Tryptophan and tumor immunity / 药学学报

As an essential amino acid, tryptophan (Trp) has various physiological functions and is of great significance in the metabolic process of tumors. In the human body, tryptophan is mainly transformed through kynurenine metabolic pathway, which not only promotes the inherent malignant properties of tumor cells, but also leads to immune-suppressive tumor microenvironment. Changes in tryptophan metabolism often occur in tumors, accompanied by abnormal gene expression of tryptophan-related enzymes, among which indoleamine 2,3-bioxygenase (IDO)-related gene expression and tryptophan 2,3-dioxygenase (TDO)-related gene changes are the most significant. A large number of clinical trials on IDO inhibitors, TDO inhibitors and combination therapy have been carried out. This paper reviewed the tryptophan metabolic pathway, regulation of IDO (TDO), kynurenine (KYN) and other related genes in tumor cells, and outlined the development of therapeutic schedule targeting tryptophan-related genes. The new progress provides new ideas for the further exploration of tumor treatment options.

Generation and phenotypic analysis of TD02 knockout mice / 中国药理学通报

Aim To construct TD02 gene knockout C57BL/6 mice, and meanwhile to study their phenotypes preliminarily. Methods The sgRNA plasmids were designed and constructed according to the principle of CRISPR-Cas9 technology, and were microinjected into mouse zygotes after transcription in vitro with Cas9 plasmids. FO generation mice with multiple genotypes were obtained by embryo transplantation. The PCR method was used to determine the genotype, and the positive F0 generation mice were obtained. F1 generation heterozygous mice were obtained by backcrossing the positive F0 generation mice and the wild type mice. The positive F1 generation heterozygous mice were matched to each other to obtain F2 generation homozygous mice. And their growth characteristics, reproductive ability, and progeny survival rate were observed and analyzed respectively. TDO2 protein expression in liver tissues of homozygous TDO2 gene knockout mice was detected by Western blot. Results TDO2 gene knockout mice were successfully bred and identified, and the genotypes of offspring mice were successfully identified by PCR. The results showed that TDO2 gene knockout was successfully conducted and TDO2 protein expression was not detected in liver tissues of TDO2 gene knockout mice. No abnormal changes were observed in diet, body weight, breeding ability of TDO2 knockout mice. Conclusions TDO2 gene knockout mice have been initially established, which would provide experimental means for studying the biological function of TDO2 gene and its regulatory role in diseases.

Desenvolvimento e validação de métodos bioanalíticos para o monitoramento dos produtos das vias metabólicas do triptofano em linhagem celular de glioma humano / Development and validation of bioanalytical methods for monitoring the product of the metabolic pathways of tryptophan in human glioma cell line

O metabolismo do triptofano (Trp) se dá pela via das quinureninas (QUIN), pela via serotoninérgica (SER) e pela via das aminas traço. A primeira gera QUIN e uma variedade de outros metabólitos secundários. Quando conduzida pela enzima indolamina 2,3 dioxigenase (IDO) contribui para os fenômenos de tolerância e imune escape de células tumorais; e quando conduzida pela triptofano 2,3 dioxigenase (TDO) no fígado, participa na síntese da niacina e NAD. A via SER leva à formação do neurotransmissor serotonina (SER), que pode gerar o hormônio melatonina (MEL), respectivamente e outros metabólitos biologicamente ativos. Outra via menos estudada, a via das aminas traço, produz produtos neuroativos. Dada a abrangência e importância das rotas metabólicas do Trp, nós desenvolvemos e validamos uma metodologia bioanalítica robusta, seletiva e sensível por cromatografia líquida de alta eficiência (HPLC), acoplado espectrometria de massas (MS) para a determinação simultânea do Trp e seus 15 metabólitos. Para tanto, escolhemos para a avaliação das três vias, linhagens de glioma humano. A escolha por este tipo celular deveu-se ao grande interesse de estudos de metabolismo de Trp em células tumorais, no qual células de glioma tem sido modelo. Nos ensaios com as células de glioma acompanhamos os efeitos de um indutor e inibidores da primeira etapa de metabolização do Trp pela via das quinureninas, ou seja, IFN-γ (indutor da IDO), 1-metiltriptofano (1-MT; inibidor competitivo da IDO) e 680C91 (inibidor seletivo da TDO). Pudemos observar o impacto que a indução ou a inibição do primeiro passo teve sobre os metabólitos subsequentes e as diferenças no metabolismo das duas linhagens estudadas, A172 e T98G. A linhagem T98G só tem atividade de IDO, enquanto que a A172 tem tanto atividade IDO quanto TDO. A indução por IFN-γ mostrou que essa citocina não só atua na formação da via QUIN, mas possui um impacto modesto nas demais rotas. Observamos também que a inibição do 1-MT mostrou seu impacto nos metabólitos invdividualmente, do que a simples relação Trp-QUIN. Contudo, nosso resultados nos permitiu mostrar pela primeira vez a descrição completa dessas vias, em especial nessas linhagens celulares, podendo supor estratégias terapêuticas nessas rotas que estão relacionadas a progressão ou não tumoral

