insights into cancer immunoediting and its three component phases—elimination, equilibrium and escape. Curr Opin Immunol 2014;27:16-25.DOIPubMedPMC
69. Makarova-Rusher OV, Medina-Echeverz J, Duffy AG, Greten TF. The yin and yang of evasion and immune activation in HCC. J Hepatol 2015;62:1420-9.DOIPubMed
70. Medina-Echeverz J, Eggert T, Han M, Greten TF. Hepatic myeloid-derived suppressor cells in cancer. Cancer Immunol Immunother 2015;64:931-40.DOIPubMed
71. Kumar V, Patel S, Tcyganov E, Gabrilovich DI. The nature of myeloid-derived suppressor cells in the tumor microenvironment. Trends Immunol 2016;37:208-20.DOIPubMedPMC
72. Gabrilovich DI, Nagaraj S. Myeloid-derived suppressor cells as regulators of the immune system. Nat Rev Immunol 2009;9:162-74.DOIPubMedPMC
73. Draghiciu O, Lubbers J, Nijman HW, Daemen T. Myeloid derived suppressor cells-an overview of combat strategies to increase immunotherapy efficacy. Oncoimmunology 2015;4:e954829.DOIPubMedPMC
74. Srivastava MK, Sinha P, Clements VK, Rodriguez P, Ostrand-Rosenberg S. Myeloid-derived suppressor cells inhibit T-cell activation by depleting cystine and cysteine. Cancer Res 2010;70:68-77.DOIPubMedPMC
75. Lu T, Gabrilovich DI. Molecular pathways: tumor-infiltrating myeloid cells and reactive oxygen species in regulation of tumor microenvironment. Clin Cancer Res 2012;18:4877-82.DOIPubMedPMC
76. Condamine T, Ramachandran I, Youn J-I J, Gabrilovich DI. Regulation of tumor metastasis by myeloid-derived suppressor cells. Annu Rev Med 2015;66:97-110.DOIPubMedPMC
77. Hoechst B, Ormandy LA, Ballmaier M, Lehner F, Krüger C, Manns MP, Greten TF, Korangy F. A new population of myeloid-derived suppressor cells in hepatocellular carcinoma patients induces CD4(+)CD25(+)Foxp3(+) T cells. Gastroenterology 2008;135:234-43.DOIPubMed
78. Gao XH, Tian L, Wu J, Ma XL, Zhang CY, Zhou Y, Sun YF, Hu B, Qiu SJ, Zhou J, Fan J, Guo W, Yang XR. Circulating CD14+HLA-DR-/low myeloid-derived suppressor cells predicted early recurrence of hepatocellular carcinoma after surgery. Hepatol Res 2017;47:1061-71.DOIPubMed
79. Wang D, An G, Xie S, Yao Y, Feng G. The clinical and prognostic significance of CD14+HLA-DR-/low myeloid-derived suppressor cells in hepatocellular carcinoma patients receiving radiotherapy. Tumor Biol 2016;37:10427-33.DOIPubMed
80. Mizukoshi E, Yamashita T, Arai K, Terashima T, Kitahara M, Nakagawa H, Iida N, Fushimi K, Kaneko S. Myeloid derived suppressor cells correlate with patient outcomes in hepatic arterial infusion chemotherapy for hepatocellular carcinoma. Cancer Immunol Immunother 2016;65:715-25.DOIPubMed
81. Arihara F, Mizukoshi E, Kitahara M, Takata Y, Arai K, Yamashita T, Nakamoto Y, Kaneko S. Increase in CD14+HLA-DR-/low myeloid-derived suppressor cells in hepatocellular carcinoma patients and its impact on prognosis. Cancer Immunol Immunother 2013;62:1421-30.DOIPubMed
82. Kapanadze T, Gamrekelashvili J, Ma C, Chan C, Zhao F, Hewitt S, Zender L, Kapoor V, Felsher DW, Manns MP, Korangy F, Greten TF. Regulation of accumulation and function of myeloid derived suppressor cells in different murine models of hepatocellular carcinoma. J Hepatol 2013;59:1007-13.DOIPubMedPMC
