The Relationship between the Levels of SIAH1, BIM and p53 Proteins in association with the Disease Course in Patients with Breast Cancer

Cancer is one of the most significant health issues worldwide, and breast cancer is among the most common types. Despite advancements in treatment methods, breast cancer remains difficult to treat effectively. Therefore, identifying new biomarkers for the diagnosis and treatment of breast cancer is of great interest. The SIAH1 (Seven in absentia homolog 1) protein is recognized as a tumor suppressor. Although studies have demonstrated its crucial roles in cancer processes, its potential in breast cancer diagnosis and treatment has not been fully explored. Previous research has shown that SIAH1 is linked with important tumor suppressor and apoptosis-inducing proteins such as p53 and BIM. In this thesis, we used immunohistochemical methods to investigate the relationship between the levels of SIAH1, BIM, and p53 proteins, which play key roles in the prognosis and apoptosis processes in breast cancer patients. Our results showed that the level of SIAH1 protein was significantly reduced in the tumor tissues of breast cancer patients. In contrast, there was no significant difference in the expression level of BIM. Additionally, p53 was not detected in 75% of the breast cancer patients, but in the remaining 25%, p53 expression was significantly increased. Our study also indicated that low SIAH1 expression levels are associated with important clinical characteristics such as tumor grade, stage, and breast cancer type. These findings suggest that SIAH1 plays a role in breast cancer formation and could be a novel biomarker for the diagnosis and treatment of breast cancer.