Immunotherapy for hepatocellular carcinoma recurrence after liver transplantation, can we harness the power of immune checkpoint inhibitors?

New Scenarios in Liver Transplantation for Hepatocellular Carcinoma

BACKGROUND AND AIMS

Despite liver transplantation (LT) is considered the optimal treatment for hepatocellular carcinoma (HCC), particularly in patients with impaired liver function, the shortage of donors has forced the application of very restrictive criteria for selecting ideal candidates for whom LT can offer the best outcome. With the evolving LT landscape due to the advent of direct-acting antivirals (DAAs) and the steady increase in donors, major efforts have been made to expand the transplant eligibility criteria for HCC. In addition, the emergence of immune checkpoint inhibitors (ICIs) for the treatment of HCC, with demonstrated efficacy in earlier stages, has revolutionized the therapeutic approach for these patients, and their integration in the setting of LT is challenging. Management of immunological compromise from ICIs, including the wash-out period before LT and post-LT immunosuppression adjustments, is crucial to balance the risk of graft rejection against HCC recurrence. Additionally, the effects of increased immunosuppression on non-hepatic complications must be understood to prevent them from becoming obstacles to long-term OS.

METHODS AND RESULTS

In this review, we will evaluate the emerging evidence and its implications for the future of LT in HCC. Addressing these novel challenges and opportunities, while integrating the current clinical evidence with predictive algorithms, would ensure a fair balance between individual patient needs and the overall population benefit in the LT system.

The Role of Liver Transplantation in Hepatocellular Carcinoma

Liver transplantation (LT) is the standard-of-care for early hepatocellular carcinoma (HCC). Current selection criteria depend primarily on measures of tumor burden and alpha-fetoprotein levels. Evolving strategies include the application of prognostic scores and the development of specialized molecular markers to predict recurrence. New technologies such as machine perfusion of donor organs are expected to dramatically improve the availability and access to LT in HCC.

Reversing NK cell exhaustion: a novel strategy combining immune checkpoint blockade with drug sensitivity enhancement in the treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common lethal cancers worldwide. Natural killer cells (NK cells) play a key role in liver immunosurveillance, but in the tumor microenvironment, NK cells are readily depleted, as evidenced by down-regulation of activating receptors, reduced cytokine secretion, and attenuated killing function. The up-regulation of inhibitory receptors, such as PD-1, TIM-3, and LAG-3, further exacerbates the depletion of NK cells. Combined blockade strategies targeting these immunosuppressive mechanisms, such as the combination of PD-1 inhibitors with other inhibitory pathways (eg. TIM-3 and LAG-3), have shown potential to reverse NK cell exhaustion in preclinical studies. This article explores the promise of these innovative strategies in HCC immunotherapy, providing new therapeutic directions for optimizing NK cell function and improving drug sensitivity.

Cirrhosis and complications hepatocellular carcinoma - expanding indications for immunotherapy

The incidence of hepatocellular carcinoma (HCC) is rising, with a shift towards Metabolic Dysfunction-associated Steatotic Liver Disease becoming the dominant risk factor in Western countries. Significant advances in treatment have broadened the range of available therapeutic options. For this reason, clinical decision-making, along with a multidisciplinary team approach, plays a crucial role in improving patient outcomes. Following several landmark trials, immune checkpoint inhibitor-based therapy has now become the established first-line standard of care for advanced HCC. Additionally, the application of immunotherapy is shifting to include patients with earlier stages of HCC. Research on the combination with locoregional therapies for intermediate-stage HCC has recently reported positive results, and other phase III trials in the same patient population and early-stage HCC are currently in progress. Furthermore, a growing number of reports support the safety and efficacy of immunotherapeutic agents as potential adjuncts for downstaging of HCC, thus facilitating successful liver transplantation. We will discuss the published and ongoing trials in the expanding field of immune checkpoint inhibitor-based therapy for different stages of HCC.

Calpain 2 promotes Lenvatinib resistance and cancer stem cell traits via both proteolysis-dependent and independent approach in hepatocellular carcinoma

