Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 1.865
Filter
Add more filters

Publication year range
1.
J Bacteriol ; 206(1): e0020223, 2024 01 25.
Article in English | MEDLINE | ID: mdl-38047707

ABSTRACT

YisK is an uncharacterized protein in Bacillus subtilis previously shown to interact genetically with the elongasome protein Mbl. YisK overexpression leads to cell widening and lysis, phenotypes that are dependent on mbl and suppressed by mbl mutations. In the present work, we characterize YisK's localization, structure, and enzymatic activity. We show that YisK localizes as puncta that depend on Mbl. YisK belongs to the fumarylacetoacetate hydrolase (FAH) superfamily, and crystal structures revealed close structural similarity to two oxaloacetate (OAA) decarboxylases: human mitochondrial FAHD1 and Corynebacterium glutamicum Cg1458. We demonstrate that YisK can also catalyze the decarboxylation of OAA (K m = 134 µM, K cat = 31 min-1). A catalytic dead variant (YisK E148A, E150A) retains wild-type localization and still widens cells following overexpression, indicating these activities are not dependent on YisK catalysis. Conversely, a non-localizing variant (YisK E30A) retains wild-type enzymatic activity in vitro but localizes diffusely and no longer widens cells following overexpression. Together, these results suggest that YisK may be subject to spatial regulation that depends on the cell envelope synthesis machinery. IMPORTANCE The elongasome is a multiprotein complex that guides lengthwise growth in some bacteria. We previously showed that, in B. subtilis, overexpression of an uncharacterized putative enzyme (YisK) perturbed function of the actin-like elongasome protein Mbl. Here, we show that YisK exhibits Mbl-dependent localization. Through biochemical and structural characterization, we demonstrate that, like its mitochondrial homolog FAHD1, YisK can catalyze the decarboxylation of the oxaloacetate to pyruvate and CO2. YisK is the first example of an enzyme implicated in central carbon metabolism with subcellular localization that depends on Mbl.


Subject(s)
Bacillus subtilis , Carboxy-Lyases , Humans , Bacillus subtilis/metabolism , Carboxy-Lyases/genetics , Pyruvic Acid , Oxaloacetates , Hydrolases/genetics
2.
J Pharmacol Exp Ther ; 390(3): 318-330, 2024 Aug 19.
Article in English | MEDLINE | ID: mdl-39009467

ABSTRACT

XELOX therapy, which comprises capecitabine and oxaliplatin, is the standard first-line chemotherapeutic regimen for colorectal cancer. However, its myelosuppressive effects pose challenges for its clinical management. Mathematical modeling combining pharmacokinetics (PK) and toxicodynamics (TD) is a promising approach for optimizing dosing strategies and reducing toxicity. This study aimed to develop a translational PK-TD model using rat data to inform dosing strategies and TD implications in humans. The rats were administered capecitabine, oxaliplatin, or XELOX combination regimen, and PK and TD data were collected. PK parameters were analyzed using sequential compartment analysis, whereas TD responses were assessed using Friberg's semiphysiological model. A toxicity intensity-based nomogram recommends optimal dosing strategies. Translational modeling techniques using the hybrid PK-TD model were employed to predict clinical responses. The PK-TD model successfully predicted the time-course profiles of hematological responses in rats following monotherapy and XELOX combination treatment. Interactive effects on lymphocytopenia were identified with the coadministration of capecitabine and oxaliplatin. A model-based recommended combination of the dose reduction rate for escaping severe lymphocytopenia was proposed as 40% and 60% doses of capecitabine and oxaliplatin, respectively. The current translational model techniques successfully simulated the time-course profiles of blood cell counts with confidence intervals in patients using rat data. Our study provides valuable insights into dose optimization strategies for each individual drug within the XELOX regimen and underscores the potential of translational modeling to improve patient outcomes. In addition to dose determination, these data will lay the groundwork for advancing drug development processes in oncology. SIGNIFICANCE STATEMENT: This study introduced a novel translational modeling approach rooted in a rat PK-TD model to optimize dosing strategies for the XELOX regimen for colorectal cancer treatment. Our findings highlight the interactive effects on lymphocytopenia and suggest a toxicity intensity-based nomogram for dose reduction, thus advancing precision medicine. This translational modeling paradigm enhances our understanding of drug interactions, offering a tool to tailor dosing, minimize hematological toxicity, and improve therapeutic outcomes in patients undergoing XELOX therapy.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols , Capecitabine , Oxaliplatin , Capecitabine/pharmacokinetics , Capecitabine/administration & dosage , Animals , Oxaliplatin/pharmacokinetics , Oxaliplatin/administration & dosage , Rats , Humans , Antineoplastic Combined Chemotherapy Protocols/pharmacokinetics , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Male , Dose-Response Relationship, Drug , Rats, Sprague-Dawley , Models, Biological , Translational Research, Biomedical , Fluorouracil/pharmacokinetics , Fluorouracil/analogs & derivatives , Fluorouracil/administration & dosage , Colorectal Neoplasms/drug therapy , Bone Marrow/drug effects , Oxaloacetates
3.
Cancer Invest ; 42(7): 661-670, 2024 Aug.
Article in English | MEDLINE | ID: mdl-39037150

