RESUMO
BACKGROUND: In the TYMS gene promoter, there is a repeat polymorphism (TSER) that affects the expression level of the thymidylate synthetase (TS) enzyme involved in the response to some anticancer drugs. The G>C transversion located in the TSER*3R allele decreases the expression level of the TS enzyme avoiding the upstream stimulatory factor (USF-1) binding site. Despite the biomedical impact of the SNP G>C, only TSER has been reported in most worldwide populations. Thus, we studied both TSER and SNP G>C variants in the Mexican population. SUBJECTS AND METHODS: A population sample (n = 156) was genotyped for the TSER and G>C variants by PCR and PCR-RFLPs, respectively, followed by PAGE and silver staining. RESULTS: For TSER, the most frequent allele was 2 R (52.56%), as well as the genotype 2 R/3R (42.3%). Comparison with Latin American, European, and American (USA) populations suggest a heterogeneous worldwide distribution (FST-value = 0.01564; p-value = 0.0000). When the G>C variant was included (2RG, 3RG, and 3RC), a high frequency of low expression genotypes was observed: 2RG/2RG, 2RG/3RC, and 3RC/3RC (84.6%). CONCLUSION: The high frequency of genotypes associated with low TS enzyme expression justifies obtaining the TYMS gene variant profile in Mexican patient's candidates to pharmaceutical treatments like 5'-Fluoracil, methotrexate, and pemetrex.
Assuntos
Fluoruracila , Polimorfismo Genético , Timidilato Sintase , Humanos , Alelos , Genótipo , Polimorfismo de Fragmento de Restrição , Timidilato Sintase/genética , Timidilato Sintase/metabolismo , MéxicoRESUMO
BACKGROUND: Gastric cancer (GC) with microsatellite instability (MSI) is a less aggressive disease and associated with resistance to 5-fluorouracil (5-FU)-based chemotherapy (CMT). Thymidylate synthase (TS) is inhibited by 5-FU, and another potential mediator of therapeutic resistance to 5-FU. Therefore, we aimed to analyze the association between MSI and TS expression in GC, and its impact on disease outcomes. METHODS: We retrospectively evaluated GC who underwent D2-gastrectomy. MSI and TS were analyzed by immunohistochemistry. We also investigated p53 expression, PD-L1 status, and tumor-infiltrating lymphocytes (CD4 and CD8). RESULTS: Out of 284 GC, 60 (21.1%) were MSI. Median TS-score for all cases was 16.5. TS expression was significantly higher in MSI compared to microsatellite-stable (MSS; p < 0.001). Considering both status, GC were classified in four groups: 167 (58.8%) MSS + TS-low; 57 (20.1%) MSS + TS-High; 24 (8.5%) MSI + TS-low; and 36 (12.7%) MSI + TS-high. MSI + TS-high group had less advanced pTNM stage, higher CD8+T cells levels (p < 0.001) and PD-L1 positivity (p < 0.001). Normal p53 expression was related to MSI GC (p < 0.001). Improved survival was observed in MSI + TS-high, but no survival benefit was seen with CMT. CONCLUSION: MSI GC was associated with high TS levels, which may explain therapeutic resistance to 5-FU. Additionally, MSI + TS-high showed better survival, but without improvement with CMT.
Assuntos
Neoplasias Gástricas , Timidilato Sintase , Antígeno B7-H1/metabolismo , Fluoruracila/uso terapêutico , Humanos , Instabilidade de Microssatélites , Repetições de Microssatélites , Prognóstico , Estudos Retrospectivos , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Timidilato Sintase/genética , Timidilato Sintase/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismoRESUMO
Down syndrome (DS) is the most common chromosomal disorder, resulting from the failure of normal chromosome 21 segregation. Studies have suggested that impairments within the one-carbon metabolic pathway can be of relevance for the global genome instability observed in mothers of individuals with DS. Based on the association between global DNA hypomethylation, genome instability, and impairments within the one-carbon metabolic pathway, the present study aimed to identify possible predictors, within the one-carbon metabolism, of global DNA methylation, measured by methylation patterns of LINE-1 and Alu repetitive sequences, in mothers of individuals with DS and mothers of individuals without the syndrome. In addition, we investigated one-carbon genetic polymorphisms and metabolites as maternal predisposing factors for the occurrence of trisomy 21 in children. Eighty-three samples of mothers of children with DS with karyotypically confirmed free trisomy 21 (case group) and 84 of mothers who had at least one child without DS or any other aneuploidy were included in the study. Pyrosequencing assays were performed to access global methylation. The results showed that group affiliation (case or control), betaine-homocysteine methyltransferase (BHMT) G742A and transcobalamin 2 (TCN2) C776G polymorphisms, and folate concentration were identified as predictors of global Alu DNA methylation values. In addition, thymidylate synthase (TYMS) 28-bp repeats 2R/3R or 3R/3R genotypes are independent maternal predisposing factors for having a child with DS. This study adds evidence that supports the association of impairments in the one-carbon metabolism, global DNA methylation, and the possibility of having a child with DS.
