Role of microRNAs in Lung Carcinogenesis Induced by Asbestos

Coronavirus infection and systemic inflammatory reaction syndrome

OBJECTIVE

Aim: The purpose of this study was a clinical approbation of the Kometad drug (international non-proprietary name sodium colistimethate), an antibiotic from the polymyxin group in patients with severe course of confirmed сoronavirus infection in the intensive care unit of the Branch of the I. Zhekenova Municipal Clinical Infectious Diseases Hospital..

PATIENTS AND METHODS

Materials and Methods: The methodology is based on both theoretical and empirical methods of scientific cognition. During the study, the features of the Coronavirus infection and the inflammatory reaction syndrome were considered, which became quite a big problem during the pandemic.

RESULTS

Results: The main indications for the tested drug and the consequences of its use for one age group were also determined.

CONCLUSION

Conclusions: The conclusion was made about the positive dynamics of the patients' health status, and recommendations were given for further research in this area. The practical significance of this study lies in the first clinical approbation of the Kometad drug, which can be used in medicine to reduce the severity of the systemic inflammatory reaction syndrome and improve the patient's health as a result of the disease of Coronavirus infection, after further clinical trials of the drug with different age groups of patients.

Molecular and Cellular Mechanism of Action of Chrysotile Asbestos in MRC5 Cell Line

Asbestos is a known carcinogen; however, the influence of chrysotile asbestos on the development of tumor-related diseases remains a subject of intense debate within the scientific community. To analyze the effect of asbestos, we conducted a study using the MRC5 cell line. We were able to demonstrate that chrysotile asbestos stimulated the production of reactive oxygen species (ROS), leading to cell death and DNA damage in the MRC5 cell line, using various techniques such as ROS measurement, comet assay, MTT assay, and qPCR. In addition, we found that chrysotile asbestos treatment significantly increased extracellular mitochondrial DNA levels in the culture medium and induced significant changes in the expression profile of several miRNAs, which was the first of its kind. Thus, our research highlights the importance of studying the effects of chrysotile asbestos on human health and reveals multiple adverse effects of chrysotile asbestos.

Vaping, Environmental Toxicants Exposure, and Lung Cancer Risk

Lung cancer (LC) is the second-most prevalent tumor worldwide. According to the most recent GLOBOCAN data, over 2.2 million LC cases were reported in 2020, with an estimated new death incident of 1,796,144 lung cancer cases. Genetic, lifestyle, and environmental exposure play an important role as risk factors for LC. E-cigarette, or vaping, products (EVPs) use has been dramatically increasing world-wide. There is growing concern that EVPs consumption may increase the risk of LC because EVPs contain several proven carcinogenic compounds. However, the relationship between EVPs and LC is not well established. E-cigarette contains nicotine derivatives (e.g., nitrosnornicotine, nitrosamine ketone), heavy metals (including organometal compounds), polycyclic aromatic hydrocarbons, and flavorings (aldehydes and complex organics). Several environmental toxicants have been proven to contribute to LC. Proven and plausible environmental carcinogens could be physical (ionizing and non-ionizing radiation), chemicals (such as asbestos, formaldehyde, and dioxins), and heavy metals (such as cobalt, arsenic, cadmium, chromium, and nickel). Air pollution, especially particulate matter (PM) emitted from vehicles and industrial exhausts, is linked with LC. Although extensive environmental exposure prevention policies and smoking reduction strategies have been adopted globally, the dangers remain. Combined, both EVPs and toxic environmental exposures may demonstrate significant synergistic oncogenicity. This review aims to analyze the current publications on the importance of the relationship between EVPs consumption and environmental toxicants in the pathogenesis of LC.

Oxidative Stress and DNA Damages Induced by Occupational Exposure to Asbestos: A Systematic Review

Background

Asbestos is one of the most important environmental and occupational carcinogens. Nevertheless, the mechanisms by which asbestos fiber exposure causes chronic diseases are not fully understood. We performed the first systematic review on the epidemiological evidence to examine the association between occupational exposure to asbestos and oxidative stress and DNA damage.

Methods

In this systematic review study, the PubMed and Scopus databases were searched for English-language publications. Eleven cross-sectional studies were included in the systematic review. A literature search was conducted by the main keywords including "Asbestos", "crocidolite", "chrysotile", "amphibole", "amosite", "Oxidative Stress", "DNA Damage", and "DNA injury". To evaluate the quality of studies, the "Newcastle-Ottawa Quality Assessment Scale" (NOS) was used.

Results

Overall, 1235 articles were achieved by searching in databases. Finally, by considering the inclusion, and exclusion criteria, 11 articles were conducted for this study. These studies were published between 1986 and 2020. Oxidative stress and DNA damage can occur in exposure to asbestos. Among various biomarkers, 8-OHdG is the best. The analysis of 8-oxodG in asbestos workers can help identify subjects with a higher level of genotoxic damage.

