In vitro assessment of the severity of deoxyribonucleic acid damage in different types of cataracts directly in lens epithelial cells

Purpose: This study aimed to assess the severity of deoxyribonucleic acid (DNA) damage in lens epithelial cells (LECs) of senile cortical, nuclear, and posterior subcapsular cataracts. Methods: LECs were obtained from senile cortical, nuclear, and subcapsular types of cataracts after surgery. DNA damage in the cells was immediately assessed quantitatively using the CometScore™ software. Results: Comets were found in cataractous LECs. The formation of “comets” in the DNA of LECs can be visualized using single?cell gel electrophoresis and indicates DNA strand breaks because the damaged DNA migrates at a different rate than the nondamaged DNA. Maximal damage was observed in Grade 3 cortical, nuclear, and subcapsular forms of cataracts. Statistically significant DNA damage was seen between grades 1 and 3 of cortical type of cataract, grades 1 and 3 of nuclear type of cataract, and grades 2 and 3 and grades 1 and 3 of posterior subcapsular type of cataract. Conclusion: In patients with senile cataract, DNA of LECs was randomly damaged, and this type of damage was possibly caused by reactive oxygen species (ROS). Maximum DNA damage was found in patients with Grade 3 senile cortical, nuclear, and subcapsular type cataracts. The pathogenesis of senile cataracts is multifactorial and includes continuous molecular stress resulting from photooxidative stress, UV irradiation, and oxidative reactions.

Cytogenetic changes in oral mucosal cells of human immunodeficiency virus-infected children and adolescents undergoing antiretroviral treatment

SUMMARY OBJECTIVE: The objective of this study was to evaluate possible cytogenetic changes in children and adolescents with human immunodeficiency virus on antiretroviral therapy, through the micronucleus test in oral mucosa. METHODS: This was a prospective study consisted of 40 individuals, of whom 21 comprised the human immunodeficiency virus group and 19 comprised the control group. Children and adolescents with human immunodeficiency virus were enrolled. The inclusion criteria were <18 years old and consent in participating in the study. The exclusion criteria were the presence of numerous systemic comorbidities, oral lesions, the habit of smoking, alcohol consumption, and X-rays or CT scans taken within 15 days prior to sample collection. A gentle scraping was performed on the inner portion of the jugal mucosa on both sides. A total of 2,000 cells per slide were analyzed for the determination of mutagenicity parameters as follows: micronuclei, binucleation, and nuclear buds. For measuring cytotoxicity, the following metanuclear changes were evaluated: pyknosis, karyolysis, and karyorrhexis, in a double-blind manner. The repair index was also evaluated in this setting. RESULTS: The human immunodeficiency virus group showed high frequencies of micronuclei (p=0.05), binucleated cells (p=0.001), and nuclear buds (p=0.03). In the cytotoxicity parameters, represented by the cell death phases, there was an increase with statistical difference (p≤0.05) in the karyorrhexis frequency (p=0.05). Additionally, repair index was decreased in the human immunodeficiency virus group. CONCLUSION: These results indicate that human immunodeficiency virus -infected individuals undergoing antiretroviral therapy have cytogenetic changes in oral mucosal cells.

Cytogenetic changes in oral mucosa cells from individuals submitted to oral human immunodeficiency virus pre-exposure prophylaxis use

SUMMARY OBJECTIVE: The objective of this study was to evaluate cytogenetic changes in individuals submitted to oral human immunodeficiency virus pre-exposure prophylaxis use through the micronucleus test in oral mucosa. METHODS: This study consisted of 37 individuals, of whom 17 comprised the pre-exposure prophylaxis group and 20 comprised the control group. A total of 2,000 cells per slide were analyzed for the determination of micronuclei, binucleation, nuclear buds, and cytotoxicity parameters: pyknosis, karyolysis, and karyorrhexis (KR), in a double-blind manner. The repair index was also evaluated in this setting. RESULTS: In the mutagenicity parameters, the pre-exposure prophylaxis group showed increased frequencies of micronuclei (p=0.0001), binucleation (p=0.001), and nuclear buds (p=0.07). Regarding the cytotoxicity parameters, there was an increase with a statistical difference (p≤0.05) in the karyorrhexis frequency (p=0.001). Additionally, the repair system efficiency decreased in the pre-exposure prophylaxis group. CONCLUSION: These results indicate that individuals undergoing pre-exposure prophylaxis use have geno- and cytotoxicity in oral mucosal cells.

