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BACKGROUND: Sirolimus, one of the immunosuppressive drugs administered to renal transplant recipients, is metabolized by cytochrome P450 (CYP) 3A5. Accordingly, CYP3A5 polymorphism is a genetic factor affecting sirolimus pharmacokinetics (PK). Therefore, we conducted a systematic review and meta-analysis on the association between sirolimus PK and CYP3A5*3 polymorphism. METHODS: We searched for studies published up to 13 June 2024 from PubMed, Embase, Cochrane Library, and Web of Science. We reviewed studies on the relationship between CYP3A5*3 polymorphism and weightadjusted trough concentration/dose (C/D) ratio and dosage of sirolimus in renal transplant recipients, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We evaluated mean differences (MDs) and 95% confidence intervals (CIs). RESULTS: A total of seven studies were included. The weight-adjusted C/D ratio of sirolimus was significantly higher in patients with the CYP3A5*3/*3 rather than CYP3A5*1/*1 or CYP3A5*1/*3 genotype (MD 95.27 ng/mL per mg/kg; 95% CI: 58.06, 132.47; I2 = 74%; p < 0.00001). Also, the weight-adjusted dosage of sirolimus was significantly lower in patients with the CYP3A5*3/*3 rather than CYP3A5*1/*1 or CYP3A5*1/*3 genotype (MD -2.60 × 10-3 mg/kg; 95% CI: -4.52, -0.69; I2 = 44%; p = 0.008). CONCLUSION: Our meta-analysis showed a significant effect for the CYP3A5*3 genotype on weight-adjusted C/D ratio and dosage of sirolimus in adult renal transplant recipients.
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Introduction: The purpose of this study is to identify the relationship between coenzyme Q 10 (CoQ10)-related gene polymorphisms and statin-related myotoxicity (SRM). Methods: We retrospectively analyzed prospectively collected samples from February to May 2021. To investigate the association between CoQ10-related genetic factors and SRM, we selected 37 single nucleotide polymorphisms from five genes (COQ2, COQ3, COQ5, COQ6, and COQ7). The odds ratio (OR) and adjusted OR with 95% confidence intervals (CI) were calculated for univariate and multivariable logistic regression analyses, respectively. Results: A total of 688 stroke patients were included in the analysis, including 56 SRM cases. In the multivariable analysis, two models were constructed using demographic factors only in model I, and demographic and genetic factors in model II. Compared to other statins, atorvastatin decreased the SRM risk whereas ezetimibe use increased the SRM risk in model I and model II. Patients with COQ2 rs4693075 G allele, COQ3 rs11548336 TT genotype, and COQ5 rs10849757 A allele had a 2.9-fold (95% CI: 1.6-5.3), 1.9-fold (95% CI: 1.1-3.5), and 3.3-fold (95% CI: 1.5-8.3) higher risk of SRM, respectively. Conclusion: This study could be utilized to develop a personalized medicine strategy in patients treated with statins.
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PURPOSE: Hepatotoxicity has emerged as a major cause of statin treatment interruption. Although organic anion-transporting polypeptide 1B1 (SLCO1B1), multidrug resistance protein 1 (ABCB1), and breast cancer resistance protein (ABCG2) have been identified as transporters of statins, knowledge of their role in statin-associated hepatotoxicity remains limited. Therefore, we aimed to conduct a comprehensive analysis to elucidate the association between hepatotoxicity and SLCO1B1, ABCB1, and ABCG2 polymorphisms. METHODS: This study retrospectively analyzed prospectively collected samples. We selected 10 single nucleotide polymorphisms (SNPs) of SLCO1B1, 9 SNPs of ABCB1, and 12 SNPs of ABCG2. We developed two models for multivariable analyses (Model I: clinical factors only; Model II: both clinical and genetic factors), and the attributable risk (%) of variables in Model II was determined. RESULTS: Among 851 patients, 66 (7.8%) developed hepatotoxicity. In Model I, lipophilic statins, atrial fibrillation (Afib), and diabetes mellitus showed a significant association with hepatotoxicity. In Model II, lipophilic statins and Afib, SLCO1B1 rs11045818 A allele, SLCO1B1 rs4149035 T allele, and ABCG2 rs2622629 TT genotype were associated with higher hepatotoxicity risk. Among them, the SLCO1B1 rs11045818 A allele exhibited the highest attributable risk (93.2%). The area under the receiver operating characteristic curve in Model I was 0.62 (95% CI: 0.55-0.69), and it was increased to 0.71 in Model II (95% CI: 0.64-0.77). CONCLUSION: This study investigated the correlation between hepatotoxicity and polymorphisms of transporter genes in patients taking statins. The findings could help improve personalized treatments for patients receiving statin therapy.
