HAX1 Upregulation Drives Hepatocellular Carcinoma Progression by Suppressing Ferroptosis via GSH/GPX4 Pathway

Hepatocellular carcinoma (HCC) remains a malignancy with poor prognosis and limited therapeutic targets, necessitating novel treatment strategies. Current standard-of-care often falls short in advanced stages, highlighting a critical need for new mechanistic insights. Emerging evidence points to iron metabolism and ferroptosis, an iron-dependent form of regulated cell death, as crucial players in tumor progression and suppression. However, the specific involvement of hematopoietic lineage cell-specific protein 1 (HAX1) in HCC, particularly its regulatory role in ferroptosis, has remained largely unexplored, representing a significant knowledge gap this study addresses.

Researchers investigated the role of HAX1 in HCC progression and ferroptosis regulation using in-vitro cell models. They manipulated HAX1 expression in HCC cells through HAX1 overexpression and HAX1 knockdown techniques. The impact on malignant phenotypes such as proliferation and migration was assessed. To evaluate ferroptosis, cells were treated with the ferroptosis inducer IKE. Key markers of ferroptosis, including intracellular ferrous iron (Fe2+) accumulation and lipid reactive oxygen species (ROS), were measured. Additionally, the GSH/GPX4 antioxidant pathway was analyzed to elucidate the underlying molecular mechanisms.

HAX1 was found to be significantly upregulated in HCC tissues, correlating with advanced pathological stages and poor patient survival, suggesting its oncogenic potential. Functionally, HAX1 overexpression promoted the proliferation and migration of HCC cells, while its knockdown effectively inhibited these malignant phenotypes. Mechanistically, HAX1 acts as a negative regulator of ferroptosis. Silencing HAX1 sensitized HCC cells to the ferroptosis inducer IKE, leading to abnormal accumulation of intracellular ferrous iron (Fe2+) and increased lipid reactive oxygen species (ROS). Conversely, HAX1 overexpression suppressed iron overload and lipid peroxidation. Furthermore, HAX1 maintains redox homeostasis by regulating the GSH/GPX4 antioxidant pathway. Knockdown of HAX1 depleted reduced glutathione (GSH), reduced glutathione peroxidase activity, and downregulated key ferroptosis defense proteins, including GPX4, FSP1, and SLC7A11.