Four-year overall survival update from the phase III HIMALAYA study of tremelimumab plus durvalumab in unresectable hepatocellular carcinoma.

BACKGROUND: In the phase III HIMALAYA study (NCT03298451) in unresectable hepatocellular carcinoma (uHCC), STRIDE (Single Tremelimumab Regular Interval Durvalumab) significantly improved overall survival (OS) versus sorafenib; durvalumab monotherapy was noninferior to sorafenib for OS. Results reported herein are from a 4-year updated OS analysis of HIMALAYA. PATIENTS AND METHODS: Participants with uHCC and no previous systemic treatment were randomized to STRIDE (n = 393), durvalumab (n = 389), or sorafenib (n = 389). The updated data cut-off was 23 January 2023. OS and serious adverse events (AEs) were assessed. Additionally, baseline characteristics and subsequent therapies were analyzed in long-term survivors (≥36 months beyond randomization). RESULTS: For STRIDE, durvalumab, and sorafenib, median [95% confidence interval (CI)] follow-up was 49.12 months (46.95-50.17 months), 48.46 months (46.82-49.81 months), and 47.31 months (45.08-49.15 months), respectively. OS hazard ratio (95% CI) for STRIDE versus sorafenib was 0.78 (0.67-0.92). The 36-month OS rate for STRIDE was 30.7% versus 19.8% for sorafenib. The 48-month OS rate remained higher for STRIDE at 25.2%, versus 15.1% for sorafenib. The long-term OS benefit of STRIDE was observed across clinically relevant subgroups and was further improved in participants who achieved disease control. Long-term survivors with STRIDE (n = 103) included participants across clinically relevant subgroups, and 57.3% (59/103) had no reported subsequent anticancer therapy. No new serious treatment-related AEs occurred with STRIDE from the primary analysis (17.5%; 68/388). Durvalumab maintained OS noninferiority to sorafenib and no late-onset safety signals were identified. CONCLUSIONS: These data represent the longest follow-up to date in phase III studies in uHCC. The unprecedented 3- and 4-year OS rates reinforce the sustained long-term OS benefit of STRIDE versus sorafenib. STRIDE maintained a tolerable yet differentiated safety profile from other current uHCC therapies. Results continue to support the long-term benefits of STRIDE in a diverse population, reflective of uHCC globally.

The mechanisms of sorafenib resistance in hepatocellular carcinoma: theoretical basis and therapeutic aspects.

Sorafenib is a multikinase inhibitor capable of facilitating apoptosis, mitigating angiogenesis and suppressing tumor cell proliferation. In late-stage hepatocellular carcinoma (HCC), sorafenib is currently an effective first-line therapy. Unfortunately, the development of drug resistance to sorafenib is becoming increasingly common. This study aims to identify factors contributing to resistance and ways to mitigate resistance. Recent studies have shown that epigenetics, transport processes, regulated cell death, and the tumor microenvironment are involved in the development of sorafenib resistance in HCC and subsequent HCC progression. This study summarizes discoveries achieved recently in terms of the principles of sorafenib resistance and outlines approaches suitable for improving therapeutic outcomes for HCC patients.

STAT3 inhibition reduces toxicity of oncolytic VSV and provides a potentially synergistic combination therapy for hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a refractory malignancy with a high mortality and increasing worldwide incidence rates, including the United States and central Europe. In this study, we demonstrate that a specific inhibitor of signal transducer and activator of transcription 3 (STAT3), NSC74859, efficiently reduces HCC cell proliferation and can be successfully combined with oncolytic virotherapy using vesicular stomatitis virus (VSV). The potential benefits of this combination treatment are strengthened by the ability of NSC74859 to protect primary hepatocytes and nervous system cells against virus-induced cytotoxicity, with an elevation of the VSV maximum tolerated dose in mice. Hereby we propose a strategy for improving the current regimen for HCC treatment and seek to further explore the molecular mechanisms underlying selective oncolytic specificity of VSV.

JNK inhibition sensitises hepatocellular carcinoma cells but not normal hepatocytes to the TNF-related apoptosis-inducing ligand.

