RESUMO
Previous theoretical investigations of the reactions between an OH radical and a nucleobase have stated the most important pathways to be the C5-C6 addition for pyrimidines and the C8 addition for purines. Furthermore, the abstraction of a methyl hydrogen from thymine has also been proven an important pathway. The conclusions were based solely on gas-phase calculations and harmonic vibrational frequencies. In this paper, we supplement the calculations by applying solvent corrections through the polarizable continuum model (PCM) solvent model and applying anharmonicity in order to determine the importance of anharmonicity and solvent effects. Density functional theory (DFT) at the ωB97-D/6-311++G(2df,2pd) level with the Eckart tunneling correction is used. The total reaction rate constants are found to be 1.48 ×10-13 cm3 molecules-1s-1 for adenine, 1.02 ×10-11 cm3 molecules-1s-1 for guanine, 5.52 ×10-13 cm3 molecules-1s-1 for thymine, 1.47 ×10-13 cm3 molecules-1s-1 for cytosine and 7.59 ×10-14 cm3 molecules-1s-1 for uracil. These rates are found to be approximately two orders of magnitude larger than experimental values. We find that the tendencies observed for preferred pathways for reactions calculated in a solvent are comparable to the preferred pathways for reactions calculated in gas phase. We conclude that applying a solvent has a larger impact on more parameters compared to the inclusion of anharmonicity. For some reactions the inclusion of anharmonicity has no effect, whereas for others it does impact the energetics.
Assuntos
Timina , Uracila , Solventes , Adenina , HidrogênioRESUMO
BACKGROUND/AIM: Uracil-tegafur+leucovorin (UFT/LV), an oral adjuvant therapy for stage II/III colorectal cancer, is non-inferior to standard weekly fluorouracil and folinate. Although polysaccharide K (PSK) has been evaluated as a postoperative adjuvant colorectal cancer drug, its efficacy remains unclear. This randomized phase II trial compared UFT/LV+PSK with UFT/LV as adjuvant chemotherapy. PATIENTS AND METHODS: Between April 2011 and August 2016, 186 patients who underwent radical resection randomly received 6 months of UFT/LV (Group A: 300 mg/m2/day UFT and 75 mg/day LV, every 35 days for five cycles), 6 months of UFT/LV+PSK (Group B: standard UFT/LV regimen and daily administration of 3 g/day of PSK), or 12 months of UFT/LV+PSK (Group C). The primary endpoint was the 3-year disease-free survival. RESULTS: Groups A, B, and C consisted of 37, 75, and 74 patients, of which treatment was completed by 33 (89.2%), 63 (84.9%), and 53 (70.4%) patients, respectively (p=0.0279). Adverse event incidence for all grades were 59.5%, 52.1%, and 59.2%, and for grade ≥3 were 13.5%, 9.6%, and 9.9%, respectively. The 3-year disease-free survival rates were 72.5%, 82.2%, and 74.2%, respectively, with no significant differences. The preoperative lymphocyte ratio did not significantly differ between groups. CONCLUSION: UFT/LV+PSK is comparable to UFT/LV therapy in terms of prognostic efficacy and reduced adverse effects. Thus, UFT/LV+PSK is a useful adjuvant chemotherapy option for patients with high-risk stage II/III colorectal cancer.
Assuntos
Quimioterapia Adjuvante , Neoplasias Colorretais , Humanos , Administração Oral , Quimioterapia Adjuvante/efeitos adversos , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/patologia , Leucovorina/uso terapêutico , Levamisol/análogos & derivados , Estadiamento de Neoplasias , Tegafur/uso terapêutico , Uracila/uso terapêuticoRESUMO
Cylindrospermopsin (CYN) can induce phytoplankton community to secrete alkaline phosphatase (ALP), which is one of the important strategies for the bloom-forming cyanobacterium Raphidiopsis to thrive in extremely low-phosphorus (P) waters. However, how bacterioplankton community, another major contributor to ALPs in waters, couples to Raphidiopsis through CYN, and the role of this coupling in supporting the dominance of Raphidiopsis in nature remain largely unknown. Here, we conducted microcosm experiments to address this knowledge gap, using a combination of differential filtration-based and metagenomics-based methods to identify the sources of ALPs. We found that, compared with algal-derived ALPs, bacteria-derived ALPs exhibited a more pronounced and sensitive response to CYN. This response to CYN was enhanced under low-P conditions. Interestingly, we found that Verrucomicrobia made the largest contribution to the total abundance of pho genes, which encode ALPs. Having high gene abundance of the CYN-sensing PI3K-AKT signaling pathway, Verrucomicrobia's proportion increased with higher concentrations of CYN under low-P conditions, thereby explaining the observed increase in pho gene abundance. Compared with other cyanobacterial genera, Raphidiopsis had a higher abundance of the pst gene. This suggests that Raphidiopsis exhibited a greater capacity to uptake the inorganic P generated by ALPs secreted by other organisms. Overall, our results reveal the mechanism of CYN-induced ALP secretion and its impact on planktonic P-cycling, and provide valuable insights into the role of CYN in supporting the formation of Raphidiopsis blooms.
