Int J Biol Sci 2011; 7(1):133-137. doi:10.7150/ijbs.7.133

Short Research Communication

MicroRNA-137 Targets Carboxyl-terminal Binding Protein 1 in Melanoma Cell Lines

Yu Deng1,4#, Hui Deng2,3,4#, Feng Bi1, Jing Liu4, Lynn T. Bemis5, David Norris4, Xiao-Jing Wang3, Qinghong Zhang3,4

1. Laboratory of Signal Transduction & Molecular Targeted Therapy, State Key Laboratory of Biotherapy/ Department of Medical Oncology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, 610041, China;
2. Department of Dermatology, The Sixth People's Hospital of Shanghai, Shanghai Jiaotong University, Yishan Road 600, Shanghai, 200211, China;
3. Department of Pathology, University of Colorado, Denver, Aurora, CO 80045, USA;
4. Department of Dermatology, University of Colorado, Denver, Aurora, CO 80045, USA;
5. Department of Medicine, University of Colorado, Denver, Aurora, CO 80045, USA.
# Co-first author

This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY-NC) License. See for full terms and conditions.
Deng Y, Deng H, Bi F, Liu J, Bemis LT, Norris D, Wang XJ, Zhang Q. MicroRNA-137 Targets Carboxyl-terminal Binding Protein 1 in Melanoma Cell Lines. Int J Biol Sci 2011; 7(1):133-137. doi:10.7150/ijbs.7.133. Available from

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Carboxyl-terminal binding protein 1 (CtBP1) is a transcriptional co-repressor that represses expression of various tumor suppressor genes. In the present study, we identified miR-137 as a potential regulator of CtBP1 expression in melanoma cells. Expression of miR-137 in melanoma cell lines was found to inversely correlate with CtBP1 levels. Target Scan predicted a putative site for miR-137 within the CtBP1 3′ untranslated region (3′UTR) at nt 710-716, which is highly conserved across species. To explore the mechanism of miR-137 targeting CtBP1, we performed an Argonaute 2 (Ago2)-pull down assay, and miR-137 was identified in complex with CtBP1 mRNA. miR-137 suppressed CtBP1 3' UTR luciferase-reporter activity, and this effect was lost with deletion of the putative 3' UTR target-site. Consistent with the results of the reporter assay, ectopic expression of miR-137 reduced expression levels of CtBP1. Furthermore, expression of miR-137 increased the immediate downstream effectors of CtBP1, such as E-cadherin and Bax. The human miR-137 gene is located at chromosome 1p22, which has previously been determined to be a susceptive region for melanoma. This study suggests miR-137 may act as a tumor suppressor by directly targeting CtBP1 to inhibit epithelial-mesenchymal transition (EMT) and inducing apoptosis of melanoma cells, thus illustrating a functional link between miR-137 and CtBP1 in melanoma development.

Keywords: CtBP1, miR-137, transcription, tumor suppressor, melanoma