Gene expression analysis of the effects of RADIOTERAPY in the differentiation of mesenchymal cells

Abstract

The purpose of this study is to evaluate the effects of ionizing radiation, simulating the total doses of a convetional radiotherapy treatment to oncologics patients, in the bone neogenesis and osseointegration of implants in femurs of rats, by means of a gene expression analysis in mesenchymal cells found in these femurs. A total of 80 rats will be used in this research, wich will receive a comercial pure titanium implant (TiCp), in their right and left femurs. The animals will be devided in 2 groups: a) Implant group (Ip): Implants installation surgery without irradiation (control group - healthy tissue); b) Immediate irradiation group (Ir): Implants installation surgery and irradiation in the same day. The animals of Ir group will be subjected to a single dose irradiation equivalent to 70 Gy in humans. The rats will be randomly subdivided in three groups and euthanized in periods of 3 days, 2 and 6 weeks after the treatment. The gene expression of Alkaline phosphatase, Integrin B1, Collagen 1, Osteocalcin, Osteopontin, Osteonectin, Sialoprotein bone, Tgf-b, Osterix, Runx2, and macrophage colony stimulating factor - Mcs-f will be analysed by qRT-PCR. The results will be evaluated using ELISA. The data will be statistically analyzed, initially througt a normal trial aiming to define the most appropriate statistical test to be applied. The adopted significance level will be the conventional value of 5%. (AU)