Assuntos
Alcaloides , Cianobactérias , Fosfatidilinositol 3-Quinases , Fosfatidilinositol 3-Quinases/metabolismo , Cianobactérias/metabolismo , Toxinas de Cianobactérias , Fósforo/metabolismo , UracilaRESUMO
BACKGROUND: Early-stage colorectal cancer had excellent outcomes after curative resection, typically. However, a perplexing survival paradox between stage II and stage III was noted. This paradox could be influenced by the administration of routine postoperative adjuvant chemotherapy and the presence of high-risk factors in stage II CRC. The objective of the study was to investigate the influence of high-risk factors on patients with stage II CRC and assess the efficacy of oral tegafur/uracil (UFT) plus leucovorin as adjuvant chemotherapy for stage II CRC patients. METHODS: A retrospective study was conducted using propensity score matching at a single medical institution. A total of 1544 patients with stage II colorectal cancer who underwent radical surgery between January 2004 and January 2009 were included. The intervention used was tegafur/uracil plus leucovorin as adjuvant chemotherapy. The main outcome measures were disease-free survival and overall survival. RESULTS: After propensity score matching, 261 patients were included in three groups: no-treatment, half-year treatment, and one-year treatment. The clinical characteristics of each group tended to be more consistent. The Cox proportional hazard models showed that tegafur/uracil treatment or not was a significant independent factor for oncological outcome. Kaplan-Meier analysis also showed significantly better disease-free survival and overall survival. Further investigation revealed that tegafur/uracil duration was an independent factor for oncological outcome. While the survival curve did not reach statistical significance, the one-year UFT treatment group demonstrated the best treatment trend. CONCLUSIONS: This study suggests that tegafur/uracil plus leucovorin is a feasible adjuvant chemotherapy regimen for patients with stage II colorectal cancer after curative surgical treatment. Prolonged tegafur/uracil plus leucovorin treatment for 12 months showed a trend towards better outcomes in patients with stage II colorectal cancer.
Assuntos
Neoplasias Colorretais , Tegafur , Humanos , Leucovorina , Taiwan , Estudos Retrospectivos , Pontuação de Propensão , Resultado do Tratamento , Uracila , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias Colorretais/cirurgia , Quimioterapia AdjuvanteRESUMO
PURPOSE: There is no consensus on the safety and effectiveness of adjuvant chemotherapy for patients with stage III colorectal cancer (CRC) aged ≥ 80 years. We conducted a prospective multi-institutional phase II study of uracil-tegafur and leucovorin (UFT/LV) as adjuvant chemotherapy in this population. PATIENTS AND METHODS: Patients with stage III CRC aged ≥ 80 years who underwent curative resection were enrolled. Eligible patients received UFT/LV therapy (UFT, 300 mg/m2 per day as tegafur; LV, 75 mg/day on days 1-28, every 35 days for five courses). Primary endpoint was feasibility, and secondary endpoints were safety and relative dose intensity. RESULTS: Sixty-nine patients were enrolled between 2013 and 2021. Of the 69 patients, 65 were included in the analysis. There were 32 males and 33 females with a median age of 82 years (range 80-88 years). In the primary endpoint, administration completion rate was 67.3% (95% confidence interval 54.9-77.6%), and the lower limit of the 95% confidence interval was below the threshold of 60%. 21 patients discontinued treatment because of adverse events (AEs) and refused treatment. The median relative dose intensities were 84% (range 4-100%) for UFT, and 100% (range 4-100%) for LV. Incidence of grade three or higher AEs were neutropenia (1.5%), aspartate transaminase elevation (3%), alanine transaminase elevation (1.5%), oral mucositis (3%), anemia (1.5%), and diarrhea (4.6%). CONCLUSIONS: The indications for adjuvant UFT/LV therapy for elderly CRC aged ≥ 80 years were considered limited. It is necessary to clarify the background of patients in whom drug administration is discontinued and investigate their impact on long-term prognosis.
