MicroRNA-33b inhibits tumor cell growth and is associated with prognosis in colorectal cancer patients.
OBJECTIVE
To explore the role of miR-33b in colorectal cancer (CRC) and the correlation between its expression and prognosis.


METHODS
The expressions of miR-33b between CRC tissues and normal tissues were measured by real-time PCR. The effects of miR-33b on cell proliferation and cell cycle progression were detected by MTT assay, colony formation assay and flow cytometry. The potential regulations of miR-33b on multiple genes expression were verified by Western blot. Furthermore, the association of miR-33b with CRC clinicopathologic features and prognosis was analyzed by Chi-squared test and Kaplan-Meier tests.


RESULTS
MiR-33b was downregulated in CRC compared with normal colorectal samples and miR-33b inhibited tumor cell growth and induced cell cycle arrest. Western blot assays and correlation analysis showed that miR-33b could regulate multiple growth-related genes. Moreover, the expression of miR-33b was associated with TNM stage and tumor size, and CRC patients with high miR-33b expression had a better prognosis.


CONCLUSIONS
Our data suggest that miR-33b functions as a tumor suppressor gene in CRC through regulating cell proliferation and cell cycle.
Department of General Surgery, Jinshan Hospital, Fudan University, No. 1508, Longhang Road, Shanghai, 201508, People's Republic of China.
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W
Liao
Department of General Surgery, Jinshan Hospital, Fudan University, No. 1508, Longhang Road, Shanghai, 201508, People's Republic of China.
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C
Gu
Department of General Surgery, Jinshan Hospital, Fudan University, No. 1508, Longhang Road, Shanghai, 201508, People's Republic of China.
A
A
Huang
Department of General Surgery, Jinshan Hospital, Fudan University, No. 1508, Longhang Road, Shanghai, 201508, People's Republic of China.
J
J
Yao
Department of General Surgery, Jinshan Hospital, Fudan University, No. 1508, Longhang Road, Shanghai, 201508, People's Republic of China. sunrongxun189@126.com.
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R
Sun
D000368:Aged; D000818:Animals; D017209:Apoptosis; D015153:Blotting, Western; D002453:Cell Cycle; D049109:Cell Proliferation; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology / Q000517:prevention & control*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D035683:MicroRNAs / Q000235:genetics*; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011379:Prognosis; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015996:Survival Rate; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays
C550416:MIRN33a microRNA, human; D035683:MicroRNAs; D012333:RNA, Messenger
Cell cycle; Colorectal cancer; Prognosis; miR-33b