Identification of novel transmembrane proteins in scirrhous-type gastric cancer by the Escherichia coli ampicillin secretion trap (CAST) method: TM9SF3 participates in tumor invasion and serves as a prognostic factor.

摘要: Objective: Scirrhous-type gastric cancer (GC) is highly aggressive and has a poor prognosis due to rapid cell infiltration accompanied by extensive stromal fibrosis. The aim of this study identify genes that encode transmembrane proteins frequently expressed in scirrhous-type GC. Methods: We compared Escherichia coli ampicillin secretion trap (CAST) libraries from 2 human GC tissues with normal stomach CAST library. By sequencing 2,880 colonies scirrhous libraries, we identified list candidate genes. Results: focused on the TM9SF3 gene because it highest clone count, immunohistochemical analysis demonstrated 46 (50%) 91 cases were positive for TM9SF3, which was observed expression showed significant correlation depth invasion, tumor stage undifferentiated There strong between patient outcome, validated two separate cohorts immunostaining quantitative RT-PCR, respectively. Transient knockdown siRNA decreased cell-invasive capacity. Conclusion: Our results indicate might be potential diagnostic therapeutic target