ABSTRACT

OBJECTIVE: In this study, we retrospectively analysed the efficacy and safety of three treatment models, namely, short-course radiotherapy sequential XELOX chemotherapy, neoadjuvant mFOLFOX6 concurrent radiotherapy and long-course concurrent radiotherapy with total mesorectal excision (TME) after treatment of locally advanced rectal cancer with high-risk factors. METHODS: We collected clinical data on 177 patients with locally advanced rectal cancer (cT3-4 and/or cN+) who were treated at the Department of Abdominal Oncology of the Affiliated Cancer Hospital of Guizhou Medical University from December 2017 to December 2022. All patients were associated with 2-3 risk factors [T4b, N2, Extramural Vascular Invasion (EMVI), Mesorectal Fascia (MRF) positivity], positive lateral lymph nodes. Among them, there were 45 cases in the short course radiotherapy sequential XELOX chemotherapy group (RT + XELOX group); 64 cases in the neoadjuvant mFOLFOX6 concurrent radiotherapy group (mFOLFOX6 + CRT group); and 68 cases in the long course concurrent radiotherapy group (CRT group). The RT + XELOX group and mFOLFOX6 + CRT group completed radiotherapy and 4 cycles of neoadjuvant chemotherapy, respectively, and then rested for 1-2 weeks before TME surgery; the CRT group completed concurrent radiotherapy and then rested for 6-8 weeks before TME surgery.Adjuvant chemotherapy was conducted after surgery in each of the three groups: 2 cycles of adjuvant chemotherapy with XELOX regimen in the RT + XELOX group, 4-6 cycles of adjuvant chemotherapy with mFOLFOX6 in the mFOLFOX6 + CRT group, and 8-12 cycles of adjuvant chemotherapy with mFOLFOX6 in the CRT group.The pathological complete response rate (pCR rate), tumour downstage rate, tumour complete resection rate (R0 resection rate), local recurrence rate, distant metastasis rate, overall survival rate, incidence of adverse reactions, surgical complications and completion rate of perioperative systemic chemotherapy were compared among patients in the three groups of cases after TME. RESULTS: The pCR rate (21.95% vs 17.24% vs 5.00%, p = 0.034) and and tumour downstage rate (78.05% vs 68.97% vs 53.33%, p = 0.029) were higher in the RT + XELOX group and mFOLFOX6 + CRT group compared to the CRT group. The RT + XELOX group had a lower 3-year distant metastasis rate (14.63% vs 36.67%, p = 0.048) and improved 3-year overall survival (76.57% vs 48.56%, p < 0.001) compared to the CRT group. There was no significant reduction in the 3-year distant metastasis rate in the mFOLFOX6 + CRT group versus the CRT group (27.59% vs 36.67%, p = 0.719), and the 3-year overall survival was similar (51.23% vs 48.56%, p = 0.35). Multi-logistic regression analysis and stratified analysis showed that patients in the RT + XELOX group and mFOLFOX6 + CRT group were more likely to achieve pCR than the CRT group (RT + XELOX group: OR 7.3, 95% CI [2.6-20.8], p < 0.001; mFOLFOX6 + CRT group OR 2.9, 95% CI [1.1-7.9], p = 0.036). The completion rates of perioperative systemic chemotherapy in the RT + XELOX, mFOLFOX6 + CRT, and CRT groups were 82.93% vs. 84.48% vs. 61.67% (χ2=9.95, p = 0.007), respectively. And there were significant differences in grade 3-4 leukopenia and thrombocytopenia (incidence of leukopenia: 15.50% vs. 7.81% vs. 1.47%, p = 0.045; incidence of thrombocytopenia: 13.33% vs 7.81% vs 1.47%, p = 0.027). There was no significant difference in the incidence of intraoperative and postoperative complications among the three groups (p > 0.05). CONCLUSIONS: RT + XELOX group and mFOLFOX6 + CRT group significantly improved the near-term outcome (e.g., pCR rate) in patients with locally advanced rectal cancer with high-risk factors compared with CRT group. The RT + XELOX group also reduced the 3-year distant metastasis rate, increased the 3-year overall survival rate, and did not increase the incidence of perioperative surgical complications. It provides an effective means for the comprehensive treatment of locally advanced rectal cancer and has important clinical guidance and application value.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols , Capecitabine , Leucovorin , Neoadjuvant Therapy , Rectal Neoplasms , Humans , Rectal Neoplasms/therapy , Rectal Neoplasms/pathology , Rectal Neoplasms/drug therapy , Rectal Neoplasms/mortality , Male , Female , Neoadjuvant Therapy/methods , Middle Aged , Retrospective Studies , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Capecitabine/administration & dosage , Capecitabine/therapeutic use , Aged , Leucovorin/administration & dosage , Leucovorin/therapeutic use , Adult , Fluorouracil/administration & dosage , Fluorouracil/therapeutic use , Organoplatinum Compounds/therapeutic use , Organoplatinum Compounds/administration & dosage , Oxaloacetates , Treatment Outcome
4.
Int J Mol Sci ; 25(10)2024 May 13.
Article in English | MEDLINE | ID: mdl-38791339

ABSTRACT

Previous studies have documented that FOLFOX and XELOX therapies negatively impact the metabolism of skeletal muscle and extra-muscle districts. This pilot study tested whether three-month FOLFOX or XELOX therapy produced changes in plasma amino acid levels (PAAL) (an estimation of whole-body amino acid metabolism) and in plasma levels of malondialdehyde (MDA), a marker of lipid hyper oxidation. Fourteen ambulatory, resected patients with colorectal cancer scheduled to receive FOLFOX (n = 9) or XELOX (n = 5) therapy, after overnight fasting, underwent peripheral venous blood sampling, to determine PAAL and MDA before, during, and at the end of three-month therapy. Fifteen healthy matched subjects (controls) only underwent measures of PAAL at baseline. The results showed changes in 87.5% of plasma essential amino acids (EAAs) and 38.4% of non-EAAs in patients treated with FOLFOX or XELOX. These changes in EAAs occurred in two opposite directions: EAAs decreased with FOLFOX and increased or did not decrease with XELOX (interactions: from p = 0.034 to p = 0.003). Baseline plasma MDA levels in both FOLFOX and XELOX patients were above the normal range of values, and increased, albeit not significantly, during therapy. In conclusion, three-month FOLFOX or XELOX therapy affected plasma EAAs differently but not the baseline MDA levels, which were already high.


