A comprehensive investigation using meta-analysis and bioinformatics on miR-34a-5p expression and its potential role...

HNSCC is the sixth most common cancer worldwide and is characterized as an aggressive, malignant tumor. MiR-34a-5p (miR-34a) expression has been strongly linked to HNSCC development. However, the exact target gene of miRNA-34a-as well as its biological and mechanistic pathways-are unclear. It is critical that the clinical value of HNSCC receive further study. We conducted a continuous variable, meta-analysis from data found in the cancer literature as well as that provided by the Cancer Genome Atlas (TCGA) to estimate miR-34a expression in HNSCC. Next, TCGA database, microarray, and MiRWalk were all used to predict the target gene of miR-34a in HNSCC. Then, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were used to explore the underlying molecular mechanism of miR-34a in HNSCC. Finally, we used Spearman's analysis and survival curves to identify the roles of related target genes involved in significant pathways during the development of HNSCC. Expression levels of miR-34a in HNSCC were significant lower than those in normal tissues (P<0.05) and summary receiver operating characteristic (sROC) was 0.72. The collective results obtained from KEGG and GO indicated that miR-34a may be involved in the development of HNSCC via known cancer pathways, including the p53 and/or PI3K-Akt signalling pathways. Our results suggested miR-34a has potential use as a novel, non-invasive and highly sensitive biomarker for diagnostic in HNSCC. Finally, it likely plays an essential role in the deterioration and ultimate tumorigenesis of HNSCC through determined cancer pathways.