83. Eggert T, Wolter K, Ji J, Ma C, Yevsa T, Klotz S, Medina-Echeverz J, Longerich T, Forgues M, Reisinger F, Heikenwalder M, Wang XW, Zender L, Greten TF. Distinct functions of senescence-associated immune responses in liver tumor surveillance and tumor progression. Cancer Cell 2016;30:533-47.DOIPubMed
84. Ju C, Tacke F. Hepatic macrophages in homeostasis and liver diseases: from pathogenesis to novel therapeutic strategies. Cell Mol Immunol 2016;13:316-27.DOIPubMedPMC
85. Jenne CN, Kubes P. Immune surveillance by the liver. Nat Immunol 2013;14:996-1006.DOIPubMed
86. Heymann F, Peusquens J, Ludwig-Portugall I, Kohlhepp M, Ergen C, Niemietz P, Martin C, van Rooijen N, Ochando JC, Randolph GJ, Luedde T, Ginhoux F, Kurts C, Trautwein C, Tacke F. Liver inflammation abrogates immunological tolerance induced by Kupffer cells. Hepatology 2015;62:279-91.DOIPubMed
87. Yan ML, Wang YD, Tian YF, Lai ZD, Yan LN. Inhibition of allogeneic T-cell response by Kupffer cells expressing indoleamine 2,3-dioxygenase. World J Gastroenterol 2010;16:636-40.DOIPubMedPMC
88. Knolle P, Schlaak J, Uhrig A, Kempf P, Meyer zum Buschenfelde KH, Gerken G. Human Kupffer cells secrete IL-10 in response to lipopolysaccharide (LPS) challenge. J Hepatol 1995;22:226-9.DOI
89. Wu K, Kryczek I, Chen L, Zou W, Welling TH. Kupffer cell suppression of CD8+ T cells in human hepatocellular carcinoma is mediated by B7-H1/programmed death-interactions. Cancer Res 2009;69:8067-75.DOIPubMedPMC
90. Ostrand-Rosenberg S, Sinha P, Beury DW, Clements VK. Cross-talk between myeloid-derived suppressor cells (MDSC), macrophages, and dendritic cells enhances tumor-induced immune suppression. Semin Cancer Biol 2012;22:275-81.DOIPubMedPMC
91. Lin EY, Li JF, Gnatovskiy L, Deng Y, Zhu L, Grzesik DA, Qian H, Xue XN, Pollard JW. Macrophages regulate the angiogenic switch in a mouse model of breast cancer. Cancer Res 2006;66:11238-46.DOIPubMed
92. Qian B, Deng Y, Im JH, Muschel RJ, Zou Y, Li J, Lang RA, Pollard JW. A distinct macrophage population mediates metastatic breast cancer cell extravasation, establishment and growth. PLoS One 2009;4:e6562.DOIPubMedPMC
93. De Palma M, Venneri MA, Galli R, Sergi Sergi L, Politi LS, Sampaolesi M, Naldini L. Tie2 identifies a hematopoietic lineage of proangiogenic monocytes required for tumor vessel formation and a mesenchymal population of pericyte progenitors. Cancer Cell 2005;8:211-26.DOIPubMed
94. Murdoch C, Tazzyman S, Webster S, Lewis CE. Expression of tie-2 by human monocytes and their responses to angiopoietin-2. J Immunol 2007;178:7405-11.DOIPubMed
95. Venneri MA, De Palma M, Ponzoni M, Pucci F, Scielzo C, Zonari E, Mazzieri R, Doglioni C, Naldini L. Identification of proangiogenic TIE2-expressing monocytes (TEMs) in human peripheral blood and cancer. Blood 2007;109:5276-85.DOIPubMed
96. Matsubara T, Kanto T, Kuroda S, Yoshio S, Higashitani K, Kakita N, Miyazaki M, Sakakibara M, Hiramatsu N, Kasahara A, Tomimaru Y, Tomokuni A, Nagano H, Hayashi N, Takehara T. TIE2 expressing monocytes as a diagnostic marker for hepatocellular carcinoma correlates with angiogenesis. Hepatology 2013;57:1416-25.DOIPubMed
97. Josefowicz SZ, Lu LF, Rudensky AY. Regulatory T cells: mechanisms of differentiation and function. Annu Rev Immunol 2012;30:531-64.DOIPubMed
98. Sprinzl MF, Galle PR. Immune control in hepatocellular carcinoma development and progression: role of stromal cells. Semin. Liver Dis 2014;34:376-88.DOIPubMed