Subject(s)
Amino Acids , Antineoplastic Combined Chemotherapy Protocols , Colorectal Neoplasms , Fluorouracil , Oxaloacetates , Humans , Colorectal Neoplasms/blood , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/surgery , Male , Female , Middle Aged , Amino Acids/blood , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Aged , Fluorouracil/therapeutic use , Leucovorin/therapeutic use , Capecitabine/therapeutic use , Malondialdehyde/blood , Deoxycytidine/analogs & derivatives , Deoxycytidine/therapeutic use , Organoplatinum Compounds/therapeutic use , Pilot Projects , Oxidation-Reduction , Adult , Lipid Peroxidation/drug effects , Lipid Metabolism/drug effects
5.
Plant Mol Biol ; 111(4-5): 429-438, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36884198

ABSTRACT

Citrate synthase (CS) catalyzes the reaction that produces citrate and CoA from oxaloacetate and acetyl-CoA in the tricarboxylic acid (TCA) cycle. All TCA cycle enzymes are localized to the mitochondria in the model organism, the red alga Cyanidioschyzon merolae. The biochemical properties of CS have been studied in some eukaryotes, but the biochemical properties of CS in algae, including C. merolae, have not been studied. We then performed the biochemical analysis of CS from C. merolae mitochondria (CmCS4). The results showed that the kcat/Km of CmCS4 for oxaloacetate and acetyl-CoA were higher than those of the cyanobacteria, such as Synechocystis sp. PCC 6803, Microcystis aeruginosa PCC 7806 and Anabaena sp. PCC 7120. Monovalent and divalent cations inhibited CmCS4, and in the presence of KCl, the Km of CmCS4 for oxaloacetate and acetyl-CoA was higher in the presence of MgCl2, the Km of CmCS4 for oxaloacetate and acetyl-CoA was higher and kcat lower. However, in the presence of KCl and MgCl2, the kcat/Km of CmCS4 was higher than those of the three cyanobacteria species. The high catalytic efficiency of CmCS4 for oxaloacetate and acetyl-CoA may be a factor in the increased carbon flow into the TCA cycle in C. merolae.


Subject(s)
Oxaloacetic Acid , Rhodophyta , Citrate (si)-Synthase/chemistry , Acetyl Coenzyme A , Oxaloacetates
6.
Neurochem Res ; 48(6): 1728-1736, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36662405

ABSTRACT

Pyruvate carboxylase (PC) is an enzyme catalyzing the carboxylation of pyruvate to oxaloacetate. The enzymatic generation of oxaloacetate, an intermediate of the Krebs cycle, could provide the cancer cells with the additional anaplerotic capacity and promote their anabolic metabolism. Recent studies revealed that several types of cancer cells express PC. The gained anaplerotic capability of cells mediated by PC correlates with their expedited growth, higher aggressiveness, and increased metastatic potential. By immunohistochemical staining and immunoblotting analysis, we investigated PC expression among samples of different types of human brain tumors. Our results show that PC is expressed by the cells in glioblastoma, astrocytoma, oligodendroglioma, and meningioma tumors. The presence of PC in these tumors suppose that PC could support the anabolic metabolism of their cellular constituents by its anaplerotic capability.


Subject(s)
Astrocytoma , Brain Neoplasms , Glioblastoma , Meningeal Neoplasms , Meningioma , Oligodendroglioma , Humans , Pyruvate Carboxylase/metabolism , Pyruvic Acid/metabolism , Oxaloacetic Acid , Oxaloacetates
7.
Appl Microbiol Biotechnol ; 107(5-6): 1845-1861, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36754884

ABSTRACT

Nitrogen metabolism can regulate mycelial growth and secondary metabolism in Ganoderma lucidum. As an important enzyme in intracellular amino acid metabolism, glutamate oxaloacetate transaminase (GOT) has many physiological functions in animals and plants, but its function in fungi has been less studied. In the present study, two GOT isoenzymes were found in G. lucidum; one is located in the mitochondria (GOT1), and the other is located in the cytoplasm (GOT2). The reactive oxygen species (ROS) level was increased in got1 silenced strains and was approximately 1.5-fold higher than that in the wild-type (WT) strain, while silencing got2 did not affect the ROS level. To explore how GOT affects ROS in G. lucidum, experiments related to the generation and elimination of intracellular ROS were conducted. First, compared with that in the WT strain, the glutamate content, one of the substrates of GOT, decreased when got1 or got2 was knocked down, and the glutathione (l-γ-glutamyl-l-cysteinylglycine) (GSH) content decreased by approximately 38.6%, 19.3%, and 40.1% in got1 silenced strains, got2 silenced strains, and got1/2 co-silenced strains respectively. Second, GOT also affects glucose metabolism. The pyruvate (PA), acetyl-CoA and α-ketoglutarate (α-KG) contents decreased in got1 and got2 silenced strains, and the transcription levels of most genes involved in the glycolytic pathway and the tricarboxylic acid cycle increased. The NADH content was increased in got1 silenced strains and got2 silenced strains, and the NAD+/NADH ratio was decreased, which might result in mitochondrial ROS production. Compared with the WT strain, the mitochondrial ROS level was approximately 1.5-fold higher in the got1 silenced strains. In addition, silencing of got1 or got2 resulted in a decrease in antioxidant enzymes, including superoxide dismutase, catalase, glutathione reductase, and ascorbate peroxidase. Finally, ganoderic acid (GA) was increased by approximately 40% in got1 silenced strains compared with the WT strain, while silencing of got2 resulted in a 10% increase in GA biosynthesis. These findings provide new insights into the effect of GOT on ROS and secondary metabolism in fungi. KEY POINTS: • GOT plays important roles in ROS level in Ganoderma lucidum. • Silencing of got1 resulted in decrease in GSH content and antioxidant enzymes activities, but an increase in mitochondrial ROS level in G. lucidum. • Silencing of got1 and got2 resulted in an increase in ganoderic acid biosynthesis in G. lucidum.


