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 single-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 tissues were studied. The IHC was done with the usual streptavidin-biotin peroxidase complement method by using monoclonal antibody DO-7. The results of staining was scored. The SSCP method was done by using Cold SSCP Electrophoresis 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 mutations were two in exon 5, one in exon 8, and seven cases in exon 7. All of 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 gene mutations.