RESUMO
The aim of this study was to investigate the DNA methylation profile in genes encoding catalase (CAT) and superoxide dismutase (SOD3) enzymes, which are involved in oxidative stress mechanisms, and in genes encoding pro-inflammatory cytokines interleukin-6 (IL6) and tumor necrosis factor-alpha (TNF-α) in the oral mucosa of oncopediatric patients treated with methotrexate (MTX®). This was a cross-sectional observational study and the population comprised healthy dental patients (n = 21) and those with hematological malignancies (n = 64) aged between 5 and 19 years. Oral conditions were evaluated using the Oral Assessment Guide and participants were divided into 4 groups: 1- healthy individuals; 2- oncopediatric patients without mucositis; 3- oncopediatric patients with mucositis; 4- oncopediatric patients who had recovered from mucositis. Methylation of DNA from oral mucosal cells was evaluated using the Methylation-Specific PCR technique (MSP). For CAT, the partially methylated profile was the most frequent and for SOD3 and IL6, the hypermethylated profile was the most frequent, with no differences between groups. For TNF-α, the hypomethylated profile was more frequent in the group of patients who had recovered from mucositis. It was concluded that the methylation profiles of CAT, SOD3, and IL6 are common profiles for oral cells of children and adolescents and have no association with oral mucositis or exposure to chemotherapy with MTX®. Hypomethylation of TNF-α is associated with oral mucosal recovery in oncopediatric patients who developed oral mucositis during chemotherapy.
Assuntos
Metotrexato , Mucosa Bucal , Estomatite , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Adulto Jovem , Antimetabólitos Antineoplásicos/efeitos adversos , Estudos de Casos e Controles , Catalase/genética , Estudos Transversais , Metilação de DNA , Neoplasias Hematológicas/genética , Neoplasias Hematológicas/tratamento farmacológico , Interleucina-6/genética , Interleucina-6/análise , Metotrexato/uso terapêutico , Metotrexato/efeitos adversos , Mucosa Bucal/efeitos dos fármacos , Mucosite/genética , Mucosite/induzido quimicamente , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Reação em Cadeia da Polimerase , Regiões Promotoras Genéticas/genética , Valores de Referência , Estatísticas não Paramétricas , Estomatite/genética , Estomatite/induzido quimicamente , Superóxido Dismutase/genética , Fator de Necrose Tumoral alfa/genéticaRESUMO
BACKGROUND AND PURPOSE: Severe diarrhoea, a common gastrointestinal manifestation of anticancer treatment with irinotecan, might involve single nucleotide polymorphisms (SNPs) of toll-like receptors (TLRs), described as critical bacterial sensors in the gut. Here, colorectal cancer patients carrying missense TLR4 A896G (rs4986790) or C1,196T (rs4986791) SNPs and Tlr4 knockout (Tlr4-/-) mice were given irinotecan to investigate the severity of the induced diarrhoea. EXPERIMENTAL APPROACH: Forty-six patients treated with irinotecan-based regimens had diarrhoea severity analysed according to TLR4 genotypes. In the experimental setting, wild-type (WT) or Tlr4-/- mice were given irinotecan (45 or 75 mg·kg-1 , i.p.) or saline (3 ml·kg-1 ). Diarrhoea severity was evaluated by measuring intestinal injury and inflammatory markers expression after animals were killed. KEY RESULTS: All patients with TLR4 SNPs chemotherapy-treated presented diarrhoea, whereas gastrointestinal toxicity was observed in 50% of the wild homozygous individuals. Mice injected with irinotecan presented systemic bacterial translocation and increased TLR4 immunostaining in the intestine. In line with the clinical findings, Tlr4 gene deficiency enhanced irinotecan-related diarrhoea and TLR9 expression in mice. An increased myeloperoxidase activity and Il-18 expression along with IL-10 decreased production in Tlr4-/- mice also indicated an intensified intestinal damage and inflammatory response. CONCLUSION AND IMPLICATIONS: TLR4 deficiency upregulates TLR9 expression and enhances intestinal damage and the severity of late-onset diarrhoea during irinotecan-based treatment. Identifying patients genetically predisposed to chemotherapy-associated diarrhoea is a strategy toward precision medicine.
Assuntos
Diarreia , Irinotecano , Mucosite , Receptor 4 Toll-Like , Receptor Toll-Like 9 , Animais , Diarreia/induzido quimicamente , Diarreia/genética , Humanos , Irinotecano/toxicidade , Camundongos , Mucosite/induzido quimicamente , Mucosite/genética , Receptor 4 Toll-Like/genética , Receptor Toll-Like 9/genéticaRESUMO
BACKGROUND: Genetic polymorphisms in patients with acute lymphoblastic leukemia (ALL) may influence the toxicity of chemotherapeutic agents. Due to the importance of the transport P-glycoprotein and methylenetetrahydrofolate reductase in the metabolism of chemotherapeutic agents, we analyzed the MDR1 rs1045642 and MTHFR rs1801133 polymorphisms and their associations with clinical outcomes in Mexican childhood ALL patients. METHODS: A total of 109 patients participated in this study. The clinical evaluation consisted of a physical examination and a laboratory test. Genotyping of MDR1 rs1045642 (3435 C>T) and MTHFR rs1801133 (677 C>T) was performed by polymerase chain reaction/restriction fragment length polymorphism. Statistical analyses were performed using SPSS 14.0. The odds ratios and 95% confidence intervals (CI) were estimated by logistic regression. RESULTS: Individuals who were CC homozygotes at MDR1 rs1045642 had lower risk of having methotrexate plasma concentrations >1 µM and leukopenia grade I (odds ratio [OR] = 0.30; 95% CI = 0.13-0.72 and OR = 0.32; 95% CI = 0.14-0.72, respectively). Patients who were CC homozygotes at MTHFR rs1801133 had a higher risk of developing mucositis (OR = 3.61; 95% CI = 1.42-9.14). CONCLUSION: MDR1 rs1045642 and MTHFR rs1801133 should be considered as diagnostic candidates for the identification of pediatric patients with a high risk of suffering adverse events during ALL treatment.