The effects of repeated doses of xylazine-ketamine and medetomidineketamine anesthesia on DNA damage in the liver and kidney

Purpose: This study evaluated the DNA damage caused by repeated doses of xylazine-ketamine and medetomidine-ketamine anesthesia in the liver and kidneys. Methods: In this study, 60 rats were used. The rats were divided into group 1 (xylazine-ketamine), and group 2 (medetomidine-ketamine), and these anesthetic combinations were administered to the rats at repeated doses with 30-min intervals. The effects of these anesthetic agents on the tumor necrosis factor-alpha gene for DNA damage were investigated. Results: According to the gene expression results, it was observed that a single dose of xylazine-ketamine was 2.9-fold expressed, while first and second repeat doses did not show significant changes in expression levels. However, in the case of the third repetition, it was observed to be 3.8-fold overexpressed. In the case of medetomidine-ketamine administration, it was observed that a single-dose application resulted in a 1.04-fold expression, while the first and the third repeat doses showed a significant down expression. The samples from the second repeat dose administration group were found to have insignificant levels of expression. Conclusions: This study can contribute to understanding the safe anesthetic combination in research and operations in which xylazine-ketamine and medetomidine-ketamine combinations are used.

Functional polymorphisms of DNA repair genes in Latin America reinforces the heterogeneity of Myelodysplastic Syndrome

Abstract Nucleotide excision repair pathway (NER) is an essential mechanism for single-strand breaks (SSB) repair while xeroderma pigmentosum family (XPA to XPG) is the most important system to NER. Myelodysplastic syndrome (MDS) is a heterogeneous hematological cancer characterized by cytopenias and risk of acute myeloid leukemia (AML) transformation. MDS pathogenesis has been associated with problems of DNA repair system. This report aimed to evaluate NER polymorphisms (XPA rs1800975, XPC rs2228000, XPD rs1799793 and XPF rs1800067) in 269 MDS patients of different populations in Latin America (173 Brazilian and 96 Argentinean). Genotypes were identified in DNA samples by RT-qPCR using TaqMan SNP Genotyping Assay. Regarding rs1799793 polymorphism of XPD for Brazilian population, the heterozygous genotype AG presented a high odds ratio (OR) to have a normal karyotype (p= 0.012, OR=3.000) and the mutant homozygous genotype AA was associated to a high OR of AML transformation (p= 0.034, OR=7.4). In Argentine population, the homozygous mutant AA genotype of rs1800975 polymorphism of XPA was associated with an increased odd to have hemoglobin levels below 8g/dL (p= 0.013, OR=10.000) while for the rs1799793 polymorphism of XPD, the heterozygous AG genotype decreased OR to be classified as good (p< 0.001, OR=9.05 × 10−10), and intermediate (p< 0.001, OR=3.08 × 10−10), according to Revised-International Prognostic Scoring System. Regarding the rs1800067 polymorphisms of XPF, the homozygous mutant AA genotype showed a decreased OR to be classified as good (p< 0.001, OR=4.03 × 10−13) and intermediate (p< 0.001, OR=2.54 × 10−13). Our report reinforces the heterogeneity of MDS and demonstrates the importance of ethnic differences and regional influences in pathogenesis and prognosis of MDS.

Genotoxicity in the oral cells of older people from a Brazilian rural area: a population-based study

Abstract The purpose of this population-based, observational, and cross-sectional study was to evaluate alterations in the oral cells of a population of older people from a Brazilian rural area, using the micronucleus technique to investigate possible associated genotoxic factors. A questionnaire was applied and clinical examination and collection of oral mucosal cells were performed for all older people (≥ 60 years) from a town in southern Brazil. Demographic and socioeconomic variables, deleterious habits (drinking and tobacco use), presence of gastro-oesophageal reflux disease (GERD), and the use of proton pump inhibitors (PPIs) were considered the exposure variables, whereas metanuclear changes (MCs) and the prevalence of cell micronuclei (MN) were considered outcomes. Out of 489 older people, 447 were included in the study, among whom 50.8% were men with a mean age of 70.9 years and 83.9% had a monthly family income greater than US$ 500.00. GERD symptoms were present in 36.2% of the individuals, and 29.1% used PPIs daily, 53.3% consumed alcoholic beverages, and 46.7% used tobacco. The analysis of 1,000 oral mucosal cells per subject showed a MN frequency of 0-2 per individual, and MCs were detected with an average of 15 units per individual (median = 11 per individual). Poisson regression did not show statistical association between the exposure variables and the outcomes (presence of MN and MCs), except for the use of PPIs, which was a protective factor for the prevalence of MN [PR 0.6 (CI 0.3-0,9)]. Age, sex, family income, tobacco use and drinking, and GERD were not associated with the number of MN and MCs in oral mucosal cells of the investigated older people.

Disulfiram enhances the antitumor activity of cisplatin by inhibiting the Fanconi anemia repair pathway / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

A series of chemotherapeutic drugs that induce DNA damage, such as cisplatin (DDP), are standard clinical treatments for ovarian cancer, testicular cancer, and other diseases that lack effective targeted drug therapy. Drug resistance is one of the main factors limiting their application. Sensitizers can overcome the drug resistance of tumor cells, thereby enhancing the antitumor activity of chemotherapeutic drugs. In this study, we aimed to identify marketable drugs that could be potential chemotherapy sensitizers and explore the underlying mechanisms. We found that the alcohol withdrawal drug disulfiram (DSF) could significantly enhance the antitumor activity of DDP. JC-1 staining, propidium iodide (PI) staining, and western blotting confirmed that the combination of DSF and DDP could enhance the apoptosis of tumor cells. Subsequent RNA sequencing combined with Gene Set Enrichment Analysis (GSEA) pathway enrichment analysis and cell biology studies such as immunofluorescence suggested an underlying mechanism: DSF makes cells more vulnerable to DNA damage by inhibiting the Fanconi anemia (FA) repair pathway, exerting a sensitizing effect to DNA damaging agents including platinum chemotherapy drugs. Thus, our study illustrated the potential mechanism of action of DSF in enhancing the antitumor effect of DDP. This might provide an effective and safe solution for combating DDP resistance in clinical treatment.

