title: Both mature miR-17-5p and passenger strand miR-17-3p target TIMP3 and induce prostate tumor growth and invasion.
abstract: MicroRNAs (miRNA) precursor (pre-miRNA) molecules can be processed to release a miRNA/miRNA* duplex. In the canonical model of miRNA biogenesis, one strand of the duplex is thought to be the biologically active miRNA, whereas the other strand is thought to be inactive and degraded as a carrier or passenger strand called miRNA* (miRNA star). However, recent studies have revealed that miRNA* strands frequently play roles in the regulatory networks of miRNA target molecules. Our recent study indicated that miR-17 transgenic mice could abundantly express both the mature miR-17-5p and the passenger strand miR-17-3p. Here, we showed that miR-17 enhanced prostate tumor growth and invasion by increasing tumor cell proliferation, colony formation, cell survival and invasion. miRNA target analysis showed that both miR-17-5p and miR-17-3p repressed TIMP metallopeptidase inhibitor 3 (TIMP3) expression. Silencing with small interfering RNA against TIMP3 promoted cell survival and invasion. Ectopic expression of TIMP3 decreased cell invasion and cell survival. Our results demonstrated that mature miRNA can function coordinately with its passenger strand, enhancing the repressive ability of a miRNA by binding the same target. Within an intricate regulatory network, this may be among the mechanisms by which miRNA can augment their regulatory capacity.
authors.affiliation: Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, M4N 3M5, Canada and Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, M5S 1A8, Canada.
authors.forename: Xiangling
authors.initials: X
authors.lastname: Yang
authors.forename: William W
authors.initials: WW
authors.lastname: Du
authors.forename: Haoran
authors.initials: H
authors.lastname: Li
authors.forename: Fengqiong
authors.initials: F
authors.lastname: Liu
authors.forename: Anna
authors.initials: A
authors.lastname: Khorshidi
authors.forename: Zina Jeyapalan
authors.initials: ZJ
authors.lastname: Rutnam
authors.forename: Burton B
authors.initials: BB
authors.lastname: Yang
mesh_terms: D000818:Animals; D063646:Carcinogenesis; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D002470:Cell Survival; D015972:Gene Expression Regulation, Neoplastic; D008297:Male; D051379:Mice; D008819:Mice, Nude; D035683:MicroRNAs / Q000378:metabolism*; D009361:Neoplasm Invasiveness; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D019717:Tissue Inhibitor of Metalloproteinase-3 / Q000235:genetics* / Q000378:metabolism
chemical_list: D035683:MicroRNAs; D019717:Tissue Inhibitor of Metalloproteinase-3