EB1 protein alteration characterizes sporadic but not ulcerative colitis associated colorectal cancer

// Timo Gemoll 1, * , Sophie L. Kollbeck 1, * , Karl F. Karstens 1 , Gia G. Hò 1 , Sonja Hartwig 2, 3 , Sarah Strohkamp 1 , Katharina Schillo 1 , Christoph Thorns 4 , Martina Oberländer 1 , Kathrin Kalies 5 , Stefan Lehr 2, 3 and Jens K. Habermann 1 1 Section for Translational Surgical Oncology and Biobanking, Department of Surgery, University of Lübeck and University Hospital Schleswig-Holstein, Campus Lübeck, D-23538 Lübeck, Germany 2 Institute of Clinical Biochemistry and Pathobiochemistry, German Diabetes Center at the Heinrich-Heine-University Düsseldorf, Leibniz Center for Diabetes Research, D-40225 Düsseldorf, Germany 3 German Center for Diabetes Research (DZD), D-85764 München-Neuherberg, Germany 4 Department of Pathology, University Hospital Schleswig-Holstein, Campus Lübeck, D-23538 Lübeck, Germany 5 Institute of Anatomy, University of Lübeck, D-23538 Lübeck, Germany * These authors contributed equally to this work Correspondence to: Timo Gemoll, email: Timo.Gemoll@uni-luebeck.de Jens K. Habermann, email: Jens.Habermann@uni-luebeck.de Keywords: ulcerative colitis associated colorectal cancer, EB1, two-dimensional gel electrophoresis, mass spectrometry, colorectal cancer Received: February 14, 2017      Accepted: June 17, 2017      Published: July 04, 2017 ABSTRACT Background: While carcinogenesis in Sporadic Colorectal Cancer (SCC) has been thoroughly studied, less is known about Ulcerative Colitis associated Colorectal Cancer (UCC). This study aimed to identify and validate differentially expressed proteins between clinical samples of SCC and UCC to elucidate new insights of UCC/SCC carcinogenesis and progression. Results: Multiplex-fluorescence two-dimensional gel electrophoresis (2-D DIGE) and mass spectrometry identified 67 proteoforms representing 43 distinct proteins. After analysis by Ingenuity Pathway Analysis ® (IPA), subsequent Western blot validation proofed the differential expression of Heat shock 27 kDA protein 1 (HSPB1) and Microtubule-associated protein R/EB family, member 1 (EB1) while the latter one showed also expression differences by immunohistochemistry. Materials and Methods: Fresh frozen tissue of UCC ( n = 10) matched with SCC ( n = 10) was investigated. Proteins of cancerous intestinal mucosal cells were obtained by Laser Capture Microdissection (LCM) and compared by 2-D DIGE. Significant spots were identified by mass spectrometry. After IPA, three proteins [EB1, HSPB1, and Annexin 5 (ANXA5)] were chosen for further validation by Western blotting and tissue microarray-based immunohistochemistry. Conclusions: This study identified significant differences in protein expression of colorectal carcinoma cells from UCC patients compared to patients with SCC. Particularly, EB1 was validated in an independent clinical cohort.