Assuntos
Neoplasias Colorretais , Tegafur , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Administração Oral , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Quimioterapia Adjuvante , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/cirurgia , Intervalo Livre de Doença , Estudos de Viabilidade , Leucovorina , Estudos Prospectivos , UracilaRESUMO
BACKGROUND AND AIMS: Measurement of plasma uracil is used before cancer treatment with fluoropyrimidines to determine if patients tolerate a full dose. Incorrect preanalytical handling may cause falsely elevated concentration and result in suboptimal cancer treatment. We aimed to examine the stability of uracil in whole blood stored at room temperature (RT) and the effect of centrifugation temperature. MATERIALS AND METHODS: EDTA tubes (6x4 mL) were collected from 25 healthy volunteers. Five samples were stored 0, 1.5, 2, 3, and 4 h at RT and centrifuged at 4 °C. The sixth sample was centrifuged at RT after 1.5 h. Uracil was measured using an in-house LC-MS/MS method. RESULTS: Storage of whole blood at RT followed by centrifugation at 4 °C caused a rapid increase in uracil concentration. Already after 1.5 h, the mean change (20.5 % (95 % CI: 11.9-29.2 %)) exceeded the maximum permissible difference. Centrifugation at RT instead of 4 °C after 1.5 h resulted in a smaller increase (7.0 % (95 % CI: 0.7-13.4 %)), although not statistically significant (p = 0.0527). CONCLUSION: Uracil was unstable in samples processed according to current recommendations. Our data indicates better stability when centrifugation is performed at RT compared with 4 °C but further research into this is necessary.
Assuntos
Neoplasias , Uracila , Humanos , Coleta de Amostras Sanguíneas/métodos , Cromatografia Líquida , Espectrometria de Massas em Tandem/métodos , Neoplasias/tratamento farmacológico , Temperatura , Fatores ImunológicosRESUMO
Uracil misincorporation during DNA replication is a major cell toxic event, of which cancer cells overcome by activating the dUTPase enzyme. The DUT gene is the only known dUTPase in human. Despite reports on common upregulations in cancers, the role of DUT in human hepatocellular carcinoma (HCC) remains largely undetermined. In this study, we investigated the mechanism underlying DUT biology in HCC and tumor susceptibility to drug targeting dUTPase. Overexpression of DUT was found in 42% of HCC tumors and correlated with advanced stage HCC. Knockout of DUT in HCC cell lines showed suppressed proliferation through cell cycle arrest and a spontaneous induction of DNA damage. A protective effect from oxidative stress was also demonstrated in both knockout and overexpression DUT assays. Transcriptome analysis highlighted the NF-κB survival signaling as the downstream effector pathway of DUT in overriding oxidative stress-induced cell death. Interestingly, stably expressed DUT in liver progenitor organoids conferred drug resistance to TKI Sorafenib. Targeting dUTPase activity by TAS-114, could potentiate suppression of HCC growth that synergized with Sorafenib for better treatment sensitivity. In conclusion, upregulated DUT represents a nucleotide metabolic weakness and therapeutic opportunity in HCC.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/genética , Linhagem Celular Tumoral , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , NF-kappa B , Nucleotídeos , Pirofosfatases , Sorafenibe/farmacologia , Uracila/metabolismoRESUMO
Early life stage folate status may influence neurodevelopment in offspring. The developmental origin of health and disease highlights the importance of the period of the first 1000 days (from conception to 2 years) of life. This study aimed to evaluate the effect of early life stage folic acid deficiency on de novo telomere synthesis, neurobehavioral development, and the cognitive function of offspring rats. The rats were divided into three diet treatment groups: folate-deficient, folate-normal, and folate-supplemented. They were fed the corresponding diet from 5 weeks of age to the end of the lactation period. After weaning, the offspring rats were still fed with the corresponding diet for up to 100 days. Neurobehavioral tests, folic acid and homocysteine (Hcy) levels, relative telomere length in brain tissue, and uracil incorporation in telomere in offspring were measured at different time points. The results showed that folic acid deficiency decreased the level of folic acid, increased the level of Hcy of brain tissue in offspring, increased the wrong incorporation of uracil into telomeres, and hindered de novo telomere synthesis. However, folic acid supplementation increased the level of folic acid, reduced the level of Hcy of brain tissue in offspring, reduced the wrong incorporation of uracil into telomeres, and protected de novo telomere synthesis of offspring, which was beneficial to the development of early sensory-motor function, spatial learning, and memory in adolescence and adulthood. In conclusion, early life stage folic acid deficiency had long-term inhibiting effects on neurodevelopment and cognitive function in offspring.
