احمد همتا - Dept. of Biology Faculty of Basic Sciences, Arak University, Arak, Iran
سید محمد علی شریعت زاده - Dept. of Faculty of Basic Sciences, Arak University, Arak, Iran
ملک سلیمانی مهرنجانی - Dept. of Faculty of Basic Sciences, Arak University, Arak, Iran
فاطمه سیفی - Dept. of Biology Faculty of Basic Sciences, Arak University, Arak, Iran

Background and Objective: Discovery of genetic changes which contribute to cellular neoplastic and malignant tumor transformation is one of the major aims in oncology researches. The aim of this study was to investigate the DMBA-induced breast cancer in SD rat strains using bioinformatical methods and also to find their homologous regions in human chromosomes. Materials and Methods: In this research, we used SD rat strains as a suitable model for DMBA-induced breast cancer. We gavaged the rats twice with ۱۰ mg DMBA solved in ۰.۵ ml sesame oil. After tumors appeared in DMBA-treated rats, they were subjected to histopathology and immunohistochemistery studies, cell culture, metaphase chromosomal preparation, and finally G-banding stain. According to databases, we collected genes in the affected area and prepared a gene list by comparing genome of the rats and human in changed chromosomal segments. Results: Our data showed numerical and frequent structural changes in different number of chromosomes. For example, we found recurrent gain in chromosomes ۳, ۴, ۸, ۱۲, ۱۷, loss in chromosomes ۳, ۹, ۱۲ and ۱۵, also deletion in chromosomes ۲, ۳, ۴, ۶, ۷, ۲۰ and addition in chromosomes ۱۱, ۱۵ and ۱۹. Conclusion: According to these chromosomal changes and based on bioinformatics studies we predict that the genesTGFBR۳, HACE۱, UBR۵, CALB۲, HPR, LCP۱, RRM۲B, ABO, ZFHX۳, TNFSF۱۱, ABL۱, EPSTI۱, PRDM۱, REG۳A, FOXA۱ and PRKD۱, probably may contribute to the development of breast cancer.

Keywords: Breast cancer, SD rat, Chromosomal changes, G-banding