99. Chen KJ, Lin SZ, Zhou L, Xie HY, Zhou WH, Taki-Eldin A, Zheng SS. Selective recruitment of regulatory T cell through CCR6-CCL20 in hepatocellular carcinoma fosters tumor progression and predicts poor prognosis. PLoS One 2011;6:e24671.DOIPubMedPMC
100. Wiedemann GM, Knott MM, Vetter VK, Rapp M, Haubner S, Fesseler J, Kühnemuth B, Layritz P, Thaler R, Kruger S, Ormanns S, Mayr D, Endres S, Anz D. Cancer cell-derived IL-1α induces CCL22 and the recruitment of regulatory T cells. Oncoimmunology 2016;5:e1175794.DOIPubMedPMC
101. Moo-Young TA, Larson JW, Belt BA, Tan MC, Hawkins WG, Eberlein TJ, Goedegebuure PS, Linehan DC. Tumor-derived TGF-beta mediates conversion of CD4+Foxp3+ regulatory T cells in a murine model of pancreas cancer. J Immunother 2009;32:12-21.DOIPubMedPMC
102. Ormandy LA, Hillemann T, Wedemeyer H, Manns MP, Greten TF, Korangy F. Increased populations of regulatory T cells in peripheral blood of patients with hepatocellular carcinoma. Cancer Res 2005;65:2457-64.DOIPubMed
103. Fu J, Xu D, Liu Z, Shi M, Zhao P, Fu B, Zhang Z, Yang H, Zhang H, Zhou C, Yao J, Jin L, Wang H, Yang Y, Fu YX, Wang FS. Increased regulatory T cells correlate with CD8 T-cell impairment and poor survival in hepatocellular carcinoma patients. Gastroenterology 2007;132:2328-39.DOIPubMed
104. Gao Q, Qiu SJ, Fan J, Zhou J, Wang XY, Xiao YS, Xu Y, Li YW, Tang ZY. Intratumoral balance of regulatory and cytotoxic T cells is associated with prognosis of hepatocellular carcinoma after resection. J Clin Oncol 2007;25:2586-93.DOIPubMed
105. Zhou J, Ding T, Pan W, Zhu LY, Li L, Zheng L. Increased intratumoral regulatory T cells are related to intratumoral macrophages and poor prognosis in hepatocellular carcinoma patients. Int J Cancer 2009;125:1640-8.DOIPubMed
106. Neaud V, Faouzi S, Guirouilh J, Le Bail B, Balabaud C, Bioulac-Sage P, Rosenbaum J. Human hepatic myofibroblasts increase invasiveness of hepatocellular carcinoma cells: evidence for a role of hepatocyte growth factor. Hepatology 1997;26:1458-66.DOIPubMed
107. Höchst B, Schildberg FA, Sauerborn P, Gäbel YA, Gevensleben H, Goltz D, Heukamp LC, Türler A, Ballmaier M, Gieseke F, Müller I, Kalff J, Kurts C, Knolle PA, Diehl L. Activated human hepatic stellate cells induce myeloid derived suppressor cells from peripheral blood monocytes in a CD44-dependent fashion. J Hepatol 2013;59:528-35.DOIPubMed
108. Resheq YJ, Li KK, Ward ST, Wilhelm A, Garg A, Curbishley SM, Blahova M, Zimmermann HW, Jitschin R, Mougiakakos D, Mackensen A, Weston CJ, Adams DH. Contact-dependent depletion of hydrogen peroxide by catalase is a novel mechanism of myeloid-derived suppressor cell induction operating in human hepatic stellate cells. J Immunol 2015;194:2578-86.DOIPubMed
109. Dunham RM, Thapa M, Velazquez VM, Elrod EJ, Denning TL, Pulendran B, Grakoui A. Hepatic stellate cells preferentially induce Foxp3+ regulatory T cells by production of retinoic acid. J Immunol 2013;190:2009-16.DOIPubMedPMC
110. Yu MC, Chen CH, Liang X, Wang L, Gandhi CR, Fung JJ, Lu L, Qian S. Inhibition of T-cell responses by hepatic stellate cells via B7-H1-mediated T-cell apoptosis in mice. Hepatology 2004;40:1312-21.DOIPubMed