Subject(s)
Reishi , Triterpenes , Reactive Oxygen Species/metabolism , Reishi/genetics , Antioxidants/metabolism , NAD/metabolism , Triterpenes/metabolism , Oxaloacetates/metabolism
8.
JAMA ; 330(21): 2064-2074, 2023 12 05.
Article in English | MEDLINE | ID: mdl-38051328

ABSTRACT

Importance: Gastric and gastroesophageal junction cancers are diagnosed in more than 1 million people worldwide annually, and few effective treatments are available. Sintilimab, a recombinant human IgG4 monoclonal antibody that binds to programmed cell death 1 (PD-1), in combination with chemotherapy, has demonstrated promising efficacy. Objective: To compare overall survival of patients with unresectable locally advanced or metastatic gastric or gastroesophageal junction cancers who were treated with sintilimab with chemotherapy vs placebo with chemotherapy. Also compared were a subset of patients with a PD ligand 1 (PD-L1) combined positive score (CPS) of 5 or more (range, 1-100). Design, Setting, and Participants: Randomized, double-blind, placebo-controlled, phase 3 clinical trial conducted at 62 hospitals in China that enrolled 650 patients with unresectable locally advanced or metastatic gastric or gastroesophageal junction adenocarcinoma between January 3, 2019, and August 5, 2020. Final follow-up occurred on June 20, 2021. Interventions: Patients were randomized 1:1 to either sintilimab (n = 327) or placebo (n = 323) combined with capecitabine and oxaliplatin (the XELOX regimen) every 3 weeks for a maximum of 6 cycles. Maintenance therapy with sintilimab or placebo plus capecitabine continued for up to 2 years. Main Outcomes and Measures: The primary end point was overall survival time from randomization. Results: Of the 650 patients (mean age, 59 years; 483 [74.3%] men), 327 were randomized to sintilimab plus chemotherapy and 323 to placebo plus chemotherapy. Among the randomized patients, 397 (61.1%) had tumors with a PD-L1 CPS of 5 or more; 563 (86.6%) discontinued study treatment and 388 (59.7%) died; 1 patient (<0.1%) was lost to follow-up. Among all randomized patients, sintilimab improved overall survival compared with placebo (median, 15.2 vs 12.3 months; stratified hazard ratio [HR], 0.77 [95% CI, 0.63-0.94]; P = .009). Among patients with a CPS of 5 or more, sintilimab improved overall survival compared with placebo (median, 18.4 vs 12.9 months; HR, 0.66 [95% CI, 0.50-0.86]; P = .002). The most common grade 3 or higher treatment-related adverse events were decreased platelet count (sintilimab, 24.7% vs placebo, 21.3%), decreased neutrophil count (sintilimab, 20.1% vs placebo, 18.8%), and anemia (sintilimab, 12.5% vs placebo, 8.8%). Conclusions and Relevance: Among patients with unresectable locally advanced or metastatic gastric and gastroesophageal junction adenocarcinoma treated with first-line chemotherapy, sintilimab significantly improved overall survival for all patients and for patients with a CPS of 5 or more compared with placebo. Trial Registration: ClinicalTrials.gov Identifier: NCT03745170.


Subject(s)
Adenocarcinoma , Antibodies, Monoclonal, Humanized , Antineoplastic Combined Chemotherapy Protocols , Esophagogastric Junction , Stomach Neoplasms , Female , Humans , Male , Middle Aged , Adenocarcinoma/drug therapy , Adenocarcinoma/immunology , Adenocarcinoma/mortality , Adenocarcinoma/pathology , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , B7-H1 Antigen/antagonists & inhibitors , B7-H1 Antigen/immunology , Capecitabine/administration & dosage , Capecitabine/adverse effects , Esophagogastric Junction/pathology , Stomach Neoplasms/drug therapy , Stomach Neoplasms/immunology , Stomach Neoplasms/mortality , Stomach Neoplasms/pathology , Antineoplastic Agents, Immunological/administration & dosage , Antineoplastic Agents, Immunological/adverse effects , Antineoplastic Agents, Immunological/therapeutic use , Antibodies, Monoclonal, Humanized/administration & dosage , Antibodies, Monoclonal, Humanized/adverse effects , Antibodies, Monoclonal, Humanized/therapeutic use , Immunoglobulin G/immunology , Double-Blind Method , Programmed Cell Death 1 Receptor/antagonists & inhibitors , Programmed Cell Death 1 Receptor/immunology , Oxaloacetates/administration & dosage , Oxaloacetates/adverse effects
9.
Cancer Sci ; 113(9): 3055-3070, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35657686

ABSTRACT

5-Fluorouracil (5-FU) is widely used in gastric cancer treatment, yet 5-FU resistance remains an important clinical challenge. We established a model based on five long noncoding RNAs (lncRNA) to effectively assess the prognosis of gastric cancer patients; among them, lncRNA OVAAL was markedly upregulated in gastric cancer and associated with poor prognosis and 5-FU resistance. In vitro and in vivo assays confirmed that OVAAL promoted proliferation and 5-FU resistance of gastric cancer cells. Mechanistically, OVAAL bound with pyruvate carboxylase (PC) and stabilized PC from HSC70/CHIP-mediated ubiquitination and degradation. OVAAL knockdown reduced intracellular levels of oxaloacetate and aspartate, and the subsequent pyrimidine synthesis, which could be rescued by PC overexpression. Moreover, OVAAL knockdown increased sensitivity to 5-FU treatment, which could be reversed by PC overexpression or repletion of oxaloacetate, aspartate, or uridine. OVAAL overexpression enhanced pyrimidine synthesis to promote proliferation and 5-FU resistance of gastric cancer cells, which could be abolished by PC knockdown. Thus, OVAAL promoted gastric cancer cell proliferation and induced 5-FU resistance by enhancing pyrimidine biosynthesis to antagonize 5-FU induced thymidylate synthase dysfunction. Targeting OVAAL-mediated nucleotide metabolic reprograming would be a promising strategy to overcome chemoresistance in gastric cancer.


