Biblioteca Virtual en Salud

Objective @#To investigate the differential expression of mitochondrial microRNAs (mitomiRs) in tongue squamous cell carcinoma (TSCC) and to screen out mitomiRs related to chemotherapy resistance. @* Methods @#Mitochondrial, cytoplasmic, and total cellular RNAs were extracted from the squamous cell carcinoma cell line CAL-27 and the cisplatin-resistant cell line CAL-27-re. High-throughput miRNA microarrays were used to screen for differentially expressed mitomiRs between the drug-resistant and parental cells. The upregulated mitomiRs in the CAL-27 and CAL-27-re cells and in samples from chemoresistant and chemosensitive tongue squamous cell carcinoma patients were verified by qRT-PCR.@*Results@#The microarray detected 263 miRNAs in 6 components of the mitochondrial, cytoplasmic and total cellular RNAs from the CAL-27 and CAL-27-re cells, including 57 mitomiRs and 134 cytoplasmic microRNAs (cytomiRs). Compared with the total miRNAs, 35 mitomiRs were upregulated in the CAL-27-re cells, and 31 mitomiRs were upregulated in the CAL-27 cells (≥ 1.5-fold). Further comparative analysis of mitomiRs that were differentially expressed between the parental and drug-resistant cells identified 11 upregulated mitomiRs (miR-2392, miR-4462, miR-1290, miR-4449, miR-1268a, miR-1246, and miR-371a-5p, miR-3934-5p, miR-4271, miR-513p, and miR-664b-3p) and 5 downregulated mitomiRs (miR-188-5p, miR-1973, miR -3653, miR-4499, and miR-5787); the expression levels of the other 41 mitomiRs were almost identical in both cell lines. The qRT-PCR results were consistent with the miRNA microarray results. The 11 upregulated mitomiRs that were validated between the CAL-27 and CAL-27-re cells included miR-1268a, miR-2392, miR-4462, and miR-1290. Additionally, 5 mitomiRs, including miR-4449, were upregulated in the clinical chemotherapy-resistant tongue squamous cell carcinoma samples.@* Conclusion@#Differentially expressed mitomiRs were found between cisplatin-resistant and cisplatin-sensitive tongue squamous cell carcinoma cells. mitomiRs with high expression levels (miR-2392, miR-4462, miR-1290, miR-4449 and miR-1268a) may play important roles in the drug resistance of tongue squamous cell carcinoma.