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Smoking cessation medications have the potential to affect the functioning of the nervous system, leading to sleep disturbances. Our study aimed to compare the sleep-related side effects (such as insomnia, abnormal dreams, nightmares, and somnolence) induced by different smoking cessation medications in non-psychiatric smokers. We conducted a thorough search of five electronic databases (Cochrane, EMBASE, PubMed, PsycInfo, and Web of Science) for randomized controlled trials. This study was registered with the PROSPERO (registration number CRD42022347976). A total of 79 full-text articles, encompassing 36,731 participants, were included in our analysis. Individuals using bupropion, bupropion in combination with a nicotinic acetylcholine receptor agonist (NRA), and bupropion in conjunction with nicotine replacement therapy (NRT) exhibited a higher likelihood of experiencing insomnia compared to those using NRT alone. Bupropion plus NRA had the highest ranking on the surface under the cumulative ranking curve (SUCRA) for insomnia risk, while placebo had the lowest ranking. Additionally, NRA plus NRT ranked first for abnormal dream outcomes, NRA alone for nightmares, and nortriptyline for somnolence, based on the SUCRA results. Healthcare providers should exercise caution when prescribing smoking cessation drugs, particularly in consideration of their potential sleep-related side effects.
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Distúrbios do Início e da Manutenção do Sono , Abandono do Hábito de Fumar , Humanos , Abandono do Hábito de Fumar/psicologia , Bupropiona/efeitos adversos , Vareniclina/uso terapêutico , Fumar/psicologia , Metanálise em Rede , Distúrbios do Início e da Manutenção do Sono/tratamento farmacológico , Sonolência , Dispositivos para o Abandono do Uso de Tabaco/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como Assunto , Agonistas Nicotínicos/efeitos adversos , SonoRESUMO
The respiratory tract represents the key target for antiviral delivery in early interventions to prevent severe COVID-19. While neutralizing monoclonal antibodies (mAb) possess considerable efficacy, their current reliance on parenteral dosing necessitates very large doses and places a substantial burden on the healthcare system. In contrast, direct inhaled delivery of mAb therapeutics offers the convenience of self-dosing at home, as well as much more efficient mAb delivery to the respiratory tract. Here, building on our previous discovery of Fc-mucin interactions crosslinking viruses to mucins, we showed that regdanvimab, a potent neutralizing mAb already approved for COVID-19 in several countries, can effectively trap SARS-CoV-2 virus-like particles in fresh human airway mucus. IN-006, a reformulation of regdanvimab, was stably nebulized across a wide range of concentrations, with no loss of activity and no formation of aggregates. Finally, nebulized delivery of IN-006 resulted in 100-fold greater mAb levels in the lungs of rats compared to serum, in marked contrast to intravenously dosed mAbs. These results not only support our current efforts to evaluate the safety and efficacy of IN-006 in clinical trials, but more broadly substantiate nebulized delivery of human antiviral mAbs as a new paradigm in treating SARS-CoV-2 and other respiratory pathologies.
