All authors declare that they have no conflict of interest.
miR-106b is overexpressed in medulloblastomas and interacts directly with PTEN
Article first published online: 29 JAN 2015
© 2014 British Neuropathological Society
Neuropathology and Applied Neurobiology
Volume 41, Issue 2, pages 145–164, February 2015
How to Cite
Li, K. K.-W., Xia, T., Ma, F. M. T., Zhang, R., Mao, Y., Wang, Y., Zhou, L., Lau, K.-M. and Ng, H.-K. (2015), miR-106b is overexpressed in medulloblastomas and interacts directly with PTEN. Neuropathology and Applied Neurobiology, 41: 145–164. doi: 10.1111/nan.12169
- Issue published online: 29 JAN 2015
- Article first published online: 29 JAN 2015
- Accepted manuscript online: 8 JUL 2014 02:27AM EST
- Manuscript Accepted: 25 JUN 2014
- Manuscript Received: 1 JAN 2014
MicroRNAs (miRNAs) are an abundant group of small non-coding RNAs that have been implicated in tumorigenesis. They regulate expression of target genes by complementary base pairing. The purposes of this study were to delineate miR-106b expression in medulloblastoma (MB) and to explore its functional contributions to MB pathogenesis.
We analysed expression of miR-106b in 32 MB samples by quantitative RT-PCR. We applied gain- and loss-of-function strategies to delineate the functional roles of miR-106b in MB. Luciferase reporter assay was conducted to confirm target gene of miR-106b.
Expression of miR-106b was overexpressed in MB, and was significantly associated with its host gene MCM7 (P = 0.020). Transfection of miR-106b inhibitor in MB cell lines markedly reduced cell proliferation, migration and invasion potential, and tumour sphere formation. Cell cycle analysis indicated that miR-106b inhibition induced G1 arrest and apoptosis. The cell cycle regulators, p21 and cyclin D1, and apoptotic marker cleaved PARP were differentially expressed in miR-106b inhibitor-transfected cells. PTEN was identified as a direct target gene of miR-106b. Luciferase reporter assay confirmed miR-106b directly interacted with the 3′ UTR of PTEN. We found miR-106b directly targeted PTEN at transcriptional and translational levels. Immunohistochemistry revealed a trend between PTEN and miR-106b in MB tumours (P = 0.07).
These data suggested the upregulation of miR-106b in MB and the involvement of miR-106b in MB biology.