We previously showed that B cell receptor associated protein 31(BAP31) was significantly upregulated in colorectal cancer compared with normal mucosa epithelia. However, its expression pattern and pathological role in colorectal cancer are not clearly understood. In this study, we investigated whether the expression of BAP31 was associated with the clinicopathological parameters of colorectal cancer. The expression pattern of BAP31 was detected by immunohistochemistry on a tissue microarray in both primary tumor and paired distant normal mucosa samples from 120 consecutive colorectal cancer patients. Furthermore, BAP31 protein expression was also determined in twenty colorectal adenomas and eight liver metastasis samples. There was positive expression of BAP31 in 64.17% of primary tumors and 6.67% in distant normal mucosa (P=0.000). Negative expression of BAP31 was correlated with distant metastasis (P=0.036) and lower tumor differentiation grade (P=0.001). Patients with BAP31-negative expression showed significantly lower overall survival rate (P=0.003) compared to patients with BAP31-positive expression. Our results demonstrate that BAP31 may serve as a candidate prognostic marker in colorectal cancer and negative BAP31 expression may lead to more aggressive invasion of colorectal cancer.
DONG LingYi JIANG KeWei ZHANG YanBin ZHANG Hui ZHUO HongQing CUI ZhiRong YE YingJiang WANG Shan
We have investigated the role of MSH2,a mismatch repair gene in cell proliferation,cell cycle control and cell invasiveness in the SW480 human colorectal cancer cell line.RNAi-mediated inhibition of MSH2 expression was achieved using MSH2 shRNA lentiviral expression vectors.Effective knockdown of endogenous MSH2 expression was determined by real-time PCR analysis.The most efficient MSH2 knockdown vector was selected for subsequent studies using SW480 cells.Endogenous MSH2 mRNA levels decreased after lentiviral delivery of the MSH2-RNAi,indicating efficient silencing of MSH2 expression in SW480 cells.Cell proliferation,cell cycle progression and cell invasiveness were quantified by MTT assays,flow cytometry and transwell assays,respectively.RNAi-mediated inhibition of MSH2 expression in SW480 cells resulted in decreased cell proliferation,cell cycle arrest at the G0/G1 phase and decreased cell invasiveness.Taken together,these results provide evidence that MSH2 stimulates cell proliferation,promotes cell cycle progression and positively regulates cell invasiveness.