The tryptophan metabolism (Trp) takes place by means of kynurenine (QUIN), by the serotonin pathway (SER) and by the pathway of trace amines synthesis. The first generates QUIN and a variety of other secondary metabolites. When driven by the enzyme indoleamine 2,3 dioxygenase (IDO) contributes to the phenomena of tolerance and immune escape of tumor cells; and when conducted by tryptophan 2,3 -dioxygenase (TDO) in the liver, participates in the niacin synthesis NAD. The SER pathway leads to the serotonin neurotransmitter (SER) formation, which can generate the hormone melatonin (MEL), respectively and other biologically active metabolites. Another less studied amines trace synthesis pathway produces neuroactive products. Given the scope and importance of Trp metabolic pathways,we developed and validated a robust, sensitive and selective bioanalytical method by high performance liquid chromatography (HPLC) coupled mass spectrometry (MS) for simultaneous determination of TRP and its 16 metabolites. Therefore, we chose to evaluate the three routes, glioma cell lines. The initial choice of this type of cell was due to the great interest in Trp metabolism studies in tumor cells, which glioma cells has been a model. In assays with glioma cells, we followed the effects of an inductor and inhibitors of the first stage of Trp metabolism, via the kynurenine pathway, or IFN -γ (IDO inducer) 1- methyltryptophane (1- MT; competitive IDO inhibitor) and 680C91 (selective TDO inhibitor). We could observe the first step induction or inhibition impact had over the further metabolites and the metabolism differences between the two studied strains, A172 and T98G. The T98G glioma cell has only IDO activity, while the A172 has both IDO and TDO activity as well. The IFN-γ indution showed that this cytokine not only acts in the formation of QUIN route, but has a modest impact on the others routes. Inhibition of IDO showed that the competitive inhibitor has activity in itself than a simple Trp-QUIN relationship. However, our results allow us to show the first time the complete description of these pathways, in particular, in these cell lines that can assume therapeutic strategies in these routes that are related or not with tumor progression

Tratamiento directamente observado de la tuberculosis en un hospital de la Ciudad de Buenos Aires / Directly observed treatment for tuberculosis in a Buenos Aires City hospital

Se describe la experiencia en la aplicación del tratamiento directamente observado de tuberculosis (TDO) en el período 1/1/1979-31/12/2009 y la comparación de los resultados obtenidos en el periodo 1979-1999 versus los de 2000- 2009. En un hospital de la Ciudad de Buenos Aires, 582 pacientes HIV negativos recibieron inicialmente rifampicina, isoniazida, pirazinamida y etambutol o estreptomicina. En la segunda fase 424 de estos pacientes tratados entre 01/01/1979 y 31/12/1999 (G1), recibieron esquemas bisemanales con rifampicina/isoniazida o isoniazida/estreptomicina y otros 158 pacientes, tratados entre 01/01/2000 y 31/12/2009 (G2) recibieron un esquema bisemanal o trisemanal con rifampicina/isoniazida. Se siguieron las recomendaciones de los programas de control de la Nación y la Ciudad. Los pacientes bajo TDO tuvieron tasas de tratamiento completo más elevadas (82.8% versus 48.7%), (p < 0.0001) con respecto a otros 483, que siguieron tratamiento autoadministrado (AUTO); la edad promedio fue de 36.3 ± 15.3 años, 63.1% eran varones y 69.4% tenían nacionalidad argentina. Presentaron tratamiento previo el 8.9%, comorbilidades el 6.1% y el 70.6% de las formas pulmonares fueron confirmadas bacteriológicamente. El 9.5% presentó efectos adversos a drogas y el sexo masculino presentó mayor frecuencia de abandonos (p = 0.004). Con respecto al G1, en el G2 hubo menor proporción de pacientes argentinos (48.7% vs. 77.1%), (p ≤ 0.0001), mayor frecuencia de comorbilidades (10.7% vs. 4.4%), (p = 0.005), de formas clínicas pulmonares con confirmación bacteriológica (95% vs. 87%), (p = 0.02) y de efectos adversos a drogas (17% vs. 6.6%), (p ≤ 0.0001). Hallamos tasas de cumplimiento total elevadas en TDO (82.8%), similares a las otras publicaciones.

