Heat Shock Protein 70 and p53 Protein Expression in Colorectal Adenomas and Carcinomas

Jang, Tae Jung; Kim, Jung Ran; Lee, Kung Bae

Abstract

Heat shock protein 70 (HSP70) is a chaperone that binds to mutant p53 and consequently can regulate its accumulation or localization. Its expression is upregulated in tumor cells. We studied 44 adenomas and 29 carcinomas of colorectum to evaluate the expression of HSP70, and to assess the correlation among p53 protein and other clinical prognostic parameters. HSP70 expression was scored according to staining intensity and extent. p53 protein expression was 45.5%(20/44) in adenomas and 79.3%(23/29) in carcinomas(P<0.01). p53 protein expression of carcinomas was 57.1%(4/7) in diploidy tumors, 100.0%(8/8) in aneuploidy tumors(P=0.07), 100.0%(8/8) in well-differentiated tumors, and 50.0%(2/4) in poorly differentiated tumors(P= 0.09). HSP70 expression mainly revealed a fine granular cytoplasmic staining pattern in tumor cells. HSP70 was focally detected in some lymphocyte, ganglion cell and normal mucosa. HSP70 expression was 46.3%(19/41) in adenomas and 93.1%(27/29) in carcinomas. HSP70 score was 0.9+/-1.3 in adenomas(n=41) and 5.5+/-3.5 in carcinomas(n=29)(P<0.0005). Its score was 1.7+/-1.6 in p53 positive adenomas and 0.3+/-0.6 in p53 negative adenomas(P<0.005), and its expression rate was higher in p53 positive carcinomas than p53 negative carcinomas (P>0.05). There was no significant correlation among HSP70, tumor size, Dukes'stage, nodal metastasis, depth of tumor invasion, DNA ploidy and tumor differentiation. In conclusion, HSP70 and p53 protein appear to be correlated to each other, and that HSP70 and p53 protein may play a certain role in the progression of colorectal tumor. Further studies are needed for determining their prognostic factors in colorectal carcinoma.