BACKGROUND

Hyaluronan-mediated motility receptor () plays a pivotal role in cell proliferation in various cancers, including lung cancer. However, its function and biological mechanism in lung adenocarcinoma (LUAD) remain unclear.

METHODS

Data on expression from several public databases were extensively analyzed, including the prognosis of in the Gene Expression Profiling Interactive Analysis (GEPIA) database. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were analyzed using DAVID and gene set enrichment analysis (GSEA) software. The correlation between expression and immune cell infiltration was analyzed in the Tumor Immune Estimation Resource (TIMER) database, and the gene and protein networks were examined using the GeneMANIA and STRING databases. Experimentally, the expression of in LUAD and lung cancer cell lines was determined using immunohistochemistry and quantitative RT-PCR assays. Besides, the function of on cancer cell proliferation and migration was examined using cell growth curve and colony formation, Transwell, and wound healing assays.

RESULTS

In this study, we found that was elevated in LUAD and that its high expression was associated with poor clinicopathological features and adverse outcomes in LUAD patients. Furthermore, our results demonstrated that the expression of was positively correlated with immune cell infiltration and immune modulation. Interestingly, diverse immune cell infiltration affects the prognosis of LUAD. In the functional assay, depletion of significantly repressed the cancer cell growth and migration of LUAD. Mechanically, we found that that the DNA methylation/TMPO-AS1/let-7b-5p axis mediated the high expression of in LUAD. Depletion of TMPO-AS1 and overexpression of let-7b-5p could result in the decreased expression of in LUAD cells. Furthermore, we found that TMPO-AS1 was positively correlated with , yet negatively correlated with let-7b-5p expression in LUAD.

CONCLUSIONS

Our findings elucidated that the DNA methylation/TMPO-AS1/let-7b-5p axis mediated the high expression of , which may be considered as a biomarker to predict prognosis in LUAD.