Expression of Bcl-2,Bcl-xL and Bax in colorectal carcinomas / 第二军医大学学报

ABSTRACT

Objective: To observe the expression of Bcl-2, Bcl-xL and Bax in colorectal cancer tissues and their corresponding adjacent tissues (>5 cm from the tumor tissue), and to study their roles in the development and progression of colorectal cancer. Methods: The mRNA levels of Bcl-2, Bcl-xL, Bax were detected by RT-PCR and their protein levels were detected by MaxVision one step method in 40 colorectal cancer tissues and their corresponding adjacent tissues. Results: The mRNA and protein levels of Bcl-2 were very low in both cancer tissues and adjacent tissues(P>0.05). Both cancer tissues and adjacent tissues had higher Bcl-xL mRNA and protein levels, with those of the cancer tissues obviously higher than those of the adjacent tissues (P<0.05). The levels of Bax MRNA and protein were higher than those of Bcl-2 and Bcl-xL in both tissues, but with no significant difference between the 2 tissues. The ratio of Bcl-2/Bax and Bcl-xL/Bax in 2 tissues had no significant difference, either. The expression of Bcl-2 protein was negatively correlated with Dukes and TNM stages of the colorectal cancer (P<0.05), and was not correlated with other factors such as sex, age, tumor size, tumor location and morphological types. Levels of mRNA and protein of Bcl-xL and Bax were not correlated with pathological factors. Conclusion: Bcl-xL expression is obviously higher than that of Bcl-2 in colorectal tissues and also higher than that of Bcl-xL in adjacent tissues, suggesting that Bcl-xL may enhance the development and progression of colorectal cancer. Bcl-2 may be a prognostic indicator for colorectal cancer because it is negatively correlated with tumor stages.