Somatic DNA damage and causative factors (occupational exposures, foods and habits etc.) are thought to contribute to the pathogenesis of atherosclerosis, although knowledge about their role in coronary artery disease is still insufficient. This study aimed to determine the effects of lymphocyte-DNA damage and blood-trace element concentrations on coronary artery disease (CAD). The single-cell alkaline comet was used in the measuring of the lymphocyte DNA damage in blood samples obtained from patients (n=99) whose CAD grade was determined by the syntax score while the angiographic intervention was carried out. Blood-trace elements (n=14) concentrations were monitored by the inductively coupled plasma atomic emission spectroscopy (ICP-OES) after the microwave digestion. The relationship between DNA damage frequencies of the participants and their syntax scores, blood-trace element concentrations, and other demographic and clinic parameters were statistically analyzed. Significant correlations were detected between comet data and syntax score (r=0.858, p<0.001), age (r=0.337, p<0.001), blood-urea (r=0.360, p<0.001), -creatinine (r=0.388, p<0.001), -HbA1c (0.218, p<0.05), ECG-QRS time (r=0.286, p<0.01), ECHO-EF (r=-0.377, p<0.001) and platelet (r=-0.222, p<0.05). The DNA damage frequencies of the groups formed according to their CAD scores were significantly different from the control group (p<0.001) and also each other (p≤0.01). Comet frequencies and CAD grades were found to be correlated with aging (p<0.05). DNA damage frequency and syntax score values were significantly (p<0.05) higher in males compare to females. Syntax scores were correlated with aging (r=0.348, p<0.01), ECHO-EF (r=0.374, p<0.001), -blood-urea (r=0.398, p<0.001), -creatinine (r=0.433, p<0.001), -glucose (0.218, p<0.05) and -HbA1c (r=0.200, p<0.05). Significant correlations were observed between trace elements and demographic values, blood parameters, diseases, angio parameters, ECHO and ECG parameters. It was observed that the concentrations of trace elements detected in the blood were 93.4% correlated with each other. Lymphocyte DNA damage is a strong biomarker for the atherosclerotic indicator of CAD. Aging is an effective factor both on the DNA damage frequency and CAD risk index. Creatinine and urea are factors that have the power the change the CAD risk index and DNA damage frequency. The higher DNA damage and CAD risk were monitored in male compare to female. The relationship between some biomarkers and blood trace element concentrations showed that further studies are needed to more accurately evaluate the relationship between trace elements, DNA damage frequencies and coronary artery disease.

The translocation of mitochondrial DNA (mtDNA) sequences into the nuclear genome, resulted in the occurrence of nuclear sequences of mitochondrial origin (NUMTs) which can be detected in nearly all sequenced eukaryotes. However, de novo mtDNA insertions can contribute to the development of pathological conditions including cancer. Recent data indicate that de novo mtDNA translocation into chromosomes can occur due to genotoxic influence of DNA double-strand break (DSB)-inducing environmental mutagens. This confirms the hypothesis of the involvement of genome instability in the occurrence of mtDNA fragments in chromosomes. Mounting evidence indicates that mitochondria can be transferred from normal cells to cancer cells and recover cellular respiration. These exchanged mitochondria can facilitate cancer progression and metastasis. This review article provides a comprehensive overview of the potential carcinogenicity of mtDNA insertions, and the relevance of mtDNA escape in cancer progression, metastasis, and treatment resistance in humans. Potential molecular targets involved in mtDNA escape and exchange of mitochondria that can be of possible clinical benefits are presented and discussed. Understanding these processes could lead to improved diagnostic approaches, novel therapeutic strategies, and a deeper understanding of the intricate relationship between mitochondria, nuclear DNA, and cancer biology.

High intake of red meat and/or dairy products may increase the concentration of iron and calcium in plasma - a risk factor for prostate cancer (PC). Despite our understandings of nutrients and their effects on the genome, studies on the effects of iron and calcium on radiation sensitivity of PC patients are lacking. Therefore, we tested the hypothesis that high plasma levels of iron and calcium could increase baseline or radiation-induced DNA damage in PC patients relative to healthy controls. The present study was performed on 106 PC pa-tients and 132 age-matched healthy individuals. CBMN assay was performed to measure mi-cronuclei (MN), nucleoplasmic bridges (NPBs) and nuclear buds (NBuds) in lymphocytes. Plasma concentrations of iron and calcium were measured using inductively coupled plasma atomic emission spectroscopy. MN, NPBs and NBuds induced by radiation ex vivo were significantly higher in PC patients with high plasma iron (p = 0.004, p = 0.047 and p = 0.0003 respectively) compared to healthy controls. Radiation-induced MN and NBuds frequency were also significantly higher in PC patients (p = 0.001 and p = 0.0001 respectively) with high plasma calcium levels relative to controls. Furthermore, radiation-induced frequency of NBuds was significantly higher in PC patients (p < 0.0001) with high plasma levels of both iron and calcium relative to controls. Our results support the hypothesis that high iron and calcium levels in plasma increases the sensitivity to radiation-induced DNA damage and point to the need of developing nutrition-based strategies to minimize DNA damage in normal tissue of PC patients undergoing radiotherapy.

