GINS4 silencing mediates hepatocellular cancer cell proliferation, cycle and ferroptosis through POLE2

GINS4 has been identified as a regulator associated with multiple types of cancers. However, the effects of GINS4 on hepatocellular carcinoma (HCC) have not been reported. GINS4 expression in HCC was evaluated utilizing UALCAN database. The relationship between the expression of GINS4 and the survival probability of HCC patients was analyzed using Kaplan-Meier Plotter. Cell viability was evaluated by CCK8 assay and EDU assay. qRT-PCR and western blot were performed to examine GINS4 expression. The level of cell cycle was measured by flow cytometry and western blot. Fe 2+ level and ferroptosis-related proteins were measured by corresponding kits and western blot. Lipid peroxidation was explored by C11 BODIPY 581/591 probe. STRING database and HDOCK database were performed to predict the binding of GINS4 to POLE2. Immunofluorescence and western blotting was adopted for assessing cell autophagy and mTOR signaling pathway. Ki67 and GPX4 levels were measured by immunohistochemistry. The expression levels of POLE2/PI3K/AKT were assessed by western blot. The data indicated that GINS4 expression was upregulated in HCC. Knockdown of GINS4 alleviated the proliferation and cycle and promoted ferroptosis of HuH7 cells. GINS4 was proved to bind to POLE2 and the silencing of GINS4 inhibited the expression of POLE2. GINS4 knockdown accelerated ferroptosis in HuH7 cells. POLE2 overexpression reversed the influences of GINS4 silencing on proliferation and cycle, and also ferroptosis. In addition, interference with GINS4 suppressed the activation of PI3K/AKT signaling via POLE2. In vivo experiments illustrated that GINS4 deletion suppressed HCC tumor growth, increased the GPX4 expression and restrained the Ki67 level, as well as reducing POLE2/PI3K/AKT signaling. GINS4 silencing suppressed proliferation and cycle while promoted ferroptosis in HCC cells by regulating PI3K/AKT signaling via binding to POLE2. • The expression of GINS4 is increased in HCC tissues and cells. • Silencing of GINS4 suppresses the proliferation and cell cycle of HuH7 cells. • Silencing of GINS4 promotes ferroptosis in HuH7 cells. • Silencing of GINS4 represses the proliferation and cycle acceleration and facilitates ferroptosis in HuH7 cells through POLE2. • GINS4 silencing inhibits the growth of HCC and the POLE2/PI3K/AKT pathway in vivo.