ATOX1 drives hepatocellular carcinoma progression through c-Myb and PI3K/AKT activation

Background and aims

Despite advancements in diagnostic and therapeutic strategies, hepatocellular carcinoma (HCC) remains a leading cause of cancer-related mortality. Antioxidant-1 (ATOX1) has been implicated in oncogenic processes across various cancer types; however, its specific role in HCC remains unclear. This study aimed to investigate the function of ATOX1 and its underlying molecular mechanisms in HCC.

Methods

Immunohistochemical analysis was conducted to assess ATOX1 expression in HCC tissues. Cell Counting Kit-8, colony formation, Transwell migration, flow cytometry, and reactive oxygen species (ROS) assays were employed to evaluate the malignant behaviors of tumor cells. A xenograft mouse model was employed to assess the effects of ATOX1 knockdown on tumor growth in vivo. DCAC50 treatment was performed to inhibit the copper transport function of ATOX1. RNA sequencing was conducted to explore the potential molecular mechanisms of ATOX1 in HCC.

Results

ATOX1 expression was significantly elevated in HCC tumor tissues. ATOX1 promoted cell proliferation, colony formation, and migration. Knockdown of ATOX1 suppressed tumor growth in vivo. Mechanistically, ATOX1 activated c-Myb, and thus enhanced the malignant phenotype of HCC cells via activation of the PI3K/AKT signaling pathway. Additionally, ATOX1 reduced intracellular copper accumulation and inhibited ROS production and apoptosis. Inhibition of ATOX1 by DCAC50 decreased cell proliferation while increasing ROS levels and apoptosis in HCC cells. Notably, acetylcysteine reversed the reduction in c-Myb expression induced by ATOX1 knockdown.

Conclusions

This study elucidates that ATOX1 promotes HCC carcinogenicity through the c-Myb/PI3K/AKT signaling pathway while inhibiting copper accumulation, ROS generation, and apoptosis. These results indicate that ATOX1 represents a potential therapeutic target for HCC. Moreover, the compound DCAC50, by obstructing ATOX1's copper transport function, effectively suppresses the malignant behavior of HCC cells, suggesting its promising role in HCC treatment, particularly when combined with PI3K/AKT pathway inhibitors.