MiR-30a and miR-379 modulate retinoic acid pathway by targeting DNA methyltransferase 3B in oral cancer

Abstract

Background: Epigenetic silencing of retinoic acid (RA) signaling-related genes have been linked with the pathogenesis and clinical outcome in oral squamous cell carcinoma (OSCC) carcinogenesis. However, the precise mechanisms underlying the abnormal silencing of RA signaling-related genes in OSCC have not been well investigated. Methods: Using combined analysis of genome-wide gene expression and methylation profile from 40 matched normaltumor pairs of OSCC specimens, we found a set of retinoid signaling related genes are frequently hypermethylated and downregulated in OSCC patient samples, including alcohol dehydrogenase, iron containing 1 (ADHFE1) and aldehyde dehydrogenase 1 family, member A2 (ALDH1A2), which are the important rate-limiting enzymes in synthesis of RA. The expression of ADHFE1 and ALDH1A2 in OSCC patients was determine by quantitative real-time PCR (qRT-PCR) and immunohistochemistry. The binding sites of miR-30a and miR-379 with DNA methyltransferase 3B (DNMT3B) were predicted using a series of bioinformatic tools, and validated using dual luciferase assay and Western blot analyses. The functions of miR-30a, miR-379, and DNMT3B were accessed by growth and colony formation analyses using gain-and loss-of-function approaches. Chromatin immunoprecipitation (ChIP) was performed to explore the molecular mechanisms by arecoline and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) treatment. Results: We demonstrated that deregulated miR-30a and miR-379 could represent a mechanism for the silencing of ADHFE1 and ALDH1A2 in OSCC through targeting DNMT3B. Ectopic expression of miR-30a and miR-379 could induce re-expression of methylation-silenced ADHFE1 and ALDH1A2, and lead to growth inhibition in oral cancer cells. Furthermore, the dysregulation of the miRNAs and DNMT-3B may result from exposure to tobacco smoking and betel quid chewing.

Pan-cancer characterization of metabolism-related biomarkers identifies potential therapeutic targets

“…MiR-30c-5p (LGHO), miR-362-5p (LGHO), and miR-379-5p (HGLO) appear to be strong regulators of tumor glycolysis and OXPHOS since they were all dysregulated in 8 cancer types and targeted several metabolism-related DEGs. Meanwhile, the three miRNAs have been reported to play an important role in tumor metabolism and progression [ 35 – 37 ], which further supports our findings.…”

Cigarette smoke-induced LKB1/AMPK pathway deficiency reduces EGFR TKI sensitivity in NSCLC

“…Since DNA methyltransferase (DNMT) has been implicated in tobacco smoking-mediated promoter methylation and gene silence [ 31 ] and CSE dramatically suppressed LKB1 expression in H1299 cells (Supplementary Fig. 7b ) which express higher DNMT isoforms [ 32 ], we next assessed whether cigarette smoke downregulates LKB1 transcription through promoter methylation.…”

Downregulation of the DNA Repair Gene DDB2 by Arecoline Is through p53’s DNA-Binding Domain and Is Correlated with Poor Outcome of Head and Neck Cancer Patients with Betel Quid Consumption

“…Whether arecoline affects methylation at the DDB2 promoter is unclear; however, arecoline is reported to increase the recruitment of DNMT3B to the ANK1 promoter [61]. Long-term arecoline treatment also enhances the expression of DNMT3B, which promotes methylation at the ALDH1A2 and ADHFE1 promoters [62]. In this regard, the methylation state of the DDB2 promoter in the long-term arecoline-treated HA60d cells, as well as in HNC specimens, can be examined in the future.…”