Search of preventive biomarkers for screening of population living in conditions of asbestos and radon pollution. Uncovering molecular and cellular mechanisms of toxic effects of chrysotile asbestos.

Objective: Lung cancer is a prominent cancer type worldwide. The primary factors contributing to lung cancer in non-smokers are asbestos exposure and air pollution containing radon. Several studies have shown that microRNA expression can change in response to environmental factors. Prolonged exposure to asbestos and radon can result in inflammation. MicroRNA, mtDNA and cytokines might serve as promising indicators for detecting asbestos and radon exposure early, potentially for preventive purposes. Methods: Plasma and serum samples were collected from 207 healthy individuals: among them, 81 individuals worked at an asbestos mining facility, 64 individuals lived in regions with high indoor radon levels and 62 individuals were not exposed to either radon or asbestos. microRNA expression levels and cf mtDNA copy number were detected using qPCR and cytokines were determined using a human ELISA kit. The toxic effects of chrysotile were studied on the MRC5 cell line. Employing various techniques including ROS measurement, Comet Assay, MTT assay, and qPCR, we were able to demonstrate that chrysotile asbestos induces the generation of reactive oxygen species (ROS), cell death, and DNA damage in MRC5 cell line. Result: Our findings suggest a clear connection between asbestos and radon exposure and alterations in microRNA expression and cytokine levels in blood samples. Specifically, miR-19b-3p and miR-1202 exhibited higher expression in both radon and asbestos exposure groups compared to the non-exposed group. сf mtDNA can be used as a biomarker of radon pollution, but is not associated with long-term asbestos exposure. Furthermore, our research reveals elevated levels of pro-inflammatory cytokines, TNF-alpha and IL-6, in response to both radon and asbestos exposure. Conversely, the anti-inflammatory cytokine IL-4 was significantly lower in both exposure groups compared to the non-exposed group.