LABORATORY RESEARCH CCN5/WISP-2 Promotes Growth Arrest of Triple-Negative Breast Cancer Cells through Accumulation and Trafficking of p27Kip1 via Skp2 and FOXO3a Regulation Scientists found that the p27Kip1 tumor suppressor protein is upregulated and relocalized to the nucleus from cytoplasm by CCN5 in triple-negative breast cancer (TNBC) cells and that these two events (upregulation and relocalization of p27Kip1) are critical for CCN5-induced growth inhibition of TNBC cells. [Oncogene] Abstract Nontranscriptional Role of Hif-1α in Activation of γ-Secretase and Notch Signaling in Breast Cancer Investigators show that hypoxia upregulates γ-secretase activity through a direct interaction with Hif-1α, revealing an unconventional function for Hif-1α as an enzyme subunit, which is distinct from its canonical role as a transcription factor. [Cell Rep] Full Article | Graphical Abstract The ErbB4 CYT2 Variant Protects EGFR from Ligand-Induced Degradation to Enhance Cancer Cell Motility Researchers found that epidermal growth factor receptor (EGFR) interacted directly with the CYT1 and CYT2 variants of ErbB4 and the membrane-anchored intracellular domain. Cultured breast cancer cells overexpressing both EGFR and ErbB4 CYT2 membrane-anchored intracellular domain exhibited increased migration. [Sci Signal] Abstract Elevated SRPK1 Lessens Apoptosis in Breast Cancer Cells through RBM4-Regulated Splicing Events Investigators observed a correlation between the cytoplasmic accumulation of RNA-binding motif protein 4 (RBM4) and up-regulated serine-arginine protein kinase 1 (SRPK1) in breast cancer cells. [RNA] Abstract Constitutively Active ErbB2 Regulates Cisplatin-Induced Cell Death in Breast Cancer Cells via Pro- and Anti-Apoptotic Mechanisms Researchers sought to identify mechanisms through which N-terminally truncated ErbB2 regulates cisplatin-induced breast cancer cell death, and determine how the Na+/H+ exchanger NHE1 impacts on this process. [Mol Cancer Res] Abstract ER-α Variant ER-α36 Mediates Antiestrogen Resistance in ER-Positive Breast Cancer Stem/Progenitor Cells Scientists investigated the function and the underlying mechanism of ER-α36-mediated antiestrogen signaling in ER-positive breast cancer stem/progenitor cells. The effects of antiestrogens tamoxifen and ICI 182, 780 on breast cancer stem cells’ ability of growth, self-renewal, differentiation and tumor seeding were examined using tumorsphere formation, flow cytometry, indirect immunofluorences and in vivo xenograft assays. [J Steroid Biochem Mol Biol] Abstract Poly(ADP-Ribose) Polymerase 1 (PARP1) Overexpression in Human Breast Cancer Stem Cells and Resistance to Olaparib To identify specific biomarkers of breast cancer stem cells (BCSCs), scientists performed comparative proteomics of BCSC-enriched and mature cancer cell populations from the human breast cancer cell line BrCA-MZ-01. [PLoS One] Full Article CLINICAL RESEARCH A Phase I/II Trial to Evaluate the Technical Feasibility of Partial Breast Irradiation with Three-Dimensional Conformal Radiation Therapy in Korean Women with Stage I Breast Carcinoma: An Initial Report of the Korean Radiation Therapy Oncology Group (KROG) Study 0804 Investigators verified the technical feasibility of partial breast irradiation in breast cancer patients with small breasts. It was designed such that if fewer than five of the first 42 evaluable patients received unacceptable scores, the treatment would be considered reproducible. [Cancer Res Treat] Abstract Neoadjuvant Chemotherapy for Different Molecular Breast Cancer Subtypes: A Retrospective Study in Russian Population Investigators evaluated the objective clinical response, pathological complete response, and progression-free survival in 231 Russian patients with four subtypes of breast cancer treated with neoadjuvant chemotherapy. [Med Oncol] Abstract |