Assuntos
Homozigoto , Leucopenia , Metotrexato , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Mucosite , Polimorfismo de Fragmento de Restrição , Leucemia-Linfoma Linfoblástico de Células Precursoras , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Leucopenia/sangue , Leucopenia/induzido quimicamente , Leucopenia/genética , Masculino , Metotrexato/administração & dosagem , Metotrexato/farmacocinética , México , Mucosite/sangue , Mucosite/induzido quimicamente , Mucosite/genética , Projetos Piloto , Leucemia-Linfoma Linfoblástico de Células Precursoras/sangue , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Fatores de RiscoRESUMO
Intestinal mucositis is a common side effect of irinotecan-based anticancer regimens. Mucositis causes cell damage, bacterial/endotoxin translocation and production of cytokines including IL-1 and IL-18. These molecules and toll-like receptors (TLRs) activate a common signaling pathway that involves the Myeloid Differentiation adaptor protein, MyD88, whose role in intestinal mucositis is unknown. Then, we evaluated the involvement of TLRs and MyD88 in the pathogenesis of irinotecan-induced intestinal mucositis. MyD88-, TLR2- or TLR9-knockout mice and C57BL/6 (WT) mice were given either saline or irinotecan (75 mg/kg, i.p. for 4 days). On day 7, animal survival, diarrhea and bacteremia were assessed, and following euthanasia, samples of the ileum were obtained for morphometric analysis, myeloperoxidase (MPO) assay and measurement of pro-inflammatory markers. Irinotecan reduced the animal survival (50%) and induced a pronounced diarrhea, increased bacteremia, neutrophil accumulation in the intestinal tissue, intestinal damage and more than twofold increased expression of MyD88 (200%), TLR9 (400%), TRAF6 (236%), IL-1ß (405%), IL-18 (365%), COX-2 (2,777%) and NF-κB (245%) in the WT animals when compared with saline-injected group (P<0.05). Genetic deletion of MyD88, TLR2 or TLR9 effectively controlled the signs of intestinal injury when compared with irinotecan-administered WT controls (P<0.05). In contrast to the MyD88-/- and TLR2-/- mice, the irinotecan-injected TLR9-/- mice showed a reduced survival, a marked diarrhea and an enhanced expression of IL-18 versus irinotecan-injected WT controls. Additionally, the expression of MyD88 was reduced in the TLR2-/- or TLR9-/- mice. This study shows a critical role of the MyD88-mediated TLR2 and TLR9 signaling in the pathogenesis of irinotecan-induced intestinal mucositis.
Assuntos
Bacteriemia/metabolismo , Diarreia/metabolismo , Enteropatias/metabolismo , Mucosite/metabolismo , Fator 88 de Diferenciação Mieloide/metabolismo , Transdução de Sinais/fisiologia , Animais , Bacteriemia/induzido quimicamente , Bacteriemia/genética , Camptotecina/análogos & derivados , Diarreia/induzido quimicamente , Diarreia/genética , Enteropatias/induzido quimicamente , Enteropatias/genética , Mucosa Intestinal/metabolismo , Irinotecano , Camundongos , Camundongos Knockout , Mucosite/induzido quimicamente , Mucosite/genética , Fator 88 de Diferenciação Mieloide/genética , Peroxidase/metabolismo , Receptor 2 Toll-Like/genética , Receptor 2 Toll-Like/metabolismo , Receptor Toll-Like 9/genética , Receptor Toll-Like 9/metabolismoRESUMO
Methylenetetrahydrofolate reductase (MTHFR) has two common variants with reduced activity due to polymorphisms at nucleotides 677 and 1298. Both affect folate metabolism and thus remethylation of homocysteine, but are also thought to affect nucleotide synthesis and DNA methylation. Methotrexate (MTX), which interrupts folate metabolism, is used in the treatment of a variety of diseases including acute lymphoblastic leukemia (ALL), but exerts in some patients toxic effects on fast dividing tissues such as mucosal epithelia. The enhanced toxicity may be due to cooperative effects between MTX and MTHFR variants. Accordingly, it has been reported that carrying the 677T allele of the MTHFR is a risk factor for MTX-associated mucositis. As in the Mexican population, which is characterized by a high prevalence of the 677T MTHFR variant, several of its commonly associated defects have not been observed, we investigated the relationship between MTX toxicity and the 677T allele. Out of 28 patients with ALL (CC: 2, CT: 10, TT: 16), 16 had episodes of MTX-associated mucositis (CC: 0, CT: 6, TT: 10). Neither at the gene level nor at the genotype level was a significant association with mucositis found. It may be postulated that the risk of higher MTX toxicity in patients with decreased MTHFR activity could be neutralized by the normally folate rich diet in Mexico.