p53 Gene Mutations in Bladder Cancer (II): Mutation Analysis by Non-isotopic SSCP Method

Park, Sung Ho; Moon, Woo Chul

Abstract

Background. p53 gene mutations are known to be an important prognostic factor in bladder cancer. Single strand conformation polymorphism (SSCP) analysis has been suggested to be a promising method to detect p53 gene mutation. However, the technical pitfalls associated with conventional SSCP using radioisotope precluded its wide application in clinical practice. We herein have tried non-isotopic SSCP and analyzed the value of this, new method for detecting mutation of p53 gene in bladder cancer. Methods. In this study of 32 bladder transitional cell carcinoma, we comparatively analyzed polymerase chain reaction (PCR) of exons 5 to 8 of p53 gene, followed by 1) conventional, isotopic-SSCP analysis, 2) non-isotopic SSCP analysis, and 3) DNA sequencing analysis. Results. On isotopic SSCP analysis, 9 out of 32 cases (28.1%) showed mobility shifts. On non-isotopic SSCP analysis, 10 cases (31.0%) showed mobility shifts. On DNA sequencing analysis, 11 cases (34.3%) showed point mutations. The results of isotopic SSCP analysis and non-isotopic SSCP analysis were concordant with that of DNA sequencing in 87.5% and 96.9% of cases, respectively. The sensitivity and specificity of detecting p53 mutations by isotopic and non-isotopic SSCP analysis were estimated to be 81.8% and 100%, and 91.0% and 100%, respectively. Non-isotopic SSCP significantly reduced the time and cost to analyze p53 mutation to 7.9% and 16.0% of those of isotopic SSCP, respectively (p<0.005) . Conclusions. Non-isotopic SSCP is a highly sensitive and specific, time-saving, and cost- effective method to detect p53 gene mutations in bladder cancer. This new method may be promising for the clinical application.