Research progress regarding programmed cell death 1/programmed cell death ligand 1 inhibitors combined with targeted therapy for treating hepatocellular carcinoma

Unresectable Hepatocellular Carcinoma: A Review of New Advances with Focus on Targeted Therapy and Immunotherapy

With an expected incidence of more than 1 million cases by 2025, liver cancer remains a problem for world health. With over 90% of cases, hepatocellular carcinoma (HCC) is the most prevalent kind of liver cancer. In this review, we presented the range of experimental therapeutics for patients with advanced HCC, the successes and failures of new treatments, areas for future development, the evaluation of dose-limiting toxicity in different drugs, and the safety profile in patients with liver dysfunction related to the underlying chronic liver disease. In addition to the unmet demand for biomarkers to guide treatment decisions and the burgeoning fields of immunotherapy and systemic therapy in hepatocellular carcinoma, the development of old and new drugs, including their failures and current advancements, has been reviewed. This review aims to evaluate the updated optimal clinical treatment of unresectable hepatocellular carcinomas in clinical practice, mainly through targeted therapy. Although surgical treatment can significantly enhance the survival probability of early and intermediate-stage patients, it is unsuitable for most HCC patients due to a lack of donors. Due to their severe toxicity, the few first-line anti-HCC drugs, such as sorafenib, are often reserved for advanced HCC patients for whom other therapies have failed. The second-line drugs are usually alternatives for patients with intolerance or resistance. Consequently, the ongoing growth of possible preclinical drugs and studies on miRNAs, lncRNAs, and numerous other signaling pathway targets for developing novel drugs may introduce additional treatment prospects for HCC.

siRNA targeting PD-L1 delivered with attenuated Salmonella enhanced the anti-tumor effect of lenvatinib on mice bearing Hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a primary liver cancer representing serious harm to human health. The effective treatment of HCC is challenging. Lenvatinib is an inhibitor of polytyrosine kinase that exerts an effect against HCC by blocking the VEGF signaling pathway. However, its efficacy in most patients remains unsatisfactory. The factors influencing tumorigenesis are diverse; thus, combined treatment is an important strategy against tumors. Programmed death ligand-1 (PD-L1), which binds to programmed death-1 (PD-1), significantly compromises the anti-tumor effect of T cells. Therefore, we designed a siRNA-PD-L1 and delivered it using attenuated Salmonella, and its synergistic effects with Lenvatinib against HCC were evaluated. The results showed that the combination of Lenvatinib and siRNA-PD-L1 inhibited tumor growth in H22 tumor-bearing mice, arrested cell proliferation, and increased cell apoptosis in the tumor. The combination treatment synergistically inhibited the expression of VEGF and PD-L1 and contributed to the increase in T-cell infiltration in the tumor tissues and the ratio of T cells in the spleen. Furthermore, the combination treatment increased the number of granzyme B⁺ T cells, indicating a significantly improved anti-tumor immunity in mice. Therefore, this combination might be a potential novel strategy for HCC treatment.