Beschreibung:
<jats:title>Abstract</jats:title>
<jats:p>MicroRNAs (miRNAs) are large tiny regulatory RNAs found ubiquitously in plants, insects and mammals. More recently, miRNAs have also been implicated in oncogenesis, acting as tumor suppressors or oncogenes. The role of miRNAs in glioma progression has been intensively investigated chiefly in glioblastomas, the most prevalent malignant glioma. However, there are few data regarding to miRNA expression in oligodendrogliomas. The main goal of this study was to evaluate miRNAs and mRNAs that are differentially expressed in a series of grade II and III oligodendrogliomas (7 per group, with duplicates) in order to obtain miRNAs that correlate with their putative target-mRNAs. After microdissection and diagnosis confirmation, miRNAs and mRNAs expression were evaluate using microarray-based expression profiling platforms (723 transcripts and 41,000 genes, respectively) at same tumor specimens. As controls, samples of temporal lobe white matter from patients operated for clinical intractable complex partial seizures were used (n = 16). Fifteen and 29 miRNAs transcripts were relatively hyper- and hypoexpressed in anaplastic oligodendrogliomas; however, after matching of miRNAs and putative target-mRNAs expressions, only 4 miRNAs transcripts remained overexpressed in which target genes have pivotal role in key cell signaling pathways. Similarly, 20 of 29 miRNAs transcripts remained down regulated. Of these, 4 miRNAs that were previously described as to be involved in cell differentiation in embryonic stem cells (ESC) are being validated through their target genes by real time PCR. Herein, we were able to identify putative oncogenic miRNAs that can be operating in oligodendrogliomas progression, expanding our knowledge about tumor biology and disclosing possible molecular targets for treatment proposals.</jats:p>
<jats:p>Support: FAPESP (Grant Proc. No. 05972–2)</jats:p>
<jats:p>Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-349. doi:10.1158/1538-7445.AM2011-LB-349</jats:p>