Genome wide association studies (GWAS) have mapped multiple independent cancer susceptibility loci to chr5p15.33. Here, we show that fine-mapping of pancreatic and testicular cancer GWAS within one of these loci (Region 2 in CLPTM1L) focuses the signal to nine highly correlated SNPs. Of these, rs36115365-C associated with increased pancreatic and testicular but decreased lung cancer and melanoma risk, and exhibited preferred protein-binding and enhanced regulatory activity. Transcriptional gene silencing of this regulatory element repressed TERT expression in an allele-specific manner. Proteomic analysis identifies allele-preferred binding of Zinc finger protein 148 (ZNF148) to rs36115365- C, further supported by binding of purified recombinant ZNF148. Knockdown of ZNF148 results in reduced TERT expression, telomerase activity and telomere length. Our results indicate that the association with chr5p15.33-Region 2 may be explained by rs36115365, a variant influencing TERT expression via ZNF148 in a manner consistent with elevated TERT in carriers of the C allele.
Bibliographical noteFunding Information:
We acknowledge the contribution of the staff of the Cancer Genomics Research Laboratory (CGR, NCI), as well as Mr Timothy Myers and Lea Jessop (LTG, DCEG, NCI) for their invaluable help throughout the project. We are grateful to Dr Francisco X. Real, The Spanish National Cancer Institute (CNIO) in Madrid, Spain for providing reagents. We are grateful to Dr Dom Esposito, Frederick National Laboratory for Cancer Research, Frederick, MD, USA, for cloning for lentiviral production. We thank Paul D.P. Pharoah, Department of Oncology, University of Cambridge, Cambridge, UK and Centre for Cancer Genetic Epidemiology, Department of Public Health and Primary Care, Strangeways Research Laboratory, Cambridge, UK for providing GWAS data. Furthermore, we thank Dr Stephen Chanock for his advice, encouragement and critical reading of the manuscript. This work was supported by the Intramural Research Program of the US National Institutes of Health (NIH), National Cancer Institute, by contract number HHSN261200800001E, by Cancer Research UK for SEARCH (C490/A10124). Funding for M.V. was provided by the Netherlands Organization for Scientific Research (NWO Gravitation Program Cancer Genomics Netherlands). Funding for M.M. was provided by a grant from the Marie Curie Initial Training Network (ITN) DevCom (FP7, grant number 607142). The content of this publication does not necessarily reflect the views or policies of the Department of Health and Human Services, nor does mention of trade names, commercial products, or organizations imply endorsement by the US Government.
© The Author(s) 2017.