Background: The function of miR-31-5p in lung squamous cell carcinoma (LUSC) remains unclear, therefore, a systematic study was performed for the clinical significance and molecular mechanism of miR-31-5p in LUSC.
Methods: Quantitative real-time reverse transcription PCR (qRT-PCR) was utilized to test the expression level of miR-31-5p in 88 LUSC tissue samples and their matching normal tissues. Data from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) were also utilized to confirm the expression level and clinical value of miR-31-5p in LUSC. The potential target genes of miR-31-5p were predicted by several online predicted software. Gene ontology (GO), protein-protein interaction (PPI) and pathway analysis were utilized to investigate the underlying molecular mechanism of miR-31-5p in LUSC.
Results: The result from qRT-PCR found that there was significant difference of miR-31-5p between LUSC and normal tissues (P<0.001). Meanwhile, Data from TCGA also showed a higher expression of miR-31-5p in LUSC tissues than that in the normal tissues (P<0.001). on the basis of the data of GEO database, five GEO datasets indicated that the expression of miR-31-5p in LUSC tissues was significantly higher than that in normal lung tissues, include GSE51858 (P=0.025), GSE74190 (P<0.000), GSE16025 (P=0.031), GSE25508 (P=0.0.01), and GSE47525 (P=0.049). Moreover, in consideration of the meta-analysis, 1,012 clinical specimens were systematically analyzed via meta-analysis, clinical specimens were systematically analyzed via meta-analysis, and the results showed that the expression of miR-31-5p in LUSC was significantly higher than in the adjacent lung tissues (SMD =0, CI: 1.08-1.45, Z=13.30, P=0.000). In addition, result from GO and pathway analyses showed that potential target genes of miR-31-5p were significantly associated with 20 GO terms and 5 pathways, such as signal transduction, transmembrane receptor protein tyrosine kinase activity, plasma membrane and Rap1 signaling pathway. Meanwhile, we also found thatmiR-31-5p target genes were related to the Rap1 signaling pathway, Oxytocin signaling pathway and Proteoglycans in cancer. Furthermore, six hub genes were identified from PPI and three hub genes, including ADCY6, ADCY9 and EGFR, proved to coexist in the Rap1 signaling pathway, oxytocin signaling pathway and Melanogenesis simultaneously.
Conclusions: According to what has been discussed above, we speculated that miR-31-5p may play a vital role in the occurrence and development of LUSC.
Keywords: Lung squamous cell carcinoma (LUSC); miR-31-5p; molecular mechanism; quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR); target genes.
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