ABSTRACT
MIA3 (melanoma inhibitory active protein 3)/TANGO1 (Golgi transporter component protein) plays an important role in the initiation, development, and metabolism of cancer. We aimed to explore the role and underlying molecular mechanisms of MIA3/TANGO1 in the growth and migration of hepatoma cells. According to the analysis of The Cancer Genome Atlas (TCGA) database, MIA3 is expressed at higher levels in hepatocellular carcinoma (HCC) tissues than in normal tissues. Real-time quantitative polymerase chain reaction (qRT-PCR), immunohistochemistry, and western blotting were used to detect mRNA and protein expression in HCC tissues and cells. The in vitro function of MIA3 in HCC cells was evaluated using Cell Counting Kit-8 (CCK-8), colony formation, cell migration and invasion, and flow cytometry assays. Hep-G2 cells with MIA3 overexpression were subjected to RNA-seq, and the downstream target gene CHAC1 (glutathione-specific γ-glutamyl cyclotransferase 1) was selected according to the results of the volcano map of gene enrichment. The relationship between MIA3 and CHAC1 was revealed by coimmunoprecipitation and confocal microscopy. MIA3 expression was upregulated in HCC organizations and HCC samples in the TCGA dataset. Knocking out MIA3 inhibited the proliferation, migration, and invasion of Hep-G2 cells and promoted the apoptosis of Hep-G2 cells. Overexpression of MIA3 in Huh7 cells promoted the proliferation, migration, and invasion and suppressed the apoptosis of Huh7 cells. Overexpression of MIA3 promoted the expression of CHAC1 and the degradation of glutathione (GSH), thereby promoting the growth and metastasis of HCC cells. Knocking out MIA3 inhibited the expression of CHAC1 and slowed the degradation of glutathione, thereby inhibiting the growth and metastasis of HCC cells. MIA3 further promotes the growth, metastasis, and invasion of hepatoma cells by binding to the CHAC1 protein and promoting GSH degradation.