111. Ji J, Eggert T, Budhu A, Forgues M, Takai A, Dang H, Ye Q, Lee JS, Kim JH, Greten TF, Wang XW. Hepatic stellate cell and monocyte interaction contributes to poor prognosis in hepatocellular carcinoma. Hepatology 2015;62:481-95.DOIPubMedPMC
112. Bricard G, Cesson V, Devevre E, Bouzourene H, Barbey C, Rufer N, Im JS, Alves PM, Martinet O, Halkic N, Cerottini JC, Romero P, Porcelli SA, Macdonald HR, Speiser DE. Enrichment of human CD4+ V(alpha)24/Vbeta11 invariant NKT-cells in intrahepatic malignant tumors. J Immunol 2009;182:5140-51.DOIPubMed
113. Quail DF, Joyce JA. Microenvironmental regulation of tumor progression and metastasis. Nat Med 2013;19:1423-37.DOIPubMedPMC
114. Xiao X, Lao XM, Chen MM, Liu RX, Wei Y, Ouyang FZ, Chen DP, Zhao XY, Zhao Q, Li XF, Liu CL, Zheng L, Kuang DM. PD-1hi identifies a novel regulatory B-cell population in human hepatoma that promotes disease progression. Cancer Discov 2016;6:546-59.DOIPubMed
115. Carambia A, Freund B, Schwinge D, Heine M, Laschtowitz A, Huber S, Wraith DC, Korn T, Schramm C, Lohse AW, Heeren J, Herkel J. TGF-β-dependent induction of CD4+CD25+Foxp3+ Tregs by liver sinusoidal endothelial cells. J Hepatol 2014;61:594-9.DOIPubMed
116. Han Y, Chen Z, Yang Y, Jiang Z, Gu Y, Liu Y, Lin C, Pan Z, Yu Y, Jiang M, Zhou W, Cao X. Human CD14+ CTLA-4+ regulatory dendritic cells suppress T-cell response by cytotoxic T-lymphocyte antigen-4-dependent IL-10 and indoleamine-2,3-dioxygenase production in hepatocellular carcinoma. Hepatology 2014;59:567-79.DOIPubMed
117. Zhao F, Hoechst B, Gamrekelashvili J, Ormandy LA, Voigtländer T, Wedemeyer H, Ylaya K, Wang XW, Hewitt SM, Manns MP, Korangy F, Greten TF. Human CCR4+CCR6+Th17 cells suppress autologous CD8+ T cell responses. J Immunol 2012;188:6055-62.DOIPubMedPMC
118. Brandau S, Dumitru CA, Lang S. Protumor and antitumor functions of neutrophil granulocytes. Semin Immunopathol 2013;35:163-76.DOIPubMed
119. Zhou SL, Zhou ZJ, Hu ZQ, Huang XW, Wang Z, Chen EB, Fan J, Cao Y, Dai Z, Zhou J. Tumor-associated neutrophils recruit macrophages and T-regulatory cells to promote progression of hepatocellular carcinoma and resistance to sorafenib. Gastroenterology 2016;150:1646-58.DOIPubMed
120. Li T, Yang Y, Hua X, Wang G, Liu W, Jia C, Tai Y, Zhang Q, Chen G. Hepatocellular carcinoma-associated fibroblasts trigger NK cell dysfunction via PGE2 and IDO. Cancer Lett 2012;318:154-61.DOIPubMed
121. Deng Y, Cheng J, Fu B, Liu W, Chen G, Zhang Q, Yang Y. Hepatic carcinoma-associated fibroblasts enhance immune suppression by facilitating the generation of myeloid-derived suppressor cells. Oncogene 2016;36:1090-101.DOIPubMed
122. Takayama T, Sekine T, Makuuchi M, Yamasaki S, Kosuge T, Yamamoto J, Shimada K, Sakamoto M, Hirohashi S, Ohashi Y, Kakizoe T. Adoptive immunotherapy to lower postsurgical recurrence rates of hepatocellular carcinoma: a randomised trial. Lancet 2000;356:802-7.DOI
123. Ma Y, Xu YC, Tang L, Zhang Z, Wang J, Wang HX. Cytokine-induced killer (CIK) cell therapy for patients with hepatocellular carcinoma: efficacy and safety. Exp Hematol Oncol 2012;1:11.DOIPubMedPMC
124. Xu L, Wang J, Kim Y, Shuang ZY, Zhang YJ, Lao XM, Li YQ, Chen MS, Pawlik TM, Xia JC, Li SP, Lau WY. A randomized controlled trial on patients with or without adjuvant autologous cytokine-induced killer cells after curative resection for hepatocellular carcinoma. Oncoimmunology 2015;5:e108367.