Assuntos
Carbono/metabolismo , Metilação de DNA/genética , Síndrome de Down/genética , Síndrome de Down/metabolismo , Estudo de Associação Genômica Ampla , Instabilidade Genômica/genética , Relações Mãe-Filho , Mães , Adolescente , Adulto , Idoso , Elementos Alu/genética , Betaína-Homocisteína S-Metiltransferase/genética , Betaína-Homocisteína S-Metiltransferase/metabolismo , Feminino , Ácido Fólico/metabolismo , Predisposição Genética para Doença/genética , Humanos , Elementos Nucleotídeos Longos e Dispersos/genética , Masculino , Pessoa de Meia-Idade , Polimorfismo Genético , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Timidilato Sintase/genética , Transcobalaminas/genética , Transcobalaminas/metabolismo , Adulto JovemRESUMO
BACKGROUND: Folate is essential for DNA synthesis, repair, and methylation. Polymorphisms in genes associated with folate metabolism may alter these processes and, consequently, modulate cancer development. AIM: We aimed to assess DNMT3B -149C/T (rs2424913), DNMT3B -283T/C (rs6087990), DNMT3B -579G/T (rs2424909), DHFR 19-pb ins/del (rs70991108), SHMT1 1420C/T (rs1979277), and TYMS 28-bp tandem repeat (rs34743033) polymorphisms with risk of head and neck cancer. METHODS: A case-control study was conducted in 1,086 Brazilian individuals. Real-time and conventional polymerase chain reactions-PCR were performed for genotyping the polymorphisms. RESULTS: The single nucleotide polymorphism (SNP), DNMT3B -283T/C, revealed a higher risk of head and neck squamous cell carcinoma (HNSCC) when compared with the C group in the codominant (p < 0.001), dominant (p <0.001), and overdominant (p= 0.001) models for T/C and C/C genotypes. DNMT3B -149C/T and DNMT3B -579G/T revealed no association between groups in any model. The DHFR 19-pb ins/del polymorphism protected against HNSCC development compared to the C group by the codominant (p < 0.001), dominant (p < 0.001), and overdominant (p < 0.001) models. In the TYMS, the 3R/3R genotype had a protective effect against HNSCC development compared with the C group by the recessive models (p= 0.009). In contrast, SHMT1 1420 C/T presented no association between the HNSCC and C groups. DHFR 19-pb ins/del polymorphisms protected against oral cavity cancer (p= 0.003), and only TYMS-28 3R/3R decreased the risk of tumor progression (p= 0.023). In the Kaplan-Meier curve, an association was found between DHFR ins/ins and TYMS -28 3R carriers with respect to relapse-free time; further, DNMT3B -579 T and TYMS-28 2R/2R carriers had longer survival times. CONCLUSION: DNMT3B -283T/C is associated with higher risk, whereas DHFR 19-pb ins/del and TYMS 28 3R/3R protect against head and neck cancer. We also highlighted the association of TYMS 3R/3R genotype carriers with relapse-free cancer protection and survival time.
