The relationship between the level of siah1,bim and P53 proteins in associated with the disease course in patients with breast cancer

Cancer is one of the leading health problems and breast cancer is one of the common cancers. In spite of the developing treatment methods, breast cancer cannot be treated effectively.Therefore, the identification of novel biomarkers that will be important in the treatment and diagnosis of breast cancer is of great interest. SIAH1 (Seven in absentia homolog 1) protein is known as a tumor suppressor protein.Although studies have shown that this protein has important roles in cancer processes, its usefulness in the treatment and diagnosis of breast cancer has not been fully elucidated.At the same time, previous studies have shown that the SIAH1 protein is associated with important tumor suppressor and apoptosis triggering proteins such as p53 and BIM. In this thesis study, by using immunohistochemical approach, we aimed to investigate the relationship between the levels of SIAH1, BIM and p53 proteins which play an important role in the prognosis and apoptosis processes of breast cancer patients. As a result, SIAH1 protein level was significantly lessened in tumor tissues of patients with breast cancer. In contrast to SIAH1 protein, no significant difference was detected in BIM expression level. In addition, p53 was not detected in 75% of the breast cancer patients. However, in 25% of the patients, p53 expression was significantly increased. Our study also showed that low SIAH1 expression level is associated with important clinic characteristics of patient such as tumor grade, stage and breast cancer type. Findings of our study show that SIAH1 has roles in breast cancer formation and might be a novel biomarker for the diagnosis and treatment of breast cancer.