La importancia de evaluar el daño al DNA / The Importance of Assessing DNA Damage

Resumen Se calcula que el cuerpo humano está conformado por billones de células, las cuales sufren cientos de miles de lesiones al día en su DNA. Aunque el DNA no es la única biomolécula que sufre daños, su importancia radica en que es la única que no puede ser sustituida por la célula, así que, cuando esta sufre daños, la célula debe repararlos, tolerarlos o, en el caso extremo, activar las vías que la llevarán a la muerte, ya que lo importante es mantener la integridad celular y la homeostasis del organismo. Hay miles de agentes que pueden dañar al DNA, algunos los produce la misma célula y se les denomina 'agentes endógenos', mientras que otros son agentes externos y se les conoce como 'agentes exógenos'. La célula no puede evitar el daño causado por los agentes endógenos, ya que son productos de la actividad metabólica, por ejemplo; así que, cuando suceden se activan de forma inmediata los mecanismos celulares para mitigarlos. Lo mismo pasa con los daños causados por agentes exógenos, ya que la célula hará todo lo posible por disminuir los efectos adversos que pueden causar. El problema se pone de manifiesto cuando la célula no puede reparar los daños o los repara mal o son tantos que los mecanismos de reparación se ven rebasados, es entonces cuando el daño permanece en el DNA y se genera un estado de inestabilidad cromosómica que puede conducir a la célula a la disfunción y a la malignización. Este estado de inestabilidad cromosómica se puede ver reflejado en el aumento de rompimientos de DNA o de micronúcleos en las células expuestas, lo que se puede cuantificar por medio de métodos especiales como el 'Ensayo Cometa' y el 'Ensayo de Micronúcleos', ya que identificar el daño en el DNA es una forma de evaluar el potencial tóxico que tienen los agentes a los que están expuestas las poblaciones, permite conocer los mecanismos de acción que tienen y, además, ayuda a comprender los factores que influyen en el detrimento de la salud poblacional.

Abstract It is estimated that the human body is made of trillions of cells, which suffer hundreds of thousands of DNA lesions every day. Although DNA is not the only biomolecule that suffers damage, its importance lies in the fact that it is the only biomolecule that cannot be replaced by the cell, so when it suffers damage, the cell must repair it, tolerate or, in a extreme case, activate pathways that will lead to death, since the objective is to maintain cell integrity and the homeostasis of the organism.There are thousands of agents that can damage DNA, some are produced by the cell and are called 'endogenous, while others are external agents and are known as 'exogenous. The cell cannot avoid the damage caused by endogenous agents, since they are products of its metabolic activity, for example, so when they occur, cellular mechanisms are immediately activated to mitigate them. The same happens with the damage caused by exogenous agents, since the cell will do everything possible to diminish the adverse effects they can cause. The problem becomes apparent when the cell is unable to repair the damage or poorly repairs it, or repairs so much that the mechanisms are overwhelmed, when the damage remains in the DNA and a state of chromosomal instability is generated that can lead the cell to dysfunction and malignization. This state of chromosomal instability can be reflected in increased DNA breaks or micronuclei in exposed cells, which can be quantified by special methods such as the 'Comet Assay' and the 'Micronucleus Assay'. Since identifying DNA damage is a way of evaluating the toxic potential of the agents to which populations are exposed, it allows us to know their mechanisms of action and helps to understand the factors that influence the detriment in population's health.

Effects of fractionated low-dose ionizing radiation in the induction of EA.hy926 cell senescence / 中国辐射卫生

Objective To investigate the mechanism of fractionated low-dose ionizing radiation (LDIR) in the induction of EA.hy926 cell senescence. Methods EA.hy926 cells were irradiated with X-ray at 0, 50, 100, and 200 mGy × 4, respectively, and cultured for 24, 48, and 72 h. Several indicators were measured, including the levels of cellular senescence-associated β-galactosidase (SA-β-gal) staining, mRNA levels of senescence-associated cell cycle protein-dependent kinase inhibitor genes CDKN1A and CDKN2A, reactive oxygen species (ROS), total antioxidant capacity (T-AOC), and phosphorylated H2A histone family member X (γ-H2AX). Results After 4 fractionated LDIR, compared with the control group, the treatment groups showed increased nucleus area, blurred cell edge, and increased SA-β-gal positive area (P < 0.05) at 24, 48 and 72 h. After 4 fractionated LDIR, the mRNA level of CDKN1A increased in the 100 and 200 mGy × 4 groups at 24 and 48 h (P < 0.05), and CDKN2A mRNA level increased in the 100 and 200 mGy × 4 groups at 48 and 72 h (P < 0.05). The fluorescence intensity of ROS increased in treatment groups at 24, 48, and 72 h after 4 fractionated LDIR (P < 0.05). After 4 fractionated LDIR, the T-AOC level increased in the 100 and 200 mGy × 4 groups at 24 h (P < 0.05), and T-AOC level increased in all treatment groups at 48 and 72 h (P < 0.05). After 4 fractionated LDIR, γ-H2AX fluorescence intensity increased in all treatment groups at 24 h (P < 0.05), and the fluorescence intensity increased in the 100 and 200 mGy × 4 groups at 48 and 72 h (P < 0.05). Conclusion Fractionated LDIR can induce cellular senescence in EA.hy926 cells by impacting the cellular oxidation-antioxidation and oxidative damage levels, and the effects were relatively evident at 100 and 200 mGy.