125. Lee JH, Lee JH, Lim YS, Yeon JE, Song TJ, Yu SJ, Gwak GY, Kim KM, Kim YJ, Lee JW, Yoon JH. Adjuvant immunotherapy with autologous cytokine-induced killer cells for hepatocellular carcinoma. Gastroenterology 2015;148:1383-91.DOIPubMed
126. Lee JH, Lee Y, Lee M, Heo MK, Song JS, Kim KH, Lee H, Yi NJ, Lee KW, Suh KS, Bae YS, Kim YJ. A phase I/IIa study of adjuvant immunotherapy with tumour antigen-pulsed dendritic cells in patients with hepatocellular carcinoma. Br J Cancer 2015;113:1666-76.DOIPubMedPMC
127. Shimizu Y, Suzuki T, Yoshikawa T, Tsuchiya N, Sawada Y, Endo I, Nakatsura T. Cancer immunotherapy-targeted glypican-3 or neoantigens. Cancer Sci 2018;109:531-41.DOIPubMedPMC
128. Palmer DH, Midgley RS, Mirza N, Torr EE, Ahmed F, Steele JC, Steven NM, Kerr DJ, Young LS, Adams DH. A phase II study of adoptive immunotherapy using dendritic cells pulsed with tumor lysate in patients with hepatocellular carcinoma. Hepatology 2009;49:124-32.DOIPubMed
129. Tsuchiya N, Yoshikawa T, Fujinami N, Saito K, Mizuno S, Sawada Y, Endo I, Nakatsura T. Immunological efficacy of glypican-3 peptide vaccine in patients with advanced hepatocellular carcinoma. Oncoimmunology 2017;6:e1346764.DOIPubMedPMC
130. Sawada Y, Yoshikawa T, Ofuji K, Yoshimura M, Tsuchiya N, Takahashi M, Nobuoka D, Gotohda N, Takahashi S, Kato Y, Konishi M, Kinoshita T, Ikeda M, Nakachi K, Yamazaki N, Mizuno S, Takayama T, Yamao K, Uesaka K, Furuse J, Endo I, Nakatsura T. Phase II study of the GPC3-derived peptide vaccine as an adjuvant therapy for hepatocellular carcinoma patients. Oncoimmunology 2016;5:e1129483.DOIPubMedPMC
131. Heo J, Reid T, Ruo L, Breitbach CJ, Rose S, Bloomston M, Cho M, Lim HY, Chung HC, Kim CW, Burke J, Lencioni R, Hickman T, Moon A, Lee YS, Kim MK, Daneshmand M, Dubois K, Longpre L, Ngo M, Rooney C, Bell JC, Rhee BG, Patt R, Hwang TH, Kirn DH. Randomized dose-finding clinical trial of oncolytic immunotherapeutic vaccinia JX-594 in liver cancer. Nat Med 2013;19:329-36.DOIPubMedPMC
132. Hoseini SS, Cheung NV. Immunotherapy of hepatocellular carcinoma using chimeric antigen receptors and bispecific antibodies. Cancer Lett 2017;399:44-52.DOIPubMed
133. Qasim W, Brunetto M, Gehring AJ, Xue SA, Schurich A, Khakpoor A, Zhan H, Ciccorossi P, Gilmour K, Cavallone D, Moriconi F, Farzhenah F, Mazzoni A, Chan L, Morris E, Thrasher A, Maini MK, Bonino F, Stauss H, Bertoletti A. Immunotherapy of HCC metastases with autologous T cell receptor redirected T cells, targeting HBsAg in a liver transplant patient. J Hepatol 2015;62:486-91.DOIPubMed
134. Sangro B, Gomez-Martin C, de la Mata M, I-arrairaegui M, Garralda E, Barrera P, Riezu-Boj JI, Larrea E, Alfaro C, Sarobe P, Lasarte JJ, Pérez-Gracia JL, Melero I, Prieto J. A clinical trial of CTLA-4 blockade with tremelimumab in patients with hepatocellular carcinoma and chronic hepatitis C. J Hepatol 2013;59:81-8.DOIPubMed
