Targeting the SMO oncogene by miR-326 inhibits glioma biological behaviors and stemness.
Neuro Oncol
; 17(2): 243-53, 2015 Feb.
Article
in En
| MEDLINE
| ID: mdl-25173582
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 U251 tumor 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.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Neoplastic Stem Cells
/
Brain Neoplasms
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Glioblastoma
/
MicroRNAs
/
Receptors, G-Protein-Coupled
Limits:
Animals
/
Humans
Language:
En
Journal:
Neuro Oncol
Journal subject:
NEOPLASIAS
/
NEUROLOGIA
Year:
2015
Document type:
Article