ABSTRACT
Purpose To investigate the expression and significance of USP10 protein and mRNA in normal colorectal mucosa and colorectal adenocarcinoma,and to analyze the cause of the disorder.Methods 99 cases of colorectal adenocarcinoma and 83 cases of normal intestinal mucosa tissue were selected.Using tissue microarray and immunohistochemistry the expression of USP10 protein was detected,and the relationship was analyzed between USP10 protein and clinical pathological parameters or prognosis survival time.The expression of USP10 mRNA was analyzed by GEO datesets.Some miRNAs that down-regulate the expression of USP10 protein were screened by bioinformatics methods.The expression of USP10 protein and miR-149 in colorectal cancer cell lines were detected by Western blot and real-time quantitative PCR.Results The positive rate of USP10 protein in normal intestinal mucosa tissues was 71.08％(59/83),which was significantly higher than that in colorectal adenocarcinoma tissues (53.54％,53/99,P =0.015).No correlation were proved between USP10 protein expression and clinical pathological parameters or survival time (P ＞ 0.05).The expression level of USP10 mRNA in colorectal adenocarcinoma was 1.07 ～ 1.45 times that were higher than that of normal intestinal mucosa,which showed that the down-regulation of USP10 protein was at the post-transcriptional level.The program predicted a putative highly-conserved binding site in the USP10 mRNA 3'UTR for miR-149 which was up regulated in colorectal adenocarcinoma tissues.In addition,the expression of miR-149 was negatively correlated with the expression of USP10 protein in colorectal cancer cell lines.Conclusion The down-regulation of USP10 protein which occurs at the post-transcriptional level is closely related to the pathogenesis of colorectal adenocarcinoma.The high expression of miR-149 may be one of the factors that negatively regulate the expression of USP10 protein.