OP1-05 INTEGRATIVE DNA METHYLATION AND GENE EXPRESSION ANALYSES IDENTIFIES DISCOIDIN DOMAIN RECEPTOR 1 (DDR1) ASSOCIATION WITH IDIOPATHIC NONOBSTRUCTIVE AZOOSPERMIA

Abstract

You have accessJournal of UrologyOutstanding Posters: Research1 Apr 2014OP1-05 INTEGRATIVE DNA METHYLATION AND GENE EXPRESSION ANALYSES IDENTIFIES DISCOIDIN DOMAIN RECEPTOR 1 (DDR1) ASSOCIATION WITH IDIOPATHIC NONOBSTRUCTIVE AZOOSPERMIA Ranjith Ramasamy, Alex Ridgeway, Josephine Addai, Larry Lipshultz, and Dolores Lamb Ranjith RamasamyRanjith Ramasamy More articles by this author , Alex RidgewayAlex Ridgeway More articles by this author , Josephine AddaiJosephine Addai More articles by this author , Larry LipshultzLarry Lipshultz More articles by this author , and Dolores LambDolores Lamb More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2014.02.613AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Spermatogenesis is a complex process that involves proliferation, differentiation, and cell adhesion. Spermatogenic failure or non−obstructive azoospermia (NOA) results from mechanisms involved are incompletely understood. DDR1 is a member of a small subfamily of receptor tyrosine kinases that is involved in adhesion, migration, proliferation, apoptosis, cell morphogenesis and differentiation. Since, DDR1 is expressed in human post−meiotic germ cells of testis, we hypothesized that abnormal DDR1 expression could be a possible mechanism that can compromise spermatogenesis in a subset of men with idiopathic NOA. METHODS We used the high resolution Infinium 450K methylation array and compared fibrobalsts cultured from testicular biopsies of 19 NOA men and 4 fertile controls. Microarray data was analyzed using Minfi (R software package) utilizing subset−quantile within array normalization. We investigated the functional role of abnormal promoter DNA methylation for selected genes using mRNA expression by quantitative RT−real time PCR. Immunohistochemistry was used to confirm testicular expression and potential importance in spermatogenesis RESULTS Differentially methylated CpG sites (∼20K) were identified using an F−Test (p<0.05) in the NOA samples. We identified 24 genes with the >30% difference in methylation within promoter region of men with NOA and fertile controls. Of the aberrantly methylated CpGs, 13 were hypomethylated and 11 were hypermethylated groups. From the top 11 hypermethylated genes, six genes (MRI1, DCAF12L1, TMEM95, CECR2, DDR1, NPHS2) were selected for validation since they were shown to be expressed in testis. Of the 6 genes validated with qPCR, DDR1 showed aberrant gene expression pattern. Four (21%) patients out of the 19 NOA men had lower expression levels (1.8x) of DDR1, whereas two (10.5%) men had higher expression levels (2.5x) of DDR1compared to fertile men (p<0.05). Immunohistochemical analysis suggests presence of DDR1 within cytoplasm of germ cells in fertile men and men with maturation arrest histology. DDR1 protein is absent in men with Sertoli−cell only or germ cell aplasia. CONCLUSIONS Aberrant expression of DDR1 is associated with NOA. The functional relevance of abnormal methylation of DDR1 to NOA warrants further investigation © 2014FiguresReferencesRelatedDetails Volume 191Issue 4SApril 2014Page: e163-e164 Advertisement Copyright & Permissions© 2014MetricsAuthor Information Ranjith Ramasamy More articles by this author Alex Ridgeway More articles by this author Josephine Addai More articles by this author Larry Lipshultz More articles by this author Dolores Lamb More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...