FAM172A is a tumor suppressor in colorectal carcinoma

The present study was designed to elucidate the regulatory role of a novel protein FAM172A in carcinogenesis of colorectal carcinoma (CRC). Investigation of clinical samples using Western blotting showed that expression of FAM172A is significantly lower in cancerous tissues than in adjacent tissues. Furthermore, we constructed in vitro model for continuous overexpression and silencing of FAM172A with a retroviral vector system. FAM172A suppressed the proliferative and invasive potentials of LOVO cells as shown in MTT test, transwell migration assay, wound healing assay, 3D-culture morphologic study, and xenograft experiment. RTPCR and Western blotting showed that FAM172A overexpression inhibited expressions of Cyclin D1, CDK2, MMP-2, MMP-9, PERK, elF2 alpha, ATF6, XBP1, and GRP78, while FAM172A silencing induced their expressions. FAM172A might regulate ERS through PERK-elF2a, ATF6-XBP1-GRP78 signal pathway. The results implicated that FAM172A functioned as a tumor suppressor in colorectal carcinoma.