Effects of Gundelia tournefortii L. on biochemical parameters, antioxidant activities and DNA damage in a rat model of experimental obesity / Efeitos de Gundelia tournefortii L. em parâmetros bioquímicos, atividades antioxidantes e danos ao DNA em um modelo de obesidade experimental de rato

Abstract The present study was designed to investigate the effects of Gundelia tournefortii L. plant extract on different tissues in terms of DNA damage, biochemical and antioxidant parameter values in rats with high-calorie diets. With this aim, Wistar albino male rats were divided into 4 groups containing 6 rats each and the study was completed over 12 weeks duration. At the end of the implementation process over the 12 weeks, rats were sacrificed and blood and tissue samples were obtained. Analyses were performed on blood and tissue samples. According to results for DNA damage (8-OHdG), in brain tissue the OG2 group was significantly reduced compared to the NC group. For MDA results in liver tissue, OG1 and OG2 groups were determined to increase by a significant degree compared to the control group, while the OG2 group was also increased significantly compared to the obese group. In terms of the other parameters, comparison between the groups linked to consumption of a high calorie diet (HCD) and administration of Gundelia tournefortii L. in terms of antioxidant activities and serum samples obtained statistically significant results. Gundelia tournefortii L. plant extracts had effects that may be counted as positive on antioxidant parameter activity and were especially identified to improve DNA damage and MDA levels in brain tissues. Additionally, consumption of Gundelia tournefortii L. plant extract in the diet may have antiobesity effects; thus, it should be evaluated for use as an effective weight-loss method and as a new therapeutic agent targeting obesity.

Resumo O presente estudo foi desenhado para investigar os efeitos do extrato da planta Gundelia tournefortii L. em diferentes tecidos em termos de danos ao DNA, valores de parâmetros bioquímicos e antioxidantes em ratos com dietas hipercalóricas. Com esse objetivo, ratos Wistar albinos machos foram divididos em 4 grupos contendo 6 ratos cada e o estudo foi concluído ao longo de 12 semanas de duração. No final desse processo de implementação, os ratos foram sacrificados e amostras de sangue e tecido foram obtidas. As análises foram realizadas em amostras de sangue e tecido. De acordo com os resultados para danos ao DNA (8-OHdG), no tecido cerebral o grupo OG2 foi significativamente reduzido em comparação com o grupo NC. Para os resultados de MDA no tecido hepático, os grupos OG1 e OG2 aumentaram significativamente em comparação ao grupo controle, enquanto o grupo OG2 também aumentou significativamente em comparação ao grupo obeso. Quanto aos demais parâmetros, a comparação entre os grupos ligados ao consumo de dieta hipercalórica (DC) e à administração de Gundelia tournefortii L. em termos de atividades antioxidantes e amostras de soro obteve resultados estatisticamente significativos. Os extratos de plantas de Gundelia tournefortii L. tiveram efeitos que podem ser considerados positivos na atividade dos parâmetros antioxidantes e foram especialmente identificados para melhorar os danos ao DNA e os níveis de MDA nos tecidos cerebrais. Além disso, o consumo de extrato vegetal de Gundelia tournefortii L. na dieta pode ter efeitos antiobesidade; portanto, deve ser avaliado para uso como um método eficaz de perda de peso e como um novo agente terapêutico voltado para a obesidade.

Effects of niraparib on the radiosensitivity of human esophageal cancer cells and its mechanism / 中华放射肿瘤学杂志