135. El-Khoueiry AB, Sangro B, Yau T, Crocenzi TS, Kudo M, Hsu C, Kim TY, Choo SP, Trojan J, Welling Rd TH, Meyer T, Kang YK, Yeo W, Chopra A, Anderson J, Dela Cruz C, Lang L, Neely J, Tang H, Dastani HB, Melero I. Nivolumab in patients with advanced hepatocellular carcinoma (CheckMate 040): an open-label, non-comparative, phase 1/2 dose escalation and expansion trial. Lancet 2017;389:2492-502.DOI
136. Brown ZJ, Heinrich B, Steinberg SM, Yu SJ, Greten TF. Safety in treatment of hepatocellular carcinoma with immune checkpoint inhibitors as compared to melanoma and non-small cell lung cancer. J Immunother Cancer 2017;5:93.DOIPubMedPMC
137. Duffy AG, Ulahannan SV, Makorova-Rusher O, Rahma O, Wedemeyer H, Pratt D, Davis JL, Hughes MS, Heller T, ElGindi M, Uppala A, Korangy F, Kleiner DE, Figg WD, Venzon D, Steinberg SM, Venkatesan AM, Krishnasamy V, Abi-Jaoudeh N, Levy E, Wood BJ, Greten TF. Tremelimumab in combination with ablation in patients with advanced hepatocellular carcinoma. J Hepatol 2017;66:545-51.DOIPubMedPMC
138. Versteven M, Van den Bergh JMJ, Marcq E, Smits ELJ, Van Tendeloo VFI, Hobo W, Lion E. Dendritic cells and programmed death-1 blockade: a joint venture to combat cancer. Front Immunol 2018;9:394.DOIPubMedPMC
139. Herbst RS, Soria JC, Kowanetz M, Fine GD, Hamid O, Gordon MS, Sosman JA, McDermott DF, Powderly JD, Gettinger SN, Kohrt HE, Horn L, Lawrence DP, Rost S, Leabman M, Xiao Y, Mokatrin A, Koeppen H, Hegde PS, Mellman I, Chen DS, Hodi FS. Predictive correlates of response to the anti-PD-L1 antibody MPDL3280A in cancer patients. Nature 2014;515:563-67.DOIPubMedPMC
140. Gibney GB, Weiner LM, Atkins MB. Predictive biomarkers for checkpoint inhibitor-based immunotherapy. Lancet Oncol 2016;16:e542-51.DOI
141. Balar AV, Weber JS. PD-1 and PD-L1 antibodies in cancer: current status and future directions. Cancer Immunol Immunother 2017;66:551-64.DOIPubMed
142. Dijkstra KK, Voabil P, Schumacher TN, Voest EE. Genomics- and transcriptomics-based patient selection for cancer treatment with immune checkpoint inhibitors: a review. JAMA Oncol 2016;2:1490-5.DOIPubMed
143. Le DT, Durham JN, Smith KN, Wang H, Bartlett BR, Aulakh LK, Lu S, Kemberling H, Wilt C, Luber BS, Wong F, Azad NS, Rucki AA, Laheru D, Donehower R, Zaheer A, Fisher GA, Crocenzi TS, Lee JJ, Greten TF, Duffy AG, Ciombor KK, Eyring AD, Lam BH, Joe A, Kang SP, Holdhoff M, Danilova L, Cope L, Meyer C, Zhou S, Goldberg RM, Armstrong DK, Bever KM, Fader AN, Taube J, Housseau F, Spetzler D, Xiao N, Pardoll DM, Papadopoulos N, Kinzler KW, Eshleman JR, Vogelstein B, Anders RA, Diaz LA Jr. Mismatch repair deficiency predicts response of solid tumors to PD-1 blockade. Science 2017;357:409-13.DOIPubMedPMC
144. Breuhahn K, Vreden S, Haddad R, Beckebaum S, Stippel D, Flemming P, Nussbaum T, Caselmann WH, Haab BB, Schirmacher P. Molecular profiling of human hepatocellular carcinoma defines mutually exclusive interferon regulation and insulin-like growth factor II overexpression. Cancer Res 2004;64:6058-64.DOIPubMed