Assuntos
DNA (Citosina-5-)-Metiltransferases/genética , Metilação de DNA , Ácido Fólico/metabolismo , Neoplasias de Cabeça e Pescoço/epidemiologia , Tetra-Hidrofolato Desidrogenase/genética , Timidilato Sintase/genética , Biomarcadores Tumorais/análise , Brasil/epidemiologia , Estudos de Casos e Controles , Feminino , Seguimentos , Regulação Neoplásica da Expressão Gênica , Predisposição Genética para Doença , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Prognóstico , Regiões Promotoras Genéticas , Fatores de Risco , Taxa de Sobrevida , DNA Metiltransferase 3BRESUMO
BACKGROUND: Cervical cancer is caused by high-risk Human Papillomavirus (hr-HPV) infection associated with cofactors that has been analyzed as predictors of the remission or persistence of cytological abnormalities remission or persistence. These cofactors can be either environmental, epigenetic, or genetic. Polymorphism in genes of enzymes that act on one-carbon metabolism alter their activity and also may be associated with cervical carcinogenesis because they affect DNA synthesis and repair, and gene expression. Therefore, this study aimed to analyze the risk of persistence of pre-neoplastic cervical lesions according to genetic polymorphisms involved in one-carbon metabolism. METHODS: Our sample consisted of 106 women, divided into two groups - Remission (n = 60), i.e., with the presence of pre-neoplastic lesions at first meeting (T1) and normal cytology after 6 months of follow-up (T2), and Persistence (n = 46), i.e., with the presence of pre-neoplastic lesions at T1 and T2. We obtained cervical samples for cytological analysis (T1 and T2), HPV detection (T1), and evaluation of polymorphism C667T of Methylenetetrahydrofolate Reductase (MTHFR C677T), A2756G of Methionine Synthase (MS A2756G), A66G of Methionine Synthase Reductase (MTRR A66G), double or triple 28 bp tandem repeat in 5'-untranslated enhanced region of Thymidylate Synthase (TSER), and 6 bp deletion at nucleotide 1494 in TS 3'-untranslated region (TS3'UTR). To analyze all genetic polymorphisms simultaneously, we calculated the Genetic Risk Score (GRS). RESULTS: We observed no differences between the Remission and Persistence groups regarding the GRS. Also, there were no differences in the genotypic and allelic distribution of MTHFR C677T and MS A2756G polymorphisms. However, the risk of persistence was higher among women with the heterozygote genotype - ins/del [OR (IC95%): 3.22 (1.19-8.69), p = 0.021], or the polymorphic genotype - del/del [OR (IC95%): 6.50 (1.71-24.70), p = 0.006] of TS3'UTR. CONCLUSIONS: The presence of the TS3'UTR polymorphism increased the risk of persistence of cervical abnormalities. This genetic variant could be a potential marker of cervical carcinogenesis and therefore assist the follow-up of women with persistent pre-neoplastic cervical lesions.
Assuntos
5-Metiltetra-Hidrofolato-Homocisteína S-Metiltransferase/genética , DNA Viral/genética , Infecções por Papillomavirus/diagnóstico , Lesões Pré-Cancerosas/genética , Timidilato Sintase/genética , Neoplasias do Colo do Útero/genética , Regiões 3' não Traduzidas , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Papillomaviridae/genética , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/genética , Polimorfismo de Nucleotídeo Único , Lesões Pré-Cancerosas/virologia , Neoplasias do Colo do Útero/virologia , Adulto JovemRESUMO
Leishmaniasis is a tropical disease found in more than 90 countries. The drugs available to treat this disease have nonspecific action and high toxicity. In order to develop novel therapeutic alternatives to fight this ailment, pteridine reductase 1 (PTR1) and dihydrofolate reductase-thymidylate synthase (DHF-TS) have been targeted, once Leishmania is auxotrophic for folates. Although PTR1 and DHFR-TS from other protozoan parasites have been studied, their homologs in Leishmania chagasi have been poorly characterized. Hence, this work describes the optimal conditions to express the recombinant LcPTR1 and LcDHFR-TS enzymes, as well as balanced assay conditions for screening. Last but not the least, we show that 2,4 diaminopyrimidine derivatives are low-micromolar competitive inhibitors of both enzymes (LcPTR1 Ki = 1.50-2.30 µM and LcDHFR Ki = 0.28-3.00 µM) with poor selectivity index. On the other hand, compound 5 (2,4-diaminoquinazoline derivative) is a selective LcPTR1 inhibitor (Ki = 0.47 µM, selectivity index = 20).
