MP37-14 RNA INTERFERENCE-MEDIATED KNOCKDOWN OF CHD1 IN HUMAN PROSTATE XENOGRAFT TUMORS ALTERS TUMOR GROWTH AND METASTATIC BEHAVIOR

Abstract

You have accessJournal of UrologyProstate Cancer: Basic Research I1 Apr 2015MP37-14 RNA INTERFERENCE-MEDIATED KNOCKDOWN OF CHD1 IN HUMAN PROSTATE XENOGRAFT TUMORS ALTERS TUMOR GROWTH AND METASTATIC BEHAVIOR Su Jung Oh, Derya Tilki, Hüseyin Sirma, Ronald Simon, and Tobias Lange Su Jung OhSu Jung Oh More articles by this author , Derya TilkiDerya Tilki More articles by this author , Hüseyin SirmaHüseyin Sirma More articles by this author , Ronald SimonRonald Simon More articles by this author , and Tobias LangeTobias Lange More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.1277AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Chromodomain helicase DNA-binding protein 1 (CHD1) is a tumor suppressor which is frequently homozygously deleted genes in prostate cancer (PCa). It still remains unclear whether this molecule is involved in metastatic behavior of PCa. To elucidate the role of CHD1 in tumor metastatic dissemination, we analyzed the tumorigenic and metastatic potential of PCa cells after RNAi-mediated knockdown (KD) of CHD1. METHODS CHD1 was stably depleted in PC-3 cells by lentiviral transduction of short hairpin RNA (shRNA) with puromycin resistance (PC-3-shCHD1). Control cells had an empty vector (PC-3-shNeg). The KD of CHD1 was confirmed by western blot. In vivo, PC-3-shCHD1 and -shNeg were subcutaneously xenografted into immunodeficient pfp−/−/rag2−/− mice. After 6 weeks, mice were euthanized. Both primary tumors and right lungs were processed for histopathological analysis. Quantification of spontaneous lung metastases was performed by direct microscopic visualization and counting. DNA from blood, left lungs and bone marrow were isolated for quantification of DTC and CTC by Alu-PCR. Effects of CHD1 depletion on cell adhesion were analyzed by static and dynamic flow adhesion assays. RESULTS KD of CHD1 by shRNA resulted in down-regulation of CHD1 protein levels by about 50%. In vivo, xenograft primary tumors were significantly larger in the CHD1-depleted group accompanied by a reduced number of DTC in the bone marrow compared to the control. Strikingly, the number of DTC in the lungs was increased. Spontaneous lung metastases consisted of several cells per metastasis after CHD1-depletion, whereas control cells predominantly formed single cell lung metastases as known from parental PC-3 in this model. Moreover, CHD1-depletion significantly increased the number of adhesive events of PC-3 under dynamic conditions. Static adhesive interactions and CTC-levels did not change upon CHD1-depletion. CONCLUSIONS KD of the tumor suppressor CHD1 increases tumorigenicity and drastically changes metastatic organotropism in a spontaneous metastasis xenograft model of human PCa. In particular, CHD1-depletion specifically promoted spontaneous dissemination into the lung, whereas dissemination into the bone marrow was abrogated. This might be reflected by the increased adhesive properties of CHD1-depleted PC-3 on pulmonary endothelium. We moreover hypothesize that CHD1 might suppress the switch of ‘dormant’ single cell DTC to proliferating metastatic colonies in the lung and indicate a possible novel role of altered CHD1 in metastatic behavior of PCa. © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e443 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Su Jung Oh More articles by this author Derya Tilki More articles by this author Hüseyin Sirma More articles by this author Ronald Simon More articles by this author Tobias Lange More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...