Uptake by human glioma cell lines and biological effects of a peptide-nucleic acids targeting miR-221.

Abstract

MicroRNAs are a family of small noncoding RNAs regulating gene expression by sequence-selective mRNA targeting, leading to a translational repression or mRNA degradation. The oncomiR miR-221 is highly expressed in human gliomas, as confirmed in this study in samples of low and high grade gliomas, as well in the cell lines U251, U373 and T98G. In order to alter the biological functions of miR-221, a peptide nucleic acid targeting miR-221 (R8-PNA-a221) was produced, bearing a oligoarginine peptide (R8) to facilitate uptake by glioma cells. The effects of R8-PNA-a221 were analyzed in U251, U373 and T98G glioma cells and found to strongly inhibit miR-221. In addition, the effects of R8-PNA-a221 on p27(Kip1) (a target of miR-221) were analyzed in U251 and T98G cells by RT-qPCR and by Western blotting. No change of p27(Kip1) mRNA content occurs in U251 cells in the presence of PNA-a221 (lacking the R8 peptide), whereas significant increase of p27(Kip1) mRNA was observed with the R8-PNA-a221. These data were confirmed by Western blot assay. A clear increment of p27(Kip1) protein expression in the samples treated with R8-PNA-a221 was detected. In addition, R8-PNA-a221 was found able to increase TIMP3 expression (another target of miR-221) in T98G cells. These results suggest that PNAs against oncomiRNA miR-221 might be proposed for experimental treatment of human gliomas.

• Authors: Eleonora Brognara, Enrica Fabbri, Elena Bazzoli, Giulia Montagner, Claudio Ghimenton, Albino Eccher, Cinzia Cantù, Alex Manicardi, Nicoletta Bianchi, Alessia Finotti, Giulia Breveglieri, Monica Borgatti, Roberto Corradini, Valentino Bezzerri, Giulio Cabrini, Roberto Gambari
• Journal: Journal of neuro-oncology (J Neurooncol) Vol. 118 Issue 1 Pg. 19-28 (May 2014) ISSN: 1573-7373 [Electronic] United States
• PMID: 24595467 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Annexin A5
• MIRN221 microRNA, human
• MicroRNAs
• Peptide Nucleic Acids
• Cyclin-Dependent Kinase Inhibitor p27

Topics

• Adult
• Analysis of Variance
• Annexin A5 (metabolism)
• Apoptosis (drug effects)
• Brain Neoplasms (genetics, metabolism)
• Cell Line, Tumor
• Cell Proliferation (drug effects)
• Cyclin-Dependent Kinase Inhibitor p27 (pharmacology)
• Dose-Response Relationship, Drug
• Flow Cytometry
• Gene Expression Regulation, Neoplastic (drug effects)
• Glioma (genetics, metabolism)
• Humans
• Male
• MicroRNAs (genetics, metabolism)
• Models, Molecular
• Peptide Nucleic Acids (pharmacology)
• Time Factors