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OBJECTIVES: To elucidate the relationship between CYP2D6 polymorphisms and Plasmodium vivax recurrence in patients receiving primaquine-based treatment through systematic review and meta-analysis. METHODS: We searched the PubMed, EMBASE, Cochrane Library, and Web of Science databases for eligible studies published up to August of 2021. We included studies investigating the associations between CYP2D6 polymorphisms and P. vivax recurrence. We evaluated the pooled odds ratio (OR) and 95% confidence interval (CI). RESULTS: Data from nine studies, including 970 patients, were analyzed. We found that CYP2D6 poor metabolizers (PMs), intermediate metabolizers (IMs), or normal metabolizers slow (NM-Ss) were associated with a 1.8-fold (95% CI, 1.34-2.45; P = 0.0001) higher recurrence of P. vivax than normal metabolizers fast (NM-Fs), extensive metabolizers (EMs), or ultrarapid metabolizer (UMs). Subgroup analysis showed that studies on both Brazilian and Southeast or East Asian individuals had similar results to the main results. Sensitivity analysis by sequentially excluding individual studies also showed robust results (OR range: 1.63-2.01). CONCLUSIONS: This meta-analysis confirmed that CYP2D6 PMs, IMs, or NM-Ss increased the risk of P. vivax recurrence compared to NM-Fs, EMs, or UMs. The results of this study could be used to predict P. vivax recurrence and suggest CYP2D6 genotype-based primaquine dosing.
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Antimaláricos , Malária Vivax , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Citocromo P-450 CYP2D6/genética , Citocromo P-450 CYP2D6/farmacologia , Citocromo P-450 CYP2D6/uso terapêutico , Genótipo , Humanos , Malária Vivax/tratamento farmacológico , Plasmodium vivax/genética , Primaquina/uso terapêutico , RecidivaRESUMO
This study aimed to investigate the influence of CYP2C9 genetic polymorphisms on the pharmacokinetics of losartan and its active metabolite, E-3174, through a systematic review and meta-analysis. Eight studies published before March 2021 were included in this study. We used PubMed, the Cochrane Library, EMBASE, and Web of Science, based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The data analysis was conducted through Review Manager (RevMan), version 5.3, and R software. We found that healthy volunteers with CYP2C9*2 or *3 carriers had higher area under the curve (AUC0-∞) of losartan (mean difference (MD) 0.17 µg·h/mL; 95% confidence intervals (CI): 0.04, 0.29) and lower AUC0-∞ of E-3174 (MD -0.35 µg·h/mL; 95% CI: -0.62, -0.08) than those with CYP2C9*1/*1. Subjects with CYP2C9*2 or *3 carriers showed lower maximum concentration (Cmax) of E-3174 than those with CYP2C9*1/*1 (MD -0.13 µg/mL; 95% CI: -0.17, -0.09). For half-life, subjects with CYP2C9*2 or *3 carriers had longer half-lives of losartan and E-3174 than those with CYP2C9*1/*1 (MD 0.47 h; 95% CI: 0.32, 0.61 and MD 0.68 h; 95% CI: 0.44, 0.92, respectively). This meta-analysis suggests that the pharmacokinetics of losartan and E-3174 are associated with the CYP2C9 polymorphisms.
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Post-replication repair (PRR) allows tolerance of chemical- and UV-induced DNA base lesions in both an error-free and an error-prone manner. In classical PRR, PCNA monoubiquitination recruits translesion synthesis (TLS) DNA polymerases that can replicate through lesions. We find that PRR responds to DNA replication stress that does not cause base lesions. Rad5 forms nuclear foci during normal S phase and after exposure to types of replication stress where DNA base lesions are likely absent. Rad5 binds to the sites of stressed DNA replication forks, where it recruits TLS polymerases to repair single-stranded DNA (ssDNA) gaps, preventing mitotic defects and chromosome breaks. In contrast to the prevailing view of PRR, our data indicate that Rad5 promotes both mutagenic and error-free repair of undamaged ssDNA that arises during physiological and exogenous replication stress.
