OBJECTIVETo establish DNA microarrays-based microRNA (miRNA) expression profiles of squamous cell carcinoma of larynx, using archived formalin-fixed paraffin-embedded tissue blocks, and to screen out and identify the differentially expressed miRNAs associated with the biological characteristics of this malignant disease.

METHODSTotal RNA was prepared from the formalin-fixed paraffin-embedded tissue blocks. After quality identification and fluorescent labeling, the RNA samples were hybridized with the Agilent human miRNA microarrays which contains 723 probes for human miRNAs. The data was processed with the softwares GeneSpring GX and R-Project.

RESULTSFrom the formalin-fixed paraffin-embedded tumor blocks collected, 24 RNA samples were obtained with the quality accorded to the requirement of miRNA microarray analysis, and both the hybridization and consequent data processing were accomplished. A total of 319 miRNAs were identified and among them 96 were detected in all the 24 formalin-fixed paraffin-embedded blocks of laryngeal carcinoma; and 5 differentially expressed miRNAs (false discovery rate < 0.05) were found to be associated significantly with the lymphatic metastasis of laryngeal squamous cell carcinoma (P < 0.05), including miR-23a(*), miR-28-5p, miR-15a, miR-16 and miR-425.

CONCLUSIONSHistopathological archives of well-annotated formalin-fixed paraffin-embedded tissue specimens are the valuable resources for miRNA study including to collect RNA samples for miRNA microarray analysis. A panel of differentially expressed miRNAs (miR-23a(*), miR-28-5p, miR-15a, miR-16 and miR-425) derived from the miRNA expression profile may serve as the potential molecular biomarkers for the prediction of metastasis development in laryngeal squamous cell carcinoma.