Fanconi Anemia: Exploration of DNA Repair Pathways from Genetic Diseases to Cancer and Prospects for Treatment / 肿瘤防治研究

Fanconi anemia (FA) is an inheritable disorder that presents with bone marrow failure, developmental anomalies, and an increased susceptibility to cancer. The etiology of this condition stems from a genetic mutation that disrupts the proper repair of interstrand DNA cross-links (ICLs). The resultant dysregulation of the DNA damage response mechanism can induce genomic instability, thereby elevating the mutation rates and the likelihood of developing cancer. The FA pathway assumes a pivotal role in safeguarding genome stability through its involvement in the repair of DNA cross-links and the maintenance of overall genomic integrity. A mutation in the germ line of any of the genes responsible for encoding the FA protein results in the development of FA. The prevalence of aberrant FA gene expression in somatic cancer, coupled with the identification of a connection between FA pathway activation and resistance to chemotherapy, has solidified the correlation between the FA pathway and cancer. Consequently, targeted therapies that exploit FA pathway gene abnormalities are being progressively developed and implemented. This review critically examines the involvement of the FA protein in the repair of ICLs, the regulation of the FA signaling network, and its implications in cancer pathogenesis and prognosis. Additionally, it explores the potential utility of small-molecule inhibitors that target the FA pathway.

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 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.

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.

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.

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.

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.

Genetic analysis of novel pathogenic gene HROB in a family with primary ovarian insufficiency / 浙江大学学报·医学版

A 13-year and 6-month-old girl attended the Hunan Children's Hospital due to delayed menarche. The laboratory test results indicated increased follicle-stimulating hormone and luteinizing hormone, decreased anti-Mullerian hormone, and pelvic ultrasound showed a cord-like uterus and absence of bilateral ovaries. Her 11-year and 5-month-old younger sister had the same laboratory and imaging findings, and both girls were diagnosed with primary ovarian insufficiency. Whole exome sequencing and Sanger sequencing confirmed that the proband and her sister carried heterozygous variants of HROB gene c.718C>T (p.Arg240*) and c.1351C>T (p.Arg451*), which were inherited from their parents respectively and consistent with autosomal recessive inheritance. Oral estradiol valerate at an initial dose of 0.125 mg/d was given to the proband, and the secondary sexual characteristics began to develop after 6 months.

Deubiquitinating enzyme JOSD2 affects susceptibility of non-small cell lung carcinoma cells to anti-cancer drugs through DNA damage repair / 浙江大学学报·医学版

OBJECTIVES@#To investigate the effects and mechanisms of deubiquitinating enzyme Josephin domain containing 2 (JOSD2) on susceptibility of non-small cell lung carcinoma (NSCLC) cells to anti-cancer drugs.@*METHODS@#The transcriptome expression and clinical data of NSCLC were downloaded from the Gene Expression Omnibus. Principal component analysis and limma analysis were used to investigate the deubiquitinating enzymes up-regulated in NSCLC tissues. Kaplan-Meier analysis was used to investigate the relationship between the expression of deubiquitinating enzymes and overall survival of NSCLC patients. Gene ontology enrichment and gene set enrichment analysis (GSEA) were used to analyze the activation of signaling pathways in NSCLC patients with high expression of JOSD2. Gene set variation analysis and Pearson correlation were used to investigate the correlation between JOSD2 expression levels and DNA damage response (DDR) pathway. Western blotting was performed to examine the expression levels of JOSD2 and proteins associated with the DDR pathway. Immunofluorescence was used to detect the localization of JOSD2. Sulforhodamine B staining was used to examine the sensitivity of JOSD2-knock-down NSCLC cells to DNA damaging drugs.@*RESULTS@#Compared with adjacent tissues, the expression level of JOSD2 was significantly up-regulated in NSCLC tissues (P<0.05), and was significantly correlated with the prognosis in NSCLC patients (P<0.05). Compared with the tissues with low expression of JOSD2, the DDR-related pathways were significantly upregulated in NSCLC tissues with high expression of JOSD2 (all P<0.05). In addition, the expression of JOSD2 was positively correlated with the activation of DDR-related pathways (all P<0.01). Compared with the control group, overexpression of JOSD2 significantly promoted the DDR in NSCLC cells. In addition, DNA damaging agents significantly increase the nuclear localization of JOSD2, whereas depletion of JOSD2 significantly enhanced the sensitivity of NSCLC cells to DNA damaging agents (all P<0.05).@*CONCLUSIONS@#Deubiquitinating enzyme JOSD2 may regulate the malignant progression of NSCLC by promoting DNA damage repair pathway, and depletion of JOSD2 significantly enhances the sensitivity of NSCLC cells to DNA damaging agents.