BACKGROUND: cJun terminal kinase (JNK) is constitutively activated in most hepatocellular carcinomas (HCCs), yet its exact role in carcinogenesis remains controversial. While tumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is known as a major mediator of acquired immune tumour surveillance, and is currently being tested in clinical trials as a novel cancer therapy, the resistance of many tumours to TRAIL and concerns about its toxicity in vivo represent obstacles to its clinical application. In this study we investigated whether JNK activity in HCC could contribute to the resistance to apoptosis in these tumours. METHODS: The effect of JNK/Jun inhibition on receptor-mediated apoptosis was analysed by pharmacological inhibition or RNA interference in cancer cells and non-tumour cells isolated from human liver or transgenic mice lacking a phosphorylation site for Jun. RESULTS: JNK inhibition caused cell cycle arrest, enhanced caspase recruitment, and greatly sensitised HCC cells but not normal hepatocytes to TRAIL. TRAIL-induced activation of JNK could be effectively interrupted by administration of the JNK inhibitor SP600125. CONCLUSIONS: Expression and TRAIL-dependent feedback activation of JNK likely represent a mechanism by which cancer cells escape TRAIL-mediated tumour surveillance. JNK inhibition might represent a novel strategy for specifically sensitising HCC cells to TRAIL thus opening promising therapeutic perspectives for safe and effective use of TRAIL in cancer treatment.

The role of the novel Th17 cytokine IL-26 in intestinal inflammation.

BACKGROUND AND AIMS: Interleukin 26 (IL-26), a novel IL-10-like cytokine without a murine homologue, is expressed in T helper 1 (Th1) and Th17 cells. Currently, its function in human disease is completely unknown. The aim of this study was to analyse its role in intestinal inflammation. METHODS: Expression studies were performed by reverse transcription-PCR (RT-PCR), quantitative PCR, western blot and immunohistochemistry. Signal transduction was analysed by western blot experiments and ELISA. Cell proliferation was measured by MTS (3-(4,5-dimethylthiazol-2-yl)-5-(carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay. IL-26 serum levels were determined by an immunoluminometric assay (ILMA). RESULTS: All examined intestinal epithelial cell (IEC) lines express both IL-26 receptor subunits IL-20R1 and IL-10R2. IL-26 activates extracellular signal-related kinase (ERK)-1/2 and stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) mitogen-activated protein (MAP) kinases, Akt and signal transducers and activators of transcription (STAT) 1/3. IL-26 stimulation increases the mRNA expression of proinflammatory cytokines but decreases cell proliferation. In inflamed colonic lesions of patients with Crohn's disease, an elevated IL-26 mRNA expression was found that correlated highly with the IL-8 and IL-22 expression. Immunohistochemical analysis demonstrated IL-26 protein expression in colonic T cells including Th17 cells expressing the orphan nuclear receptor RORgammat, with an increased number of colonic IL-26-expressing cells in active Crohn's disease. CONCLUSION: Intestinal cells express the functional IL-26 receptor complex. IL-26 modulates IEC proliferation and proinflammatory gene expression and its expression is upregulated in active Crohn's disease, indicating a role for this cytokine system in the innate host cell response during intestinal inflammation. For the first time, IL-26 expression is demonstrated in colonic RORgammat-expressing Th17 cells in situ, supporting a role for this cell type in the pathogenesis of Crohn's disease.

Inhibition of Src tyrosine kinase reverts chemoresistance toward 5-fluorouracil in human pancreatic carcinoma cells: an involvement of epidermal growth factor receptor signaling.

Resistance to chemotherapy is believed to be a major cause of treatment failure in pancreatic cancer. Thus, it is necessary to explore alternative therapeutic modalities to overcome drug resistance in pancreatic cancer treatment. We tested the hypothesis that Src tyrosine kinase inhibition could augment the chemosensitivity of 5-fluorouracil (5-FU)-resistant human pancreatic cancer cells to 5-FU. As detected by MTT proliferation assay, propidium iodide and annexin V staining, a combination of 5-FU+Src kinase inhibitor PP2 (4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine) reflected the chemotherapeutic sensitivity and restored the 5-FU-induced apoptosis in 5-FU-resistant cells. Furthermore, when small-interfering RNA approach to silence Src gene expression was applied, the degree of 5-FU-induced apoptosis was increased in all cell lines independently of the chemoresistance status. Western blotting and RT-PCR analysis revealed that the expression of thymidylate synthase (TS) was higher in 5-FU-resistant cells, however, decreased significantly after pretreatment with PP2. Furthermore, the combination of 5-FU+PP2 decreased the 5-FU-induced activation of epidermal growth factor receptor (EGFR)-AKT pathway. Finally, PP2 in combination with 5-FU substantially decreased the in vivo tumor growth and inhibited distant metastases. Taken together, 5-FU chemoresistance can be reversed through indirect TS regulation by inhibiting Src tyrosine kinase. A potential mechanism of action of Src kinase inhibitors on 5-FU chemosensitivity might be linked to the inhibition of 5-FU-induced EGFR-AKT activation.