Targeting the SMO oncogene by miR-326 inhibits glioma biological behaviors and stemness. Issue 2 (25th August 2014)

• Record Type: Journal Article
• Authors: Du, Wenzhong; Liu, Xing; Chen, Lingchao; Dou, Zhijin; Lei, Xuhui; Chang, Liang; Cai, Jinquan; Cui, Yuqiong; Yang, Dongbo; Sun, Ying; Li, Yongli; Jiang, Chuanlu
• Is Part Of: Neuro-oncology. Volume 17:Issue 2(2015:Feb.)
• Page Start: 243
• Page End: 253
• Publication Date: 2014-08-25
• Subjects: glioma -- hedgehog -- miRNA -- SMO -- stemness; Brain Neoplasms -- Periodicals; Brain -- Tumors -- Periodicals; Brain -- Cancer -- Periodicals; Nervous system -- Cancer -- Periodicals; 616.99481
• DOI: 10.1093/neuonc/nou217
• Languages: English
• ISSNs: 1522-8517

Abstract

Abstract: Background: Few studies have associated microRNAs (miRNAs) with the hedgehog (Hh) pathway. Here, we investigated whether targeting smoothened (SMO) with miR-326 would affect glioma biological behavior and stemness. Methods: To investigate the expression of SMO and miR-326 in glioma specimens and cell lines, we utilized quantitative real-time (qRT)-PCR, Western blot, immunohistochemistry, and fluorescence in situ hybridization. The luciferase reporter assay was used to verify the relationship between SMO and miR-326. We performed cell counting kit-8, transwell, and flow cytometric assays using annexin-V labeling to detect changes after transfection with siRNA against SMO or miR-326. qRT-PCR assays, neurosphere formation, and immunofluorescence were utilized to detect the modification of self-renewal and stemness in U251tumor stem cells. A U251-implanted intracranial model was used to study the effect of miR-326 on tumor volume and SMO suppression efficacy. Results: SMO was upregulated in gliomas and was associated with tumor grade and survival period. SMO inhibition suppressed the biological behaviors of glioma cells. SMO expression was inversely correlated with miR-326 and was identified as a novel direct target of miR-326. miR-326 overexpression not only repressed SMO and downstream genes but also decreased the activity of the Hh pathway. Moreover, miR-326 overexpression decreased self-renewal and stemness and partially prompted differentiation in U251 tumor stem cells. In turn, the inhibition of Hh partially elevated miR-326 expression. Intracranial tumorigenicity induced by the transfection of miR-326 was reduced and was partially mediated by the decreased SMO expression. Conclusions: This work suggests a possible molecular mechanism of the miR- 326/SMO axis, which can be a potential alternative therapeutic pathway for gliomas.