An Immunohistochemical Evaluation of Phosphorylated Akt at Threonine 308 [pAkt(Thr308)] in Invasive Breast Cancer

Abstract

Background: Akt is a serine/threonine kinase which is fully activated when phosphorylated (pAkt). The aim of this study was to investigate the expression pattern of phosphorylated Akt at Threonine 308 [pAkt(Thr308)] in association with clinicopathological parameters and various biological markers. Materials and Methods: Immunohistochemistry was performed on paraffin-embedded tissue specimens from 152 invasive breast carcinomas to detect the expression of the proteins pAkt(Thr308), estrogen (ER) and progesterone (PR) receptors, p53, Ki-67 and c-erbB-2. Results: pAkt(Thr308) protein was immunodetected in the cytoplasm and the nuclei of the malignant cells. pAkt was found to be positively associated with the lobular histological type, while it was found to exert no impact on patients' survival. pAkt(Thr308) immunopositivity was inversely related to Ki-67 and p53 (p=0.013 and p=0.020, respectively), while being positively associated with cerbB2 expression (p=0.005). Conclusion: This is the first study to show a frequent detection of pAkt(Thr308) in lobular breast carcinomas and an association of its expression with indices of proliferation (c-erbB2, Ki-67) and apoptosis (p53).