Background: Metastasis often leads to poor prognosis in nasopharyngeal carcinoma (NPC) patients. Evidence has indicated the important roles of microRNA (miRNA) in cancer metastasis. The aim of this study was to identify and verify the key miRNAs that might be involved in the development of NPC metastasis.
Methods: Microarray data were obtained and analyzed to screen the differentially expressed miRNAs (DEMs) between NPC tissues with metastasis and those without metastasis. The target genes of the DEMs were predicted and their functions were annotated. Then, candidate hub genes were screened out through protein-protein interaction analysis, and the key miRNAs were identified. Afterwards, the expression levels of the key miRNAs were assessed by qRT-PCR based on an in vitro model.
Results: A total of 22 DEMs were screened out, and 616 target genes were predicted. Gene Ontology (GO) and pathway enrichment analysis showed that the target genes may be enriched in a diversity of GO terms and signaling pathways. Among them, eleven hub genes were identified, such as PTEN, KAT2B, CCND1, STAT3, and MAP3K5. Moreover, a five-miRNA profile (miR-106b, miR-17, miR-20b, miR-18a and miR-93) was identified and their expression levels were tested to be up-regulated in high-metastatic NPC cells relative to low-metastatic ones.
Conclusion: The present study revealed that five miRNAs (miR-106b, miR-17, miR-20b, miR-18a and miR-93) and several hub genes such as PTEN, KAT2B, CCND1, STAT3, and MAP3K5, might play critical roles in the development of NPC metastasis. Future investigations are needed to confirm the results.
Keywords: Nasopharyngeal carcinoma; metastasis; microRNA; microarray; qRT-PCR.