Stromal PTEN inhibits the expansion of mammary epithelial stem cells through Jagged-1.

This corrects the article DOI: 10.1038/onc.2016.383.

Stromal PTEN inhibits the expansion of mammary epithelial stem cells through Jagged-1.

Fibroblasts within the mammary tumor microenvironment are active participants in carcinogenesis mediating both tumor initiation and progression. Our group has previously demonstrated that genetic loss of phosphatase and tensin homolog (PTEN) in mammary fibroblasts induces an oncogenic secretome that remodels the extracellular milieu accelerating ErbB2-driven mammary tumor progression. While these prior studies highlighted a tumor suppressive role for stromal PTEN, how the adjacent normal epithelium transforms in response to PTEN loss was not previously addressed. To identify these early events, we have evaluated both phenotypic and genetic changes within the pre-neoplastic mammary epithelium of mice with and without stromal PTEN expression. We report that fibroblast-specific PTEN deletion greatly restricts mammary ductal elongation and induces aberrant alveolar side-branching. These mice concomitantly exhibit an expansion of the mammary epithelial stem cell (MaSC) enriched basal/myoepithelial population and an increase in in vitro stem cell activity. Further analysis revealed that NOTCH signaling, specifically through NOTCH3, is diminished in these cells. Mechanistically, JAGGED-1, a transmembrane ligand for the NOTCH receptor, is downregulated in the PTEN-null fibroblasts leading to a loss in the paracrine activation of NOTCH signaling from the surrounding stroma. Reintroduction of JAGGED-1 expression within the PTEN-null fibroblasts was sufficient to abrogate the observed increase in colony forming activity implying a direct role for stromal JAGGED-1 in regulation of MaSC properties. Importantly, breast cancer patients whose tumors express both low stromal JAG1 and low stromal PTEN exhibit a shorter time to recurrence than those whose tumors express low levels of either alone suggesting similar stromal signaling in advanced disease. Combined, these results unveil a novel stromal PTEN-to-JAGGED-1 axis in maintaining the MaSC niche, and subsequently inhibiting breast cancer initiation and disease progression.

Phase III randomized double-blind study to evaluate the efficacy of a polycarbophil-based vaginal moisturizer in women with breast cancer.

PURPOSE: Vaginal dryness and dyspareunia are significant estrogen-depletion symptoms that affect many breast cancer survivors. The present trial was developed to evaluate the nonhormonal vaginal lubricating preparation, Replens, for alleviating these symptoms. MATERIALS AND METHODS: A double-blind, crossover, randomized clinical trial was developed. Patients received 4 weeks of Replens (Columbia Research Laboratories, Rockville Centre, NY) followed by a 1-week washout period followed by 4 weeks of a placebo lubricating product, or vice versa. Weekly patient-completed diaries were used for measuring efficacies and toxicities of therapy. RESULTS: The 45 assessable patients provided well-balanced treatment groups. During the first 4 weeks, average vaginal dryness decreased by 62% and 64% in the placebo and Replens groups, respectively (P = .3). Average dyspareunia scores also improved by 41% and 60%, respectively (P = .05). Crossover analysis indicated that the bulk of the beneficial effects appeared within the first 2 weeks of the first treatment and remained constant thereafter. Both treatments were relatively well tolerated. CONCLUSION: Both Replens and the placebo appear to substantially ameliorate vaginal dryness and dyspareunia in breast cancer survivors.

The ultimate rejection: helping the survivors of teen suicide victims.

Each year, teens who commit suicide leave behind more than 25,000 survivors. In addition to feelings of depression, anger, and guilt, the survivors must cope with societal attitudes toward suicide. Few resources are available to deal with the problem. This paper discusses the impact of teen suicide on survivors, and outlines educational and administrative postincident intervention guidelines for schools.