Abstract
Glioblastoma is the most aggressive and invasive brain tumor and has a poor prognosis; elucidating the underlying molecular mechanisms is essential to select molecular targeted therapies. Here, we investigated the effect of microRNAs on the marked invasiveness of glioblastoma. U373 glioblastoma cells were infected with 140 different microRNAs from an OncomiR library, and the effects of the invasion-related microRNAs and targeted molecules were investigated after repeated Matrigel invasion assays. Screening of the OncomiR library identified miR-23a as a key regulator of glioblastoma invasion. In six glioblastoma cell lines, a positive correlation was detected between the expression levels of miR-23a and invasiveness. A luciferase reporter assay demonstrated that homeobox D10 (HOXD10) was a miR-23a-target molecule, which was verified by high scores from both the PicTar and miRanda algorithms. Forced expression of miR-23a induced expression of invasion-related molecules, including uPAR, RhoA, and RhoC, and altered expression of glial-mesenchymal transition markers such as Snail, Slug, MMP2, MMP9, MMP14, and E-cadherin; however, these changes in expression levels were reversed by HOXD10 overexpression. Thus, miR-23a significantly promoted invasion of glioblastoma cells with polarized formation of focal adhesions, while exogenous HOXD10 overexpression reversed these phenomena. Here, we identify miR-23a-regulated HOXD10 as a pivotal regulator of invasion in glioblastoma, providing a novel mechanism for the aggressive invasiveness of this tumor and providing insight into potential therapeutic targets.
Highlights
Glioblastoma (GBM) is the most invasive and aggressive primary brain tumor and has a poor prognosis, showing a 5-year survival rate of 7%
More than 140 gene mutations have been reported in GBM, most frequently in EGFR, TP53, PTEN, PIK3CA, PIK3R1, PDGFRA, ATRX, IDH1, RB1, LZTR1, and PTPN11, while TMZ-dependent hypermutations are highly expressed in recurrent tumors.[4,5,6]
To identify microRNAs that confer aggressive invasion in GBM cells, an OncoMir Precursor Virus Library including 140 cancer-related oncomiRs was infected into U373 cells with low intrinsic invasion capabilities
Summary
Glioblastoma (GBM) is the most invasive and aggressive primary brain tumor and has a poor prognosis, showing a 5-year survival rate of 7%. RNA was isolated from cells with been reported.[27] Among these miRNAs, miR-10b, which regulates elevated invasion ability, and semi quantitative RT-PCR using the homeobox D10 (HOXD10), and miR-21, which targets RECK, are OncoMir Precursor Library primers (System Bioscience) and important in facilitating glioblastoma invasion.[28,29] sequencing were performed to identify the infected oncomiRs. miR-23a has been reported to regulate several physiological phenomena by targeting MURF1, MAFbx, and GLS, leading to promotion of cardiac hypertrophy, inhibition of muscular atrophy, and suppression of glutamine metabolism, respectively.[30] In. Matrigel invasion assay A Matrigel invasion assay was performed as described previously[33] using a BioCoat Matrigel invasion chamber (24-well chambers) addition, dysregulated expression of miR-23a has been reported with 8-μm pores (BD Biosciences, MA). Formation of focal adhesions, resulting in profound tumor invasion These findings suggest that miR-23a and HOXD10 are potentially powerful therapeutic targets for GBM treatment. The HOXD10-3′UTR was cloned into the region downstream of the Firefly luciferase gene in a pGL3-
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
