MiRNAs are small, noncoding RNA molecules that act as posttranscriptional regulators of gene expression and function as important regulators in cancer-related processes. The miR-19a is overexpressed in various cancers and has been causally related to cellular proliferation and growth. To determine whether miR-19a plays a role in laryngeal squamous cell carcinoma (LSCC), we used quantitative real time PCR to detect miR-19a expression in LSCC tissues. We found that miR-19a is overexpressed in LSCC and correlated with neck nodal metastasis, poor differentiation and advanced stage. Statistical analysis suggests that higher level of miR-19a was associated with reduced overall survival. In vitro functional study showed that inhibition of miR-19a by antisense oligonucleotides (ASO) led to apoptosis and reduction of cell proliferation in LSCC cells. Furthermore, growth of LSCC xenograft tumors was significantly suppressed by repeated injection of ASO-miR-19a lentivirus. The TUNEL stain and transmission electron microscopy also detected increased apoptotic cells in ASO-miR-19a treated LSCC xenografts. In addition, both realtime PCR and western blot showed ASO-miR-19a can upregulate TIMP-2 expression and this suggests miR-19a is related with TIMP-2 pathway in LSCC cells. Taken together, these data suggest that miR-19a plays an oncogenic role in the progression of LSCC, and may serve as a biomarker or therapeutic target for patients with LSCC.
Keywords: LSCC; TIMP-2; apoptosis; miR-19a.