Targeting of YAP1 by microRNA-15a and microRNA-16-1 exerts tumor suppressor function in gastric adenocarcinoma.
BACKGROUND
MicroRNAs (miRNAs) have been reported to play an important role in tumorigenesis. In this study, the role of miR-15a and miR-16-1 in gastric adenocarcinoma (GAC) was investigated.


METHODS
The expression of miR-15a and miR-16-1 in cell lines and primary tumors was examined by miRNA qRT-PCR. Proliferative assays, colony formation, cell invasion and migration, flow cytometry analysis and in vivo study were performed by ectopic expression of miR-15a and miR-16-1. The putative target genes of miR-15a and miR-16-1 were explored by TargetScan and further validated.


RESULTS
We found that miR-15a and miR-16-1 were down-regulated in GAC cell lines and primary tumor samples compared with normal gastric epithelium. Functional study demonstrated that ectopic expression of miR-15a and miR-16-1 suppressed cell proliferation, monolayer colony formation, invasion and migration, and xenograft formation in vivo. In addition, miR-15a and miR-16-1 induced G0/G1 cell cycle arrest which was further confirmed by Western blot and qRT-PCR of related cell cycle regulators. YAP1 was confirmed to be a functional target of miR-15a and miR-16-1 in GAC. YAP1 re-expression partly abrogated the inhibitory effect of miR-15a and miR-16-1 in GAC cells. In clinical samples, YAP1 protein expression shows negative correlation with miR-15a and miR-16-1 expression.


CONCLUSIONS
In conclusion, targeting YAP1 by tumor suppressor miRNA miR-15a and miR-16-1 plays inhibitory effect and this might have a therapeutic potential in GAC.
Department of Anatomical and Cellular Pathology, State Key Laboratory of Oncology in South China, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, SAR, PR China. weikang@cuhk.edu.hk.|Institute of Digestive Disease, Partner State Key Laboratory of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, SAR, PR China. weikang@cuhk.edu.hk.|Li Ka Shing Institute of Health Science, Sir Y.K. Pao Cancer Center, The Chinese University of Hong Kong, Hong Kong, SAR, PR China. weikang@cuhk.edu.hk.|Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, PR China. weikang@cuhk.edu.hk.
Wei
W
Kang
Department of Anatomical and Cellular Pathology, State Key Laboratory of Oncology in South China, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, SAR, PR China. jtong@cuhk.edu.hk.|Institute of Digestive Disease, Partner State Key Laboratory of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, SAR, PR China. jtong@cuhk.edu.hk.|Li Ka Shing Institute of Health Science, Sir Y.K. Pao Cancer Center, The Chinese University of Hong Kong, Hong Kong, SAR, PR China. jtong@cuhk.edu.hk.
Joanna H M
JH
Tong
Department of Anatomical and Cellular Pathology, State Key Laboratory of Oncology in South China, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, SAR, PR China. Raymond_lung@cuhk.edu.hk.|Li Ka Shing Institute of Health Science, Sir Y.K. Pao Cancer Center, The Chinese University of Hong Kong, Hong Kong, SAR, PR China. Raymond_lung@cuhk.edu.hk.
Raymond W M
RW
Lung
Institute of Digestive Disease, Partner State Key Laboratory of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, SAR, PR China. celia.yj.dong@gmail.com.
Yujuan
Y
Dong
Institute of Digestive Disease, Partner State Key Laboratory of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, SAR, PR China. zhaojh_gz@163.com.
Junhong
J
Zhao
Institute of Digestive Disease, Partner State Key Laboratory of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, SAR, PR China. JessieQY@cuhk.edu.hk.
Qiaoyi
Q
Liang
Department of Anatomical and Cellular Pathology, State Key Laboratory of Oncology in South China, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, SAR, PR China. yblhzl@hotmail.com.|Li Ka Shing Institute of Health Science, Sir Y.K. Pao Cancer Center, The Chinese University of Hong Kong, Hong Kong, SAR, PR China. yblhzl@hotmail.com.
Li
L
Zhang
Department of Anatomical and Cellular Pathology, State Key Laboratory of Oncology in South China, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, SAR, PR China. panyi@cuhk.edu.hk.|Institute of Digestive Disease, Partner State Key Laboratory of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, SAR, PR China. panyi@cuhk.edu.hk.|Li Ka Shing Institute of Health Science, Sir Y.K. Pao Cancer Center, The Chinese University of Hong Kong, Hong Kong, SAR, PR China. panyi@cuhk.edu.hk.
Yi
Y
Pan
School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, PR China. weiqinyang1021@cuhk.edu.hk.
Weiqin
W
Yang
Department of Anatomical and Cellular Pathology, State Key Laboratory of Oncology in South China, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, SAR, PR China. jessepang@cuhk.edu.hk.|Li Ka Shing Institute of Health Science, Sir Y.K. Pao Cancer Center, The Chinese University of Hong Kong, Hong Kong, SAR, PR China. jessepang@cuhk.edu.hk.
Jesse C S
JC
Pang
Institute of Digestive Disease, Partner State Key Laboratory of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, SAR, PR China. alfredcheng@cuhk.edu.hk.|Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, PR China. alfredcheng@cuhk.edu.hk.|School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, PR China. alfredcheng@cuhk.edu.hk.
Alfred S L
AS
Cheng
Institute of Digestive Disease, Partner State Key Laboratory of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, SAR, PR China. junyu@cuhk.edu.hk.|Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, PR China. junyu@cuhk.edu.hk.|Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong, PR China. junyu@cuhk.edu.hk.
Jun
J
Yu
Department of Anatomical and Cellular Pathology, State Key Laboratory of Oncology in South China, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, SAR, PR China. kfto@cuhk.edu.hk.|Institute of Digestive Disease, Partner State Key Laboratory of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, SAR, PR China. kfto@cuhk.edu.hk.|Li Ka Shing Institute of Health Science, Sir Y.K. Pao Cancer Center, The Chinese University of Hong Kong, Hong Kong, SAR, PR China. kfto@cuhk.edu.hk.|Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, PR China. kfto@cuhk.edu.hk.
Ka Fai
KF
To
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics*; D000230:Adenocarcinoma / Q000235:genetics*; D000818:Animals; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics; D049109:Cell Proliferation / Q000235:genetics; D015536:Down-Regulation / Q000235:genetics; D059585:G1 Phase Cell Cycle Checkpoints / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D016147:Genes, Tumor Suppressor / Q000502:physiology*; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D035683:MicroRNAs / Q000235:genetics*; D010750:Phosphoproteins / Q000235:genetics*; D016192:Resting Phase, Cell Cycle / Q000235:genetics; D013274:Stomach Neoplasms / Q000235:genetics*; D014157:Transcription Factors; D000091102:YAP-Signaling Proteins
D048868:Adaptor Proteins, Signal Transducing; C505361:MIRN15 microRNA, human; C505362:MIRN16 microRNA, human; D035683:MicroRNAs; D010750:Phosphoproteins; D014157:Transcription Factors; D000091102:YAP-Signaling Proteins; C088374:YAP1 protein, human