Novel microRNAs expression of patients with chemotherapy drug-resistant and chemotherapy-sensitive epithelial ovarian cancer.

The aim of this study is to examine the microRNA (miRNA) expression of epithelial ovarian cancer (EOC) in both drug-resistant and drug-sensitive tissues and to explore the pathogenic characteristics of drug-resistant miRNAs in EOC. The samples with 10 cases of drug-resistant and drug-sensitive EOC tissue were obtained from undergoing surgical resection of ovarian cancer (OC). Total miRNAs were extracted and isolated, respectively. Hybridization was carried out on miRNA microarray chip. Real-time polymerase chain reaction (RT-PCR) was performed to confirm the difference of miRNA expression. Bioinformatic software was used to predict the possible target genes of each miRNA which expressed differently. The results indicated that four miRNAs related drug-resistance been identified, and the expression of hsa-miR-152 and hsa-miR-381 in drug-resistant OC tissue was significantly higher compared with those in drug-sensitive tissue (P < 0.01). However, expression of hsa-miR-200a-3p and hsa-miR-429 were downregulated in drug-resistant tissues (P < 0.01). The results obtained by miRNA microarrays of differential expression with hsa-miR-106b-3p, hsa-miR-152, hsa-miR-200a-3p, hsa-miR-381, and hsa-miR-429 were confirmed by real-time PCR. There were 62 significantly different miRNAs, including 42 significant upregulated miRNAs and 20 significant downregulated miRNAs in the drug-resistant tissue. Five databases, including Target Scan, miRanda, miRDB, PicTar5, and RNA22, were used for bioinformatics prediction. In conclusion, miRNA microarray analysis has become a fast and efficient molecular biological technology for the study of biological information. hsa-miR-152, hsa-miR-200a-3p, hsa-miR-381, and hsa-miR-429 may participate in the formation of drug resistance in EOC through the target genes predicted.