Objective:To evaluate the effect of niraparib, the poly (ADP-ribose) polymerase (PARP) inhibitor, on the radiosensitivity of esophageal squamous cell carcinoma (ESCC) and to preliminarily investigate its mechanism.Methods:Human esophageal squamous cell carcinoma cells ECA-109 and KYSE-150 were divided into the control, niraparib, single irradiation, combined (niraparib+irradiation) groups. Cell proliferation was measured by CCK-8 assay. The changes of cell survival rate were detected by colony formation assay. The changes of cell cycle and apoptosis were analyzed by flow cytometry. The number of γH2AX foci was detected by immunofluorescence, and the expression levels of PARP-1, cleaved-PARP, RAD51, mitogen-activated protein kinase (MAPK) [extracellular signal-regulated kinase 1 and 2 (ERK1/2) ] and p-MAPK (ERK1/2) proteins were determined by Western blot. All data were expressed as Mean±SD. Data between two groups conforming to normal distribution through the normality test were subject to independent sample t-test and multiple groups were analyzed using one-way ANOVA. Results:In human ESCC cells ECA-109 and KYSE-150, the proliferation of ESCC cells was significantly inhibited by niraparib combined with irradiation, and the values of average lethal dose (D 0), quasi-threshould dose(D q), survival fraction after 2 Gy irradiation (SF 2) in the combined group were decreased compared with those in the single irradiation group. The effect of irradiation alone on apoptosis of ECA-109 and KYSE-150 cells was limited. Compared to single irradiation group, irradiation combined with niraparib further increased the apoptosis rate in ESCC cells ( P=0.015, P=0.006). In ECA-109 cells, G 2/M phase arrest was significantly increased in combined group compared with irradiation alone group ( P<0.001). In ECA-109 cells, the number of γH2AX foci in combined group was higher than that in the single irradiation group after 2 h, and showed a significantly slower decay of γH2AX foci ( P<0.001). Moreover, niraparib combined with irradiation enhanced the radiation-induced cleavage of PARP-1 and down-regulated the expression of Rad51 and p-MAPK(ERK1/2). Conclusion:Niraparib can increase the radiosensitivity of esophageal cancer cells by inhibiting cell proliferation, promoting cell apoptosis, inhibiting the repair of DNA damage and regulating the MARK-ERK signaling pathway.

Research progress of DNA-PK inhibitors in the cancer treatment / 药学学报

The most toxic DNA damage is DNA double strand breaks (DSBs), which are mainly repaired by non-homologous end joining (NHEJ). DNA-dependent protein kinase (DNA-PK) belongs to phosphatidylinositol-3-kinase-related protein kinase family (PIKK) and plays a key role in NHEJ. DNA-PK is overexpressed in a variety of cancer cells and is related to the occurrence, development and drug resistance of malignant tumors. In this article, the representative DNA-PK inhibitors with anticancer effects are reviewed, in order to provide a reference to discovery novel DNA-PK inhibitors.

Effect of Paint Exposure Among Paint Workers and DNA Damage: A Scoping Review

@#Paint contains various complex chemical mixtures, such as aliphatic hydrocarbons, aromatic hydrocarbons (primarily toluene), ketones, and benzene as reported at previous studies. Toxicity from some chemicals can cause early DNA damage with various factors. A scoping review was conducted via literature review on relevant studies on the effect of paint exposure on paint workers and DNA damage. A systematic search was conducted in October 2021 via PubMed, Scopus, and Web of Science databases. The key terms used were paint, solvent-based paint, organic solvent, mixed organic solvent, occupational exposure and DNA damage, oxidative stress, genotoxicity on a painter, paint worker. From 561 articles, only 13 articles were finally selected based on the inclusion, exclusion criteria, and eligibility criteria. The literature showed that biomonitoring studies on painters were consistently reporting positive and significant DNA damage due to exposure to different types of compounds mixed in a paint. However, there were fewer studies on paint manufacturing factory workers compared to painters while paint manufacturing workers exposed various chemical everyday during the paint production which potentially susceptible to occupational toxicity. In conclusion, this review suggests that exposure to paints could induce early DNA damage among paint workers and further investigations on paint exposure among paint manufacturing factory workers and the DNA damage were needed in order to improve occupational health among paint workers in the future.

In vitro cytotoxicity of curcuminoids against head and neck cancer HNO97 cell line / Citotoxicidade in vitro de curcuminoides contra a linhagem de células HNO97 de câncer de cabeça e pescoço

Oral squamous cell carcinoma (OSCC) is a malignant tumour of Head and Neck Cancer (HNC). The recent therapeutic approaches used to treat cancer have adverse side effects. The natural agents exhibiting anticancer activities are generally considered to have a robust therapeutic potential. Curcuminoids, one of the major active compounds of the turmeric herb, are used as a therapeutic agent for several diseases including cancer. In this study, the cytotoxicity of curcuminoids was investigated against OSCC cell line HNO97. Our data showed that curcuminoids significantly inhibits the proliferation of HNO97 in a time and dose-dependent manner (IC50=35 μM). Cell cycle analysis demonstrated that curcuminoids increased the percentage of G2/M phase cell populations in the treated groups. Treating HNO97 cells with curcuminoids led to cell shrinking and increased detached cells, which are the typical appearance of apoptotic cells. Moreover, flow cytometry analysis revealed that curcuminoids significantly induced apoptosis in a time-dependent manner. Furthermore, as a response to curcuminoids treatment, comet tails were formed in cell nuclei due to the induction of DNA damage. Curcuminoids treatment reduced the colony formation capacity of HNO97 cells and induced morphological changes. Overall, these findings demonstrate that curcuminoids can in vitro inhibit HNC proliferation and metastasis and induce apoptosis.

