Regulation of ITGA3 by the dual-stranded microRNA-199 family as a potential prognostic marker in bladder cancer.
BACKGROUND
Based on the microRNA (miRNA) signature of bladder cancer (BC) by deep sequencing, we recently found that several double-stranded mature miRNAs derived from the same pre-miRNAs were sufficiently expressed and acted as tumour suppressors by regulating common target genes in BC. Our deep-sequencing signature of BC showed that all miR-199 family members (miR-199a-3p/-5p and miR-199b-3p/-5p) were also downregulated. We hypothesised that these miRNAs may function as tumour suppressors by regulating common target genes.


METHODS
Functional assays of BC cells were performed using transfection of mature miRNA. In silico analyses and luciferase reporter analyses were applied to identify target genes of these miRNAs. The overall survival of patients with BC in The Cancer Genome Atlas (TCGA) database was evaluated by the Kaplan-Meier method.


RESULTS
Restoration of these miRNAs significantly inhibited cell migration and invasion in BC cells. Integrin α3 (ITGA3) was directly regulated by these miRNAs. The Cancer Genome Atlas database showed that patients with low pre-miR-199 family (miR-199a-1/-2 and miR-199b) expression exhibited significantly poorer overall survival compared with patients with high pre-miR-199 family expression.


CONCLUSIONS
miR-199 family miRNAs functioned as tumour suppressors in BC cells by targeting ITGA3 and might be good prognostic markers for predicting survival in patients with BC.
Department of Urology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan.
Takashi
T
Sakaguchi
Department of Urology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan.
Hirofumi
H
Yoshino
Department of Urology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan.
Masaya
M
Yonemori
Department of Urology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan.
Kazutaka
K
Miyamoto
Department of Urology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan.
Satoshi
S
Sugita
Department of Urology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan.
Ryosuke
R
Matsushita
Department of Urology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan.
Toshihiko
T
Itesako
Department of Urology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan.
Shuichi
S
Tatarano
Department of Urology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan.
Masayuki
M
Nakagawa
Department of Urology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan.
Hideki
H
Enokida
D017209:Apoptosis; D014408:Biomarkers, Tumor; D015153:Blotting, Western; D002465:Cell Movement; D049109:Cell Proliferation; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007124:Immunoenzyme Techniques; D039422:Integrin alpha3 / Q000235:genetics / Q000378:metabolism*; D035683:MicroRNAs / Q000235:genetics*; D009367:Neoplasm Staging; D011379:Prognosis; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured; D001749:Urinary Bladder Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology
D014408:Biomarkers, Tumor; C000599264:ITGA3 protein, human; D039422:Integrin alpha3; D035683:MicroRNAs; D012333:RNA, Messenger; C531408:mirn199 microRNA, human