Subject(s)
RNA, Long Noncoding , Stomach Neoplasms , Aspartic Acid/pharmacology , Aspartic Acid/therapeutic use , Cell Line, Tumor , Drug Resistance, Neoplasm/genetics , Fluorouracil/pharmacology , Fluorouracil/therapeutic use , Humans , Nucleotides/pharmacology , Nucleotides/therapeutic use , Oxaloacetates/pharmacology , Oxaloacetates/therapeutic use , Pyruvate Carboxylase/genetics , RNA, Long Noncoding/genetics , Stomach Neoplasms/drug therapy , Stomach Neoplasms/genetics , Stomach Neoplasms/metabolism
10.
Yeast ; 39(5): 337-347, 2022 05.
Article in English | MEDLINE | ID: mdl-35384037

ABSTRACT

The yeast Komagataella phaffii (a.k.a. Pichia pastoris) harbours a unique glutamate utilization pathway in which the cytosolic enzymes glutamate dehydrogenase 2 (GDH2), aspartate aminotransferase 2 (AAT2) and phosphoenolpyruvate carboxykinase (PEPCK) catalyze the sequential conversion of glutamate to α-ketoglutarate, oxaloacetate and phosphoenolpyruvate respectively. GDH2 and PEPCK are essential for glutamate catabolism. Their synthesis is induced by autophagy during carbon starvation and are essential for cell survival. Here, we demonstrate that GDH2 and PEPCK reciprocally regulate each other's protein levels during glutamate catabolism such that GDH2 is downregulated in Δpepck and PEPCK is downregulated in Δgdh2. We further demonstrate that sequential conversion of glutamate to α-ketoglutarate and oxaloacetate by GDH2 and AAT2, respectively, is essential for PEPCK synthesis in cells metabolizing glutamate. Our studies indicate that translation of GDH2 mRNA is induced by glutamate while oxaloacetate derived from glutamate is likely to be the inducer of PEPCK mRNA translation during glutamate catabolism. Thus, GDH2- and PEPCK-catalyzed reactions are essential for ATP generation and gluconeogenesis respectively during carbon starvation and glutamate catabolism in K. phaffii. We conclude that K. phaffii harbours a unique translational regulatory circuit in which substrates of GDH2 and PEPCK act as inducers of their synthesis, a phenomenon not reported in any yeast species.


Subject(s)
Glutamate Dehydrogenase , Ketoglutaric Acids , Carbon/metabolism , Gene Expression Regulation, Fungal , Glutamate Dehydrogenase/genetics , Glutamate Dehydrogenase/metabolism , Glutamates/metabolism , Oxaloacetates , Phosphoenolpyruvate , Phosphoenolpyruvate Carboxykinase (ATP)/genetics , Phosphoenolpyruvate Carboxykinase (ATP)/metabolism , Saccharomycetales , Yeasts/metabolism
11.
BMC Gastroenterol ; 22(1): 121, 2022 Mar 14.
Article in English | MEDLINE | ID: mdl-35287591

ABSTRACT

BACKGROUND: Previous studies have confirmed that systemic immune-inflammatory index (SII) and prognostic nutritional index (PNI) can predict the prognosis and chemotherapy efficacy of various malignant tumors. However, to the best of our knowledge, no study investigated the SII combined with PNI score to predict the efficacy of anti-programmed death 1 (anti-PD-1) antibody sintilimab and XELOX regimen (capecitabine plus oxaliplatin) in the treatment of locally advanced gastric cancer. This study aims to evaluate the predictive value of pre-treatment SII-PNI score on the sensitivity of sintilimab immunotherapy combined with XELOX chemotherapy in patients with locally advanced gastric cancer. METHODS: We registered a prospective clinical study involving 30 locally advanced gastric cancer patients from March 2020 to July 2021. The pre-treatment SII and PNI were calculated from peripheral blood samples, and the cut-off value was calculated by receiver operating characteristic. The SII-PNI score ranged from 0 to 2 and were categorized into the following: score of 2, high SII (≥ 568.5) and low PNI (≤ 52.7); score of 1, either high SII or low PNI; score of 0, no high SII nor low PNI. RESULTS: All patients were evaluated by RECIST1.1 criteria after four cycles of sintilimab immunotherapy combined with XELOX chemotherapy, including 5 patients with TRG 3 and 25 patients with non-TRG 3. The SII-PNI score of non-TRG 3 patients was significantly lower than that of TRG 3 patients (P = 0.017). The medial progression free survival of patients with low SII-PNI score was significantly better than that of patients with high SII-PNI score (P < 0.001). Multivariate analysis showed that SII-PNI score was an independent prognostic factor for predicting progression-free survival (P = 0.003). CONCLUSION: The pre-treatment SII-PNI score is a significant indicator for predicting chemosensitivity of locally advanced patients after sintilimab immunotherapy combined with XELOX chemotherapy, which can help to identify high-risk groups and predict prognosis. TRIAL REGISTRATION: The registered name of the trial is "Prospective clinical study of sintilimab combined with chemotherapy for neoadjuvant therapy in locally advanced gastric cancer". Its Current Controlled Trials number is ChiCTR2000030414. Its date of registration is 01/03/2020.


Subject(s)
Neoadjuvant Therapy , Stomach Neoplasms , Antibodies, Monoclonal, Humanized , Antineoplastic Combined Chemotherapy Protocols , Capecitabine/therapeutic use , Humans , Immunotherapy , Nutrition Assessment , Oxaloacetates , Prognosis , Programmed Cell Death 1 Receptor , Prospective Studies , Retrospective Studies , Stomach Neoplasms/drug therapy
12.
Altern Ther Health Med ; 28(6): 65-71, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35452419

ABSTRACT

Background and Objectives: Colorectal cancer (CRC) is a malignant tumor with an extremely high incidence rate worldwide. This study explores the influence of mindfulness-based stress reduction (MBSR) in the care of patients with CRC undergoing bevacizumab (BVZ) plus XELOX chemotherapy, aiming at providing reliable reference and guidance for further improving their rehabilitation and prognosis. Methods: Between January 2019 and March 2020, 88 patients with CRC admitted consecutively to Jiangsu Cancer Hospital in China were enrolled in the study. Of them, 42 patients receiving BVZ plus XELOX chemotherapy, conventional care and MBSR intervention were assigned to the intervention group, and the remaining 46 patients receiving XELOX chemotherapy and conventional care were included in the control group. Clinical efficacy, safety and improvement in functional status were compared. Patients' psychological state, treatment compliance and self-care ability were evaluated. Finally, prognostic quality of life (QoL) was recorded at 1-year follow-up. Results: The overall response rate and incidence of adverse events in the intervention group were not different in the control group, but the total control rate and improvement rate in the intervention group were higher. After treatment, Sedation-Agitation Scale (SAS) and Self-Rating Depression Scale (SDS) scores in the intervention group were decreased, compliance and self-care ability were improved, all of which were better than in the control group. Prognostic follow-up showed that the QoL in the intervention group was also higher than in the control group. Conclusions: The combined use of BVZ in XELOX-based chemotherapy can improve the clinical outcome and functional status of patients with CRC. In addition, MBSR intervention implemented during chemotherapy can effectively optimize patients' psychological state and treatment compliance, strengthen their self-care ability and improve their prognostic QoL.