Lenvatinib, an approved first-line regimen, has been widely applied in hepatocellular carcinoma (HCC). However, clinical response towards Lenvatinib was limited, emphasizing the importance of understanding the underlying mechanism of its resistance. Herein, we employed integrated bioinformatic analysis to identify calpain-2 (CAPN2) as a novel key regulator for Lenvatinib resistance in HCC, and its expression greatly increased in both Lenvatinib-resistant HCC cell lines and clinical samples. Further in vitro and in vivo experiments indicated that knocking down CAPN2 greatly sensitized HCC cells to Lenvatinib treatment, while overexpression of CAPN2 achieved opposite effects in a Lenvatinib-sensitive HCC cell line. Interestingly, we observed a close relationship between CAPN2 expression and cancer stem cell (CSC) traits in HCC cells, evidenced by impaired sphere-forming and CSC-related marker expressions after CAPN2 knockdown, and verse vice. Mechanistically, we strikingly discovered that CAPN2 exerted its function by both enzyme-dependent and enzyme-independent manner simultaneously: activating β-Catenin signaling through its enzyme activity, and preventing GLI1/GLI2 degradation through direct binding to YWHAE in an enzyme-independent manner, which disrupting the association between YWHAE and GLI1/GLI2 to inhibit YWHAE-induced degradation of GLIs. Notably, further co-immunoprecipitation assays revealed that YWHAE could promote the protein stability of CAPN2 via recruiting a deubiquitinase COPS5 to prevent ubiquitination-induced degradation of CAPN2. In summary, our data demonstrated that CAPN2 promoted Lenvatinib resistance via both catalytic activity-dependent and -independent approaches. Reducing CAPN2 protein rather than inhibiting its activity might be a promising strategy to improve Lenvatinib treatment efficiency in HCC.

Immunofluorescence-Verified Sphingolipid Signatures Indicate Improved Prognosis in Liver Cancer Patients

Background: Hepatocellular carcinoma (HCC) is a highly heterogeneous malignancy, with its pathogenesis involving a complex interplay of molecular mechanisms, including cell cycle dysregulation, evasion of apoptosis, enhanced angiogenesis, and aberrant immune responses. Precision medicine approaches that target specific molecular subtypes through multi-omics integration hold promise for improving patient survival. Among the various molecular players, sphingolipids have emerged as pivotal regulators of tumor growth and apoptosis, positioning them as key targets in the search for novel anticancer therapies. Methods: To identify critical genes involved in sphingolipid metabolism (SM), we employed the AUCell algorithm and correlation analysis in conjunction with scRNA-seq data. A robust prognostic risk model was developed using Cox proportional hazards and Lasso regression, and its predictive performance was validated using an independent cohort from the International Cancer Genome Consortium (ICGC). The model's evaluation also incorporated analyses of the tumor microenvironment (TME), immunotherapy responses, mutational landscape, and pathway enrichment across different risk strata. Finally, we conducted multiplex immunofluorescence assays to investigate the functional role of ZC3HAV1 in HCC. Results: Our analysis yielded a 9-gene signature risk model with strong prognostic capabilities, effectively stratifying HCC patients into high- and low-risk groups, with significant differences in survival outcomes. Notably, the model revealed distinct variations in the immune microenvironment and responsiveness to immunotherapy between the risk groups. Further experimental validation identified ZC3HAV1 as a key gene, with multiplex immunofluorescence suggesting its involvement in promoting malignant progression in HCC through modulation of the epithelial-mesenchymal transition (EMT). Conclusion: This sphingolipid metabolism-based prognostic model is not only predictive of survival in HCC but also indicative of immunotherapy efficacy in certain patient subsets. Our findings underscore the crucial role of sphingolipid metabolism in shaping the immune microenvironment, offering new avenues for targeted therapeutic interventions.

Significant Association of PD-L1 With CD44 Expression and Patient Survival: Avenues for Immunotherapy and Cancer Stem Cells Downregulation in Pancreatic Cancers

Background: Pancreatic cancers are known for their aggressive nature. This aggressiveness may be attributed to the presence of cancer stem cells (CSCs), which promote relapse, metastasis, and resistance to chemotherapy. Targeting CSCs is essential to reverse this aggressiveness in pancreatic malignancies. Literature highlights the association of PD-L1 expression with CSCs in various cancers, suggesting immunotherapy as a promising therapeutic approach. This study is aimed at investigating the potential of immunotherapy in pancreatic cancers by examining its association with selected CSC marker expression. Method: A retrospective cohort study was conducted involving 56 patients with confirmed diagnoses of pancreatic cancers at Aga Khan University Hospital from January 2015 to October 2022. After exclusions, based on refusal to provide consent or incomplete follow-up data, 38 patients were enrolled in the study. Immunohistochemistry was performed on formalin-fixed paraffin-embedded (FFPE) tumor tissue samples to assess the expression of CSC markers (CD133, CD44, and L1CAM) and immune checkpoint inhibitor marker (PD-L1). Statistical analysis was employed to determine associations between marker expression, clinical factors, and overall survival. Results: The study revealed that 86.8% of pancreatic cancer cases exhibited positive PD-L1 expression. Moreover, a significant association of PD-L1 expression was observed with the presence of CD44 protein (p = 0.030), as well as with the overall survival of patients (p = 0.023). Conclusion: Our findings show a significant association of PD-L1 with CD44 marker expression as well as patient survival. This research shows the potential to serve as the foundation for investigating the efficacy of immunotherapy in reducing CD44-expressing CSCs in pancreatic cancer, potentially enhancing patient outcomes.