Assuntos
Deficiência de Ácido Fólico , Animais , Cognição , Suplementos Nutricionais , Feminino , Ácido Fólico/metabolismo , Deficiência de Ácido Fólico/complicações , Deficiência de Ácido Fólico/metabolismo , Ratos , Telômero/metabolismo , UracilaRESUMO
OBJECTIVES: To explore the effect of Acai berry on the pharmacokinetics of Atorvastatin (ATR), Alogliptin (ALO) and Empagliflozin (EMPA) in SD rats. METHOD: Thirty-six rats were divided into six groups (n = 6). First three groups were treated with Acai berry (PO; 250 mg/kg); fourth, fifth and sixth groups received sodium CMC (vehicle) for 10 days and on eleventh day, first and fourth groups were administered with ATR (PO; 10 mg/kg); second and fifth groups with ALO (PO; 25 mg/kg) and third and sixth groups received EMPA (PO; 25 mg/kg). KEY FINDINGS: Co-intake of ATR with Acai berry resulted in slight decrease in Cmax from 41.78 to 34.65 ng/ml and AUC from 227.66 to 136.31 (µg/ml) *h, while there was an increase in the Cmax from 43.43 to 68.71 ng/ml and AUC from 117.6 to 207.1 (µg/ml) *h in ALO treated groups and Cmax from 173.99 to 250.1 ng/ml and AUC from 400.37 to 518.35 (µg/ml) *h in the EMPA-treated groups. CONCLUSION: There was a significant change in the AUC0-t and Cmax of ATR, ALO and EMPA after co-administration with Acai berry. Further studies are recommended to confirm the clinical significance of these interactions.
Assuntos
Euterpe , Interações Ervas-Drogas , Animais , Atorvastatina , Compostos Benzidrílicos , Glucosídeos , Piperidinas , Ratos , Ratos Sprague-Dawley , Uracila/análogos & derivadosRESUMO
Oral uracil and tegafur plus Leucovorin(UFT/LV)therapy is one of the standard adjuvant chemotherapies for colorectal cancer, and is widely used without any serious adverse events. Herein, we describe a case of UFT/LV-induced acute liver failure in a 75-year-old woman who underwent laparoscopic sigmoidectomy for sigmoid colon cancer. She was diagnosed with advanced colon cancer and lymph node metastasis by postoperative histopathological analysis, and adjuvant chemotherapy was initiated. After 30 days of commencing the therapy, the patient visited our hospital with complaints of severe diarrhea and difficulty in food intake. The apparent cause of these symptoms was unclear on computed tomography(CT), and mild liver damage was revealed in blood test results. The hepatic disorder gradually progressed after the hospitalization, and the condition was diagnosed as acute hepatic insufficiency. Additionally, obvious atrophy of the liver parenchyma and significant ascites were confirmed on CT. Two months later, the platelet count decreased markedly, but fortunately, no bleeding occurred. There has been no recurrence since 2 years after the surgery without any additional adjuvant therapy.
Assuntos
Falência Hepática Aguda , Neoplasias do Colo Sigmoide , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Feminino , Humanos , Leucovorina/uso terapêutico , Falência Hepática Aguda/tratamento farmacológico , Neoplasias do Colo Sigmoide/tratamento farmacológico , Neoplasias do Colo Sigmoide/patologia , Neoplasias do Colo Sigmoide/cirurgia , Tegafur/efeitos adversos , Uracila/efeitos adversosRESUMO
Objective: To explore the effects of systematic diet education combined with multidisciplinary nursing on nutritional status and calcium and phosphorus metabolism in patients with diabetic kidney disease (DKD) in uremic phase after treatment with alogliptin. Methods: A total of 90 DKD patients with uremia admitted to our hospital from January 2020 to January 2021 were selected as the research objects. The subjects were divided into combined group and routine group by random number table method. All patients received alogliptin medication. The combination group received systematic dietary education combined with multidisciplinary nursing after the medication, and the conventional group received conventional intervention. Serum albumin, blood calcium, and other indexes were detected between both groups after intervention. Results: After intervention, compared with the conventional group, all nutritional indexes of the combined group were obviously higher, levels of serum phosphorus and calcium-phosphorus product of the combined group were obviously lower (P < 0.001), the incidence of hypoglycemia and hyperglycemia of the combined group was obviously lower (P < 0.05), the total compliance rate of the combined group was obviously higher (P < 0.05), and the SAS score of the combined group was obviously lower (P < 0.001). Conclusion: With conspicuous intervention effect, systematic diet education combined with multidisciplinary nursing is a reliable method that can improve the nutritional status and levels of calcium and phosphorus metabolism, enhance treatment compliance, and reduce anxiety. Further research will help to provide a better solution for patients. This trial is registered with ChiCTR2200057011.
