Chloride intracellular channel 6 inhibits hepatocellular carcinoma progression by modulating immune cell balance and promoting tumor cell apoptosis.

OBJECTIVE: Chloride intracellular channel 6 (CLIC6) is essential for the development of cancer, and it is widely studied for the treatment of various cancers. This study aimed to explore the potential mechanisms of CLIC6 in the treatment of hepatocellular carcinoma (HCC). MATERIAL AND METHODS: Initially, a subcutaneous xenograft model of HCC was established. The model groups were treated with varying levels of CLIC6 recombinant protein. After 21 days, tumor and liver tissues were harvested. Tumor size and weight were measured, and hematoxylin-eosin staining was used to assess histopathological changes in the tumor tissues. Terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick-end labeling staining was employed to evaluate apoptosis in tumor tissue cells. Quantitative real-time polymerase chain reaction and Western blot were utilized to analyze cytokine messenger ribonucleic acid ( mRNA) levels in the liver or tumor tissues, and immunohistochemistry was conducted to assess cytokine expression. RESULTS: CLIC6 significantly inhibits tumor proliferation and enhances apoptosis in tumor tissue cells. CLIC6 markedly reduces the mRNA levels of interleukin (IL)-6, IL-1β, interferon-γ, tumor necrosis factor-α, and IL-17A in liver tissue when increasing transforming growth factor-β and IL-4 mRNA levels. CLIC6 potentially modulates Th cell balance by regulating forkhead box protein P3, GATA-binding protein 3, T-box expressed in T cell, and retinoic acid receptor-related orphan receptor γt (ROR-γt) expression, thereby restraining HCC progression in mice. Moreover, CLIC6 mitigates hepatic oxidative damage via the Janus tyrosine kinase 1/signal transducer and activator of the transcription pathway, attenuates c-Jun N-terminal kinase (JNK) phosphorylation, and modulates apoptosis-related proteins, effectively hindering HCC development. CONCLUSION: CLIC6 demonstrates potent antitumor effects in HCC through inhibition of proliferation, promotion of apoptosis, modulation of cytokine levels, regulation of immune cell balance, and attenuation of oxidative stress pathways.