Prognostic Significance of Heat Shock Protein 70 Expression in Bladder Tumor

Choi, Chang Jun; Park, Dong Soo; Oh, Kil Hyun

Abstract

Heat Shock Protein (HSP) is a genetic product reacting on stress. HSP is increased by physiological or environmental stress and expressed at gastrointestinal tumors such as stomach cancer, pancreatic cancer and large intestinal cancer, and at other various tumors such as lymphoma and breast cancer. The role of HSP is to interrupt the process of apoptosis interfering with formation of tumors, and weaken function of tumor control beyond that of immune surveillance. In case of causing the normal p53 to be mutated, it leads to morphological change of p53 protein and combine with HSP. But, it has not been clarified yet. We intend to examine the meaning of HSP 70 in bladder tumor by investigating the relations among HSP expression and tumor stage, tumor grade, P-gp (glycoprotein) expression as a product of multi-drug resistant gene, and p53 expression in 59 cases of bladder tumor. 1) There were HSP expressions of 8 cases (22%) among 36 superficial bladder tumors and of 9 cases (39%) among 23 invasive bladder tumors. 2) HSP positive reactions were observed in 1 case (8%) of 13 Grade I, and 6 cases (29%) of 21 Grade II and 10 cases (40%) of 25 Grade III. 3) Positive reactions of HSP were showed in 10 cases (40%) among 25 P-gp expression, and in 7 cases (21%) among 34 P-gp non-expression. 4) The p53 proteins were expressed in 12 cases (29%) among 42 ones of HSP non-expression and in 8 cases (47%) among 17 ones of HSP expression. 5) Positive reactions of HSP were showed in 9 cases (23%) among 39 ones of p53 non-expression, and in 8 cases (40%) among 20 ones of p53 expression. 6) 5 patients of 6 with negative expression of HSP and strong positive expression of p53 had poorly differentiated transitional cells, in which one of the patients accompanied with lung metastasis. In view of above study, HSP expression has no correlation with P-gp and stage in bladder tumor, but it has probable pertaining to tumor grade and p53. As it were, tumor cellular differentiation and p53 expression have weak correlations with HSP 70 expression. Meanwhile, judging from poor differentiation, in most cases of HSP non-expressed but p53 strongly expressed, HSP is insufficient to be a prognostic factor of bladder tumor independently, however, in case of using it, as supplementary one, concurrently with p53, it would be valuable prognostic factor in bladder tumor.