Study On The Differential Expression Of MicroRNAs Between Squammous Cell Carcinomas Of Larynx And The Adjacent Normal Tissues

Study on the differential expression of microRNAs between squammous cell carcinomas of larynx and the adjacent normal tissuesObjective The early diagnosis of laryngeal squamous cell carcinomas and early detection of the recurrence are very important in the treatment of laryngeal carcinomas. Unfortunately, our recognization of the related molecular mechanism and biomolecular signature of laryngeal carcinomas is still limited. The study of miRNA expression profiles in the laryngeal squamous cell carcinomas and screening for altered miRNAs between laryngeal squamous cell carcinomas and adjacent normal tissues by miRNA microarry will play a foundation for realizing the bimolecular mechanism of carcinogeneisis and development of laryngeal carcinomas and exploring related biomolecular markers.Methods Total RNA was isolated from 8 primary fresh-frozen samples of laryngeal squamous cell carcinomas and their matched adjacent normal tissues by Trizol method. The quality of extracted total RNA was determined by Agilent 2100 Bioanalyzer to ensure the successflul microarry hybridization. Then the total RNA samples were labelized with Cyanine3-pCp by Agilent miRNA Complete Labeling and Hyb Kit(P/N 5190-0456) and hybridized with human 723 miRNA microarrays(Human miRNA Microarray version 2 Kit, P/N G4470B). The hybridized microarrays were washed and scanned with Agilent microarray scanner. The data in the microarrays was extracted with Feature Extraction software. The significant differential expression miRNAs between laryngeal carcinomas and adjacent normal tissues were determined by t-test(P < 0.05 and Fold Change > 2) using GeneSpring software. The Putative target genes of the differential expression miRNAs were predicted by TargetScans, Pictar, Miranda and Mirtarget2 methods.Results 132 miRNAs were detected in all the 8 samples of laryngeal carcinoma. Fifty-three miRNAs were determined to be significantly regulated in the squamous cell carcinoma when compared with their normal tissue counterparts. Twenty-two miRNAs were upregulated in squamous cell carcinomas of larynx and thirty-one miRNAs were downregulated. Eight miRNAs including miR-196b, miR-196a, miR-375, miR-139-5p, miR-7, miR-338-3p, miR-183 and miR-370 were found to be more than five fold alterations, three of which were more than eight fold alterations including miR-196b, miR-196a and miR-375.Conclusions Microarray technique is an effective high-flux mthod to detecting differential miRNA expression in squamous cell carcinomas of larynx. Fifty-three miRNAs differed significantly between laryngeal sqamous cell carcinomas and the adjacent normal tissues by preliminary miRNA microarray analysis, eight of which showed more significant alterations and may be potential molecular signatures for the squamous cell carcinomas of larynx. Predicting the putative target genes of the miRNAs with bioinformatic softwares may play a foundation for further studies exploring the bimolecular mechanism of carcinogeneisis and development of laryngeal carcinomas and searching for related biomolecular markers of diagnosis and treatment in the squamous cell carcinomas of larynx.