Immunotherapy for transplantation of hepatocellular carcinoma: the next frontier in adjunctive therapy

PURPOSE OF REVIEW

The increasing success of liver transplantation in hepatocellular carcinoma (HCC) drives an ever-evolving search for innovative strategies to broaden eligible patients' pools. Recent advances in immuno-oncology have turned the spotlight on immune checkpoint inhibitors (ICIs). This review offers an updated overview of ICIs in liver transplantation for HCC, exploring neoadjuvant and adjuvant approaches and addressing unanswered questions on safety, patients' selection, and response predictors.

RECENT FINDINGS

ICIs have transitioned from being a last-chance therapeutic hope to becoming an integral cornerstone in the treatment of advanced HCC, holding great promise as a compelling option not only to downstage patients for transplantation but also as an alternative strategy in addressing posttransplantation disease recurrence. Despite ongoing refinements in immunotherapeutic agents, the complex molecular pathways involved emphasize the need for a comprehensive approach to integrate immunotherapy in liver transplantation.

SUMMARY

Initial concerns about graft rejection, with ICIs as a bridging therapy to liver transplantation, were successfully addressed using adequate immunosuppressants strategies and minimized with a sufficient washout period. Post-liver transplantation disease recurrence remains challenging, requiring a balance between effective therapy and preserving graft function. Emphasis should be placed on clinical trials validating the risk-benefit ratio of ICIs for liver transplantation, guiding appropriate patients' selection, and establishing clear management pathways.

LILRB4 Checkpoint for Immunotherapy: Structure, Mechanism and Disease Targets

LILRB4, a myeloid inhibitory receptor belonging to the family of leukocyte immunoglobulin-like receptors (LILRs/LIRs), plays a pivotal role in the regulation of immune tolerance. LILRB4 primarily mediates suppressive immune responses by transmitting inhibitory signals through immunoreceptor tyrosine-based inhibitory motifs (ITIMs). This immune checkpoint molecule has gained considerable attention due to its potent regulatory functions. Its ability to induce effector T cell dysfunction and promote T suppressor cell differentiation has been demonstrated, indicating the therapeutic potential of LILRB4 for modulating excessive immune responses, particularly in autoimmune diseases or the induction of transplant tolerance. Additionally, through intervening with LILRB4 molecules, immune system responsiveness can be adjusted, representing significant value in areas such as cancer treatment. Thus, LILRB4 has emerged as a key player in addressing autoimmune diseases, transplant tolerance induction, and other medical issues. In this review, we provide a comprehensive overview of LILRB4, encompassing its structure, expression, and ligand molecules as well as its role as a tolerance receptor. By exploring the involvement of LILRB4 in various diseases, its significance in disease progression is emphasized. Furthermore, we propose that the manipulation of LILRB4 represents a promising immunotherapeutic strategy and highlight its potential in disease prevention, treatment and diagnosis.

The evolving role of lenvatinib at the new era of first-line hepatocellular carcinoma treatment

Emergence of multi-targeted kinase inhibitors (MTIs) and immune checkpoint inhibitors (ICI) have changed the landscape of management in hepatocellular carcinoma (HCC). Combination therapy involving ICI has superseded sorafenib as the first-line treatment option for advanced HCC due to their superior response rates and survival benefits based on recently published phase III trials. However, the role of first-line lenvatinib remains uncertain as no prospective trials have compared its efficacy with ICI in advanced HCC. Several retrospective studies have shown that first-line lenvatinib may not be inferior to ICI combination. Indeed, a growing body of evidence suggests that ICI treatment is associated with inferior treatment outcome in non-viral HCC patients, questioning the supremacy of ICI treatment in all patients and rendering first-line lenvatinib as a potential preferred treatment option. Furthermore, in high-burden intermediate-stage HCC, accumulating evidence supports first-line lenvatinib, or in combination with transarterial chemoembolization (TACE), as a preferred treatment option over TACE alone. In this Review, we describe the latest evidence surrounding the evolving role of first-line lenvatinib in HCC.

Emerging treatment strategies in hepatobiliary cancer

INTRODUCTION

There have been significant advances in the treatment of hepatobiliary cancers, especially for advanced-stage disease. However, data is limited for optimal therapy selection in the first line and sequencing of available options.

AREAS COVERED

This review covers the systemic treatment of hepatobiliary cancers with an emphasis on the advanced stage. The previously published and ongoing trials will be discussed to create an algorithm for the current practice and to give future perspectives on how the field could go forward.

EXPERT OPINION

While there is no standard-of-care option in the adjuvant treatment of hepatocellular cancer, capecitabine is the standard of care for biliary tract cancer. The efficacy of adjuvant gemcitabine and cisplatin and the added benefit of radiotherapy to chemotherapy are yet to be defined. For the advanced stage, immunotherapy-based combinations became the standard of care for both hepatocellular and biliary tract cancers. The molecularly targeted therapy has profoundly changed the second-line and later treatment for biliary tract cancers, while the optimal second-line treatment for advanced hepatocellular cancer is yet to be defined due to rapid advances in the first-line setting.