PMID- 29379304
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20220317
IS  - 1178-6930 (Print)
IS  - 1178-6930 (Electronic)
IS  - 1178-6930 (Linking)
VI  - 11
DP  - 2018
TI  - miR-99a-5p acts as tumor suppressor via targeting to mTOR and enhances 
      RAD001-induced apoptosis in human urinary bladder urothelial carcinoma cells.
PG  - 239-252
LID - 10.2147/OTT.S114276 [doi]
AB  - INTRODUCTION: miR-99a-5p, known to play an important role in mammalian target of 
      rapamycin (mTOR) regulation, is downregulated in human bladder cancer. The study 
      aimed to investigate the anticancer activity of miR-99a-5p and the possible 
      mechanism associated with mTOR in bladder cancer cells. MATERIALS AND METHODS: 
      Vectors expressing miR-99a-5p were transfected into human urinary bladder 
      urothelial carcinoma (5637 and T24) cells. The level of miR-99a-5p was monitored 
      by microRNA (miRNA) quantitative polymerase chain reaction (QPCR). Luciferase 
      reporter assays were performed to verify the direct binding of miR-99a-5p to mTOR 
      transcripts. The mTOR transcripts and protein levels were measured by QPCR and 
      Western blot, respectively. Cell viability of miR-99a-5p-transfected cells was 
      detected by tetrazolium salt (WST-1). Inhibition of mTOR complex 1 (mTORC1) and 
      mTOR complex 2 (mTORC2) signaling was detected by the phosphorylation of mTOR and 
      AKT using Western blot. The ability of miR-99a-5p to enhance RAD001-induced 
      apoptosis was determined as the expression of cleaved caspase 3 and levels of DNA 
      fragmentation. RESULTS: Transfection of miR-99a-5p-expressing vector elevated the 
      expression level of miR-99a-5p up to sixfold compared to vector-only controls. 
      The results from luciferase assay verified that miR-99a-5p directly binds to the 
      predicted sequence in the 3' untranslated region (3'-UTR) of mTOR. The levels of 
      mTOR RNA and protein were decreased in miR-99a-5p-transfected cells. Dual 
      inhibition of mTORC1 and mTORC2 by miR-99a-5p was confirmed by the decreased 
      phosphorylation of mTOR (at Ser2448 and Ser2481), phospho-rpS6 and phospho-4EBP1. 
      The phosphorylation of AKT was significantly inhibited in miR-99a-5p-transfected 
      cells upon RAD001 treatment. Enforced expression of miR-99a-5p potentiated 
      RAD001-induced apoptosis in these cells. CONCLUSION: This is the first study 
      showing that miR-99a-5p markedly inhibits the growth of bladder cancer cells via 
      dual inhibition of mTORC1 and mTORC2. Our data demonstrated that forced 
      expression of miR-99a-5p inhibits the feedback of AKT survival pathway and 
      enhances the induction of apoptosis in RAD001-treated bladder cancer cells.
FAU - Tsai, Te-Fu
AU  - Tsai TF
AD  - Department of Urology.
FAU - Lin, Ji-Fan
AU  - Lin JF
AD  - Central Laboratory.
FAU - Chou, Kuang-Yu
AU  - Chou KY
AD  - Department of Urology.
FAU - Lin, Yi-Chia
AU  - Lin YC
AD  - Department of Urology.
FAU - Chen, Hung-En
AU  - Chen HE
AD  - Department of Urology.
FAU - Hwang, Thomas I-Sheng
AU  - Hwang TI
AD  - Department of Urology.
AD  - Division of Urology, Department of Surgery, Shin-Kong Wu Ho-Su Memorial Hospital.
AD  - Department of Urology, Taipei Medical University.
AD  - Division of Urology, School of Medicine, Fu-Jen Catholic University, Taipei, 
      Taiwan, Republic of China.
LA  - eng
PT  - Journal Article
DEP - 20180104
PL  - New Zealand
TA  - Onco Targets Ther
JT  - OncoTargets and therapy
JID - 101514322
PMC - PMC5757495
OTO - NOTNLM
OT  - RAD001
OT  - apoptosis
OT  - bladder cancer
OT  - mTOR
OT  - miR-99a-5p
COIS- Disclosure The authors report no conflicts of interest in this work.
EDAT- 2018/01/31 06:00
MHDA- 2018/01/31 06:01
PMCR- 2018/01/04
CRDT- 2018/01/31 06:00
PHST- 2018/01/31 06:00 [entrez]
PHST- 2018/01/31 06:00 [pubmed]
PHST- 2018/01/31 06:01 [medline]
PHST- 2018/01/04 00:00 [pmc-release]
AID - ott-11-239 [pii]
AID - 10.2147/OTT.S114276 [doi]
PST - epublish
SO  - Onco Targets Ther. 2018 Jan 4;11:239-252. doi: 10.2147/OTT.S114276. eCollection 
      2018.