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Quebras de DNA de Cadeia Simples , DNA Helicases/metabolismo , Reparo do DNA , Replicação do DNA , DNA Fúngico/metabolismo , DNA de Cadeia Simples/metabolismo , Mutação , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/enzimologia , Sítios de Ligação , Cromossomos Fúngicos , DNA Helicases/genética , DNA Fúngico/genética , DNA de Cadeia Simples/genética , DNA Polimerase Dirigida por DNA/genética , DNA Polimerase Dirigida por DNA/metabolismo , Mitose , Nucleotidiltransferases/genética , Nucleotidiltransferases/metabolismo , Antígeno Nuclear de Célula em Proliferação/genética , Antígeno Nuclear de Célula em Proliferação/metabolismo , Ligação Proteica , Reparo de DNA por Recombinação , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Proteínas de Saccharomyces cerevisiae/genética , UbiquitinaçãoRESUMO
BACKGROUND: Adventitious root (AR) formation is a complex genetic trait, which is controlled by various endogenous and environmental cues. Auxin is known to play a central role in AR formation; however, the mechanisms underlying this role are not well understood. RESULTS: In this study, we showed that a previously identified auxin signaling module, AUXIN RESPONSE FACTOR(ARF)7/ARF19-LATERAL ORGAN BOUNDARIES DOMAIN(LBD)16/LBD18 via AUXIN1(AUX1)/LIKE-AUXIN3 (LAX3) auxin influx carriers, which plays important roles in lateral root formation, is involved in AR formation in Arabidopsis. In aux1, lax3, arf7, arf19, lbd16 and lbd18 single mutants, we observed reduced numbers of ARs than in the wild type. Double and triple mutants exhibited an additional decrease in AR numbers compared with the corresponding single or double mutants, respectively, and the aux1 lax3 lbd16 lbd18 quadruple mutant was devoid of ARs. Expression of LBD16 or LBD18 under their own promoters in lbd16 or lbd18 mutants rescued the reduced number of ARs to wild-type levels. LBD16 or LBD18 fused to a dominant SRDX repressor suppressed promoter activity of the cell cycle gene, Cyclin-Dependent Kinase(CDK)A1;1, to some extent. Expression of LBD16 or LBD18 was significantly reduced in arf7 and arf19 mutants during AR formation in a light-dependent manner, but not in arf6 and arf8. GUS expression analysis of promoter-GUS reporter transgenic lines revealed overlapping expression patterns for LBD16, LBD18, ARF7, ARF19 and LAX3 in AR primordia. CONCLUSION: These results suggest that the ARF7/ARF19-LBD16/LBD18 transcriptional module via the AUX1/LAX3 auxin influx carriers plays an important role in AR formation in Arabidopsis.
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Proteínas de Arabidopsis/fisiologia , Arabidopsis/crescimento & desenvolvimento , Raízes de Plantas/crescimento & desenvolvimento , Fatores de Transcrição/fisiologia , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Hipocótilo/crescimento & desenvolvimento , Hipocótilo/metabolismo , Raízes de Plantas/metabolismo , Fatores de Transcrição/metabolismoRESUMO
Obesity-induced chronic low-grade inflammation, in particular in adipose tissue, contributes to the development of insulin resistance and type 2 diabetes. However, the mechanism by which obesity induces adipose tissue inflammation has not been completely elucidated. Recent studies suggest that alteration of the nuclear lamina is associated with age-associated chronic inflammation in humans and fly. These findings led us to investigate whether the nuclear lamina regulates obesity-mediated chronic inflammation. In this study, we show that lamin A/C mediates inflammation in macrophages. The gene and protein expression levels of lamin A/C are significantly increased in epididymal adipose tissues from obese rodent models and omental fat from obese human subjects compared to their lean controls. Flow cytometry and gene expression analyses reveal that the protein and gene expression levels of lamin A/C are increased in adipose tissue macrophages (ATMs) by obesity. We further show that ectopic overexpression of lamin A/C in macrophages spontaneously activates NF-κB, and increases the gene expression levels of proinflammatory genes, such as Il6, Tnf, Ccl2, and Nos2. Conversely, deletion of lamin A/C in macrophages reduces LPS-induced expression of these proinflammatory genes. Importantly, we find that myeloid cell-specific lamin A/C deficiency ameliorates obesity-induced insulin resistance and adipose tissue inflammation. Thus, our data suggest that lamin A/C mediates the activation of ATM inflammation by regulating NF-κB, thereby contributing to the development of obesity-induced insulin resistance.
