Immunohistochemical Evaluation of mTOR and Beclin-1 Protein Expression in Human Breast Cancer and Adjacent Normal Tissues, A Study in Malaysian Patients

摘要

Autophagy is a protein degradation process within the cell and its deregulation has been linked to variousdiseases and the formation of cancer. Both mTOR and Beclin-1 are important proteins involved in the regulation ofautophagy process and tumorigenesis. The aims of the study were to assess the expression of autophagic-related proteinsin breast cancer tissues and normal breast tissues adjacent to the tumor. Immunohistochemical staining with anti-mTOR,anti-p-mTOR and anti-Beclin-1 antibody was carried out on tissue samples of 24 patients from our local hospitals. Theresults showed that mTOR and Beclin-1 proteins were present in both types of tissues in all the cases. However, asignificant majority of the adjacent normal breast tissues were found to have stronger immunoreactivity towardsphosphorylated mTOR (p-mTOR) as compared to the corresponding tumor tissues. Since increased expression of pmTORis known to be correlated with tumorigenesis, this may indicate the presence of molecular changes in these cellsadjacent to the tumor tissues. Patients with mTOR positive tumors may benefit from use of mTOR inhibitors as part oftheir pharmacotherapy management.