Subject(s)
Colorectal Neoplasms , Mindfulness , Antineoplastic Combined Chemotherapy Protocols , Bevacizumab/therapeutic use , Capecitabine , Colorectal Neoplasms/chemically induced , Colorectal Neoplasms/drug therapy , Deoxycytidine/adverse effects , Fluorouracil/adverse effects , Humans , Oxaloacetates , Quality of Life , Treatment Outcome
13.
Int J Mol Sci ; 23(11)2022 May 27.
Article in English | MEDLINE | ID: mdl-35682716

ABSTRACT

Gastric cancer (GC) is one of the most common cancers and a leading cause of cancer deaths around the world. Chemotherapy is one of the most effective treatments for cancer patients, and has remarkably enhanced survival rates. However, it has many side effects. Recently, microRNAs (miRNAs) have been intensively studied as potential biomarkers for cancer diagnosis and treatment monitoring. However, definitive biomarkers in chemotherapy-induced peripheral neuropathy (CIPN) are still lacking. The aim of this study was to identify the factors significant for neurological adverse events in GC patients receiving XELOX (oxaliplatin and capecitabine) chemotherapy. The results show that XELOX chemotherapy induces changes in the expression of hsa-miR-200c-3p, hsa-miR-885-5p, and hsa-miR-378f. Validation by qRT-PCR demonstrated that hsa-miR-378f was significantly downregulated in CIPN. Hsa-miR-378f was identified as showing a statistically significant correlation in GC patients receiving XELOX chemotherapy according to the analysis of differentially expressed (DE) miRNAs. Furthermore, 34 potential target genes were predicted using a web-based database for miRNA target prognostication and functional annotations. The identified genes are related to the peptidyl-serine phosphorylation and regulation of alternative mRNA splicing with enrichment in the gastric cancer, neurotrophin, MAPK, and AMPK signaling pathways. Collectively, these results provide information useful for developing promising strategies for the treatment of XELOX-chemotherapy-induced peripheral neuropathy.


Subject(s)
Antineoplastic Agents , Circulating MicroRNA , MicroRNAs , Peripheral Nervous System Diseases , Stomach Neoplasms , Antineoplastic Agents/adverse effects , Antineoplastic Combined Chemotherapy Protocols , Biomarkers , Capecitabine/adverse effects , Circulating MicroRNA/genetics , Gene Expression Profiling , Humans , MicroRNAs/genetics , MicroRNAs/metabolism , Oxaloacetates , Peripheral Nervous System Diseases/chemically induced , Peripheral Nervous System Diseases/genetics , Stomach Neoplasms/drug therapy , Stomach Neoplasms/genetics
14.
Int J Mol Sci ; 23(18)2022 Sep 06.
Article in English | MEDLINE | ID: mdl-36142128

ABSTRACT

Actinidia eriantha is a unique germplasm resource for kiwifruit breeding. Genetic diversity and nutrient content need to be evaluated prior to breeding. In this study, we looked at the metabolites of three elite A. eriantha varieties (MM-11, MM-13 and MM-16) selected from natural individuals by using a UPLC-MS/MS-based metabolomics approach and transcriptome, with a total of 417 metabolites identified. The biosynthesis and metabolism of phenolic acid, flavonoids, sugars, organic acid and AsA in A. eriantha fruit were further analyzed. The phenolic compounds accounted for 32.37% of the total metabolites, including 48 phenolic acids, 60 flavonoids, 7 tannins and 20 lignans and coumarins. Correlation analysis of metabolites and transcripts showed PAL (DTZ79_15g06470), 4CL (DTZ79_26g05660 and DTZ79_29g0271), CAD (DTZ79_06g11810), COMT (DTZ79_14g02670) and FLS (DTZ79_23g14660) correlated with polyphenols. There are twenty-three metabolites belonging to sugars, the majority being sucrose, glucose arabinose and melibiose. The starch biosynthesis-related genes (AeglgC, AeglgA and AeGEB1) were expressed at lower levels compared with metabolism-related genes (AeamyA and AeamyB) in three mature fruits of three varieties, indicating that starch was converted to soluble sugar during fruit maturation, and the expression level of SUS (DTZ79_23g00730) and TPS (DTZ79_18g05470) was correlated with trehalose 6-phosphate. The main organic acids in A. eriantha fruit are citric acid, quinic acid, succinic acid and D-xylonic acid. Correlation analysis of metabolites and transcripts showed ACO (DTZ79_17g07470) was highly correlated with citric acid, CS (DTZ79_17g00890) with oxaloacetic acid, and MDH1 (DTZ79_23g14440) with malic acid. Based on the gene expression, the metabolism of AsA acid was primarily through the L-galactose pathway, and the expression level of GMP (DTZ79_24g08440) and MDHAR (DTZ79_27g01630) highly correlated with L-Ascorbic acid. Our study provides additional evidence for the correlation between the genes and metabolites involved in phenolic acid, flavonoids, sugars, organic acid and AsA synthesis and will help to accelerate the kiwifruit molecular breeding approaches.


