Upregulation of two human microRNAs which might be involved in the carcinogenesis of nasopharyngeal cancer and that are promising for biomarker development

One of the biggest problems in diagnosing nasopharyngeal carcinoma (NPC) is the lack of biomarkers to detect the disease in its early stages. Thus, the exploration of biomarkers, which have the potential to be used to diagnose NPC in its early stages, is crucial. NPC is allegedly controlled by microRNAs (miRNAs); these molecules can be secreted out of cells and can be found in the serum—two aspects that make them potential biomarkers to be developed for non-invasive diagnosis of NPC. In this study, we analyzed the profile of miRNA expression in NPC biopsy tissue compared to normal tissues. The miRNA expression is taken from 246 samples of patients with NPC, compared to 17 samples from non-NPC subjects as the control. The results of the analysis identified more than 100 miRNAs that underwent an upregulation of expression in NPCs compared to that in the control group. Further analysis was focused on understanding the role of the miRNAs that were upregulated in NPCs. The results of this analysis reveal that there are six miRNAs: hsa-miR-1246, hsa-miR-320a, hsa-miR-1290, hsa-miR-146b-5p, hsa-miR-107, and hsa-miR-1305, which underwent increased expression and that are closely related to process of cancer (carcinogenesis) in NPC. Among the upregulated miRNA, the two miRNAs, miR-1290 and miR-1246, were found upregulated in the serum of NPC patients compared to the health persons. Moreover, the target genes of the miRNAs are also targets of the oncovirus protein that is involved in controlling the cell cycle and apoptosis. Upregulation of the miRNA might stimulate carcinogenesis through repressing guard genes for controlling cell cycle and apoptosis. The mechanism seems similar to the way the oncovirus initiates cancer.