case-control study of vitamin d, dickkopf homolog 1 (dkk1) gene methylation, vdr gene polymorphism and the risk of colon adenoma in african americans病例对照研究的维生素d,dickkopf同族体1(dkk1)基因甲基化,vdr基因多态性和结肠癌的风险腺瘤在非洲裔美国人.pdf

Case-Control Study of Vitamin D, dickkopf homolog 1 (DKK1) Gene Methylation, VDR Gene Polymorphism and the Risk of Colon Adenoma in African Americans 1 1 1 2 1 Hassan Ashktorab *, Bijou Nguza , Mehrnaz Fatemi , Mehdi Nouraie , Duane T. Smoot , Alejandro A. ¨ 4 5 6 3 Schaffer , Sonia S. Kupfer , Carlos A. Camargo Jr , Hassan Brim 1 Department of Medicine and Cancer Center, College of Medicine, Howard University, Washington, D. C., United States of America, 2 Center for Sickle Cell Disease, College of Medicine, Howard University, Washington, D. C., United States of America, 3 Department of Pathology, College of Medicine, Howard University, Washington, D. C., United States of America, 4 National Center for Biotechnology Information, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland, United States of America, 5 Section of Gastroenterology, Department of Medicine, University of Chicago, Chicago, Illinois, United States of America, 6 Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America Abstract Background: There are sparse data on genetic, epigenetic and vitamin D exposure in African Americans (AA) with colon polyp. Consequently, we evaluated serum 25(OH) D levels, vitamin D receptor (VDR) polymorphisms and the methylation status of the tumor suppressor gene dickkopf homolog 1 (DKK1) as risk factors for colon polyp in this population. Methods: The case-control study consisted of 93 patients with colon polyp (cases) and 187 healthy individuals (controls) at Howard University Hospital. Serum levels of 25(OH)D (