Subject(s)
Actinidia , Lignans , Actinidia/genetics , Actinidia/metabolism , Arabinose , Ascorbic Acid/metabolism , Chromatography, Liquid , Citric Acid/metabolism , Coumarins/metabolism , Fruit/genetics , Fruit/metabolism , Galactose/metabolism , Glucose/metabolism , Humans , Hydroxybenzoates , Lignans/metabolism , Melibiose/metabolism , Metabolomics , Oxaloacetates/metabolism , Phosphates/metabolism , Plant Breeding , Polyphenols/metabolism , Quinic Acid/metabolism , Starch/metabolism , Succinates/metabolism , Sucrose/metabolism , Tandem Mass Spectrometry , Tannins/metabolism , Transcriptome , Trehalose/metabolism
15.
World J Microbiol Biotechnol ; 38(12): 255, 2022 Nov 02.
Article in English | MEDLINE | ID: mdl-36319705

ABSTRACT

Phosphate (Pi) is essential for life as it is an integral part of the universal chemical energy adenosine triphosphate (ATP), and macromolecules such as, DNA, RNA proteins and lipids. Despite the core roles and the need of this nutrient in living cells, some bacteria can grow in environments that are poor in Pi. The metabolic mechanisms that enable bacteria to proliferate in a low phosphate environment are not fully understood. In this study, the soil microbe Pseudomonas (P.) fluorescens was cultured in a control and a low Pi (stress) medium in order to delineate how energy homeostasis is maintained. Although there was no significant variation in biomass yield in these cultures, metabolites like isocitrate, oxaloacetate, pyruvate and phosphoenolpyruvate (PEP) were markedly increased in the phosphate-starved condition. Components of the glycolytic, glyoxylate and tricarboxylic acid cycles operated in tandem to generate ATP by substrate level phosphorylation (SLP) as NADH-producing enzymes were impeded. The α-ketoglutarate (KG) produced when glutamine, the sole carbon nutrient was transformed into phosphoenol pyruvate (PEP) and succinyl-CoA (SC), two high energy moieties. The metabolic reprogramming orchestrated by isocitrate lyase (ICL), phosphoenolpyruvate synthase (PEPS), pyruvate phosphate dikinase (PPDK), and succinyl-CoA synthetase fulfilled the ATP budget. Cell free extract experiments confirmed ATP synthesis in the presence of such substrates as PEP, oxaloacetate and isocitrate respectively. Gene expression profiling revealed elevated transcripts associated with numerous enzymes including ICL, PEPS, and succinyl-CoA synthetase (SCS). This microbial adaptation will be critical in promoting biological activity in Pi-poor ecosystems.


Subject(s)
Pseudomonas fluorescens , Pseudomonas fluorescens/metabolism , Adenosine Triphosphate/metabolism , Isocitrates/metabolism , Phosphates/metabolism , Ecosystem , Phosphoenolpyruvate/metabolism , Homeostasis , Pyruvic Acid/metabolism , Oxaloacetates/metabolism , Ligases/metabolism
16.
Bratisl Lek Listy ; 123(7): 487-490, 2022.
Article in English | MEDLINE | ID: mdl-35907054

ABSTRACT

Pyruvate carboxylase (PC) is a mitochondrial enzyme catalyzing the ATP-dependent reaction of pyruvate prolongation with bicarbonate ion to oxaloacetate. The synthesis of oxaloacetate by PC, an intermediate of the Krebs cycle, is recently recognized as a significant anaplerotic reaction that supports the biosynthetic capability, growth, aggressiveness, and even viability of several cancer cell types. PC expression was confirmed in several types of cancer cells and tumors. To evaluate the possibility that prostate tumor-forming cells are also exploiting the anaplerotic role of PC, we applied immunoblotting analysis to estimate its presence. Our results revealed that PC is present among the lysate proteins derived from prostate cancer and benign prostatic hyperplasia samples. The expression of PC in cells of prostate tumors and benign prostatic hyperplasia supposes that PC could facilitate the formation of oxaloacetate in situ and enhance the autonomy of their biosynthetic metabolism from the availability of extracellular substrates by increasing the cellular anaplerotic capability (Tab. 1, Fig. 1, Ref. 30). Keywords: pyruvate carboxylase, prostate cancer, cancer metabolism, anaplerosis.


Subject(s)
Prostatic Hyperplasia , Prostatic Neoplasms , Humans , Male , Oxaloacetates , Pyruvate Carboxylase/metabolism , Pyruvic Acid/metabolism
17.
Gan To Kagaku Ryoho ; 49(2): 226-228, 2022 Feb.
Article in Japanese | MEDLINE | ID: mdl-35249069

ABSTRACT

A 54-year-old woman visited our hospital complaining of abdominal distension. Endoscopic examination revealed type 3 tumor in the rectum located 15 cm from the anal edge. Enhanced computed tomography showed multiple ground glass-like shadows in both lungs that were suspected of multiple metastases. We diagnosed as having rectal cancer with multiple lung metastases. After placing the stent transanally to release the intestinal obstruction, we performed laparoscopic high anterior resection. Then, the patient received chemotherapy with 10 courses of XELOX plus bevacizumab and 9 courses of the regimen without oxaliplatin. A whole-body CT revealed complete response. And while taking capecitabine the patient remains well and without recurrence. We describe the present case with reference to the literature.


Subject(s)
Lung Neoplasms , Rectal Neoplasms , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Bevacizumab , Capecitabine , Female , Fluorouracil , Humans , Lung Neoplasms/drug therapy , Lung Neoplasms/secondary , Lung Neoplasms/surgery , Middle Aged , Oxaloacetates , Rectal Neoplasms/drug therapy , Rectal Neoplasms/pathology , Rectal Neoplasms/surgery
18.
Br J Surg ; 108(5): 511-520, 2021 05 27.
Article in English | MEDLINE | ID: mdl-33724296

