RRM
2008 Rustbelt RNA Meeting
RRM
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Poster abstracts
Abstract:
Despite rigorous research in the field of prostate cancer, the molecular mechanisms underlying the critical transition of prostate cancer from androgen-dependent to the fatal androgen-independent stage are poorly understood. Given the important regulatory roles of microRNAs (miRNAs) in carcinogenesis, we asked whether miRNAs are involved in the pathogenesis of androgen-independent prostate cancer. In order to answer this question, we have profiled the expression of 12 miRNAs organized in three clusters (miRNA 17-92 cluster, miRNA 106b-25 cluster and miRNA 23b-24 cluster) in hormone-dependent and hormone-independent prostate cancer cell culture models. About one third of human miRNAs are hosted in the introns of annotated mRNAs. The biological significance of locating miRNAs in the introns of host genes is poorly understood. The prevailing view is that intronic miRNAs are processed from the same primary transcript as their host genes and thus, their expression is regulated by the expression of the host mRNA. However, this hypothesis has not been extensively tested. In this context, we also profiled the expression of the host transcripts – C13orf25, MCM7 and Aminopeptidase O, which harbor the miRNA clusters, 17-92, 106b-25 and 23b-24 respectively. Our data show no significant correlation between the expression profile of the three miRNA clusters and the hormone responsive status of prostate cancer cells. Hence, these miRNAs may not be important for the development of androgen independence. Further, we found no correlation between the expression of host transcript and the expression of its resident miRNAs. This observation raises interesting questions regarding the biogenesis of intronic miRNAs and suggests the possibility of independent transcription and/or posttranscriptional regulation of intronic miRNAs.
Keywords: Prostate cancer, microRNA, host transcripts
