Summary
This study investigated the effect of etoposide, an anticancer chemotherapy drug, on B7-H1 expression in retinoblastoma (Rb) cells and the role of miR-513a-5p in the process. Rb cells were divided into control and etoposide groups. In the etoposide group, cells were treated with etoposide at different concentrations (2.5, 5, 10, 20 and 40 μg/mL) for 24 h. Those given no treatment of etopside served as controls. Reverse transcription polymerase chain reaction (RT-PCR), fluorescence quantitative PCR and flow cytometry were performed to measure the mRNA and protein expression of B7-H1 in Rb cells. The mRNA expression of miR-513a-5p in Rb cells before and after etoposide treatment was also detected by fluorescence quantitative PCR. The miR-513a-5p mimics and the miR-513a-5p inhibitor were transfected into Rb cells separately, and fluorescence quantitative PCR and flow cytometry were used to detect the effect of the miR-513a-5p mimics or inhibitor on B7-H1 expression. TargetScan5.2 was employed to predict the miR-513a-5p binding sites in the 3′-untranslated region of B7-H1 mRNA. Luciferase reporter plasmids carrying this site were prepared and transfected into Rb cells and luciferase activity analyzed. The results showed that etoposide stimulated the mRNA and protein expression of B7-H1 in Rb cells, which reached a maximal level after treatment with 5 μg/mL etoposide (P<0.05). However, miR-513a-5p expression was decreased in Rb cells after etoposide treatment. When the miR-513a-5p inhibitor was added, B7-H1 expression was increased with the concentration of the miR-513a-5p inhibitor (P<0.05). Moreover, B7-H1 expression was decreased gradually with the concentration of the miR-513a-5p mimics increased (P<0.01). Additionally, the miR-513a-5p mimics were found to inhibit the luciferase activity. It was concluded that etoposide can promote B7-H1 expression in Rb cells, which may be associated with chemoresistance. The promoting effect of etoposide on B7-H1 expression can be reversed by miR-513a-5p mimics. MiR-513a-5p inhibits the mRNA and protein expression of B7-H1 via binding to the 3′-UTR of B7-H1 mRNA.
Similar content being viewed by others
References
Aerts I, Lumbroso-Le Rouic L, Gauthier-Villars M, et al. Retinoblastoma. Orphanet J Rare Dis, 2006,1(9):31
Smyth MJ, Godfrey DI, Trapani JA. A fresh look at tumor immunosurveillance and immunotherapy. Nat Immunol, 2001,2(4):293–299
Khong HT, Restifo NP. Natural selection of tumor variants in the generation of “tumor escape” phenotypes. Nat Immunol, 2002,3(11):999–1005
Dunn GP, Bruce AT, Ikeda H, et al. Cancer immunoediting: from immunosurveillance to tumor escape. Nat Immunol, 2002,3(11):991–998
Dong H, Chen L. B7-H1 pathway and its role in the evasion of tumor immunity. J Mol Med (Berl), 2003,81(5): 281–287
Hwang HW, Mendell JT. MicroRNAs in cell proliferation, cell death, and tumorigenesis. Br J Cancer, 2006,94(6): 776–780
Metzler M, Wilda M, Busch K, et al. High expression of precursor microRNA-155/BIC RNA in children with Burkitt lymphoma. Genes Chromosomes Cancer, 2004,39(2):167–169
Calin GA, Ferracin M, Cimmino A, et al. A microRNA signature associated with prognosis and progression in chronic lymphocytic leukemia. N Engl J Med, 2005,353(17):1793–1801
Bartel DP. MicroRNAs: genomics, biogenesis, mechanism, and function. Cell, 2004, 116(2):281–297
Gong AY, Zhou R, Hu G, et al. MicroRNA-513 regulates B7-H1 translation and is involved in IFN-gamma-induced B7-H1 expression in cholangiocytes. J Immunol, 2009,182(3):1325–1333
Muhlbauer M, Fleck M, Schutz C, et al. PD-L1 is induced in hepatocytes by viral infection and by interferon-alpha and -gamma and mediates T cell apoptosis. J Hepatol, 2006,45(4):520–528
Curiel TJ, Wei S, Dong H, et al. Blockade of B7-H1 improves myeloid dendritic cell-mediated antitumor immunity. Nat Med, 2003,9(5):562–567
Azuma T, Yao S, Zhu G, et al. B7-H1 is a ubiquitous antiapoptotic receptor on cancer cells. Blood, 2008,111(7): 3635–3643
Usui Y, Okunuki Y, Hattori T, et al. Expression of costimulatory molecules on human retinoblastoma cells Y-79: functional expression of CD40 and B7H1. Invest Ophthalmol Vis Sci, 2006,47(10):4607–4613
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Wu, L., Chen, Z., Zhang, J. et al. Effect of miR-513a-5p on etoposide-stimulating B7-H1 expression in retinoblastoma cells. J. Huazhong Univ. Sci. Technol. [Med. Sci.] 32, 601–606 (2012). https://doi.org/10.1007/s11596-012-1004-8
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11596-012-1004-8