ABSTRACT

BACKGROUND: The trial hypothesis was that, in a resource-constrained situation, short-course radiotherapy would improve treatment compliance compared with conventional chemoradiotherapy for locally advanced rectal cancer, without compromising oncological outcomes. METHODS: In this open-label RCT, patients with cT3, cT4 or node-positive non-metastatic rectal cancer were allocated randomly to 5 × 5 Gy radiotherapy and two cycles of XELOX (arm A) or chemoradiotherapy with concurrent capecitabine (arm B), followed by total mesorectal excision in both arms. All patients received a further six cycles of adjuvant chemotherapy with the XELOX regimen. The primary endpoint was treatment compliance, defined as the ability to complete planned treatment, including neoadjuvant radiochemotherapy, surgery, and adjuvant chemotherapy to a dose of six cycles. RESULTS: Of 162 allocated patients, 140 were eligible for analysis: 69 in arm A and 71 in arm B. Compliance with planned treatment (primary endpoint) was greater in arm A (63 versus 41 per cent; P = 0.005). The incidence of acute toxicities of neoadjuvant therapy was similar (haematological: 28 versus 32 per cent, P = 0.533; gastrointestinal: 14 versus 21 per cent, P = 0.305; grade III-IV: 2 versus 4 per cent, P = 1.000). Delays in radiotherapy were less common in arm A (9 versus 45 per cent; P < 0.001), and overall times for completion of neoadjuvant treatment were shorter (P < 0.001). The rates of R0 resection (87 versus 90 per cent; P = 0.554), sphincter preservation (32 versus 35 per cent; P = 0.708), pathological complete response (12 versus 10 per cent; P = 0.740), and overall tumour downstaging (75 versus 75 per cent; P = 0.920) were similar. Downstaging of the primary tumour (ypT) was more common in arm A (P = 0.044). There was no difference in postoperative complications between trial arms (P = 0.838). CONCLUSION: Reduced treatment delays and a higher rate of compliance were observed with treatment for short-course radiotherapy with consolidation chemotherapy, with no difference in early oncological surgical outcomes. In time- and resource-constrained rectal cancer units in developing countries, short-course radiotherapy should be the standard of care.


Subject(s)
Chemoradiotherapy/methods , Consolidation Chemotherapy , Dose Fractionation, Radiation , Rectal Neoplasms/therapy , Adenocarcinoma/mortality , Adenocarcinoma/pathology , Adenocarcinoma/therapy , Adult , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Capecitabine/therapeutic use , Developing Countries , Female , Humans , Male , Middle Aged , Neoadjuvant Therapy , Oxaloacetates/therapeutic use , Patient Compliance , Prospective Studies , Rectal Neoplasms/mortality , Rectal Neoplasms/pathology
19.
BMC Cancer ; 21(1): 1111, 2021 Oct 16.
Article in English | MEDLINE | ID: mdl-34656107

ABSTRACT

BACKGROUND: Among patients with colorectal cancer (CRC) treated with oxaliplatin (L-OHP)-based chemotherapy, delayed chemotherapy-induced nausea and vomiting (CINV) have not been well controlled. METHODS: We pooled data from two prospective observational studies in Japan and one phase III clinical trial to assess whether delayed CINV could be controlled with a combination of three antiemetics adding a neurokinin-1 receptor antagonist and identified individual risk factors, using an inverse probability treatment-weighted analysis. RESULTS: A total of 661 patients were evaluable in this study (median age: 64 years; 391 male, and 270 female). 3 antiemetics controlled delayed nausea (33.18% vs. 42.25%; p = 0.0510) and vomiting (4.15% vs. 16.08%; p < 0.0001) better than with 2 antiemetics. Female and 2 antiemetics were risk factors for both delayed nausea (female-odds ratio [OR]: 1.918; 95% confidence interval [CI]: 1.292-2.848; p = 0.0012; 2 antiemetics-OR: 1.485; 95% CI: 1.000-2.204; p = 0.0498) and delayed vomiting (female-OR: 2.735; 95% CI: 1.410-5.304; p = 0.0029; 2 antiemetics-OR: 4.551; 95% CI: 2.116-9.785; p = 0.0001). CONCLUSIONS: Identifying individual risk factors can facilitate personalized treatments for delayed CINV. We recommend a 3-antiemetic combination prophylaxis for CRC patients treated with L-OHP-based chemotherapy, especially for female patients.


Subject(s)
Antiemetics/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Colorectal Neoplasms/drug therapy , Nausea/drug therapy , Vomiting/drug therapy , Aged , Capecitabine/adverse effects , Clinical Trials, Phase III as Topic , Drug Therapy, Combination , Female , Fluorouracil/adverse effects , Humans , Japan , Leucovorin/adverse effects , Male , Middle Aged , Nausea/chemically induced , Neurokinin-1 Receptor Antagonists/therapeutic use , Observational Studies as Topic , Organoplatinum Compounds/adverse effects , Oxaloacetates/adverse effects , Randomized Controlled Trials as Topic , Risk Factors , Sex Factors , Vomiting/chemically induced
20.
Anticancer Drugs ; 32(10): 1123-1126, 2021 11 01.
Article in English | MEDLINE | ID: mdl-34261916

ABSTRACT

Cetuximab is an IgG1 chimeric mAb against epidermal growth factor receptor, which can be used for chemotherapy failure or tolerance in patients with epidermal growth factor receptor expressed RAS wild-type metastatic colorectal cancer. We report on a patient who developed rapid-onset interstitial pneumonia while being treated with cetuximab plus XELOX (oxaliplatin, capecitabine) for metastatic colorectal cancer. A 75-year-old man patient was administered cetuximab plus XELOX regularly. After his cetuximab schedule was adjusted from 1 to 2 weeks, he rapidly developed interstitial pneumonia which led to acute respiratory distress syndrome. Our literature review indicated that, for patients with risk factors, a 2-week regimen of cetuximab might lead to interstitial pneumonia. Clinicians should closely monitor patients for adverse drug reactions to improve drug safety.


Subject(s)
Antineoplastic Agents, Immunological/adverse effects , Cetuximab/adverse effects , Lung Diseases, Interstitial/chemically induced , Aged , Antineoplastic Agents, Immunological/therapeutic use , Antineoplastic Combined Chemotherapy Protocols , Capecitabine , Cetuximab/therapeutic use , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/pathology , Humans , Male , Neoplasm Metastasis , Oxaloacetates
SELECTION OF CITATIONS
SEARCH DETAIL