145. Budhu A, Forgues M, Ye QH, Jia HL, He P, Zanetti KA, Kammula U, Chen Y, Qin L, Tang ZY, Wang XW. Prediction of venous metastases, recurrence, and prognosis in hepatocellular carcinoma based on a unique immune response signature of the liver microenvironment. Cancer Cell 2006;10:99-111.DOIPubMed
146. Chiang DY, Villanueva A, Hoshida Y, Peix J, Newell P, Minguez B, LeBlanc AC, Donovan DJ, Thung SN, Solé M, Tovar V, Alsinet C, Ramos AH, Barretina J, Roayaie S, Schwartz M, Waxman S, Bruix J, Mazzaferro V, Ligon AH, Najfeld V, Friedman SL, Sellers WR, Meyerson M, Llovet JM. Focal gains of VEGFA and molecular classification of hepatocellular carcinoma. Cancer Res 2008;68:6779-88.DOIPubMedPMC
147. Sakai Y, Honda M, Fujinaga H, Tatsumi I, Mizukoshi E, Nakamoto Y, Kaneko S. Common transcriptional signature of tumor-infiltrating mononuclear inflammatory cells and peripheral blood mononuclear cells in hepatocellular carcinoma patients. Cancer Res 2008;68:10267-79.DOIPubMed
148. Hoshida Y, Villanueva A, Kobayashi M, Peix J, Chiang DY, Camargo A, Gupta S, Moore J, Wrobel MJ, Lerner J, Reich M, Chan JA, Glickman JN, Ikeda K, Hashimoto M, Watanabe G, Daidone MG, Roayaie S, Schwartz M, Thung S, Salvesen HB, Gabriel S, Mazzaferro V, Bruix J, Friedman SL, Kumada H, Llovet JM, Golub TR. Gene expression in fixed tissues and outcome in hepatocellular carcinoma. N Engl J Med 2008;359:1995-2004.DOIPubMedPMC
149. Sia D, Jiao Y, Martinez-Quetglas I, Kuchuk O, Villacorta-Martin C, Castro de Moura M, Putra J, Camprecios G, Bassaganyas L, Akers N, Losic B, Waxman S, Thung SN, Mazzaferro V, Esteller M, Friedman SL, Schwartz M, Villanueva A, Llovet JM. Identification of an immune-specific class of hepatocellular carcinoma, based on molecular features. Gastroenterology 2017;153:812-26.DOIPubMed
150. Carone C, Olivani A, Dalla Valle R, Manuguerra R, Silini EM, Trenti T, Missale G, Cariani E. Immune gene expression profile in hepatocellular carcinoma and surrounding tissue predicts time to tumor recurrence. Liver Cancer 2018; doi: 10.1159/000486764.DOI
151. Ayers M, Lunceford J, Nebozhyn M, Murphy E, Loboda A, Kaufman DR, Albright A, Cheng D, Kang SP, Shankaran V, Piha-Paul SA, Yearley J, Seiwert TY, Ribas A, McClanahan TK. IFN-γ-related mRNA profile predicts clinical response to PD-1 blockade. J Clin Invest 2017;127:2930-40.DOIPubMedPMC
152. Spranger S, Bao R, Gajewski TF. Melanoma-intrinsic b-catenin signalling prevents anti-tumour immunity. Nature 2015;523:231-5.DOIPubMed
Missale G, Cariani E. Time for hepatocellular carcinoma immunotherapy: insights for successful clinical applications in this challenging tumor. Hepatoma Res 2018;4:22. http://dx.doi.org/10.20517/2394-5079.2018.72
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