Assuntos
Diabetes Mellitus , Nefropatias Diabéticas , Cálcio , Nefropatias Diabéticas/tratamento farmacológico , Dieta , Feminino , Humanos , Masculino , Estado Nutricional , Fósforo , Piperidinas , Uracila/análogos & derivadosRESUMO
BACKGROUND: The efficacy of adjuvant chemotherapy for high-risk stage II colon cancer (CC) has not been well established. We compared the effects of surgery with and without oral uracil and tegafur plus leucovorin (UFT/LV) in patients with high-risk stage II CC, adjusting for potential risk factors. METHODS: We enrolled patients with histologically confirmed stage II colon adenocarcinoma with at least one of the following conditions: T4 disease, perforation/penetration, poorly differentiated adenocarcinoma/mucinous carcinoma, or < 12 dissected lymph nodes. Patients chose to be non-randomized or randomized to undergo surgery alone (NR-Group S or R-Group S) or surgery followed by 6 months of UFT/LV (NR-Group U or R-Group U). The primary endpoint was disease-free survival (DFS) after adjusting for previously reported risk factors using propensity score matching (1:2) and inverse probability of treatment weighting (IPTW) in the non-randomized arm. RESULTS: Overall, 1,902 (98%) and 36 (2%) patients were enrolled in the non-randomized and randomized arms, respectively. There were too few patients in the randomized arm and these were therefore excluded from the analysis. Of the 1,902 patients, 402 in NR-Group S and 804 in NR-Group U were propensity score-matched. The 3-year DFS rate (95% confidence interval) was significantly higher in NR-Group U (80.9% [77.9%-83.4%]) than in NR-Group S (74.0% [69.3%-78.0%]) (hazard ratio, 0.64 [0.50-0.83]; P = 0.0006). The 3-year overall survival rate was not significantly different between NR-Group S and NR-Group U. Significantly higher 3-year DFS (P = 0.0013) and overall survival (P = 0.0315) rates were observed in NR-Group U compared with NR-Group S using IPTW. CONCLUSIONS: Adjuvant chemotherapy with UFT/LV showed a significant survival benefit over surgery alone in patients with high-risk stage II CC characterized by at least one of the following conditions: T4 disease, perforation/penetration, poorly differentiated adenocarcinoma/mucinous carcinoma, or < 12 dissected lymph nodes. TRIAL REGISTRATION: Japan Registry of Clinical Trials: jRCTs031180155 (date of registration: 25/02/2019) (UMIN Clinical Trials Registry: UMIN000007783 , date of registration: 18/04/2012).
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Neoplasias do Colo/tratamento farmacológico , Leucovorina/administração & dosagem , Tegafur/administração & dosagem , Uracila/administração & dosagem , Administração Oral , Adulto , Idoso , Idoso de 80 Anos ou mais , Quimioterapia Adjuvante , Neoplasias do Colo/mortalidade , Intervalo Livre de Doença , Feminino , Humanos , Japão , Excisão de Linfonodo , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/tratamento farmacológico , Estadiamento de Neoplasias , Pontuação de Propensão , Estudos Prospectivos , Fatores de Risco , Taxa de Sobrevida , Resultado do TratamentoRESUMO
Selenium nucleic acids possess unique properties and have been demonstrated to have a wide range of applications such as in DNA X-ray crystallography and novel medical therapies. However, as a heavy atom, selenium substitution may easily alter the photophysical properties of a nucleic acid by red-shifting the absorption spectra and introducing effective intersystem crossing to triplet excited states. In present work, the excited state dynamics of a naturally occurring selenium substituted uracil (2-selenuracil, 2SeU) is studied by using femtosecond transient absorption spectroscopy as well as quantum chemistry calculations. Ultrafast intersystem crossing to the lowest triplet state (T1) and effective non-radiative decay of this state to the ground state (S0) are demonstrated in the neutral form 2SeU. However, the triplet lifetime of the deprotonated form 2SeU is found to be almost one order of magnitude longer than that in the neutral one. Quantum chemistry calculations indicate that the short triplet lifetime in 2SeU is due to excited state population decay through a crossing point between T1 and S0. In the deprotonated form, shortening the N1-C2 bond length makes the structural distortion more difficult and brings a larger energy barrier on the pathway to the T1/S0 crossing point, resulting in one order of magnitude increase of the triplet state lifetime. Our study reveals one key factor to regulate the triplet lifetime of 2SeU and sets the stage to further investigate the photophysical and photochemical properties of 2SeU-containing DNA/RNA duplexes.
