Microarray-based analysis: Identification of hypoxia-regulated microRNAs in retinoblastoma cells

  • Authors:
    • Xiaofang Xu
    • Renbing Jia
    • Yixiong Zhou
    • Xin Song
    • Jing Wang
    • Guanxiang Qian
    • Shengfang Ge
    • Xianqun Fan
  • Corresponding author:
  • View Affiliations

  • Published online on: Thursday, March 3, 2011
  • Pages: 1385-1393 DOI: 10.3892/ijo.2011.961

Abstract

Hypoxia is an essential feature of retinoblastoma and contributes to poor prognosis and resistance to conventional therapy. MicroRNAs (miRNAs) are small non-coding RNAs involved in a wide variety of biological processes, including cell differentiation, proliferation, death and metabolism. However, the relationship between hypoxia and the expression of miRNAs in retinoblastoma is not well understood. In this study, we aimed to analyze the pattern of miRNA expression in a retinoblastoma cell line under hypoxic conditions and to identify the miRNAs regulated by hypoxia, as well as their possible functions. miRNA expression profiling in retinoblastoma cells (HXO-RB44) under normal and hypoxic conditions was assessed by microarray techniques. The differentially expressed miRNAs were subjected to bioinformatic analyses to predict and categorise the key miRNAs and their target genes. A quantitative real-time RT-PCR approach was used to validate their expression. A Cell Counting kit was used to evaluate the functional significance of miR-181b in RB cell proliferation. There were 46 miRNAs that changed expression more than 2-fold in response to hypoxia (34 up-regulated and 12 down-regulated). We identified a cluster of miRNAs that includes miR-181b, miR-125a-3p, miR-30c-2, miR-497 and miR-491-3p as hypoxia-regulated miRNAs (HRMs) in retinoblastoma cells, of which miR-181b was the most typically differentially expressed miRNA under hypoxic conditions. Functionally, these HRMs are involved in apoptosis, cell adhesion, cell proliferation and mRNA processing, all processes that associate closely with the hypoxia response of cancer cells. Additionally, we found that administration of miR-181b inhibitor can suppress proliferation of retinoblastoma cells. These findings provide the first evidence that miRNAs play an important role in the hypoxia response of retinoblastoma cells. MiR-181b, the most typically up-regulated miRNA may aid in future clinical intervention of retinoblastoma.
Journal Cover

May 2011
Volume 38 Issue 5

Print ISSN: 1019-6439
Online ISSN:1791-2423

2013 Impact Factor: 2.773
2014 I.F. (Expected) ≥ 3.310 Ranked #30/202 Oncology
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APA
Xu, X., Jia, R., Zhou, Y., Song, X., Wang, J., Qian, G. ... Fan, X. (2011). Microarray-based analysis: Identification of hypoxia-regulated microRNAs in retinoblastoma cells. International Journal of Oncology, 38, 1385-1393. http://dx.doi.org/10.3892/ijo.2011.961
MLA
Xu, X., Jia, R., Zhou, Y., Song, X., Wang, J., Qian, G., Ge, S., Fan, X."Microarray-based analysis: Identification of hypoxia-regulated microRNAs in retinoblastoma cells". International Journal of Oncology 38.5 (2011): 1385-1393.
Chicago
Xu, X., Jia, R., Zhou, Y., Song, X., Wang, J., Qian, G., Ge, S., Fan, X."Microarray-based analysis: Identification of hypoxia-regulated microRNAs in retinoblastoma cells". International Journal of Oncology 38, no. 5 (2011): 1385-1393. http://dx.doi.org/10.3892/ijo.2011.961