Here we show that heterozygous inactivation of the tumor suppressor gene Pten leads to the formation of basal-like mammary tumors in mice, and that loss of PTEN expression is significantly associated with the BBC subtype in human sporadic and BRCA1-associated hereditary breast cancers.
The nine coding exons of the PTEN gene were screened for harboring germline mutations using denaturing gradient gel electrophoresis (DGGE) complemented by sequencing, in two subsets of Israeli patients: 12 patients clinically diagnosed with BRRS, and 89 women with an apparent inherited predisposition to breast cancer, some with salient features of CD.
Also, based on their predictive value of response to therapy, evaluating MGMT and PTEN and learning to interpret their patterns of immunoexpression will undoubtedly lead to a greater understanding of breast cancer and its treatment.
While preliminary, these findings suggest that further study is warranted to determine whether this allelic variant of PTEN could function as a low penetrance breast cancer susceptibility allele.
We analyzed PTENP1 and PTEN levels in clinical BC samples and cell lines, and found that PTENP1 and PTEN were confirmed and closely correlated with the malignancy of BC cell lines and poor clinical prognosis.
Also, primary breast cancer specimens, all ER positive and HER2 negative, were immunohistochemically investigated for phospho-S6 (pS6) and PTEN, to evaluate the mTOR and PIK3CA/Akt pathways.
Cellular levels of p-AKT(Ser473/Thr308) and p-ERK1/2(Thr202/Tyr204), activating mutations of PIK3CA and inactivating mutations of PTEN may predict response to everolimus in breast cancer cells; these findings have potential applications for treatment personalization of everolimus in breast cancer patients.
In addition, the interaction of exogenous RILPL2 with TUBB3 resulted in the downregulation of BC cell proliferation and migration and upregulation of PTEN expression by promoting destabilization of TUBB3.
This review will discuss the importance of the EGFR/PI3K/PTEN/Akt/mTORC1/GSK-3 pathway primarily in breast cancer but will also include relevant examples from other cancer types.