SIRT2 expression in colorectal cancer patients with liver metastasis and its clinical significance

Abstract

Objective To investigate SIRT2 expression and its significance in colorectal cancer liver metastasis. Methods The expression level of SIRT2 was detected in 25 cases of colorectal cancer tissues and corresponding liver metastasis tissues and another 60 cases of colorectal cancer tissues and corresponding adjacent normal tissues by immunohistochemical method. The clinicopathologic correlations of SIRT2 expression were performed using chi-square test. Kaplan-Meier method was used to evaluate the overall survival. Transwell method was used to evaluate invasiveness of SW480 cell line. qRT-PCR was applied to assess expression level of E-cadherin and MMP2. Results SIRT2 expression significantly decreased in colorectal cancer liver metastases (3.6±0.5 vs. 6.5±0.8, t=15.37, P<0.01). The low expression level of SIRT2 was significantly associated with tumor differentiation (χ2=7.475, P=0.024). Patients with low SIRT2 expression had a shorter overall survival than those with high SIRT2 expression [(42.5±6.0)mon vs. (60.5±5.4)mon, χ2=5.493, P=0.019]. Multivariate analysis showed that SIRT2 expression and distant metastasis were the two factors that were independently associated with prognosis. Overexpression of SIRT2 significantly weakened the invasive ability of SW480 cell line. Conclusion Downregulation of SIRT2 predicts poor prognosis of patients with colorectal cancer for enhancing tumor cell invasive ability. Key words: Colorectal neoplasms; Neoplasm metastasis; Prognosis