Instabilità delle sequenze microsatellite del DNA associata ad alterazioni genetiche nei tumori della testa e del collo. Revisione della letteratura e presentazione dei risultati preliminari di un progetto di ricerca. [Instability of micro-satellite sequences of DNA associated with genetic alterations in head and neck neoplasms. Review of the literature and preliminary results of a research plan].

It is known that tumoral progression towards a metastatic stage is identifiable with a genomic instability. This instability leads to both primary and secondary genetic alterations. It can give some selective proliferative advantages. This study aims to review the literature on instability of the microsatellite sequences of DNA associated with genetic alterations in tumors of the head and neck. In particular, the studies on relations between instability of micro-satellite sequences and expression of MLH1, MSH2, PMS1, PMS2 genes have been reviewed. Further aim of this study is to present preliminary results of a research project into distribution of hMLH1 and hMLH2 proteins in oral tissues. Nine formalin fixed and paraffin embedded samples (8M/1F; mean age 58 years) of oral squamous cell carcinomas tissues have been analysed for the presence of hMSH2 and hMLH1 by using streptavidin-biotin immunoperoxidase technique. Samples have been analysed by optical microscope by two observers evaluating the positive cell percentage for three representative fields. Immunohistochemistry demonstrated that hMLH1 and hMSH2 are widely expressed nuclear proteins in oral tissues. The localization of hMLH1 and hMSH2 in oral epithelium are consistent with the biochemical function of these proteins in DNA mismatch repair. Z9 0