The effect of Maras powder and smoking on the microRNA deregulation of oral mucosa.

Betül Taş,Ali Osmay Güre

doi:10.1590/1678-7757-2019-0382

Betül Taş, Ali Osmay Güre

Open Access

https://doi.org/10.1590/1678-7757-2019-0382

Copy DOI

Abstract

Objective This study aimed to investigate the effects of Maras powder (a type of smokeless tobacco obtained from Nicotiana rustica Linn and mixed with the ashes of wood, especially from oak, walnut or grapevine) on the microRNA (miRNA) deregulation of oral mucosa, and it compares these effects with those of smoking.Methodology Oral mucosal samples were collected from 74 patients, consisting of 16 nonusers, 26 smokers, and 32 Maras powder users. Genes associated with oral cancer were selected and 90 microRNAs targeting these genes were identified. MicroRNA were isolated and purified using the microRNA isolation kit. MicroRNA were expressed using Fluidigm RT-PCR.Results A positive correlation between the duration of Maras powder use with miR-31 expression levels, and a negative correlation between the Maras powder chewing time and miR-372 expression levels was found. In addition, there is a negative correlation between the amount of Maras powder consumed and expression levels of miR-375, miR-378a, miR-145, and miR-10b; moreover, another negative correlation is observed between the number of cigarettes consumed and the expression levels of miR-23a, miR-23b, miR-203a, miR-200b, and miR-375. However, miR-200b and miR-92a levels were downregulated significantly more in Maras powder users when compared with smokers and nonusers (p<0.05).Conclusion The results show both chewing Maras powder and smoking have an effect on deregulation of miR-200b and miR-92a expressions. This leads to the belief that assessing the expression of these two miRNAs is a promising noninvasive method of analysis, especially in mutagen exposures. Finally, large-scale and high-throughput studies may help to identify an extensive miRNA expression profile associated with tobacco use and improve the understanding of oral malignancies.

Highlights

MicroRNAs are endogenous small noncoding RNAs that function in messenger RNA silencing and in the post-transcriptional regulation of gene expression1
This study aimed to investigate the effects of Maras powder on the microRNA deregulation of oral mucosa, and it compares these effects with those of smoking
The mean (±standard deviation (SD)) expression level of miR-92a was 5.979 (±1.22) in smokers, 5.343 (±1.62) in Maras powder (MP) users, and 6.461 (±1.22) in nonusers (Figure 2), and the difference was statistically significant between the groups (f=4.790, p=0.011)

Summary

Introduction

MicroRNAs (miRNAs) are endogenous small noncoding RNAs that function in messenger RNA (mRNA) silencing and in the post-transcriptional regulation of gene expression. MiRNAs are important in various cellular processes, such as proliferation, differentiation, cell growth, and cell death. Recent studies have discovered deregulated expression of miRNAs in oral infections, periodontal diseases, and oral cancer. Et al. (2011) performed a preliminary comparison of healthy and inflamed gingiva (10 healthy and 10 inflamed gingiva). They found 12 miRNAs, functioning in inflammatory processes and expressed differently, and reported a probable close relationship between miRNAs and periodontal diseases. Nahid, et al. (2011) found a persistent association between periodontal pathogens and miR-146a expression, suggesting miRNAs may promote periodontal diseases. Likewise, understanding the relationship between miRNAs and oral malignancies has become increasingly important. In addition to the oral cancer, oral precancerous lesions affect deregulation of miRNA expression

Methods

Results

Conclusion