ATMIN enhances invasion by altering PARP1 in MSS colorectal cancer.

Genomic instability is a key cancer indicator. It results from defects in the DNA damage response (DDR) and increased replication stress. Herein, we examined how ataxia-telangiectasia mutated interactor (ATMIN), a DDR pathway involved in mismatch repair-proficient (microsatellite stability [MSS]), acts in colorectal carcinoma (CRC). Firstly, ATMIN mRNA expression was detected in CRC specimens with MSS characteristics, and the effects of ectopic ATMIN expression and ATMIN knockdown on invasion abilities were gauged in MSS cell lines. To understand the molecular mechanism, co-immunoprecipitation analyses in vitro were employed. Interestingly, ATMIN expression was positively correlated with advanced stages (P < .001), lymph node metastases (P = .002), and deeper invasion (P = .037) in MSS tumors; and significantly changed the cell motility in vitro. In the high-throughput analysis, ATMIN was found to act on the Wnt signaling pathway via PARP1. PAPR1 inhibition, in turn, significantly decreased invasion abilities resulting from ATMIN overexpression in cancer cell. Taken together, ATMIN, which alters the Wnt signaling pathway regulating CRC progression, plays as a crucial prognostic factor in MSS tumors.