Assuntos
Selênio/química , Uracila/química , Teoria da Densidade Funcional , Simulação de Dinâmica Molecular , PrótonsRESUMO
In this study, we provide experimental (Protein Data Bank (PDB) inspection) and theoretical (RI-MP2/def2-TZVP level of theory) evidence of the involvement of charge assisted chalcogen bonding (ChB) interactions in the recognition and folding mechanisms of S-adenosylmethionine (SAM) riboswitches. Concretely, an initial PDB search revealed several examples where ChBs between S-adenosyl methionine (SAM)/adenosyl selenomethionine (EEM) molecules and uracil (U) bases belonging to RNA take place. While these interactions are usually described as a merely Coulombic attraction between the positively charged S/Se group and RNA, theoretical calculations indicated that the σ holes of S and Se are involved. Moreover, computational models shed light on the strength and directionality properties of the interaction, which was also further characterized from a charge-density perspective using Bader's "Atoms in Molecules" (AIM) theory, Non-Covalent Interaction plot (NCIplot) visual index, and Natural Bonding Orbital (NBO) analyses. As far as our knowledge extends, this is the first time that ChBs in SAM-RNA complexes have been systematically analyzed, and we believe the results might be useful for scientists working in the field of RNA engineering and chemical biology as well as to increase the visibility of the interaction among the biological community.
Assuntos
Calcogênios/química , S-Adenosilmetionina/química , Selênio/química , Enxofre/química , Bases de Dados de Proteínas , Ligação de Hidrogênio , Modelos Moleculares , Conformação Molecular , Teoria Quântica , RNA/metabolismo , Riboswitch , Selenometionina/química , Eletricidade Estática , Termodinâmica , Uracila/metabolismoRESUMO
Disturbed deoxythymidine triphosphate biosynthesis due to the inhibition of thymidylate synthase (TS) can lead to uracil accumulation in DNA, eventually, lead to neurocytes apoptosis and cognitive decline. Folic acid supplementation delayed cognitive decline and neurodegeneration in senescence-accelerated mouse prone 8 (SAMP8). Whether folic acid, one of nutrition factor, the effect on the expression of TS is unknown. The study aimed to determine if folic acid supplementation could alleviate age-related cognitive decline and apoptosis of neurocytes by increasing TS expression in SAMP8 mice. According to folic acid concentration in diet, four-month-old male SAMP8 mice were randomly divided into three different diet groups by baseline body weight in equal numbers. Moreover, to evaluate the role of TS, a TS inhibitor was injected intraperitoneal. Cognitive test, apoptosis rates of neurocytes, expression of TS, relative uracil level in telomere, and telomere length in brain tissue were detected. The results showed that folic acid supplementation decreased deoxyuridine monophosphate accumulation, uracil misincorporation in telomere, alleviated telomere length shorting, increased expression of TS, then decreased apoptosis rates of neurocytes, and alleviated cognitive performance in SAMP8 mice. Moreover, at the same concentration of folic acid, TS inhibitor raltitrexed increased deoxyuridine monophosphate accumulation, uracil misincorporation in telomere, and exacerbated telomere length shorting, decreased expression of TS, then increased apoptosis rates of neurocytes, and decreased cognitive performance in SAMP8 mice. In conclusion, folic acid supplementation alleviated age-related cognitive decline and inhibited apoptosis of neurocytes by increasing TS expression in SAMP8 mice.
