BCL-2 Inhibition Targets Oxidative Phosphorylation and Selectively Eradicates Quiescent Human Leukemia Stem Cells Researchers evaluated mechanisms controlling oxidative state in primary specimens derived from acute myelogenous leukemia patients. Their studies demonstrate three striking findings. First, the majority of functionally defined leukemia stem cells (LSCs) are characterized by relatively low levels of reactive oxygen species (termed ROS-low). Second, ROS-low LSCs aberrantly overexpress BCL-2. Third, BCL-2 inhibition reduced oxidative phosphorylation and selectively eradicated quiescent LSCs. [Cell Stem Cell] Abstract | Press Release Tumor-Specific Activation of the c-JUN/MELK Pathway Regulates Glioma Stem Cell Growth in a p53-Dependent Manner Scientists demonstrated that MELK depletion by shRNA diminishes the growth of glioma stem cell (GSC)-derived mouse intracranial tumors in vivo, induces GFAP (+) glial differentiation of GSCs leading to decreased malignancy of the resulting tumors, and prolongs survival periods of tumor-bearing mice. [Stem Cells] Abstract | Full Article IGF1 Receptor Signaling Regulates Adaptive Radioprotection in Glioma Stem Cells Results showed that glioma stem cells (GSCs) evade the damage of repeated radiation not only through innate properties, but also through gradual inducement of resistance pathways and identify the dynamic regulation of GSCs by insulin-like growth factor type 1 (IGF1) receptor signaling as a novel mechanism of adaptive radioprotection. [Stem Cells] Abstract Chromatin Effector Pygo2 Regulates Mammary Tumor Initiation and Heterogeneity in MMTV-Wnt1 Mice Results suggest that Pygopus 2 (Pygo2) acts at a step downstream of mammary stem cell accumulation to facilitate transformation, and that it regulates the tumor initiating capacity and lineage preference of the already transformed mammary cells, in MMTV-Wnt1 mice. [Oncogene] Abstract TLR2 Enhances Ovarian Cancer Stem Cell Self-Renewal and Promotes Tumor Repair and Recurrence The authors have shown previously that CD44+/MyD88+ epithelial ovarian cancer stem cells are responsible for tumor initiation. In this study, they demonstrated that this population drives tumor repair following surgery- and chemotherapy-induced tumor injury. [Cell Cycle] Abstract The Cancer Stem Cell Marker CD133 Interacts with Plakoglobin and Controls Desmoglein-2 Protein Levels Scientists described a cancer stem cell line established from clear cell carcinoma of the ovary (CCC) and show that CD133 interacts with plakoglobin, a desmosomal linker protein. They further demonstrated that knockdown of CD133 by RNA interference results in the downregulation of desmoglein-2, a desmosomal cadherin, and abrogates cell-cell adhesion and tumorigenicity of CCC stem cells. [PLoS One] Full Article Tumor Cells Positive and Negative for the Common Cancer Stem Cell Markers Are Capable of Initiating Tumor Growth and Generating Both Progenies Investigators showed that tumor cells both positive and negative for the cancer stem cell (CSC) marker (CSC+ and CSC− cells, respectively) exhibit similar proliferation in the native states. Using a cell tracing method, they demonstrated that CSC− cells exhibit similar tumorigenesis and proliferation as CSC+ cells when they were co-transplanted into immunodeficient mice. Through serial single-cell derived subline construction, the authors further demonstrated that CSC+ and CSC− cells from CSC marker expressing tumors could invariably generate both progenies, and their characteristics are maintained among different generations irrespective of the origins. [PLoS One] Full Article Role of the IL-6-JAK1-STAT3-Oct-4 Pathway in the Conversion of Non-Stem Cancer Cells into Cancer Stem-Like Cells The authors used cancer stem cell (CSC)-like human breast cancer cells and their alternate subset non-CSCs to investigate how interleukin-6 (IL-6) regulates the conversion of non-CSCs to CSCs. [Cell Signal] Abstract Leading Malignant Cells Initiate Collective Epithelial Cell Invasion in a Three-Dimensional Heterotypic Tumor Spheroid Model Researchers found that “invasion-competent” malignant cells induced the collective invasion of otherwise “invasion-incompetent” epithelial cells, and that these two cell types consistently exhibited distinct leader and follower roles during invasion. [Clin Exp Metastasis] Abstract Prostate Cancer Stem-Like Cells/Cancer-Initiating Cells Have an Autocrine System of Hepatocyte Growth Factor Researchers found that prostate cancer stem-like cells (CSCs)/cancer-initiating cells (CICs) expressed higher levels of growth factors including hepatocyte growth factor (HGF). The results indicate that HGF secreted by prostate CSCs/CICs and prostate myofibroblasts has a role in the maintenance of prostate CSCs/CICs in an autocrine and paracrine fashion. [Cancer Sci] Abstract  |