RESUMO
MicroRNAs (miRNAs) are small noncoding RNA molecules that negatively modulate gene expression at the post-transcriptional level. A growing number of studies has shown that more and more miRNAs are aberrantly expressed and involved in the pathogenesis of several types of cancers. Here, we report that the down-regulated hsa-miR-34c was also involved in oncogenesis of laryngeal carcinoma. Our studies indicated that hsa-miR-34c functioned as a tumor suppressor which inhibited growth and invasion of human laryngeal carcinoma cells. Furthermore, in our study, an inverse relationship between the expression of hsa-miR-34c and c-Met was identified in 10 paired fresh samples from tumor tissues and adjacent normal tissues. Infection of hsa-miR-34c mediated by lentivirus suppressed the expression of c-Met directly. In addition, introduction of c-Met cDNA lacking 3'-UTR largely abrogated hsa-miR-34c-induced cell growth and invasion inhibition. These findings suggest aberrantly down-regulated hsa-miR-34c is a critical factor that contributes to malignancy in human laryngeal carcinoma by a mechanism involving targeting of c-Met.
