Polymorphisms in DNA Repair and Xenobiotic Biotransformation Enzyme Genes and Lung Cancer Risk in Coal Mine Workers

Background: Currently coal mining employs over 7 million miners globally. This occupational setting is associated with exposure to dust particles, heavy metals, polycyclic aromatic hydrocarbons and radioactive radon, significantly increasing the risk of lung cancer (LC). The susceptibility for LC is modified by genetic variations in xenobiotic detoxification and DNA repair capacity. The aim of this study was to investigate the association between GSTM1 (deletion), APEX1 (rs1130409), XPD (rs13181) and NBS1 (rs1805794) gene polymorphisms and LC risk in patients who worked in coal mines. Methods: The study included 639 residents of the coal region of Western Siberia (Kemerovo region, Russia): 395 underground miners and 244 healthy men who do not work in industrial enterprises. Genotyping was performed using real-time and allele-specific PCR. Results: The results show that polymorphisms of APEX1 (recessive model: OR_adj = 1.87; CI 95%: 1.01–3.48) and XPD (log additive model: OR_adj = 2.25; CI 95%: 1.59–3.19) genes were associated with increased LC risk. GSTM1 large deletion l was linked with decreased risk of LC formation (OR_adj = 0.59, CI 95%: 0.36–0.98). The multifactor dimensionality reduction method for 3-loci model of gene–gene interactions showed that the GSTM1 (large deletion)—APEX1 (rs1130409)—XPD (rs13181) model was related with a risk of LC development. Conclusions: The results of this study highlight an association between gene polymorphism combinations and LC risks in coal mine workers.

Rogue versus chromothriptic cell as biomarker of cancer

New molecular cytogenetic biomarkers may significantly contribute to biodosimetry, whose application is still globally diverse and not fully standardized. In 2011, a new term, chromothripsis, was introduced raising great interest among researchers and soon motivating further investigations of the phenomenon. Chromothripsis is described as a single event in which one or more chromosomes go through severe DNA damage very much resembling rogue cells (RC) described more than 50 years ago. In this review, we for the first time compare these two multi-aberrant cells types, RC versus chromothriptic cells, giving insight into the similarities of the mechanisms involved in their etiology. In order to make a better comparison, data on RC in 3366 subjects from studies on cancer patients, Chernobyl liquidators, child victims of the Chernobyl nuclear plant accident, residentially and occupationally exposed population have been summarized for the first time. Results of experimental and epidemiological analysis show that chromothriptic cells and RC may be caused by exposure to high LET ionizing radiation. Experience and knowledge collected on RC may be used in future for further investigations of chromothripsis, introducing a new class of cells which include both chromothriptic and RC, and better insight into the frequency of chromothriptic cell per subject, which is currently absent. Both cell types are relevant in investigations of cancer etiology, biomonitoring of accidentally exposed population to ionizing radiation and biomonitoring of astronauts due to their exposure to high LET ionizing radiation during interplanetary voyages.