Possible tumor suppressive role of the miR-144/451 cluster in esophageal carcinoma as determined by principal component regression analysis

MicroRNA (miRNA) clusters are expressed universally across different types of organisms, and an accumulating number of studies have demonstrated that miRNA clusters function more efficiently compared with single miRNAs during the development of certain cancer types. miRNA clusters may have increased stability and reliability over individual miRNAs as diagnostic or therapeutic biomarkers. In the present study, the expression levels of mature miRNAs within the miR-144/451 cluster were examined using stem-loop reverse transcription-quantitative polymerase chain reaction in 102 patients pathologically diagnosed with esophageal carcinoma. Bioinformatics tools were used to identify a possible miRNA-mediated network of the miR-144/451 cluster. The expression levels of hsa-miR-451a, hsa-miR-144-3p and hsa-miR-144-5p in tumor tissues were significantly lower compared with those in adjacent non-tumor tissues (P<0.05). Pearson correlation analysis demonstrated that the expression levels of individual miR-144/451 cluster members were correlated with each other, except for the pair of hsa-miR-144-3p and hsa-miR-4732-3p. In particular, hsa-miR-144-5p expression was highly associated with hsa-miR-4732-5p and hsa-miR-451a expression levels, with correlation coefficients of 0.729 and 0.608, respectively. Furthermore, the low expression levels of hsa-miR-144-3p [odds ratio (OR), 0.85; P<0.05] and hsa-miR-144-5p (OR, 0.84; P<0.05) were determined to be risk factors for esophageal carcinoma development. Kyoto Encyclopedia of Genes and Genomes pathway analysis demonstrated that miRNAs forming the miR-144/451 cluster may cooperate to regulate the cell cycle. Therefore, the miR-144/451 cluster may serve an important role in the progression of esophageal carcinoma and may be considered as a biomarker for the detection of esophageal carcinoma at an early stage.