O carcinoma de células escamosas oral (OSCC) é um tumor maligno do câncer de cabeça e pescoço (HNC). As recentes abordagens terapêuticas usadas para tratar o câncer têm efeitos colaterais adversos. Os agentes naturais que exibem atividades anticâncer são geralmente considerados como tendo um potencial terapêutico robusto. Curcuminoides, um dos principais compostos ativos da erva cúrcuma, são usados como agente terapêutico para várias doenças, incluindo câncer. Neste estudo, a citotoxicidade dos curcuminoides foi investigada contra a linha de células OSCC HNO97. Nossos dados mostraram que os curcuminoides inibem significativamente a proliferação de HNO97 de forma dependente do tempo e da dose (IC50 = 35 μM). A análise do ciclo celular demonstrou que os curcuminoides aumentaram a porcentagem de populações de células da fase G2 / M nos grupos tratados. O tratamento das células HNO97 com curcuminoides levou ao encolhimento celular e ao aumento das células destacadas, que são a aparência típica das células apoptóticas. Além disso, a análise de citometria de fluxo revelou que os curcuminoides induziram significativamente a apoptose de uma maneira dependente do tempo. Além disso, em resposta ao tratamento com curcuminoides, caudas de cometa foram formadas nos núcleos das células devido à indução de danos ao DNA. O tratamento com curcuminoides reduziu a capacidade de formação de colônias das células HNO97 e induziu alterações morfológicas. No geral, esses achados demonstram que os curcuminoides podem inibir in vitro a proliferação e metástase de HNC e induzir apoptose.

Effects of Gundelia tournefortii L. on biochemical parameters, antioxidant activities and DNA damage in a rat model of experimental obesity / Efeitos de Gundelia tournefortii L. em parâmetros bioquímicos, atividades antioxidantes e danos ao DNA em um modelo de obesidade experimental de rato

The present study was designed to investigate the effects of Gundelia tournefortii L. plant extract on different tissues in terms of DNA damage, biochemical and antioxidant parameter values in rats with high-calorie diets. With this aim, Wistar albino male rats were divided into 4 groups containing 6 rats each and the study was completed over 12 weeks duration. At the end of the implementation process over the 12 weeks, rats were sacrificed and blood and tissue samples were obtained. Analyses were performed on blood and tissue samples. According to results for DNA damage (8-OHdG), in brain tissue the OG2 group was significantly reduced compared to the NC group. For MDA results in liver tissue, OG1 and OG2 groups were determined to increase by a significant degree compared to the control group, while the OG2 group was also increased significantly compared to the obese group. In terms of the other parameters, comparison between the groups linked to consumption of a high calorie diet (HCD) and administration of Gundelia tournefortii L. in terms of antioxidant activities and serum samples obtained statistically significant results. Gundelia tournefortii L. plant extracts had effects that may be counted as positive on antioxidant parameter activity and were especially identified to improve DNA damage and MDA levels in brain tissues. Additionally, consumption of Gundelia tournefortii L. plant extract in the diet may have antiobesity effects; thus, it should be evaluated for use as an effective weight-loss method and as a new therapeutic agent targeting obesity.

O presente estudo foi desenhado para investigar os efeitos do extrato da planta Gundelia tournefortii L. em diferentes tecidos em termos de danos ao DNA, valores de parâmetros bioquímicos e antioxidantes em ratos com dietas hipercalóricas. Com esse objetivo, ratos Wistar albinos machos foram divididos em 4 grupos contendo 6 ratos cada e o estudo foi concluído ao longo de 12 semanas de duração. No final desse processo de implementação, os ratos foram sacrificados e amostras de sangue e tecido foram obtidas. As análises foram realizadas em amostras de sangue e tecido. De acordo com os resultados para danos ao DNA (8-OHdG), no tecido cerebral o grupo OG2 foi significativamente reduzido em comparação com o grupo NC. Para os resultados de MDA no tecido hepático, os grupos OG1 e OG2 aumentaram significativamente em comparação ao grupo controle, enquanto o grupo OG2 também aumentou significativamente em comparação ao grupo obeso. Quanto aos demais parâmetros, a comparação entre os grupos ligados ao consumo de dieta hipercalórica (DC) e à administração de Gundelia tournefortii L. em termos de atividades antioxidantes e amostras de soro obteve resultados estatisticamente significativos. Os extratos de plantas de Gundelia tournefortii L. tiveram efeitos que podem ser considerados positivos na atividade dos parâmetros antioxidantes e foram especialmente identificados para melhorar os danos ao DNA e os níveis de MDA nos tecidos cerebrais. Além disso, o consumo de extrato vegetal de Gundelia tournefortii L. na dieta pode ter efeitos antiobesidade; portanto, deve ser avaliado para uso como um método eficaz de perda de peso e como um novo agente terapêutico voltado para a obesidade.