Assuntos
Inibidores Enzimáticos/farmacologia , Leishmania infantum/enzimologia , Complexos Multienzimáticos/antagonistas & inibidores , Oxirredutases/antagonistas & inibidores , Timidilato Sintase/antagonistas & inibidores , Catálise , Cromatografia de Afinidade , Clonagem Molecular , Avaliação Pré-Clínica de Medicamentos , Eletroforese em Gel de Poliacrilamida , Escherichia coli/genética , Concentração Inibidora 50 , Complexos Multienzimáticos/genética , Complexos Multienzimáticos/isolamento & purificação , Complexos Multienzimáticos/metabolismo , Oxirredutases/genética , Oxirredutases/isolamento & purificação , Oxirredutases/metabolismo , Tetra-Hidrofolato Desidrogenase/genética , Tetra-Hidrofolato Desidrogenase/isolamento & purificação , Tetra-Hidrofolato Desidrogenase/metabolismo , Timidilato Sintase/genética , Timidilato Sintase/isolamento & purificação , Timidilato Sintase/metabolismoRESUMO
Pemetrexed is an antimetabolite approved for treatment of non-small cell lung cancer. Harbouring interindividual variability in both the pharmacokinetic and pharmacogenetic profiles may lead to life-threatening toxicities. A prospective cohort study of adult patients initiating treatment with pemetrexed in combination with platinum between 2013 and 2015 were follow up. Primary exposure were the methylenetetrahydrofolate reductase (MTHFR) single base polymorphisms in exon 4 and 7 and 5'-UTR- thymidylate synthase (TYMS) VNTR genotypes, in addition to baseline clinical and demographic variables. We used a Cox regression model to evaluate patient's survival and toxicity experience and its association with both baseline characteristics, and a-priori determined genetic polymorphisms. Seventy two patients were included, 52.7% developed severe hematologic toxicity during follow-up. None of the tested genotypes were significantly associated with the main outcome on multivariate analysis, nor other basal clinical variables. Overall survival between patients experiencing the outcome was not different from those without it, but hospital admissions were more frequent. MTHFR and 5'-UTR-TYMS genotypes were not useful for predicting high grade toxicity events in patients under treatment with pemetrexed.
Assuntos
Antineoplásicos/efeitos adversos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/diagnóstico , Neoplasias Pulmonares/tratamento farmacológico , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Pemetrexede/efeitos adversos , Índice de Gravidade de Doença , Timidilato Sintase/genética , Adulto , Idoso , Antineoplásicos/administração & dosagem , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/etiologia , Feminino , Seguimentos , Genótipo , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Pemetrexede/administração & dosagem , Polimorfismo de Nucleotídeo Único , Valor Preditivo dos TestesRESUMO
Methotrexate (MTX), a structural analog of folic acid, is widely employed in the treatment of different cancers and autoimmune diseases. Despite the successful results observed, the main disadvantage lies in interpatient variability in the pharmacokinetic and pharmacodynamic parameters. In particular, adverse events and toxicities induced by MTX are a matter of concern and can be the cause of dose reduction or treatment discontinuation. Among the different approaches to reduce MTX therapeutic limitations, pharmacogenomics contributes by considering the effect of inherited genetic differences on those parameters. This review provides an update on MTX pharmacogenomics. It reports the contribution of main gene polymorphisms involved in the influx, efflux, cellular effect, and elimination on MTX toxicity and efficacy, on all the diseases treated with this drug. From the analysis of the data presented in this review, we concluded that only gene polymorphisms MTHFR rs1801133, SLC19A1 rs1051266, and TYMS rs34743033 could influence clinical decision-making.
