MicroRNA-148b suppresses cell growth by targeting cholecystokinin-2 receptor in colorectal cancer.
MicroRNAs (miRNAs) play an important role in the regulation of a variety of cellular processes, including cell growth, differentiation, apoptosis and carcinogenesis. The purpose of this study was to elucidate the molecular mechanisms by which miR-148b acts as a tumor suppressor in colorectal cancer. The expression of miR-148b was significantly downregulated in 96 pairs of human colorectal cancer tissues (p<0.0001) and three cell lines (p<0.01) compared with non-tumor adjacent tissues by quantitative real-time PCR. The results of in situ hybridization highlighted that miR-148b was important in the cancer transformation process. Using statistical analysis, we found that the expression level of miR-148b was associated with tumor size (p=0.033) in colorectal cancer patients. Moreover, overexpression of miR-148b in HCT-116 and HT-29 cells could inhibit cell proliferation in vitro and suppress tumorigenicity in vivo. Importantly, the result of luciferase activity assay and western blot showed that the cholecystokinin-2 receptor gene (CCK2R) was a target of miR-148b and was downregulated by miR-148b at the translational level. Then, we used siRNA, radioimmunoassay and ELISA to demonstrate that miR-148b might have an effect on cell proliferation by regulating the expression of CCK2R which functioned depending on the gastrin in colorectal cancer. Taken together, our data provides the first evidences that miR-148b acts as a tumor suppressor in colorectal cancer and should be further evaluated as a biomarker and therapeutic tool against colorectal cancer.
Department of Surgical Oncology and General Surgery, First Hospital of China Medical University, Heping District, Shenyang City, China.
Yongxi
Y
Song
Yingying
Y
Xu
Zhenning
Z
Wang
Yue
Y
Chen
Zhenyu
Z
Yue
Peng
P
Gao
Chengzhong
C
Xing
Huimian
H
Xu
D000818:Animals; D015153:Blotting, Western; D049109:Cell Proliferation; D003106:Colon / Q000378:metabolism / Q000473:pathology; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005755:Gastrins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007124:Immunoenzyme Techniques; D017403:In Situ Hybridization; D008156:Luciferases / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D035683:MicroRNAs / Q000235:genetics*; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D011863:Radioimmunoassay; D060888:Real-Time Polymerase Chain Reaction; D043887:Receptor, Cholecystokinin B / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D012007:Rectum / Q000378:metabolism / Q000473:pathology; D020133:Reverse Transcriptase Polymerase Chain Reaction
D005755:Gastrins; C550570:MIRN148 microRNA, human; D035683:MicroRNAs; D011498:Protein Precursors; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D043887:Receptor, Cholecystokinin B; C013706:big gastrin; D008156:Luciferases