Expression of deleted in liver cancer 2 in colorectal cancer and its correlation with clinicopathological parameters

Deleted in liver cancer 2 (DLC2) has been identified as a tumor suppressor gene. DLC2 is closely related to deleted in liver cancer 1 (DLC1) and is located at chromosome 13q12.3. The expression of DLC2 mRNA has been found in a wide range of cancers, including colorectal cancer (CRC). However, there are no available data on the expression status of DLC2 in Chinese patients with CRC and its correlation with clinicopathological parameters. The aim of this study was to investigate the expression levels of DLC2 mRNA and protein in Chinese patients with CRC and the correlation between DLC2 expression and clinicopathological parameters. To this end, real-time PCR, western blotting and immunohistochemistry were employed to detect DLC2 mRNA and protein expression in CRC and pericarcinomatous intestinal tissue (PCIT) specimens, which were obtained from 102 Chinese CRC patients who underwent surgical resection between October 2010 and February 2012. We also analyzed the correlations between DLC2 expression and the clinicopathological parameters of CRC patients. Our results showed that CRC tissues had significantly lower levels of DLC2 mRNA compared with PCITs (P<0.05); however, the protein expression levels were not significantly different between CRCs and PCITs. The expression levels of DLC2 mRNA and protein were significantly correlated with lymph node metastasis and tumor TNM stage. Additionally, DLC2 mRNA expression levels were also correlated with tumor histopathological degree (P<0.05). Collectively, our results suggest that the downregulated expression of DLC2 participates in CRC carcinogenesis, invasion and lymph node metastasis. Furthermore, our results imply that DLC2 is be a potential prognostic marker for CRC patients.