Technical approach for the study of the genetic evolution of breast cancer from paraffin-embedded tissue sections

摘要: We have optimized a technique that allows the study of numerous chromosomal loci (n = 20-50) from single paraffin-embedded tissue sections by microsatellite length polymorphism analysis. DNA samples normal and breast cancerous can be obtained same section means microdissection. This was further improved subjecting to several cycles amplification with degenerate (universal) primer then specific primers. amplified also used screen for mutations in p53 gene PCR-SSCP. In addition adjacent were assess chromosome copy number interphase cytogenetic analyses (chromosome situ hybridization) analyze expression genes such as ERBB2. As an example use our approach we performed detailed 17 allelotypic analysis 22 tumors (5 ductal carcinomas situ, 13 invasive carcinomas, 4 lobular carcinomas). detected PCR-SSCP 36% samples. Samples significant levels protein accumulation immunohistochemistry positive mobility shifts SSCP observed allelic losses imbalance occurred at early stage carcinoma (DCIS). Although some cases or affecting 17p13 region, close locus, showed dissociation between loss mutation. Lobular predominantly disomic contrast tumors, which often polysomy 17. comprehensive correlating tumor subtype, its allelotype, preinvasive cancer lesions will potentially provide information relevance better understanding multistep mechanisms carcinogenesis.