Several bioactive compounds, such as polyphenols, demonstrate low toxicity and prominent effects on cancer cells with antioxidant, anti-inflammatory, and antitumor activities. Such compounds can be found in Amazon mosses Leucobryum martianum (Hornsch.) Hampe ex Müll. Hal. (Hornsch.) and Leucobryum laevifolium (Broth). Antimutagenic assay with Salmonella enterica serovar Typhimurium and cytotoxicity with different eukaryotic cell lines were carried out to screen aqueous, hydroalcoholic, and ethanolic extracts of those Amazon mosses for anticancer potential. The results indicate the capacity of all extracts of both mosses to exert chemopreventive effects against 4-nitroquinoline-N-oxide (4NQO) and 2-aminoanthracene (2-AA), which are direct or indirect mutagens. In particular, the ethanolic and aqueous extract from L. martianum. The ethanolic extract from L. martianum induces significant cytotoxicity by mitochondrial metabolism and cell membrane disruption pathways to tumor or non-tumor cells. The aqueous extract from L. martianum showed a mainly cytotoxic response in the HepG2 cells, a human liver carcinoma, reaching ~90% cytotoxicity. The same extract did not induce significant damage to normal liver cells (F C3H cells) by membrane interaction pathway. The selective cytotoxicity in the aqueous extract of L. martianum makes it a candidate against liver cancer. Further studies, including in vivo models, are necessary to validate the efficacy and safety of the aqueous extract of L. martianum.

Hepatic leukemia factor (HLF), a transcription factor, is dysregulated in many cancers. This study investigates the function of HLF in prostate cancer (PCa) and its relation to tensin 1 (TNS1). Clinical tissues were collected from 24 PCa patients. DU145 and PC3 cells overexpressing HLF were established. HLF signaling was downregulated in PCa tissues compared to adjacent tissues and in DU145 and PC3 cells compared to prostate epithelial cells RWPE-1 or prostate stromal cells (WPMY-1). PCa cell lines with overexpression of HLF had reduced proliferative, migratory, and invasive activity, increased apoptosis, and cell mitosis mostly in the G0/G1 phase. HLF induced the TNS1 transcription to activate the p53 pathway. Depletion of TNS1 reversed the anti-tumor effects of HLF on PCa cells and tumor growth and metastasis in vivo. In summary, our findings suggest that HLF suppressed PCa progression by upregulating TNS1 expression and inducing the p53 pathway activation, which might provide insights into novel strategies for combating PCa.

Cadmium chloride (CdCl2) is a known genotoxic carcinogen, with a mechanism of action thought to partly involve the generation of reactive oxygen species (ROS). We applied here a multi-endpoint approach in vitro to explore the impact of CdCl2 on both the genome and on wider cell biology pathways relevant to cancer. Multi-endpoint approaches are believed to offer greater promise in terms of understanding the holistic effects of carcinogens in vitro. This richer understanding may help better classification of carcinogens as well as allowing detailed mechanisms of action to be identified. We found that CdCl2 caused DNA damage (micronuclei; MN) in both TK6 and NH32 cells in a dose dependent manner after 4 hours exposure (plus 23 hours recovery), with lowest observable effect levels (LOELs) for MN induction of 1μM (TK6) and 1.6μM (NH32). This DNA damage induction in TK6 cells was ROS dependent as pre-treatment with the antioxidant N Acetyl Cysteine (1mM), abrogated this effect. However, DCFDA was not capable of detecting the ROS induced by CdCl2. The use of NH32 cells allowed an investigation of the role of p53 as they are a p53 null cell line derived from TK6. NH32 showed a 10-fold increase in MN in untreated cells and a similar dose dependent effect after CdCl2 treatment. In TK6 cells, CdCl2 also caused activation of p53 (accumulation of total and phosphorylated p53), imposition of cell cycle checkpoints (G2/M) and intriguingly the production of smaller and more eccentric (elongated) cells. Overall, this multi-endpoint study suggests a carcinogenic mechanism of CdCl2 involving ROS generation, oxidative DNA damage and p53 activation, leading to cell cycle abnormalities and impacts of cell size and shape. This study shows how the integration of multiple cell biology endpoints studied in parallel in vitro can help mechanistic understanding of how carcinogens disrupt normal cell biology.

