Home2022Identification of Mechanism of Cancer-cell-specific Reactivation of hTERT Offers Therapeutic Opportunities for Blocking Telomerase Specifically in Human Colorectal Cancer (Nucleic Acids Res., June 2022)
Identification of Mechanism of Cancer-cell-specific Reactivation of hTERT Offers Therapeutic Opportunities for Blocking Telomerase Specifically in Human Colorectal Cancer (Nucleic Acids Res., June 2022)
1Division of Cancer Genetics and Therapeutics, Laboratory of NF?B Signaling, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 138673, Singapore.
2Cancer Science Institute of Singapore, National University of Singapore, 117599, Singapore.
3Laboratory of Precision Oncology and Cancer Evolution, Genome Institute of Singapore, A*STAR, 138672, Singapore.
4Genome Institute of Singapore, Agency for Science, Technology and Research (A*STAR), 138672, Singapore.
5Department of Medical Oncology, National Cancer Centre Singapore, 169610, Singapore.
6School of Biological Sciences, Nanyang Technological University, 637551, Singapore.
7Department of Pathology, Yong Loo Lin School of Medicine, National University of Singapore (NUS), 119074, Singapore.
8Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore (NUS), 117596, Singapore.
Transcriptional reactivation of hTERT is the limiting step in tumorigenesis. While mutations in hTERT promoter present in 19% of cancers are recognized as key drivers of hTERT reactivation, mechanisms by which wildtype hTERT (WT-hTERT) promoter is reactivated, in majority of human cancers, remain unknown. Using primary colorectal cancers (CRC) we identified Tert INTeracting region 2 (T-INT2), the critical chromatin region essential for reactivating WT-hTERT promoter in CRCs. Elevated ?-catenin and JunD level in CRC facilitates chromatin interaction between hTERT promoter and T-INT2 that is necessary to turn on hTERTexpression. Pharmacological screens uncovered salinomycin, which inhibits JunD mediated hTERT-T-INT2 interaction that is required for the formation of a stable transcription complex on the hTERT promoter. Our results showed for the first time how known CRC alterations, such as APC, lead to WT-hTERT promoter reactivation during stepwise-tumorigenesis and provide a new perspective for developing cancer-specific drugs.