Expression Of HER-2 And K-RAS And Its Significance In Human Colorectal Cancer

Objective To explore the relationshipbetween HER-2 gene, K-RAS gene, the carcinogenesis mechanism of colorectal cancer by the determination of the expression of HER-2 and K-RAS in colorectal cancer tissues.Methods The expression of HER-2 and K-RAS was detected with immunohistochemical methods in normal mucosal tissue, colorectal adenoma, colorectal cancer and metastatic lymph nodes. Results The positive rates of HER-2 and K-RAS high expression were 67.5% and 51.2%, respectively,in colorectal cancer, and 80.0% and 33.3% respectively in colorectal adenoma, while those in normal mucosal tissue were only 33.3% and 0. The expression of HER-2 and K-RAS in colorectal cancer and colorectal adenoma were significantly higher than those in normal mucosal tissue, but no significant differences existed between colorectal cancer and colorectal adenoma. In colorectal cancer, high expression of both proteins occurred in 36.3% of the cases. The positive rate of HER-2 hyperexpression in cell membrane was 38.2%, which showed a positive correlation with depth of invasion. high expression of K-RAS was not correlated with clinicopathologic parameters. In the colorectal cancer, the HER-2 hyperexpression was not positively correlated with K-RAS hyperexpression ( P> 0.05).But in the metastatic lymph nodes, the HER-2 hyperexpression was positively correlated with K-RAS hyperexpression ( r= 0.458, P< 0.05) . There was nosignificant association between their high expressions and prognosis in colorectal carcinoma.Conclusion HER-2 and K-RAS may play a combined role in the development of colorectal cancer. Hyperexpression of HER-2 in cell membrane was significantly associated with invasiveness.