RT Journal Article
SR Electronic
T1 miR-128 inhibits telomerase activity by targeting TERT mRNA
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 195198
DO 10.1101/195198
A1 Herlinda Guzman
A1 Katie Sanders
A1 Adam Idica
A1 Aurore Bochnakian
A1 Douglas Jury
A1 Iben Daugaard
A1 Dimitrios G Zisoulis
A1 Irene Munk Pedersen
YR 2017
UL http://biorxiv.org/content/early/2017/10/06/195198.abstract
AB Telomerase is a unique cellular reverse transcriptase essential for maintaining telomere stability and required for the unlimited proliferation of cancer cells. The limiting determinant of telomerase activity is the catalytic component TERT, and TERT expression is closely correlated with telomerase activity and cancer initiation and disease progression. For this reason the regulation of TERT levels in the cell is of great importance. microRNAs (miRs) function as an additional regulatory level in cells, crucial for defining expression boundaries, proper cell fate decisions, cell cycle control, genome integrity, cell death and metastasis. We performed an anti-miR library screen to identity novel miRs, which participate in the control of telomerase. We identified the tumor suppressor miR (miR-128) as a novel endogenous telomerase inhibitor and determined that miR-128 significantly reduces the mRNA and protein levels of Tert in a panel of cancer cell lines. We further evaluated the mechanism by which miR-128 regulates TERT and demonstrated that miR-128 interacts directly with the coding sequence of TERT mRNA in both HeLa cells and teratoma cells. Interestingly, the functional miR-128 binding site in TERT mRNA, is conserved between TERT and the other cellular reverse transcriptase encoded by Long Interspaced Elements-1 (LINE-1 or L1), which can also contribute to the oncogenic phenotype of cancer. This finding supports the novel idea that miRs may function in parallel pathways to inhibit tumorigenesis, by regulating a group of enzymes (RT) by targeting conserved binding sites in the coding region of both enzymes.NOVELTY AND IMPACT Telomerase is an RNA-dependent DNA polymerase that synthesizes telomeric DNA sequences and almost universally provides the molecular basis for unlimited proliferative potential. Expression of human telomerase alone is sufficient for the immortalization of diverse cell types. We have identified the tumor suppressor microRNA (miR-128) as a novel regulator of telomerase, which directly targets the coding sequence (CDS) of TERT mRNA and significantly represses Tert protein expression in a panel of cancer cell lines.AgoArgonauteBMI-1BMI1 Proto-Oncogene, Polycomb Ring FingerCDScoding sequenceGAPDHGlyceraldehyde 3-phosphate dehydrogenaseGFPgreen fluorescent proteiniPSCinduced pluripotent stem cellsL1 or LINE-1long-interspaced element-1miRmicroRNAmiRISCmiR-induced silencing complexmRNAmessenger RNAORFopen reading framePUMAp53 upregulated modulator of apoptosisq-TRAPReal-time quantitative telomeric repeat amplificationRIPArgonaute-RNA immuno-purificationRTreverse transcriptaseSIRT1silent mating type information regulation 2 homologshRNAshort hairpin RNATERTTelomerase Reverse TranscriptaseTERCtelomerase RNA componentWTwild type