German Cancer Consortium (DKTK) 4 articles published in JoVE Developmental Biology CRISPR-mediated Loss of Function Analysis in Cerebellar Granule Cells Using In Utero Electroporation-based Gene Transfer Weijun Feng*1, Lena Herbst*2, Peter Lichter2, Stefan M. Pfister3,4,5, Hai-Kun Liu1, Daisuke Kawauchi3,4 1Division of Molecular Neurogenetics, German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, 2Division of Molecular Genetics, German Cancer Research Center (DKFZ), and German Cancer Consortium (DKTK), 3 Conventional loss-of-function studies of genes using knockout animals have often been costly and time-consuming. Electroporation-based CRISPR-mediated somatic mutagenesis is a powerful tool to understand gene functions in vivo. Here, we report a method to analyze knockout phenotypes in proliferating cells of the cerebellum. Cancer Research Isolation of Circulating Tumor Cells in an Orthotopic Mouse Model of Colorectal Cancer Susan Kochall1, May-Linn Thepkaysone1, Sebastián A. García1, Alexander M. Betzler1, Jürgen Weitz1,2,3, Christoph Reissfelder1, Sebastian Schölch1,2,3 1Department of Gastrointestinal, Thoracic and Vascular Surgery, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, 2German Cancer Consortium (DKTK), 3German Cancer Research Center (DKFZ) We describe the establishment of orthotopic colorectal tumors via injection of tumor cells or organoids into the cecum of mice and the subsequent isolation of circulating tumor cells (CTCs) from this model. Cancer Research A Genetically Engineered Mouse Model of Sporadic Colorectal Cancer Alexander M. Betzler1, Susan Kochall1, Linda Blickensdörfer2, Sebastian A. Garcia1, May-Linn Thepkaysone1, Lahiri K. Nanduri1, Michael H. Muders3, Jürgen Weitz1,4,5, Christoph Reissfelder1, Sebastian Schölch1,4,5 1Department of Gastrointestinal, Thoracic and Vascular Surgery, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, 2Department of General, Gastrointestinal and Transplant Surgery, University of Heidelberg, 3Department of Pathology, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, 4German Cancer Consortium (DKTK), 5German Cancer Research Center (DKFZ) A protocol for the establishment of a genetically engineered mouse model of colorectal cancer by segmental adeno-cre infection and its surveillance via high-resolution colonoscopy is presented. Medicine Quantitative Mass Spectrometric Profiling of Cancer-cell Proteomes Derived From Liquid and Solid Tumors Hanibal Bohnenberger1, Philipp Ströbel1, Sebastian Mohr2, Jasmin Corso3, Tobias Berg2, Henning Urlaub3,4, Christof Lenz3,4, Hubert Serve2,5,6, Thomas Oellerich2,5,6 1Institute of Pathology, University Medical Center, Göttingen, 2Department of Hematology/Oncology, Goethe University of Frankfurt, 3Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, 4Bioanalytics, Institute of Clinical Chemistry, University Medical Center, Göttingen, 5German Cancer Consortium, 6German Cancer Research Center In-depth analyses of cancer cell proteomes facilitate identification of novel drug targets and diagnostic biomarkers. We describe an experimental workflow for quantitative analysis of (phospho-)proteomes in cancer cell subpopulations derived from liquid and solid tumors. This is achieved by combining cellular enrichment strategies with quantitative Super-SILAC-based mass spectrometry.