Abnormal expression of p190RhoGAP in colorectal cancer patients with poor survival.

PURPOSE: This study aims to investigate the expression and clinical significance of p190RhoGAP, a member of the RhoGAP family, in colorectal cancer (CRC).

METHODS: The expression p190RhoGAP was detected by RT-PCR, western blot (WB) and immunohistochemistry (IHC) in 14 paired CRCs and matched non-cancerous mucosal tissues. The protein content of p190RhoGAP was identified in 114 CRCs by IHC. In addition, the association of the expression of p190RhoGAP with carcinogenesis, distant metastasis and prognosis was further evaluated.

RESULTS: In 14 paired fresh tissues, the mRNA (P<0.0001) and protein (P = 0.003) expression levels of p190RhoGAP were significantly higher in primary CRCs than in paired non-cancerous mucosal tissues; and was consistent with WB results. The expression of p190RhoGAP increased from normal mucosa to adenoma, and became even greater in primary carcinoma (P = 0.001). The expression level of p190RhoGAP was highest in liver metastasis compared to primary carcinoma (P = 0.028). The incidence of p190RhoGAP expression-positive cases was 58.77% in 114 CRC tissues. Furthermore, the enhanced expression of p190RhoGAP was significantly associated with shorter disease-specific survival (P<0.001) and shorter disease-free survival (P<0.001). Cox regression analysis indicated that p190RhoGAP was an independent prognostic parameter for CRC.

CONCLUSION: p190RhoGAP may be an independent predictive factor for the prognosis of CRC, and the abnormal expression of p190RhoGAP may play a crucial role in colorectal carcinogenesis and distant metastasis.