In vitro cytotoxicity of curcuminoids against head and neck cancer HNO97 cell line

Abstract Oral squamous cell carcinoma (OSCC) is a malignant tumour of Head and Neck Cancer (HNC). The recent therapeutic approaches used to treat cancer have adverse side effects. The natural agents exhibiting anticancer activities are generally considered to have a robust therapeutic potential. Curcuminoids, one of the major active compounds of the turmeric herb, are used as a therapeutic agent for several diseases including cancer. In this study, the cytotoxicity of curcuminoids was investigated against OSCC cell line HNO97. Our data showed that curcuminoids significantly inhibits the proliferation of HNO97 in a time and dose-dependent manner (IC50=35 M). Cell cycle analysis demonstrated that curcuminoids increased the percentage of G2/M phase cell populations in the treated groups. Treating HNO97 cells with curcuminoids led to cell shrinking and increased detached cells, which are the typical appearance of apoptotic cells. Moreover, flow cytometry analysis revealed that curcuminoids significantly induced apoptosis in a time-dependent manner. Furthermore, as a response to curcuminoids treatment, comet tails were formed in cell nuclei due to the induction of DNA damage. Curcuminoids treatment reduced the colony formation capacity of HNO97 cells and induced morphological changes. Overall, these findings demonstrate that curcuminoids can in vitro inhibit HNC proliferation and metastasis and induce apoptosis.

Resumo O carcinoma de células escamosas oral (OSCC) é um tumor maligno do câncer de cabeça e pescoço (HNC). As recentes abordagens terapêuticas usadas para tratar o câncer têm efeitos colaterais adversos. Os agentes naturais que exibem atividades anticâncer são geralmente considerados como tendo um potencial terapêutico robusto. Curcuminoides, um dos principais compostos ativos da erva cúrcuma, são usados como agente terapêutico para várias doenças, incluindo câncer. Neste estudo, a citotoxicidade dos curcuminoides foi investigada contra a linha de células OSCC HNO97. Nossos dados mostraram que os curcuminoides inibem significativamente a proliferação de HNO97 de forma dependente do tempo e da dose (IC50 = 35 M). A análise do ciclo celular demonstrou que os curcuminoides aumentaram a porcentagem de populações de células da fase G2 / M nos grupos tratados. O tratamento das células HNO97 com curcuminoides levou ao encolhimento celular e ao aumento das células destacadas, que são a aparência típica das células apoptóticas. Além disso, a análise de citometria de fluxo revelou que os curcuminoides induziram significativamente a apoptose de uma maneira dependente do tempo. Além disso, em resposta ao tratamento com curcuminoides, caudas de cometa foram formadas nos núcleos das células devido à indução de danos ao DNA. O tratamento com curcuminoides reduziu a capacidade de formação de colônias das células HNO97 e induziu alterações morfológicas. No geral, esses achados demonstram que os curcuminoides podem inibir in vitro a proliferação e metástase de HNC e induzir apoptose.

Effects of Gundelia tournefortii L. on biochemical parameters, antioxidant activities and DNA damage in a rat model of experimental obesity

Abstract The present study was designed to investigate the effects of Gundelia tournefortii L. plant extract on different tissues in terms of DNA damage, biochemical and antioxidant parameter values in rats with high-calorie diets. With this aim, Wistar albino male rats were divided into 4 groups containing 6 rats each and the study was completed over 12 weeks duration. At the end of the implementation process over the 12 weeks, rats were sacrificed and blood and tissue samples were obtained. Analyses were performed on blood and tissue samples. According to results for DNA damage (8-OHdG), in brain tissue the OG2 group was significantly reduced compared to the NC group. For MDA results in liver tissue, OG1 and OG2 groups were determined to increase by a significant degree compared to the control group, while the OG2 group was also increased significantly compared to the obese group. In terms of the other parameters, comparison between the groups linked to consumption of a high calorie diet (HCD) and administration of Gundelia tournefortii L. in terms of antioxidant activities and serum samples obtained statistically significant results. Gundelia tournefortii L. plant extracts had effects that may be counted as positive on antioxidant parameter activity and were especially identified to improve DNA damage and MDA levels in brain tissues. Additionally, consumption of Gundelia tournefortii L. plant extract in the diet may have antiobesity effects; thus, it should be evaluated for use as an effective weight-loss method and as a new therapeutic agent targeting obesity.

Resumo O presente estudo foi desenhado para investigar os efeitos do extrato da planta Gundelia tournefortii L. em diferentes tecidos em termos de danos ao DNA, valores de parâmetros bioquímicos e antioxidantes em ratos com dietas hipercalóricas. Com esse objetivo, ratos Wistar albinos machos foram divididos em 4 grupos contendo 6 ratos cada e o estudo foi concluído ao longo de 12 semanas de duração. No final desse processo de implementação, os ratos foram sacrificados e amostras de sangue e tecido foram obtidas. As análises foram realizadas em amostras de sangue e tecido. De acordo com os resultados para danos ao DNA (8-OHdG), no tecido cerebral o grupo OG2 foi significativamente reduzido em comparação com o grupo NC. Para os resultados de MDA no tecido hepático, os grupos OG1 e OG2 aumentaram significativamente em comparação ao grupo controle, enquanto o grupo OG2 também aumentou significativamente em comparação ao grupo obeso. Quanto aos demais parâmetros, a comparação entre os grupos ligados ao consumo de dieta hipercalórica (DC) e à administração de Gundelia tournefortii L. em termos de atividades antioxidantes e amostras de soro obteve resultados estatisticamente significativos. Os extratos de plantas de Gundelia tournefortii L. tiveram efeitos que podem ser considerados positivos na atividade dos parâmetros antioxidantes e foram especialmente identificados para melhorar os danos ao DNA e os níveis de MDA nos tecidos cerebrais. Além disso, o consumo de extrato vegetal de Gundelia tournefortii L. na dieta pode ter efeitos antiobesidade; portanto, deve ser avaliado para uso como um método eficaz de perda de peso e como um novo agente terapêutico voltado para a obesidade.

