ERMP1 Facilitates The Malignant Characteristics of Colorectal Cancer Cells through Modulating PI3K/AKT/β-Catenin Pathway and Localization of GRP78.

objectiveEndoplasmic reticulum-metallopeptidase 1 (ERMP1) is involved in cellular response to oxidative stress. However, its functional role in proliferation and progression of cancer cells remains unknown. The focus of this study was to investigate the molecular-mechanisms in which ERMP1 modulates the proliferation and progression of colorectal cancer (CRC) cells under normal and environment stress conditions. MATERIALS AND

methodsIn this experimental study, ERMP1 expression was evaluated using reverse transcriptionquantitative polymerase chain reaction (RT-qPCR) in CRC cells. ERMP1 was knocked down using lentiviral transduction of ERMP1-specific shRNA into HCT116 cells. ERMP1 was also upregulated using lipofectamine transfection of ERMP1-overexpressing vector into SW48 cells. To evaluate the role of ERMP1 in the cellular and environmental stress conditions, ERMP1-downregulated cells were exposed to stressful conditions including starvation, serum free medium, and treatment with redox or chemotherapy agents for 72 hours. The expression of AKT, p-AKT, phospho-mammalian target of rapamycin (p-mTOR), β-catenin, p-β-catenin, E-cadherin, and Glucose-regulating protein 78 (GRP78) proteins was evaluated by western blotting. The expression of

resultsERMP1 knock-down reduced the cellular proliferation, inactivated the PI3K/AKT pathway, prompted the G1 arrest, and attenuated the free β-catenin and

conclusionERMP1 functioned as an oncogene in CRC cells by promoting malignant characteristics. The phosphoinositide 3-kinases (PI3K)/AKT/β-catenin pathway and localization of GRP78 were closely related to the effects of ERMP1. Consequently, ERMP1 might be regarded as a promising target in therapeutic strategies related to CRC.