The outcomes of directly observed therapy of tuberculosis (DOT) between 1/1/1979 and 12/31/2009 were analyzed. Results obtained in the 1979-1999 period were compared with those achieved in the 2000-2009 period. In a Buenos Aires City hospital, 582 HIV negative TB patients received rifampin, isoniazid, pyrazinamide and ethambutol or streptomycin in the initial stage, followed by a second stage where patients were included in two groups: G1 composed by 424 patients (period 1/1/1979-12/31/1999) who received either rifampin and isoniazid or rifampin and streptomicin twice a week, and G2, with 158 patients (period 1/1/2000-12/31/2009) who received either rifampin and isoniazid twice or three times a week. National and Buenos Aires City TB Control Programs recommendations were followed. Patients who underwent DOT had higher completeness rates than those included in self-administered therapy (82.8% vs. 48.7%), (p <0.0001). Mean age: 36.3±15.3 years, males: 63.1% and 69.4% were Argentine citizens. A 8.9% had been previously treated, 6.1% had co-morbidities. A 70.6% of pulmonary cases was bacteriologically confirmed, 82.8% of them completed the treatment, while 11.5% defaulted. Adverse effects to antituberculosis drugs were observed in 9.5% of cases; male patients showed higher rates of non adherence. G2 had a lower proportion of native people (48.7% vs. 77.1%), (p ≤ 0.0001), higher frequency of co-morbidities (10.7% vs. 4.4%), (p = 0.005), of bacteriologically confirmed pulmonary cases (95% vs. 87%), (p = 0.02) and more adverse effects than G1 (17% vs. 6.6%), (p ≤ 0.0001). In coincidence with other experiences, this work shows high treatment success rates in patients treated under DOT strategy.

Family-Based Association Study of Tryptophan-2,3 Dioxygenase (TDO2) Gene and Autism Spectrum Disorder in the Korean Population

OBJECTIVES: Autism is a complex neurodevelopmental spectrum disorder with a strong genetic component. Previous neurochemical and genetic studies have suggested the possible involvement of the serotonin system in autism. Tryptophan 2,3-dioxygenase(TDO2) is the rate-limiting enzyme in the catabolism of tryptophan, which is the precursor of serotonin synthesis. The aim of this study was to investigate the association between the TDO2 gene and autism spectrum disorders(ASD) in a Korean population. METHODS: The patients were diagnosed with ASD on the basis of the DSM-IV diagnostic classification outlined in the Korean version of the Autism Diagnostic Interview-Revised and Autism Diagnostic Observation Schedule. The present study included the detection of four single nucleotide polymorphisms(SNPs) in the TDO2 gene(rs2292536, rs6856558, rs6830072, rs6830800) and the family-based association analysis of the single nucleotide polymorphisms in Korean ASD trios using a transmission disequilibrium test(TDT) and haplotype analysis. The family trios of 136 probands were included in analysis. 87.5% were male and 86.0% were diagnosed with autism. The mean age of the probands was 78.5+/-35.8 months(range: 26-264 months). RESULTS: Two SNPs showed no polymorphism, and there was no significant difference in transmission in the other two SNPs. We also could not find any significant transmission in the haplotype analysis(p>.05). CONCLUSION: We could not find any significant statistical association between the transmission of SNPs in the TDO2 gene and ASD in a Korean population. This result may not support the possible involvement of the TDO2 gene in the development of ASD, and further exploration might be needed to investigate other plausible SNP sites.