Microdissecção e captura a laser na investigação do gene TP53 em tecidos incluídos em parafina

Abstract

Background: Laser-capture micro-dissection (LCM) is a recently developed procedure that provides single cells or specific cell groups for molecular analysis. Currently, there are few LCM systems in Brazil, in such a way that it is necessary to disseminate the technical procedures inherent to the methodology, and also to characterize its enormous potential for diagnosis and research. Objective: This study describes the standardization of LCM and DNA extraction from formalin fixed and paraffin-embedded tissues. Material and Method: The gene TP53 exon 8 and the cyclophilin gene were studied in normal and neoplastic liver and kidney samples from a chemical carcinogenesis model in rat. DNA extraction was confirmed by nested-PCR. Results: Histological sections preparation for LCM and the nested-PCR procedures were standardized; 48.3% amplifications of the gene TP53 exon 8 and 51.7% of the cyclophilin gene samples were obtained. When at least one of the gene segments was considered, 79.3% samples presented amplification. Discussion and Conclusion: Procedures for DNA extraction from formalin fixed and paraffin-embedded tissues collected by LCM were standardized. They can be useful for DNA collection for molecular studies.