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Tecido Adiposo Branco/metabolismo , Resistência à Insulina , Lamina Tipo A/metabolismo , Macrófagos/metabolismo , Obesidade/metabolismo , Animais , Expressão Gênica , Células HEK293 , Células HeLa , Humanos , Inflamação/metabolismo , Lamina Tipo A/genética , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , NF-kappa B/metabolismoRESUMO
This corrects the article DOI: 10.1038/nbt.3836.
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To induce blue-shifted emission of siloles, two tolyl-substituted derivatives - 1,1-diphenyl-2,3,4,5-tetra(m-tolyl)-1H-silole (m-TS) and 1,1-diphenyl-2,3,4,5-tetra(o-tolyl)-1H-silole (o-TS) - were prepared, and their photophysical properties were compared with those of a reference compound, hexaphenylsilole (HPS). By substituting methyl groups at ortho positions of peripheral tetraphenyl rings on the silacyclopentadiene ring, intramolecular rotations could be successfully controlled and the photophysical properties were varied, while substituting methyl groups at meta positions showed similar photophysical properties compared with the case of HPS. That is, simple structural modification at the ortho position significantly affects the geometry and the photophysical properties of silole, which leads to blue-shifted emission. Finally, two tolyl-substituted siloles and HPS were employed as chemosensors for the detection of nitro explosives, and o-TS showed the highest sensing ability.
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The heterogeneity of cellular states in cancer has been linked to drug resistance, cancer progression and the presence of cancer cells with properties of normal tissue stem cells. Secreted Wnt signals maintain stem cells in various epithelial tissues, including in lung development and regeneration. Here we show that mouse and human lung adenocarcinomas display hierarchical features with two distinct subpopulations, one with high Wnt signalling activity and another forming a niche that provides the Wnt ligand. The Wnt responder cells showed increased tumour propagation ability, suggesting that these cells have features of normal tissue stem cells. Genetic perturbation of Wnt production or signalling suppressed tumour progression. Small-molecule inhibitors targeting essential posttranslational modification of Wnt reduced tumour growth and markedly decreased the proliferative potential of lung cancer cells, leading to improved survival of tumour-bearing mice. These results indicate that strategies for disrupting pathways that maintain stem-like and niche cell phenotypes can translate into effective anti-cancer therapies.
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Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Progressão da Doença , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Nicho de Células-Tronco , Proteínas Wnt/biossíntese , Via de Sinalização Wnt , Adenocarcinoma de Pulmão , Animais , Proliferação de Células/efeitos dos fármacos , Feminino , Humanos , Masculino , Camundongos , Transplante de Neoplasias , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/farmacologia , Taxa de Sobrevida , Proteínas Wnt/química , Proteínas Wnt/metabolismoRESUMO
In vivo interrogation of the function of genes implicated in tumorigenesis is limited by the need to generate and cross germline mutant mice. Here we describe approaches to model colorectal cancer (CRC) and metastasis, which rely on in situ gene editing and orthotopic organoid transplantation in mice without cancer-predisposing mutations. Autochthonous tumor formation is induced by CRISPR-Cas9-based editing of the Apc and Trp53 tumor suppressor genes in colon epithelial cells and by orthotopic transplantation of Apc-edited colon organoids. ApcΔ/Δ;KrasG12D/+;Trp53Δ/Δ (AKP) mouse colon organoids and human CRC organoids engraft in the distal colon and metastasize to the liver. Finally, we apply the orthotopic transplantation model to characterize the clonal dynamics of Lgr5+ stem cells and demonstrate sequential activation of an oncogene in established colon adenomas. These experimental systems enable rapid in vivo characterization of cancer-associated genes and reproduce the entire spectrum of tumor progression and metastasis.
