Life Science Journal, 2012;9(3) http://www.lifesciencesite.com 667 RASSF1A Gene Hypermethylation in Tissue and Serum Together with Tissue Protein Expression in Breast Cancer Patients Heba H. Gawish 1 , Hoda A. Hagrass 1 andEman H. Abdel Bary 2 . 1 Clinical Pathology Department,Faculty of Medicine, Zagazig University, Egypt 2 Pathology Department, Faculty of Medicine, ZagazigUniversity ,Egypt hebagawish@yahoo.com Abstract: Background:Recently genetics and epigenetics alterations have been found to be characteristic of malignancy and hence can be used as targets for detection of neoplasms. RASSF1A genehypermethylation has been a subject of interest in recent researches on cancer breast patients. Design and methods: We investigated 30 breast cancer patients and 10 control subjects diagnosed with benign lesions of the breast for RASSF1A methylation status in paired tissue and serum samples using MSP and we evaluated RASSF1A protein expression in tissues by IHC .Results were studied in relation to known prognostic clinicopathplogical features in breast cancer. Results: We evaluated 30 breast cancer patients mean age (50.9±7.7) years and 10 control patients mean age (38.4±8.6 years). Frequency of RASSF1A methylation in tissues, serum were 73% and 63.3% respectively and RASSF1A protein expression showed frequency of 46.7%. There was an association between RASSF1A methylation in tissues, serum and loss of protein expression in tissues with invasive carcinoma, advanced stage breast cancer, L.N metastasis, ER/PR negativity and HER2 positivity.RASSF1A methylation in serum showed high degree of concordance with methylation in tissues (Kappa =0.851, P <0.001). Conclusion: RASSF1A hypermethylation in tissues and serum and its protein expression may be a valid, reliable and sensitive tool for detection and follow up of breast cancer patients. [Heba H. Gawish , Hoda A. Hagrass andEman H. Abdel Bary RASSF1A Gene Hypermethylation in Tissue and Serum Together with Tissue Protein Expression in Breast Cancer Patients. Life Sci J 2012;9(3):667- 675] (ISSN:1097-8135). http://www.lifesciencesite.com . 93 Key words:RASSF1A;hypermethylation;MSP;cancer breast. Abbreviations: RASSF1A, RAS association domain family protein 1A; PCR,Polymerase chain reaction; CIS, carcinoma in situ;IHC, immunohistochemistry. 1-Introduction: Breast cancer is the most common cancer and the second most common cause of death from cancer in women. Every year more than one million women are diagnosed with breast cancer and approximately 400,000 die (1) .Breast cancer is the most common malignancy among Egyptianwomen (2) ,.For successful treatment and outcome, early detection of breast cancer is a necessity. Despite the availability of mammography and prevalence of self-examination, there is still additional benefit to be gained from additional screening methodologies. The genetic and epigenetic alterations that initiate and drive tumorgenesis can be used as targets for detection of neoplasms in body fluids (3) ,because they may precede clinically obvious cancer, can be detected at sensitive levels, may be specific for tumor cells, and can potentially provide information about the prognosis and treatment of the disease (4,5) . CpG islands located in promoter regions of genes are normally unmethylated. In cancer cells, aberrant hypermethylation of these promoter regions is associated with transcriptional silencing. Hypermethylation is therefore an alternative mechanism for inactivation of tumor suppressor genes (6,7) . Also It has been found that gene hypermethylation is a common and early alteration in many tumor types (8-10) , including breast (11,12) , hence it is considered as a promising target for detection strategies in clinical specimens (4,5) . RASSF1 encodes several isoforms, including RASSF1A, RASSF1B, and RASSF1C, which are derived from alternative mRNA splicing and promoter usage (13) . RAS association domain family protein 1A (RASSF1A) methylation status has been examined in different tumors (13,14,15) and breast cancer (3,14) . RASSF1A identified at 3p21.3 was suggested as the major target tumor suppressor on the basis of its frequent epigenetic silencing (13) .It was reported previously that RASSF1A is epigenetically inactivated in 40 –72% of primary lung tumors by de novo methylation at the CpG island in the promoter (16,17,14) . Methylation-associated inactivation of RASSF1A was also observed in a considerable proportion of breast, ovarian, and nasopharyngeal cancer cell lines and primary tumors (14,17-20) . In small cell lung cancers, allelic deletion at 3p21.3 is associated with RASSF1A methylation, suggesting that both genetic and epigenetic steps are crucial for RASSF1A inactivation in some tumor types. The tumor suppressor function of RASSF1A has been suggested by observations that exogenous expression of RASSF1A decreases in vitro-colony formation, suppresses anchorage-independent growth, and dramatically reduces tumorigenicityin