LABORATORY RESEARCH Dynamic Methylation of Numb by Set8 Regulates Its Binding to p53 and Apoptosis Although Numb exhibits its tumor-suppressive function in breast cancer in part by binding to and stabilizing p53, it is unknown how the Numb-p53 interaction is regulated in cells. The authors found that Numb is methylated in its phosphotyrosine-binding domain by the lysine methyltransferase Set8. Moreover, methylation uncouples Numb from p53, resulting in increased p53 ubiquitination and degradation. [Mol Cell] Abstract | Press Release Usp18 Deficient Mammary Epithelial Cells Create an Antitumor Environment Driven by Hypersensitivity to Interferon-λ and Elevated Secretion of Cxcl10 Using the PyVmT model of mammary tumorigenesis, researchers showed that lack of the Usp18 gene significantly inhibits tumor growth by creating a tumor-suppressive microenvironment. Generation of this antitumor environment is driven by elevated secretion of the potent T-cell chemoattractant Cxcl10 by Usp18 deficient mammary epithelial cells, which leads to recruitment of Th1 subtype CD4+ T cells. [EMBO Mol Med] Abstract Regulation of FAK Activation, Breast Cancer Cell Motility and Amoeboid Invasion by the RhoA GEF Net1 Scientists showed that expression of both Net1 isoforms in breast cancer cells is required for efficient cell motility. Although loss of Net1 isoform expression only partially blocks RhoA activation, it inhibits LPA-stimulated migration as efficiently as knockdown of RhoA itself. [Mol Cell Biol] Abstract Silencing the Mannose 6-Phosphate/IGF-II Receptor Differentially Affects Tumorigenic Properties of Normal Breast Epithelial Cells Researchers investigated the impact of mannose 6-phosphate/insulin-like growth factor-II receptor (M6P/IGF-IIR) silencing using phenotypically normal (MCF-10A) and oncogenically transformed human breast epithelial cell lines as model systems. In both cell lines, silencing of M6P/IGF-IIR increased cell proliferation and motility, with the effects being more pronounced in MCF-10A cells. [Int J Cancer] Abstract Progesterone Metabolites Regulate Induction, Growth and Suppression of Estrogen- and Progesterone Receptor-Negative Human Breast Cell Tumors In vivo studies were conducted to investigate the ability of 5alphaP and 3alphaHP to control initiation, growth and regression of estrogen receptor (ER)/progesterone receptor (PR)-negative human breast cell tumors. ER/PR-negative human breast cells were implanted into mammary fat pads of immunosuppressed mice and the effects of 5alphaP and 3alphaHP treatments on tumor initiation, growth, suppression/regression and histopathology were assessed in five separate experiments. [Breast Cancer Res] Abstract | Full Article | Press Release RANKL/RANK/MMP-1 Molecular Triad Contributes to the Metastatic Phenotype of Breast and Prostate Cancer Cells In Vitro To investigate the interaction between RANK expression in human breast and prostate cancer cells and their pro-metastatic phenotype, the authors analyzed the activation of RANKL-RANK pathway and its effects on cell migration, invasion, gene expression in vitro, and osteolysis-inducing ability in vivo. [PLoS One] Full Article Dietary Chemopreventative Benzyl Isothiocyanate Inhibits Breast Cancer Stem Cells In Vitro and In Vivo Scientists demonstrated the efficacy of benzyl isothiocyanate (BITC) against breast cancer stem cells in vitro and in vivo. Mammosphere formation frequency and CD44high/CD24low/ESA+ and/or ALDH1+ populations in cultured MCF-7 and SUM159 human breast cancer cells were decreased significantly in the presence of plasma achievable concentrations of BITC. [Cancer Prev Res] Abstract Naringin Inhibits Growth Potential of Human Triple-Negative Breast Cancer Cells by Targeting β-Catenin Signaling Pathway Triple-negative breast cancer (TNBC) cell lines-based in vitro and in vivo models were used to explore the anticancer effect and mechanism of naringin. Data demonstrated that naringin inhibited cell proliferation, and promoted cell apoptosis and G1 cycle arrest, accompanied by increased p21 and decreased survivin. [Toxicol Lett] Abstract Human T47D Breast Cancer Cells with Tetracycline-Dependent ERβ Expression Reflect ERα/ERβ Ratios in Rat and Human Breast Tissue T47D-ERβ breast cancer cells with tetracycline-dependent ERβ expression and constant ERα expression can be used to investigate effects of varying ERα/ERβ ratios on estrogen-induced cellular responses. Investigators defined conditions at which ERα/ERβ ratios in T47D-ERβ cells best mimic ERα/ERβ ratios in breast and other estrogen-sensitive tissues in vivo in rat as well as in human. [Toxicol In Vitro] Abstract CLINICAL RESEARCH Overdiagnosis in Breast Cancer Screening: The Importance of Length of Observation Period and Lead Time The authors postulated a female population aged 50-79 with a similar age structure and age-specific breast cancer incidence as in England and Wales before the screening program. They then imposed a two-yearly screening program; screening women aged 50-69, to run for twenty years, with exponentially distributed lead time with an average of 40 months in screen-detected cancers. [Breast Cancer Res] Abstract | Full Article Implementation of Breast Tomosynthesis in a Routine Screening Practice: An Observational Study Scientists used verified practice- and outcome-related databases to compute and compare recall rates, biopsy rates, cancer detection rates, and positive predictive values for six radiologists who interpreted screening mammography studies without and with the use of tomosynthesis. [Am J Roentgenol] Abstract | Press Release
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