miR-135a Inhibits Cancer Stem Cell-Driven Medulloblastoma Development by Directly Repressing Arhgef6 Expression Scientists investigated the putative role of microRNAs (miRNAs) in modulating the tumor-initiating potential of mouse medulloblastoma-derived cancer stem cells (CSCs). Enforced expression of miR-135a in highly tumorigenic CSCs strongly inhibited tumorigenesis by repressing the miR-135a direct target gene Arhgef6. [Stem Cells] Abstract SOX9 Inhibits β-TrCP-Mediated Protein Degradation to Promote Nuclear GLI1 Expression and Cancer Stem Cell Properties The High Mobility Group box protein SOX9 and the GLI1 transcription factor play protumorigenic roles in pancreatic ductal adenocarcinoma (PDA). Researchers observed positive feedback, such that SOX9-deficient PDA cells have severely repressed levels of endogenous GLI1, attributed to loss of GLI1 protein stability. [J Cell Sci] Abstract ADAM-9 Is a Novel Mediator of Tenascin-C-Stimulated Invasiveness of Brain Tumor-Initiating Cells Tenascin-C (TNC), an extracellular matrix protein overexpressed in malignant gliomas, stimulates invasion of conventional glioma cell lines. Researchers addressed whether and how TNC may regulate the invasiveness of brain tumor-initiating cells that give rise to glioma progenies. [Neuro Oncol] Abstract TGF-β1 Acts through miR-155 to Down-Regulate TP53INP1 in Promoting Epithelial-Mesenchymal Transition and Cancer Stem Cell Phenotypes Researchers report that miR-155 regulates not only the epithelial-mesenchymal transition but also the stem-like transition in liver cancer cells. Up-regulated miR-155 significantly increases the population of stem-like cancer stem cells among liver cancer cells and the ability to form tumor spheres. [Cancer Lett] Abstract The Telomerase Inhibitor Imetelstat Alone, and in Combination with Trastuzumab, Decreases the Cancer Stem Cell Population and Self-Renewal of HER2+ Breast Cancer Cells The authors investigated the effects of a telomerase antagonistic oligonucleotide, imetelstat, on cancer stem cell (CSC) and non-CSC populations of HER2+ breast cancer cell lines. Imetelstat alone and in combination with trastuzumab reduced the CSC fraction and inhibited CSC functional ability, as shown by decreased mammosphere counts and invasive potential. [Breast Cancer Res Treat] Abstract A Critical Dose of Doxorubicin Is Required to Alter the Gene Expression Profiles in MCF-7 Cells Acquiring Multidrug Resistance Investigators studied gene expression profiling circumstances in MCF-7 during multidrug resistance development. MCF-7/ADR-1024 cells exerted CSC-like cell surface marker CD44 high/CD24 low and form mammospheres. [PLoS One] Full Article Antisense Inhibition of MicroRNA-21 and MicroRNA-221 in Tumor-Initiating Stem-Like Cells Modulates Tumorigenesis, Metastasis, and Chemotherapy Resistance in Pancreatic Cancer Researchers identified a small population side population (SP) cells in pancreatic cancer cells with stem cell-like properties, which were able to induce fast and aggressive tumor formation in nude mice. Sorted SP cells from gemcitabine-resistant highly metastatic human pancreatic cancer cell line cells were orthotopically implanted in nude mice with or without miRNA-21 and miRNA-221 antisense oligonucleotides mono- and combination therapy. [Target Oncol] Abstract Adoptive T-Cell Therapy of Prostate Cancer Targeting the Cancer Stem Cell Antigen EpCAM Because cancer stem cells (CSCs) play an important role in tumor growth and metastasis, scientists hypothesized that adoptive transfer of T cells targeting a CSC antigen could result in dramatic anti-tumor effects. An EpCAM-specific chimeric antigen receptor was constructed to transduce human peripheral blood lymphocytes and thereby enable them to target the CSC marker EpCAM. [BMC Immunol] Full Article p53 Upregulated Modulator of Apoptosis Sensitizes Drug-Resistant U251 Glioblastoma Stem Cells to Temozolomide through Enhanced Apoptosis A temozolomide (TMZ)-resistant glioblastoma cell line, U251R, was developed and subsequently divided into two subpopulations according to the CD133 immunophenotype. TMZ achieves its cytotoxic effect by inducing DNA lesions and p53 upregulated modulator of apoptosis is an essential mediator of DNA damage-induced apoptosis independently of p53 status. [Mol Med Rep] Abstract | Download Full Article |