Conclusion

This systematic review suggests that oxidative stress and DNA damage are two main outputs of asbestos exposure. Therefore, oxidative stress and DNA damage biomarkers can be used for identifying subjects at higher risk of cancer. These findings support policy initiatives aimed at detecting and eliminating asbestos fiber exposure and preventing potential health hazards in occupational settings.

Expression of microRNAs in leukocytes and serum of asbestosis patients

BACKGROUND

Although asbestos use is banned in many countries, long latency of asbestos-related diseases like pleural plaques or asbestosis mean it is still a public health issue. People suffering from these diseases have a higher risk of developing mesothelioma or lung cancer, which can progress quickly and aggressively. MicroRNAs were suggested as potential biomarkers in several diseases. However, in asbestosis, blood microRNAs are less explored. Since miR-32-5p, miR-143-3p, miR-145-5p, miR-146b-5p, miR-204-5p and miR-451a are involved in fibrotic processes and in cancer, expression of these microRNAs was analyzed in leukocytes and serum of asbestosis patients.

METHODS

MicroRNA expression was analyzed in leukocytes and serum of 36 patients (26 affected by pleural plaques and 10 by asbestosis) and 15 healthy controls by real-time RT-PCR. Additionally, data analyses were performed regarding disease severity based on ILO classification.

RESULTS

MicroRNA miR-146b-5p was significantly down-regulated in leukocytes of patients suffering from pleural plaques with a large effect indicated by η²_p = 0.150 and Cohen's f = 0.42, a value of difference of 0.725 and a 95% confidence interval of 0.070-1.381. In patients suffering from asbestosis miR-146b-5p was not significantly regulated. However, data analyses considering disease severity only, revealed that miR-146b-5p was significantly down-regulated in leukocytes of mildly diseased patients compared to controls with a large effect indicated by η²_p = 0.178 and Cohen's f = 0.465, a value of difference of 0.848 and a 95% confidence interval of 0.097-1.599. Receiver operating characteristic (ROC) curve and an area under the ROC curve value of 0.757 for miR-146b-5p indicated acceptable discrimination ability between patients suffering from pleural plaques and healthy controls. Less microRNAs were detectable in serum than in leukocytes, showing no significant expression differences in all participants of this study. Moreover, miR-145-5p was regulated significantly differently in leukocytes and serum. An R² value of 0.004 for miR-145-5p indicated no correlation in microRNA expression between leukocytes and serum.

CONCLUSION

Leukocytes seem more suitable than serum for microRNA analyses regarding disease and potentially cancer risk assessment of patients suffering from asbestos-related pleural plaques or asbestosis. Long-term studies may reveal whether down-regulation of miR-146b-5p in leukocytes might be an early indicator for an increased cancer risk.

The Role of Mitochondrial miRNAs in the Development of Radon-Induced Lung Cancer

MicroRNAs are short, non-coding RNA molecules regulating gene expression by inhibiting the translation of messenger RNA (mRNA) or leading to degradation. The miRNAs are encoded in the nuclear genome and exported to the cytosol. However, miRNAs have been found in mitochondria and are probably derived from mitochondrial DNA. These miRNAs are able to directly regulate mitochondrial genes and mitochondrial activity. Mitochondrial dysfunction is the cause of many diseases, including cancer. In this review, we consider the role of mitochondrial miRNAs in the pathogenesis of lung cancer with particular reference to radon exposure.

A Cascade Flexible Neural Forest Model for Cancer Subtypes Classification on Gene Expression Data

The correct classification of cancer subtypes is of great significance for the in-depth study of cancer pathogenesis and the realization of accurate treatment for cancer patients. In recent years, the classification of cancer subtypes using deep neural networks and gene expression data has become a hot topic. However, most classifiers may face the challenges of overfitting and low classification accuracy when dealing with small sample size and high-dimensional biological data. In this paper, the Cascade Flexible Neural Forest (CFNForest) Model was proposed to accomplish cancer subtype classification. CFNForest extended the traditional flexible neural tree structure to FNT Group Forest exploiting a bagging ensemble strategy and could automatically generate the model's structure and parameters. In order to deepen the FNT Group Forest without introducing new hyperparameters, the multilayer cascade framework was exploited to design the FNT Group Forest model, which transformed features between levels and improved the performance of the model. The proposed CFNForest model also improved the operational efficiency and the robustness of the model by sample selection mechanism between layers and setting different weights for the output of each layer. To accomplish cancer subtype classification, FNT Group Forest with different feature sets was used to enrich the structural diversity of the model, which make it more suitable for processing small sample size datasets. The experiments on RNA-seq gene expression data showed that CFNForest effectively improves the accuracy of cancer subtype classification. The classification results have good robustness.