Assuntos
Envelhecimento , Encéfalo/metabolismo , Disfunção Cognitiva/dietoterapia , Suplementos Nutricionais , Ácido Fólico/administração & dosagem , Neurônios/fisiologia , Nucleotídeos de Timina/biossíntese , Animais , Apoptose , Ácido Fólico/sangue , Ácido Fólico/metabolismo , Masculino , Memória , Camundongos , Teste do Labirinto Aquático de Morris , Quinazolinas/farmacologia , Encurtamento do Telômero , Tiofenos/farmacologia , Timidilato Sintase/antagonistas & inibidores , Timidilato Sintase/genética , Timidilato Sintase/metabolismo , Uracila/metabolismoRESUMO
BACKGROUND: The ACTS-CC 02 trial demonstrated that S-1 plus oxaliplatin (SOX) was not superior to tegafur-uracil and leucovorin (UFT/LV) in terms of disease-free survival (DFS) as adjuvant chemotherapy for high-risk stage III colon cancer (any T, N2, or positive nodes around the origin of the feeding arteries). We now report the final overall survival (OS) and subgroup analysis according to the pathological stage (TNM 7th edition) for treatment efficacy. PATIENTS AND METHODS: Patients who underwent curative resection for pathologically confirmed high-risk stage III colon cancer were randomly assigned to receive either UFT/LV (300 mg/m2 of UFT and 75 mg/day of LV on days 1-28, every 35 days, five cycles) or SOX (100 mg/m2 of oxaliplatin on day 1 and 80 mg/m2/day of S-1 on days 1-14, every 21 days, eight cycles). The primary endpoint was DFS and the patients' data were updated in February 2020. RESULTS: A total of 478 patients in the UFT/LV group and 477 patients in the SOX group were included in the final analysis. With a median follow-up time of 74.3 months, the 5-year DFS rate was 55.2% in the UFT/LV group and 58.1% in the SOX group [stratified hazard ratio (HR) 0.92; 95% confidence interval (CI) 0.76-1.11; P = 0.3973], and the 5-year OS rates were 78.3% and 79.1%, respectively (stratified HR 0.97; 95% CI 0.76-1.24; P = 0.8175). In the subgroup analysis, the 5-year OS rates in patients with T4N2b disease were 51.0% and 64.1% in the UFT/LV and SOX groups, respectively (HR 0.72; 95% CI 0.40-1.31). CONCLUSION: Our final analysis reconfirmed that SOX as adjuvant chemotherapy is not superior to UFT/LV in terms of DFS in patients with high-risk stage III colon cancer. The 5-year OS rate was similar in the UFT/LV and SOX groups.
Assuntos
Neoplasias do Colo , Leucovorina , Oxaliplatina , Tegafur , Uracila , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Quimioterapia Adjuvante , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/patologia , Humanos , Leucovorina/uso terapêutico , Estadiamento de Neoplasias , Oxaliplatina/uso terapêutico , Tegafur/uso terapêutico , Uracila/uso terapêuticoRESUMO
PURPOSE: This randomized phase II trial compared tegafur-uracil/leucovorin (UFT/LV) plus oxaliplatin (TEGAFOX) to UFT/LV as adjuvant chemotherapy for patients with high-risk stage II/III colorectal cancer. METHODS: From 2010 to April 2015, 159 patients who underwent curative resection were randomly assigned to receive TEGAFOX (85 mg/m2 oxaliplatin on days 1 and 15, 300 mg/m2/day UFT and 75 mg/day LV on days 1-28, every 35 days for five cycles) or UFT/LV. The primary study endpoint was disease-free survival. RESULTS: The 3-year disease-free survival rate was 84.2% in the TEGAFOX arm, versus 62.1% for UFT/LV. The stratified hazard ratio for disease-free survival for TEGAFOX compared to UFT/LV was 0.338 (P < 0.01). The incidence of any-grade adverse events was significantly higher in the TEGAFOX arm (96.1%) than in the UFT/LV arm (76.6%; P < 0.01). The rates of any-grade neutropenia, thrombocytopenia, aspartate aminotransferase/alanine aminotransferase elevation, and peripheral sensory neuropathy were higher in the TEGAFOX group, whereas the incidence of grade ≥ 3 adverse events did not differ between the groups. CONCLUSIONS: TEGAFOX is an additional adjuvant chemotherapy option for high-risk stage II/III colorectal cancer. TRIAL REGISTRATION: UMIN ID: 000007696, date of registration: April 10, 2012.
