Article open access publication

Functional Screening Identifies miRNAs Influencing Apoptosis and Proliferation in Colorectal Cancer

PLoS ONE, Public Library of Science (PLoS), ISSN 1932-6203

Volume 9, 6, 2014

DOI:10.1371/journal.pone.0096767, Dimensions: pub.1021899896, PMC: PMC4043686, PMID: 24892549,

Affiliations

Organisations

  1. (1) Colorectal Cancer Research Group, Department of Molecular Medicine (MOMA), Aarhus University Hospital, University of Aarhus, Aarhus, Denmark
  2. (2) Rigshospitalet, grid.475435.4, Capital Region
  3. (3) VTT Technical Research Centre of Finland, grid.6324.3
  4. (4) Bladder Cancer Research Group, Department of Molecular Medicine (MOMA), Aarhus University Hospital, University of Aarhus, Aarhus, Denmark
  5. (5) Aarhus University, grid.7048.b, AU
  6. (6) Ludwig Cancer Research, grid.482095.2
  7. (7) University of Melbourne, grid.1008.9
  8. (8) Western Hospital, grid.417075.0
  9. (9) Vejle Sygehus, grid.417271.6, Southern Denmark Region
  10. (10) University of Copenhagen, grid.5254.6, KU
  11. (11) Pomeranian Medical University, grid.107950.a
  12. (12) Department of Pathology, Aarhus University Hospital, University of Aarhus, Aarhus, Denmark
  13. (13) Department of Surgery, Aarhus University Hospital, University of Aarhus, Aarhus, Denmark

Description

MicroRNAs (miRNAs) play a critical role in many biological processes and are aberrantly expressed in human cancers. Particular miRNAs function either as tumor suppressors or oncogenes and appear to have diagnostic and prognostic significance. Although numerous miRNAs are dys-regulated in colorectal cancer (CRC) only a small fraction has been characterized functionally. Using high-throughput functional screening and miRNA profiling of clinical samples the present study aims at identifying miRNAs important for the control of cellular growth and/or apoptosis in CRC. The high-throughput functional screening was carried out in six CRC cell lines transfected with a pre-miR library including 319 synthetic human pre-miRs. Phenotypic alterations were evaluated by immunostaining of cleaved cPARP (apoptosis) or MKI67 (proliferation). Additionally, TaqMan Human MicroRNA Array Set v2.0 was used to profile the expression of 667 miRNAs in 14 normal colon mucosa and 46 microsatellite stable stage II CRC patients. Among the miRNAs that induced growth arrest and apoptosis in the CRC cell lines, and at same time were dys-regulated in the clinical samples, miR-375 was selected for further analysis. Independent in vitro analysis of transient and stable transfected CRC cell lines confirmed that miR-375 reduces cell viability through the induction of apoptotic death. We identified YAP1 as a direct miR-375 target in CRC and show that HELLS and NOLC1 are down-stream targets. Knock-down of YAP1 mimicked the phenotype induced by miR-375 over-expression indicating that miR-375 most likely exerts its pro-apoptotic role through YAP1 and its anti-apoptotic down-stream targets BIRC5 and BCL2L1. Finally, in vivo analysis of mouse xenograft tumors showed that miR-375 expression significantly reduced tumor growth. We conclude that the high-throughput screening successfully identified miRNAs that induce apoptosis and/or inhibit proliferation in CRC cells. Finally, combining the functional screening with profiling of CRC tissue samples we identified clinically relevant miRNAs and miRNA targets in CRC.

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Times Cited: 37

Field Citation Ratio (FCR): 5.91

Relative Citation ratio (RCR): 1.64

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