Immunohistochemical study of PTEN and phosphorylated mTOR proteins in familial and sporadic invasive breast carcinomas

Bakarakos P, Theohari I, Nomikos A, Mylona E, Papadimitriou C, Dimopoulos A‐M & Nakopoulou L (2010) Histopathology 56, 876–882 Immunohistochemical study of PTEN and phosphorylated mTOR proteins in familial and sporadic invasive breast carcinomas Aims: Loss of phosphatase and tensin homologue (PTEN) leads to activation of several kinases, including mammalian target of rapamycin (mTOR), which promotes cell cycle progression. The aim was to study the expression of PTEN and phosphorylated (p)‐mTOR in familial and sporadic invasive breast carcinomas and their relation to clinicopathological features, molecular indices (Wnt1) and patients’ survival. Methods and results: PTEN and p‐mTOR were detected immunohistochemically in 215 sections of invasive breast carcinomas (112 with a familial history of breast cancer). Image analysis was used and univariate and multivariate analyses employed for statistical evaluation of results. PTEN was detecte5d in the nucleus (73.5%) and p‐mTOR in the cytoplasm (44.2%) of cancer cells. Loss of PTEN protein was more frequently detected in women with a familial history of breast cancer (72%) (P