Assuntos
Antimetabólitos Antineoplásicos/efeitos adversos , Imunossupressores/efeitos adversos , Metotrexato/efeitos adversos , Farmacogenética/métodos , Variantes Farmacogenômicos , Polimorfismo Genético , Medicina de Precisão/métodos , Antimetabólitos Antineoplásicos/administração & dosagem , Antimetabólitos Antineoplásicos/farmacocinética , Tomada de Decisão Clínica , Humanos , Imunossupressores/administração & dosagem , Imunossupressores/farmacocinética , Metotrexato/administração & dosagem , Metotrexato/farmacocinética , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Metilenotetra-Hidrofolato Redutase (NADPH2)/metabolismo , Seleção de Pacientes , Testes Farmacogenômicos , Valor Preditivo dos Testes , Proteína Carregadora de Folato Reduzido/genética , Proteína Carregadora de Folato Reduzido/metabolismo , Medição de Risco , Timidilato Sintase/genética , Timidilato Sintase/metabolismoRESUMO
OBJECTIVE: To examine the association between TYMS 2R3R polymorphism and DPYD [IVS]14+1G>A mutation by comparing healthy subjects with colorectal cancer (CRC) patients in the Mexican population. METHOD: Genotyping of the 2R/3R was performed by polymerase chain reaction (PCR) and [IVS]14+1G>A mutation by real-time PCR analysis. RESULTS: The observed frequencies of the TYMS 2R3R polymorphism and the -[IVS]14+1G>A mutation in DPYD did not indicate an increased risk for CRC (p>0.05). However we observed an association of the 2R/2R (OR 3.08, 95% CI 1.66-6.08, p=0.0017) and heterozygous (OR 1.98, 95% CI 1.32-2.97, p=0.0012) genotypes as risk factors when comparing controls and CRC patients that were also tobacco consumers. An association between the genotype and the disease was evident. The distribution of the 2R/2R genotype and hematological toxicity (adjusted OR 2.26, 95% CI 1.54-4.45, p=0.0259), heterozygous (2R/3R) with tumor stage III-IV (OR 1.81, 95% CI 1.11-2.94, p=0.020) and 2R/2R-2R/3R in non-chemotherapy response CRC patients with hematological (OR 2.3, 95% CI 1.21-4.4, p=0.014) and gastric toxicities (OR 3.11, 95% CI 1.18-8.2, p=0.035) confirmed that this factor may significantly contribute to the CRC susceptibility. CONCLUSION: TYMS 2R3R polymorphism and the -[IVS]14+1G>A mutation in DPYD was not associated with susceptibility to CRC. However, the 2R/2R and 2R/3R genotypes of TYMS polymorphism could significantly contribute to hematological and gastric toxicity in CRC patients in this sample population.
Assuntos
Neoplasias Colorretais/genética , Di-Hidrouracila Desidrogenase (NADP)/genética , Mutação , Polimorfismo Genético , Timidilato Sintase/genética , Adulto , Idoso , Feminino , Predisposição Genética para Doença , Genótipo , Doenças Hematológicas/genética , Humanos , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Gastropatias/genética , Uso de TabacoRESUMO
BACKGROUND: Fluoropyrimidines form the chemotherapy backbone of advanced and metastatic colorectal cancer (CRC). These drugs are frequently associated with toxicity events that result in dose adjustments and even suspension of the treatment. The thymidylate synthase (TYMS) gene is a potential marker of response and toxicity to fluoropyirimidines as this enzyme is the molecular target of these drugs. Our aim was to assess the association between variants of TYMS with response and toxicity to fluoropyrimidines in patients with CRC in independent retrospective and prospective studies. METHODS: Variants namely rs45445694, rs183205964, rs2853542 and rs151264360 of TYMS were genotyped in 105 CRC patients and were evaluated to define their association with clinical response and toxicity to fluoropyrimidines. Additionally, the relationship between genotypes and tumor gene expression was analyzed by quantitative polymerase chain reaction. RESULTS: The 2R/2R (rs45445694) was associated with clinical response (p=0.05, odds ratio (OR)=3.45) and severe toxicity (p=0.0014, OR=5.21, from pooled data). Expression analysis in tumor tissues suggested a correlation between the 2R/2R genotype and low TYMS expression. CONCLUSIONS: The allele 2R (rs45445694) predicts severe toxicity and objective response in advanced CRC patients. In addition, the alleles G(rs2853542) and 6bp-(rs151264360) are independent predictors of response failure to chemotherapy. This is the first study made on a Latin American population that points out TYMS gene variants have predictive values for response and toxicity in patients with CRC treated with fluoropyrimidine-based chemotherapy.