[Expressions of heat shock protein (HSP) family HSP 60, 70 and 90alpha in colorectal cancer tissues and their correlations to pathohistological characteristics].

BACKGROUND AND OBJECTIVE

Colorectal cancer is the third common malignant tumor in the world. Heat shock protein (HSP) family has been reported to play an important role in carcinogenesis of various cancers. However, little is known about expressions of HSP60,HSP70 and HSP90alpha in colorectal cancer. This study was to investigate expressions of HSP 60, 70 and 90alpha, and analyzed their correlations to pathohistologic characteristics in colorectal cancer.

METHODS

Colorectal cancer tissues and adjacent normal tissues 2 cm away from the tumor focus were collected from 49 patients. Expressions of HSP60, HSP70 and HSP90alpha mRNA were detected by RT-PCR. The protein expressions of HSP60, HSP70 and HSP90alpha were determined by immunohistochemistry and western blot.

RESULTS

The mRNA and protein levels of HSP60, HSP70 and HSP90alpha, as well as their positive rates were significantly increased in tumor tissues compared with those in para-cancerous tissues. The overexpression rates of HSP60, HSP70 and HSP90alpha were also significantly higher in the colorectal cancer tissues than those in the corresponding para-cancerous tissues. The positive and overexpression rates of HSP60, HSP70 and HSP90alpha in well, moderately and poorly differentiated colorectal cancer were not significantly different.

CONCLUSIONS

HSP60, HSP70 and HSP90alpha may play important roles in the pathogenesis of colorectal cancer, although they are not correlated with the pathological grading.