The aim of this study was to investigate if age and body mass of humans have an impact on the DNA-damaging properties of high-frequency mobile phone-specific electromagnetic fields (HF-EMF, 1950 MHz, universal mobile telecommunications system, UMTS signal) and if this form of radiation has an impact on the genotoxic effects of occupationally relevant exposures. Pooled peripheral blood mononuclear cells (PBMC) from three groups [young normal weight, young obese (YO), and older age normal weight individuals] were exposed to different doses of HF-EMF (0.25, 0.5, and 1.0 W/kg specific absorption rate-SAR) and simultaneously or sequentially to different chemicals which cause DNA damage (CrO3, NiCl2, benzo[a]pyrene diol epoxide-BPDE, and 4-nitroquinoline 1-oxide-4NQO) via different molecular mechanisms. We found no difference in regard to the background values in the three groups but a significant increase of DNA damage (81% without and 36% with serum) in cells from old participants after radiation with 1.0 W/kg SAR 16 h. In combined treatment experiments we found no impact of the UMTS signal on chemically induced DNA damage in the different groups in general. However, a moderate decrease of DNA damage was seen in simultaneous treatment experiments with BPDE and 1.0 W/kg SAR in the YO group (decline 18%). Taken together our findings indicate that HF-EMF cause DNA damage in PBMC from older subjects (69.1 years). Furthermore, they show that the radiation does not increase induction of DNA damage by occupationally relevant chemicals.

DNA oxidation is a serious threat to genome integrity and involved in mutations and cancer initiation. The G base is most frequently damaged, and 8-oxo-7,8-dihydroguanine (G O, 8-hydroxyguanine) is one of the predominant damaged bases. In human cells, G O causes a G:C➔T:A transversion mutation at the modified site, and also induces untargeted substitution mutations at the G bases of 5'-GpA-3' dinucleotides (action-at-a-distance mutations). The 5'-GpA-3' sequences are complementary to the 5'-TpC-3' sequences, the preferred substrates for apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like 3 (APOBEC3) cytosine deaminases, and thus their contribution to mutagenesis has been considered. In this study, APOBEC3B, the most abundant APOBEC3 protein in human U2OS cells, was knocked down in human U2OS cells, and a G O-shuttle plasmid was then transfected into the cells. The action-at-a-distance mutations were reduced to ~25% by the knockdown, indicating that G O-induced action-at-a-distance mutations is highly dependent on APOBEC3B in this cell line.

Post-COVID conditions are defined as the continuation of the symptoms of Coronavirus Disease 2019 (COVID-19) 3 months after the initial Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection, with no other explanation. Post-COVID conditions are seen among 30%-60% of patients with asymptomatic or mild forms of COVID-19. The underlying pathophysiological mechanisms of post-COVID conditions are not known. In SARS-CoV-2 infection, activation of the immune system leads to increased production of reactive oxygen molecules, depleted antioxidant reserve, and finally occurrence of oxidative stress. In oxidative stress conditions, DNA damage increases and DNA repair systems impair. In this study, glutathione (GSH) level, glutathione peroxidase (GPx) activity, 8-hydroxydeoxyguanosine (8-OHdG) level, basal, induced, and post-repair DNA damage were investigated in individuals suffering from post-COVID conditions. In the red blood cells, GSH levels and GPx activities were measured with a spectrophotometric assay and a commercial kit. Basal, in vitro H2O2 (hydrogen peroxide)-induced, and post-repair DNA damage (DNA damage after a repair incubation following H2O2-treatment, in vitro) were determined in lymphocytes by the comet assay. The urinary 8-OHdG levels were measured by using a commercial ELISA kit. No significant difference was found between the patient and control groups for GSH level, GPx activity, and basal and H2O2-induced DNA damage. Post-repair DNA damage was found to be higher in the patient group than those in the control group. Urinary 8-OHdG level was lower in the patient group compared to the control group. In the control group, GSH level and post-repair DNA damage were higher in the vaccinated individuals. In conclusion, oxidative stress formed due to the immune response against SARS-COV-2 may impair DNA repair mechanisms. Defective DNA repair may be an underlying pathological mechanism of post-COVID conditions.

The formamidopyrimidine DNA glycosylase (Fpg)-modified comet assay is widely used for the measurement of oxidatively generated damage to DNA. However, there has not been a recommended long-term positive control for this version of the comet assay. We have investigated potassium bromate as a positive control for the Fpg-modified comet assay because it generates many Fpg-sensitive sites with a little concurrent generation of DNA strand breaks. Eight laboratories used the same procedure for the treatment of monocytic THP-1 cells with potassium bromate (0, 0.5, 1.5, and 4.5 mM) and subsequent cryopreservation in a freezing medium consisting of 50% foetal bovine serum, 40% RPMI-1640 medium, and 10% dimethyl sulphoxide. The samples were analysed by the Fpg-modified comet assay three times over a 3-year period. All laboratories obtained a positive concentration-response relationship in cryopreserved samples (linear regression coefficients ranging from 0.79 to 0.99). However, there was a wide difference in the levels of Fpg-sensitive sites between the laboratory with the lowest (4.2% Tail DNA) and highest (74% Tail DNA) values in THP-1 cells after exposure to 4.5 mM KBrO3. In an attempt to assess sources of inter-laboratory variation in Fpg-sensitive sites, comet images from one experiment in each laboratory were forwarded to a central laboratory for visual scoring. There was high consistency between measurements of %Tail DNA values in each laboratory and the visual score of the same comets done in the central laboratory (r = 0.98, P < 0.001, linear regression). In conclusion, the results show that potassium bromate is a suitable positive comet assay control.