Detecting p53 gene mutation of breast cancer and defining differences between silver staining PCR-SSCP and immunohistochemical staining

This study detects and defines the patterns of p53 gene mutations in breast cancers. We analyse p53 gene mutations through comparing the results of si ngle-strand-conformation-polymorphism (SSCP) and immunohistochemistry (IHC) , and we try to define the differences between the results of SSCP and IHC. Twenty-seven fresh primary breast cancer tissues and eight normal breast t issues were studied. The IHC was done with the usual streptavidin-biotin pe roxidase complement method by using monoclonal antibody DO-7. The results o f staining was scored. The SSCP method was done by using Cold SSCP Electrop horesis System. Overexpressions of p53 protein were seven (25.9%) among 27 cancer cases on IHC. Four (57.1%) of seven cases were positive in SSCP. In SSCP, the mutations were detected in 10 (37%) among 27 cancer cases. The mu tations were two in exon 5, one in exon 8, and seven cases in exon 7, All o f 10 mutations were proved by sequencing analysis. Of them, only four (40%) were positive in IHC. We consider the IHC as a screening method for p53 ge ne mutations.