PIMREG, a Marker of Proliferation, Facilitates Aggressive Development of Cholangiocarcinoma Cells Partly Through Regulating Cell Cycle-Related Markers.

Phosphatidylinositol binding clathrin assembly protein interacting mitotic regulator (PIMREG) is a protein associated with cell proliferation. Its aberrant expression was reported to be correlated with the development in multiple tumors. However, its role in cholangiocarcinoma (CAA) has not yet been evaluated in detail. Data were acquired from the public TCGA database for evaluating the expression pattern of PIMREG and assessing its clinical relevance as well as its correlation with overall survival. RBE and HUH28 cell lines were selected to perform loss- and gain-of-function of PIMREG assays respectively. Quantitative real-time PCR (RT-qPCR) and western blot analyses were used to measure the mRNA and protein levels of PIMREG. Cell Counting Kit-8, colony formation tests, and Transwell assays served to measure the effect of PIMREG on the proliferative, invasive and migratory capacities of CAA cells, appropriately. Gene set enrichment analysis (GSEA) was conducted to identify PIMREG associated gene set, which was further confirmed by western blot. PIMREG was found to be highly expressed in CAA tissues and cell lines according to the public dataset and RT-qPCR analysis, and negatively related to the prognosis of patients with CAA. Moreover, knockdown of PIMREG suppressed and overexpression of PIMREG promoted the proliferation, invasion and migration of CAA cells. Furthermore, GSEA revealed that high PIMREG expression was positively associated with cell cycle signaling. And the next western blot analysis demonstrated that silencing PIMREG resulted in a reduction on the levels of p-CDK1, CCNE1, and CCNB1, whereas PIMREG overexpression led to an opposite result. The results suggested that PIMREG facilitates the growth, invasion and migration of CAA cells partly by regulating the cell cycle relative biomarkers, revealing that PIMREG may be a crucial molecule in the progression of CAA.