Effect of hexavalent chromium-induced ribosomal DNA copy number variation on DNA damage response in various cell lines / 预防医学

Objective@#To investigate the effect of ribosomal DNA (rDNA) copy number variation caused by hexavalent chromium exposure on DNA damage response in different cell lines, so as to provide insights into the involvement of hexavalent chromium-induced rDNA copy number variation in DNA damage responses. @*@#Methods Human lung epithelial BEAS-2B cells and human embryonic lung MRC-5 cells were treated with 2 μmol/L potassium dichromate for 24 hours, and then cells were transferred to fresh media for further incubation, while cells treated with the same volume of phosphate buffer solution served as controls. Cells treated with potassium dichromate for 24 hours, and 3 and 7 days post-detoxification, were harvested, and rDNA copy number was quantified in cells using a quantitative fluorescent real-time PCR assay. Cell cycle, apoptosis and DNA damage were detected using a Muse cell analyzer, and the DNA damage was evaluated with the proportion of ataxia telangiectasia-mutated (ATM) gene activation, proportion of double-strand DNA breaks and the percentage of the H2A.X variant histone phosphorylatio.@*@# Results The 45S and 5S rDNA copy numbers of were significantly higher in MRC-5 cells than in BEAS-2B cells [(1.54±0.26) vs. (1.02±0.18), P<0.05; (6.97±1.07) vs. (3.00±0.15), P<0.05]. The 45S rDNA copy number was lower in MRC-5 cells 3 days post-detoxification (0.80±0.04) than in controls (P<0.05), and was higher in BEAS-2B cells 3 days post-detoxification (1.43±0.07) than in controls (P<0.05) . G0/G1 phase arrest was found in MRC-5 cells 24 hours post-treatment, and the apoptotic rates were significantly higher in MRC-5 cells 3 and 7 days post-detoxification than in controls [(11.53±1.53)%, (18.33±0.70)% vs. (3.53±0.93)%, P<0.05]. The overall apoptotic rates 24 hours post-treatment and 3 days post-detoxification [(2.80±0.17)%, (3.33±0.57)% vs. (1.53±0.61)%, P<0.05], proportion of ATM gene activation 3 days post-detoxification [(3.37±0.67%) vs. (1.18±0.22)%, P<0.05], proportion of double-strand DNA breaks 3 days post-detoxification [(4.45±0.85)% vs. (0.97±0.21)%, P<0.05] and percentage of the H2A.X variant histone phosphorylation 3 days post-detoxification [(1.68±0.56)% vs. (0.29±0.06)%, P<0.05] in BEAS-2B cells were higher than in controls. @*Conclusions@#Hexavalent chromium-induced rDNA copy number variation affects DNA damage response in different cell lines. A stronger DNA damage response is found in BEAS-2B cells with a low rDNA copy number, and a relative stable response is observed in MRC-5 cells with a high rDNA copy number.

Effects of low-dose radiation on oxidative stress and damage repair in HBE cells / 中国辐射卫生

@#<b>Objective</b> To investigate the effects of lowdose ionizing radiation (LDIR) on oxidative stress and damage repair in human bronchial epithelial (HBE) cells. <b>Methods</b> HBE cells were divided into 0, 50, 100, and 200 mGy groups, and cultured for 24 and 48 h after X-ray irradiation, respectively. The cell viability, levels of glutathione (GSH), malondialdehyde (MDA), and 8-hydroxy-2’-deoxyguanosine (8-OHdG), and transcriptional levels of DNA damage repair genes <i>PPP2R2D</i> and <i>TP53</i> were measured. <b>Results</b> At 24 h after irradiation, there was no significant difference in the cell viability between the dose groups and the control group (<i>P</i> > 0.05); all dose groups had significantly increased MDA level, dose-dependently decreased GSH level, dose-dependently increased 8-OHdG level, and significantly increased mRNA level of <i>PPP2R2D</i> gene (all <i>P</i> < 0.05); the mRNA expression level of <i>TP53</i> gene was significantly increased in the 50 mGy group (<i>P</i> < 0.05). At 48 h after irradiation, there were the highest cell viability, significantly decreased MDA and 8-OHdG levels, and significantly increased mRNA expression levels of <i>PPP2R2D</i> and <i>TP53</i> genes in the 50 mGy group compared with the control group (all <i>P</i> < 0.05); the GSH level in the 100 mGy group was significantly increased (<i>P</i> < 0.05). <b>Conclusion</b> LDIR, especially radiation at 50 mGy, can affect the oxidative-antioxidant level in HBE cells and the transcript-level differential expression of DNA damage repair genes.