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Neoplasias Colorretais/genética , Modelos Animais de Doenças , Edição de Genes/métodos , Genes Neoplásicos/genética , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/secundário , Transplante de Órgãos/métodos , Animais , Carcinogênese/genética , Linhagem Celular Tumoral , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Feminino , Masculino , Camundongos , Camundongos Transgênicos , Metástase NeoplásicaRESUMO
BACKGROUND: We aimed to establish a prospectively enrolled colorectal cancer (CRC) cohort for targeted sequencing of primary tumors from CRC patients. In parallel, we established collateral PDC models from the matched primary tumor tissues, which may be later used as preclinical models for genome-directed targeted therapy experiments. RESULTS: In all, we identified 27 SNVs in the 6 genes such as PIK3CA (N = 16), BRAF (N = 6), NRAS (N = 2), and CTNNB1 (N = 1), PTEN (N = 1), and ERBB2 (N = 1). RET-NCOA4 translocation was observed in one out of 105 patients (0.9%). PDC models were successfully established from 62 (55.4%) of the 112 samples. To confirm the genomic features of various tumor cells, we compared variant allele frequency results of the primary tumor and progeny PDCs. The Pearson correlation coefficient between the variants from primary tumor cells and PDCs was 0.881. METHODS: Between April 2014 and June 2015, 112 patients with CRC who underwent resection of the primary tumor were enrolled in the SMC Oncology Biomarker study. The PDC culture protocol was performed for all eligible patients. All of the primary tumors from the 112 patients who provided written informed consent were genomically sequenced with targeted sequencing. In parallel, PDC establishment was attempted for all sequenced tumors. CONCLUSIONS: We have prospectively sequenced a CRC cohort of 105 patients and successfully established 62 PDC in parallel. Each genomically characterized PDCs can be used as a preclinical model especially in rare genomic alteration event.
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Biomarcadores Tumorais/genética , Neoplasias Colorretais/genética , Predisposição Genética para Doença/genética , Mutação , Adulto , Idoso , Idoso de 80 Anos ou mais , Classe I de Fosfatidilinositol 3-Quinases/genética , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/patologia , Feminino , GTP Fosfo-Hidrolases/genética , Frequência do Gene , Humanos , Estimativa de Kaplan-Meier , Masculino , Proteínas de Membrana/genética , Pessoa de Meia-Idade , PTEN Fosfo-Hidrolase/genética , Polimorfismo de Nucleotídeo Único , Estudos Prospectivos , Proteínas Proto-Oncogênicas B-raf/genética , Receptor ErbB-2/genética , Análise de Sequência de DNA/métodos , Células Tumorais Cultivadas , beta Catenina/genéticaRESUMO
High dietary intakes and high blood levels of ß-carotene are associated with a decreased incidence of various cancers. The anticancer effect of ß-carotene is related to its pro-oxidant activity. DNA repair Ku proteins, as a heterodimer of Ku70 and Ku80, play a crucial role in DNA double-strand break repair. Reductions in Ku70/80 contribute to apoptosis. Previously, we showed that reactive oxygen species (ROS) activate caspase-3 which induces degradation of Ku proteins. In the present study, we investigated the mechanism of ß-carotene-induced apoptosis of gastric cancer AGS cells by determining cell viability, DNA fragmentation, apoptotic indices (increases in cytochrome c and Bax, decrease in Bcl-2), ROS levels, mitochondrial membrane potential, caspase-3 activity, Ku70/80 levels, and Ku-DNA-binding activity of the cells treated with or without antioxidant N-acetyl cysteine and caspase-3 inhibitor z-DEVED-fmk. As a result, ß-carotene induced apoptosis (decrease in cell viability, increases in DNA fragmentation and apoptotic indices) and caspase-3 activation, but decreased Ku70/80 levels and Ku-DNA-binding activity. ß-Carotene-induced alterations (increase in caspase-3 activity, decrease in Ku proteins) and apoptosis were inhibited by N-acetyl cysteine and z-DEVED-fmk. Increment of intracellular and mitochondrial ROS levels and loss of mitochondrial membrane potential were suppressed by N-acetyl cysteine, but not by z-DEVED-fmk in ß-carotene-treated cells. Therefore, ß-carotene-induced increases in ROS and caspase-3 activity may lead to reduction of Ku70/80 levels, which results in apoptosis in gastric cancer cells. Loss of Ku proteins might be the underlying mechanism for ß-carotene-induced apoptosis in gastric cancer cells.