A Pyrrolo-Pyrimidine Derivative Targets Human Primary AML Stem Cells In Vivo The authors performed a large-scale chemical library screen that integrated a high-throughput enzyme inhibition assay, in silico binding prediction, and crystal structure determination and found a candidate hematopoietic cell kinase inhibitor, RK-20449, a pyrrolo-pyrimidine derivative with an enzymatic IC50 in the subnanomolar range. In vivo administration of RK-20449 to nonobese diabetic/severe combined immunodeficient/IL2rgnull mice engrafted with highly aggressive therapy-resistant acute myeloid leukemia (AML) significantly reduced human leukemia stem cell and non-stem AML burden. [Sci Transl Med] Abstract | Press Release The Identification and Characterization of Breast Cancer CTCs Competent for Brain Metastasis In epithelial cell adhesion molecule (EpCAM)-negative circulating tumor cells (CTCs), researchers identified a potential signature of brain metastasis comprising “brain metastasis selected markers” HER2+/EGFR+/HPSE+/Notch1+. These CTCs, which are not captured by the CellSearch platform because of their EpCAM negativity, were analyzed for cell invasiveness and metastatic competency in vivo. [Sci Transl Med] Abstract | Press Release Protein Kinase Cα Suppresses Kras-Mediated Lung Tumor Formation through Activation of a p38 MAPK-TGFβ Signaling Axis Protein kinase C alpha (PKCα) can activate both pro- and anti-tumorigenic signaling depending upon cellular context. Researchers investigated the role of PKCα in lung tumorigenesis in vivo. [Oncogene] Abstract Propagation of Human Prostate Cancer Stem-Like Cells Occurs through EGFR-Mediated ERK Activation Researchers provided evidence that epidermal growth factor receptor (EGFR) signaling promotes prostate cancer stem-like cell self-renewal, in part, by activating the MEK-extracellular signal-related kinase (ERK) pathway. [PLoS One] Full Article G Protein-Coupled Receptor 87 (GPR87) Promotes the Growth and Metastasis of CD133+ Cancer Stem-Like Cells in Hepatocellular Carcinoma Investigators explored the role of GPR87 in the regulation of CD133 expression. They demonstrated that the overexpression of GPR87 up-regulated CD133 expression, promoted cancer stem cell-associated migratory and invasive properties in vitro, and increased tumor initiation in vivo. [PLoS One] Full Article miR-125b Regulates Side Population in Breast Cancer and Confers a Chemoresistant Phenotype Researchers isolated and characterized side population (SP) cells in a panel of breast cancer cell lines and primary cancer cells from breast cancer patients. SP cells showed cancer stem cells properties, including self-renewal, resistance to chemotherapy and high expression of stem cell markers. [J Cell Biochem] Abstract The Usefulness of Three-Dimensional Cell Culture in Induction of Cancer Stem Cells from Esophageal Squamous Cell Carcinoma Cell Lines Cancer stem cells are assumed to be present in esophageal cancer, but experimental methods for identification and culture of these cells have not yet been established. To solve this problem, researchers created spheroids using a NanoCulture® Plate for three-dimensional (3-D) cell culture, which was designed as a means for experimentally reproducing the 3-D structures found in the body. They investigated the potential for induction of cancer stem cells from esophageal cancer cells. [Biochem Biophys Res Commun] Abstract Epithelial-Mesenchymal Transition Triggers Cancer Stem Cell Generation in Human Thyroid Cancer Cells Results indicate that EMT induction promotes cancer stem cell traits and cell proportions in the thyroid cancer cells, which implies that EMT could induce cancer stem cell generation and tumor progression in thyroid cancers. [Int J Oncol] Abstract |