Establishment of Human Lung Adenocarcinoma Radioresistant Cell Lines and the Mechanism of Radioresistance / 中国肺癌杂志

BACKGROUND@#Radiotherapy is one of the most common treatments for lung cancer, and about 40%-50% of patients after radiotherapy will appear uncontrolled or recurrence in the case of local tumors. Radioresistance is the predominant cause of local therapeutic failure. Nevertheless, the lack of in vitro radioresistance models is an influential factor obstructing the study of its mechanism. Therefore, the establishment of radioresistant cell lines, H1975DR and H1299DR, was beneficial to explore the mechanism of radioresistance in lung adenocarcinoma.@*METHODS@#The radioresistant cell lines of H1975DR and H1299DR were obtained from H1975 and H1299 cells irradiated with equal doses of X-rays; Clonogenic assays were performed to compare the clone-forming ability of H1975 vs H1975DR cells, H1299 vs H1299DR cells, then fitting cell survival curve by linear quadratic model; The comet assay was employed to examine DNA damage repair and calculate the percentage of DNA tails; The optical microscopy, CCK-8, flow cytometry, Transwell invasion assays were used to compare biological characteristics such as cell morphology, cell proliferation, apoptosis level, cycle distribution, cell migration and invasion; Western blot was carried out to measure the protein expression of DNA damage repair factors, such as DNA-PKcs, 53BP1, RAD51, and p-ATM.@*RESULTS@#After five months of continuous irradiation and stable culture, radioresistant cell lines H1975DR and H1299DR were obtained. The cell proliferation activity, clone formation ability and DNA damage repair ability of the two radioresistant cell lines were significantly improved under X-ray irradiation. The proportion of the G2/M phase was markedly decreased and the proportion of the G0/G1 phase was increased. Cell migration and invasion ability were significantly enhanced. Relative expression levels of p-DNA-PKcs (Ser2056), 53BP1 in the nonhomologous end-joining (NHEJ) repair pathway and p-ATM (Ser1981), RAD51 in the homologous recombination (HR) repair pathway were higher than those in H1975 and H1299.@*CONCLUSIONS@#H1975 and H1299 cell lines can be able to differentiate into lung adenocarcinoma radioresistant cell lines H1975DR and H1299DR by equal dose fractional irradiation, which provided an in vitro cytological model for the study of radiotherapy resistance mechanism of lung cancer patients.

Advances of structure and mechanisms of bromodomain-containing protein 4 and its related research in tumors / 生物工程学报

The bromodomain and extraterminal domain (Bet) family are the regulators of the epigenome and also the pivotal driving factors for the expression of tumor related genes that tumor cells depend on for survival and proliferation. Bromodomain-containing protein 4 (Brd4) is a member of the Bet protein family. Generally, Brd4 identifies acetylated histones and binds to the promoter or enhancer region of target genes to initiate and maintain expression of tumor related genes. Brd4 is closely related to the regulation of multiple transcription factors and chromatin modification and is involved in DNA damage repair and maintenance of telomere function, thus maintaining the survival of tumor cells. This review summarizes the structure and function of Brd4 protein and the application of its inhibitors in tumor research.

On-demand integrated nano-engager converting cold tumors to hot via increased DNA damage and dual immune checkpoint inhibition

Cancer immunotherapy has become a promising strategy. However, the effectiveness of immunotherapy is restricted in "cold tumors" characterized with insufficient T cells intratumoral infiltration and failed T cells priming. Herein, an on-demand integrated nano-engager (JOT-Lip) was developed to convert cold tumors to hot via "increased DNA damage and dual immune checkpoint inhibition" strategy. JOT-Lip was engineered by co-loading oxaliplatin (Oxa) and JQ1 into liposomes with T-cell immunoglobulin mucin-3 antibodies (Tim-3 mAb) coupled on the liposomal surface by metalloproteinase-2 (MMP-2)-sensitive linker. JQ1 inhibited DNA repair to increase DNA damage and immunogenic cell death (ICD) of Oxa, thus promoting T cells intratumoral infiltration. In addition, JQ1 inhibited PD-1/PD-L1 pathway, achieving dual immune checkpoint inhibition combining with Tim-3 mAb, thus effectively promoting T cells priming. It is demonstrated that JOT-Lip not only increased DNA damage and promoted the release of damage-associated molecular patterns (DAMPs), but also enhanced T cells intratumoral infiltration and promoted T cell priming, which successfully converted cold tumors to hot and showed significant anti-tumor and anti-metastasis effects. Collectively, our study provides a rational design of an effective combination regimen and an ideal co-delivery system to convert cold tumors to hot, which holds great potential in clinical cancer chemoimmunotherapy.