MCM2 promotes the proliferation, migration and invasion of cholangiocarcinoma cells by reducing the p53 signaling pathway.

The abnormal expressions of minichromosome maintenance protein 2 (MCM2) are closely related to the development of various kinds of cancers. We aimed to explore the functions and potential molecular mechanisms of MCM2 gene in cholangiocarcinoma (CCA) cell lines (Huh28 and RBE). First, the cell counting kit-8 (CCK-8), plate clone formation, transwell and invasion assays showed that MCM2 promotes the proliferation, migration and invasion of CCA cells. Flow cytometry assays showed that MCM2 significantly promotes the cell cycle, and inhibits the apoptosis of CCA cells. Further, by analyzing the RNA sequencing data of cholangiocarcinoma, we found that MCM2 gene is significantly negatively correlated with p53 signaling pathway. Quantitative real time polymerase chain reaction (qRT-PCR) and Western blotting (WB) assays confirmed that MCM2 in CCA cells significantly down-regulated the mRNA and protein expression levels of p53 and BAX, and up-regulated the mRNA and protein expression levels of BCL2 and CCND1. Flow cytometry, qRT-PCR and WB assays confirmed that MCM2 promotes CCA through p53 pathway. Finally, we found that MCM2 is up-regulated in CCA tissues compared to the matched non-tumor cholangiocarcinoma tissues, and the high expressions of MCM2 are significantly associated with the poor clinical outcomes of CCA patients. In conclusion, this study revealed that MCM2 promotes the development of CCA by reducing the p53 pathway, and its high expression levels predict poor prognosis in CCA patients. These results provide a theoretical basis for the development of new clinical diagnosis and treatment of cholangiocarcinoma in the future.