Vector-Based let-7a miRNAs Function as Suppressors of Multiple Oncogenes in SK-N-MC and SHEP Neuroblastoma Cells
|Guan J1,2*, Guo S3, Zeng X2, Luo Y2, Yang T2 and Cao J2|
|1Department of Scientific Research, Peking Union Medical College (PUMC) Hospital, Beijing|
|2Department of Pathology, Peking Union Medical College (PUMC) Hospital, Beijing|
|3Human and Health Scientific Data Sharing Platform, Clinical Center, Peking Union Medical College (PUMC) Hospital, Beijing|
|Corresponding Author :||Guan J
Department of Scientific Research
Department of Pathology, PUMC Hospital
CAMS/PUMC, No.1, Shuaifuyuan Street, Dongcheng
District, Beijing 100730 China
E-mail: [email protected]
|Received: September 30, 2015; Accepted: January 19, 2015; Published: January 22, 2015|
|Citation: Guan J, Guo S, Zeng X, Luo Y, Yang T, et al. (2016) Vector-Based let-7a miRNAs Function as Suppressors of Multiple Oncogenes in SK-N-MC and SHEP Neuroblastoma Cells. J Carcinog Mutagene 7:248. doi:10.4172/2157-2518.1000248|
|Copyright: © 2015, Guan J. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.|
|Related article at Pubmed, Scholar Google|
Objective: This study was designed to determine the anti-tumor effect of vector-based let-7a miRNA in neuroblastoma cell lines.
Methods: A tetracycline (tet)-inducible let-7a expression vector was constructed and used to stably transfect SKN- MC and SHEP neuroblastoma cells. The effects of let-7a overexpression induced by tetracycline on cell proliferation and adhesion were analyzed in vitro by MTT assays and adhesion assays. The mRNA expression of the let-7 target oncogenes NRAS, KRAS, c-myc, and HMGA2 was examined by quantitative real-time reverse transcription polymerase chain reaction. Protein expression of N-RAS, K-RAS, c-Myc, HMGA2, NeuN, and β3- tubulin was analyzed using western blot and immunocytochemistry. Morphology of SK-N-MC and SHEP cells was also observed. Additionally, the let-7a-inducible vector-transfected SHEP cells were subcutaneously injected in nude mice, and tumor growth in vivo was also evaluated.
Results: Let-7a expression was significantly induced in neuroblastoma cells and inhibited cell proliferation and adhesion in both SK-N-MC and SHEP cells. Let-7a up-regulated β3-tubulin and NeuN expression in SK-N-MC and SHEP cells. However, short neurite-like outgrowth was observed only in SK-N-MC cells, but not in SHEP cells. Let-7a overexpression decreased the expression of N-RAS and HMGA2 proteins in both SK-N-MC and SHEP cells. c-Myc expression also decreased in SK-N-MC cells. The tumor sizes of SHEP xenografts in the tet-inducible group were smaller than those in the mice without tetracycline induction.
Conclusion: Taken together, our data demonstrate the anti-tumor effects of vector-based let-7a miRNA overexpression in SK-N-MC and SHEP neuroblastoma cells against multioncogenes. Let-7a miRNA is a potential therapeutic molecule for the treatment of neuroblastoma.