The protein 14-3-3σ is involved in the regulation of cellular processes such as apoptosis, cell cycle progression and proliferation. Disruption of protein expression has been implicated in a number of malignancies. Here we examine the expression pattern of 14-3-3σ in breast cancer and specifically consider whether expression in ductal carcinoma in situ (DCIS) lesions is predictive of disease outcome. We examined 14-3-3σ protein expression and localization using immunohistochemical staining on a high-density tissue microarray consisting of 157 invasive breast cancer patients. Statistical analyses were used to assess the correlation of 14-3-3σ expression with clinico-pathological parameters and patient outcome. We observed a statistically significant increase in 14-3-3σ protein expression in ductal hyperplasia, DCIS, and invasive ductal carcinoma (IDC) as compared normal glandular epithelium. In IDC, lower expression of 14-3-3σ tended to predicted poorer survival time while in DCIS lesions, there was a stronger correlation between relatively higher levels of 14-3-3σ predicting shorter survival time. Further, of patients who had concurrent DCIS and IDC lesions, those that exhibited a decrease of 14-3-3σ expression from DCIS to IDC had significantly shorter survival time. Our findings indicate that 14-3-3σ expression may be a useful prognostic indicator for survival in patients with breast cancer with an elevated 14-3-3σ in earlier disease predicting a less favorable disease outcome. To our knowledge this is the first published study associating 14-3-3σ protein expression with breast cancer survival.
Keywords: Tissue microarray, breast cancer, tumor marker, 14-3-3 σ, prognostic marker, DCIS