Characterization of skin field of cancerization: nuclear morphometric aspects, chromatin texture, proliferation and apoptosis

• Grant number: 13/00988-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2013
• End date: April 30, 2014
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Juliano Vilaverde Schmitt
• Grantee: Mariana Anteghini Castilho
• Host Institution: Faculdade de Medicina (FMB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Actinic keratosis (AK) is a preneoplastic skin lesion caused mainly by solar radiation on chronic photo exposed areas. It is characterized by the atypical proliferation of the skin's keratinocyte and has a significant risk of progression to squamous cell carcinoma (SCC). Nowadays it is known that about 60% of SCCs are originated from actinic keratosis. Chronically photo exposed skin presents genomic damage that predisposes to carcinogenesis. The appearance of AKs in this region configures the existence of a cancerization field. Early intervention can result in the primary prevention of SCC. Our study has the objective of recognizing early signs of nuclear transformation in order to characterize the cancerization field in studies of skin carcinogenesis. To achieve this we used 38 fragments of skin from three distinct regions of skin: (1) actinic keratosis; (2) perilesional photo exposed skin and (3) axillary protected skin. We expect that the keratinocyte from the photo exposed skin possesses less phenotypic alterations than the photoprotected, identified by the nuclear shape alterations, nuclear size, and heterogeneity of chromatin (HE coloration); as well as immunohistochemistry expression of proliferation and apoptosis resistance markers (Ki-67, p53, and survivin). Thirty nuclei per fragment will be analyzed. The performance of the variables for the characterization of the regions will be compared by Fisher's linear discriminant. The correlations between the variables will be evaluated by Pearson's coefficient. We believe that morphometric and chromatin heterogeneity alterations can constitute an efficient method to characterize the field of cancerization when compared to immunohistochemistry methods. (AU)