LABORATORY RESEARCH Exosomes from Bone Marrow Mesenchymal Stem Cells Contain a MicroRNA that Promotes Dormancy in Metastatic Breast Cancer Cells Coculturing human breast cancer cells (BM2) with bone marrow mesenchymal stem cells (BM-MSCs) isolated from human donors revealed that BM-MSCs suppressed the proliferation of BM2 cells, decreased the abundance of stem cell-like surface markers, inhibited their invasion through Matrigel Transwells, and decreased their sensitivity to docetaxel, a common chemotherapy agent. [Sci Signal] Abstract The E2F Transcription Factors Regulate Tumor Development and Metastasis in a Mouse Model of Metastatic Breast Cancer Using genomic signature methods, scientists predicted a role for the activator E2F transcription factors in the MMTV-PyMT mouse model of metastatic breast cancer. [Mol Cell Biol] Abstract The SMRT Coregulator Enhances Growth of Estrogen Receptor-α-Positive Breast Cancer Cells by Promotion of Cell Cycle Progression and Inhibition of Apoptosis Small-interfering RNA and short-hairpin RNA approaches were used to determine the effects of SMRT (silencing mediator of retinoic acid and thyroid hormone receptor) depletion on growth of estrogen receptor-α (ERα)-positive MCF-7 and ZR-75-1 breast cancer cells, as well as the ERα-negative MDA-MB-231 breast cancer line. [Endocrinology] Abstract Estrogen Regulation of Anti-Apoptotic Bcl-2 Family Member Mcl-1 Expression in Breast Cancer Cells In estrogen receptor-α (ERα) positive cell lines MCF-7 and ZR-75, estrogen treatment increased Mcl-1 expression at both the protein and mRNA level. In two ERα negative cell lines, SK-BR-3 and MDA-MB-231, estrogen failed to increase in Mcl-1 protein expression. [PLoS One] Full Article CD24 Regulates Stemness and the Epithelial to Mesenchymal Transition through Modulation of Notch1 mRNA Stability by p38MAPK Researchers report that CD24 knockdown resulted in decreased expression of Notch1 in MCF-7 cells. CD24-downstream p38MAPK was shown to regulate Notch1 at the level of mRNA stability. They also found that CD24-mediated cell migration, invasion, mammosphere formation, and drug resistance was regulated by its downstream target Notch1. [Arch Biochem Biophys] Abstract Matrix Metalloproteinase 1 and Circulating Tumor Cells in Early Breast Cancer Researchers assessed the correlation between circulating tumor cells and tumor matrix metalloproteinases in breast cancer. They studied 149 primary breast cancer patients treated by surgery. [BMC Cancer] Full Article Perfluorooctanoic Acid Stimulates Breast Cancer Cells Invasion and Up-Regulates Matrix Metalloproteinase-2/-9 Expression Mediated by Activating NF-κB Scientists explored the molecular mechanisms undergoing the stimulation effects of perfluorooctanoic acid (PFOA) on cancer cell invasion and matrix metalloproteinases expression. Trans-well filter assay showed that PFOA exposure (≥5 nM) evidently enhanced the invasion ability of the breast cancer cells MDA-MB-231. [Toxicol Lett] Abstract Formononetin Inhibits Migration and Invasion of MDA-MB-231 and 4T1 Breast Cancer Cells by Suppressing MMP-2 and MMP-9 through PI3K/AKT Signaling Pathways Researchers examined the effect of formononetin on the migration and invasion of breast cancer cells MDA-MB-231 and 4T1 in vitro and in vivo. Results suggest that formononetin inhibited breast cancer cell migration and invasion by reducing the expression of matrix metalloproteinase-2 (MMP-2) and MMP-9 through the PI3K/AKT signaling pathway. [Horm Metab Res] Abstract CLINICAL RESEARCH Improved Overall Survival after Contralateral Risk-Reducing Mastectomy in BRCA1/2 Mutation Carriers with a History of Unilateral Breast Cancer: A Prospective Analysis Researchers examined the efficacy of contralateral risk-reducing mastectomy on overall survival in mutation carriers with a history of primary breast cancer. [Int J Cancer] Abstract Efficacy of Six Month Neoadjuvant Endocrine Therapy in Postmenopausal, Hormone Receptor-Positive Breast Cancer Patients – A Phase II Trial Investigators present the outcomes of the TEAM IIA trial, a multicenter, Phase II trial investigating the efficacy of six months of neoadjuvant exemestane in postmenopausal, strong estrogen receptor-positive breast cancer patients. [Eur J Cancer] Abstract |