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.

FARSB stratifies prognosis and cold tumor microenvironment across different cancer types: an integrated single cell and bulk RNA sequencing analysis / 南方医科大学学报

OBJECTIVE@#Immunotherapy has brought significant clinical benefits to a subset of patients, but has thus far been disappointing in the treatment of immunologically "cold" tumors. Existing biomarkers that can precisely identify these populations are insufficient. In this context, a potential cold tumor microenvironment (TME) marker FARSB was investigated to reveal its impact on TME and patients' response to immunotherapy across pan-cancer.@*METHODS@#The expression levels and mutational landscape of FARSB in pan-cancer were investigated. Kaplan-Meier and univariate Cox regression analyses were applied to analyze the prognostic significance of FARSB. Pathways affected by FARSB were investigated by gene set enrichment and variation analysis. The relationship between FARSB expression and immune infiltration was examined using the TIMER2 and R packages. Single-cell RNA sequencing (scRNA-seq) data of several cancer types from GSE72056, GSE131907, GSE132465, GSE125449 and PMID32561858 were analyzed to validate the impact of FARSB on the TME. The predictive effect of FARSB on immunotherapy efficacy was explored in 3 immune checkpoint inhibitors (ICIs)- treated cohorts (PMID32472114, GSE176307, and Riaz2017).@*RESULTS@#FARSB expression was significantly higher in 25 tumor tissues than in normal tissues and was associated with poor prognosis in almost all tumor types. FARSB expression exhibited a strong association with several DNA damage repair pathways and was significantly associated with TP53 mutation in lung adenocarcinoma (P < 0.0001, OR=2.25). FARSB characterized a typical immune desert TME and correlated with impaired expression of chemokines and chemokines receptors. Large-scale scRNA-seq analysis confirmed the immunosuppressive role of FARSB and revealed that FARSB potentially shapes the cold TME by impeding intercellular interactions. In 3 ICI-treated cohorts, FARSB demonstrated predictive value for immunotherapy.@*CONCLUSION@#This study provides a pan-cancer landscape of the FARSB gene by integrated single-cell and bulk DNA sequencing analysis and elucidates its biological function to promote DNA damage repair and construct the immune desert TME, suggesting the potential value of FARSB as a novel marker for stratifying patients with poor immunotherapeutic benefits and "cold" TME.

Mismatch repair gene germline mutations in patients with prostate cancer / 浙江大学学报·医学版

OBJECTIVES@#To investigate the prevalence of pathogenic germline mutations of mismatch repair (MMR) genes in prostate cancer patients and its relationship with clinicopathological characteristics.@*METHODS@#Germline sequencing data of 855 prostate cancer patients admitted in Fudan University Shanghai Cancer Center from 2018 to 2022 were retrospectively analyzed. The pathogenicity of mutations was assessed according to the American College of Medical Genetics and Genomics (ACMG) standard guideline, Clinvar and Intervar databases. The clinicopathological characteristics and responses to castration treatment were compared among patients with MMR gene mutation (MMR+ group), patients with DNA damage repair (DDR) gene germline pathogenic mutation without MMR gene (DDR+MMR－ group) and patients without DDR gene germline pathogenic mutation (DDR－ group).@*RESULTS@#Thirteen (1.52%) MMR+ patients were identified in 855 prostate cancer patients, including 1 case with MLH1 gene mutation, 6 cases with MSH2 gene mutation, 4 cases with MSH6 gene mutation and 2 cases with PMS2 gene mutation. 105 (11.9%) patients were identified as DDR gene positive (except MMR gene), and 737 (86.2%) patients were DDR gene negative. Compared with DDR－ group, MMR+ group had lower age of onset (P<0.05) and initial prostate-specific antigen (PSA) (P<0.01), while no significant differences were found between the two groups in Gleason score and TMN staging (both P>0.05). The median time to castration resistance was 8 months (95%CI: 6 months-not achieved), 16 months (95%CI: 12-32 months) and 24 months (95%CI: 21-27 months) for MMR+ group, DDR+MMR－ group and DDR－ group, respectively. The time to castration resistance in MMR+ group was significantly shorter than that in DDR+MMR－ group and DDR－ group (both P<0.01), while there was no significant difference between DDR+MMR－ group and DDR－ group (P>0.05).@*CONCLUSIONS@#MMR gene mutation testing is recommended for prostate cancer patients with early onset, low initial PSA, metastasis or early resistance to castration therapy.

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.

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.