Assuntos
Neoplasias Colorretais , Tegafur , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/cirurgia , Humanos , Leucovorina/efeitos adversos , Oxaliplatina/efeitos adversos , Tegafur/efeitos adversos , Uracila/efeitos adversosRESUMO
Mucosal-associated invariant T (MAIT) cells are a population of innate-like T cells that utilize a semi-invariant T cell receptor (TCR) α chain and are restricted by the highly conserved antigen presenting molecule MR1. MR1 presents microbial riboflavin biosynthesis derived metabolites produced by bacteria and fungi. Consistent with their ability to sense ligands derived from bacterial sources, MAIT cells have been associated with the immune response to a variety of bacterial infections, such as Mycobacterium spp., Salmonella spp. and Escherichia coli. To date, MAIT cells have been studied in humans, non-human primates and mice. However, they have only been putatively identified in cattle by PCR based methods; no phenotypic or functional analyses have been performed. Here, we identified a MAIT cell population in cattle utilizing MR1 tetramers and high-throughput TCR sequencing. Phenotypic analysis of cattle MAIT cells revealed features highly analogous to those of MAIT cells in humans and mice, including expression of an orthologous TRAV1-TRAJ33 TCR α chain, an effector memory phenotype irrespective of tissue localization, and expression of the transcription factors PLZF and EOMES. We determined the frequency of MAIT cells in peripheral blood and multiple tissues, finding that cattle MAIT cells are enriched in mucosal tissues as well as in the mesenteric lymph node. Cattle MAIT cells were responsive to stimulation by 5-OP-RU and riboflavin biosynthesis competent bacteria in vitro. Furthermore, MAIT cells in milk increased in frequency in cows with mastitis. Following challenge with virulent Mycobacterium bovis, a causative agent of bovine tuberculosis and a zoonosis, peripheral blood MAIT cells expressed higher levels of perforin. Thus, MAIT cells are implicated in the immune response to two major bacterial infections in cattle. These data suggest that MAIT cells are functionally highly conserved and that cattle are an excellent large animal model to study the role of MAIT cells in important zoonotic infections.
Assuntos
Infecções Bacterianas/imunologia , Bovinos/imunologia , Células T Invariantes Associadas à Mucosa/imunologia , Animais , Citocinas/farmacologia , Feminino , Antígenos de Histocompatibilidade Classe I/imunologia , Humanos , Masculino , Camundongos , Antígenos de Histocompatibilidade Menor/imunologia , Fenótipo , Ribitol/análogos & derivados , Ribitol/farmacologia , Uracila/análogos & derivados , Uracila/farmacologiaRESUMO
LESSONS LEARNED: The 3-year disease-free survival rate of the twice-daily regimen was not inferior to that of the conventional three-times-daily regimen, and the twice-daily regimen did not lead to an increase in adverse events. The effectiveness of the twice-daily regimen highlights an increased number of treatment options for patients. This will facilitate personalized medicine, particularly for elderly or frail patients who may experience more severe side effects from the combination therapy. BACKGROUND: Tegafur-uracil (UFT)/leucovorin calcium (LV) is an adjuvant chemotherapy treatment for colorectal cancer. We conducted a multicenter randomized trial to assess the noninferiority of a twice-daily compared with a three-times-daily UFT/LV regimen for stage II/III colorectal cancer in an adjuvant setting. METHODS: Patients were randomly assigned to group A (three doses of UFT [300 mg/m2 per day]/LV [75 mg per day]) or B (two doses of UFT [300 mg/m2 per day]/LV [50 mg per day]). The primary endpoint was 3-year disease-free survival. RESULTS: In total, 386 patients were enrolled between July 28, 2011, and September 27, 2013. The 3-year disease-free survival rates of group A (n = 194) and B (n = 192) were 79.4% and 81.4% (95% confidence interval, 72.6-84.4-74.5-85.9), respectively. The most common grade 3/4 adverse events in group A and B were diarrhea (3.9% vs. 7.3%), neutropenia (2.9% vs. 1.6%), increase in aspartate aminotransferase (4.0% vs. 3.9%), increase in alanine aminotransferase (6.2% vs. 6.8%), nausea (1.7% vs. 3.4%), and fatigue (1.1% vs. 2.3%). CONCLUSION: Group B outcomes were not inferior to group A outcomes, and adverse events did not increase.
Assuntos
Neoplasias Colorretais , Tegafur , Administração Oral , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Cálcio , Quimioterapia Adjuvante , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/cirurgia , Humanos , Leucovorina/efeitos adversos , Tegafur/efeitos adversos , Uracila/efeitos adversosRESUMO
We unveil in this work the main factors that govern the turn-on/off fluorescence of a Se-modified uracil probe at the ribosomal RNA A-site. Whereas the constraint into an "in-plane" conformation of the two rings of the fluorophore is the main driver for the observed turn-on fluorescence emission in the presence of the antibiotic paromomycin, the electrostatics of the environment plays a minor role during the emission process. Our computational strategy clearly indicates that, in the absence of paromomycin, the probe prefers conformations that show a dark S1 electronic state with participation of nπ* electronic transition contributions between the selenium atom and the π-system of the uracil moiety.