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Anais Da Academia Brasileira de Ciencias 2023The aim of the present study was to perform in vitro and in vivo assessments of the antineoplastic action of 4-amino-pyrimidine encapsulated in liposomes. Liposomes were...
The aim of the present study was to perform in vitro and in vivo assessments of the antineoplastic action of 4-amino-pyrimidine encapsulated in liposomes. Liposomes were prepared and characterized for particle size and drug encapsulation and submitted to long-term stability tests. Cytotoxicity assays were performed in HeLa cells. Antineoplastic activity was investigated using the experimental sarcoma 180 tumor in Swiss albino mice. Encapsulation efficiency was 82.93 ± 0.04% and no significant changes were found with respect to particle size or pH after centrifugation and mechanical agitation tests. The in vitro results at concentration of 20 μg/mL indicated a considerable reduction in cell viability after treatment with encapsulated pyrimidine (75.91%). The in vivo assays using the compounds in encapsulated and free forms and 5-fluorouracil achieved tumor inhibition rates of 66.47 ± 26.8%, 50.46 ± 16.24% and 14.47 ± 9.22%, respectively. Mitotic counts demonstrated a greater reduction in the number of mitoses in animals treated with liposomal pyrimidine (32.15%) compared to those treated with the pyrimidine free (87.69%) and 5-fluorouracil (71.39%). This study demonstrated that the development of liposome formulations containing 4-amino-pyrimidine is a promising alternative for overcoming limitations related to the toxicity of current cancer treatment, ensuring greater therapeutic efficacy.
Topics: Mice; Humans; Animals; Liposomes; HeLa Cells; Antineoplastic Agents; Fluorouracil; Mitosis; Neoplasms
PubMed: 37436228
DOI: 10.1590/0001-3765202320211078 -
The EMBO Journal Sep 2023Replication of the mitochondrial genome and expression of the genes it encodes both depend on a sufficient supply of nucleotides to mitochondria. Accordingly,...
Replication of the mitochondrial genome and expression of the genes it encodes both depend on a sufficient supply of nucleotides to mitochondria. Accordingly, dysregulated nucleotide metabolism not only destabilises the mitochondrial genome, but also affects its transcription. Here, we report that a mitochondrial nucleoside diphosphate kinase, NME6, supplies mitochondria with pyrimidine ribonucleotides that are necessary for the transcription of mitochondrial genes. Loss of NME6 function leads to the depletion of mitochondrial transcripts, as well as destabilisation of the electron transport chain and impaired oxidative phosphorylation. These deficiencies are rescued by an exogenous supply of pyrimidine ribonucleosides. Moreover, NME6 is required for the maintenance of mitochondrial DNA when the access to cytosolic pyrimidine deoxyribonucleotides is limited. Our results therefore reveal an important role for ribonucleotide salvage in mitochondrial gene expression.
Topics: Genes, Mitochondrial; Pyrimidines; Mitochondria; Nucleotides; DNA, Mitochondrial; Ribonucleotides
PubMed: 37439264
DOI: 10.15252/embj.2022113256 -
The Clinical Respiratory Journal Nov 2023Our purpose of this study is to evaluate the effect and safety of macitentan in the treatment of pulmonary hypertension (PH). (Meta-Analysis)
Meta-Analysis
INTRODUCTION
Our purpose of this study is to evaluate the effect and safety of macitentan in the treatment of pulmonary hypertension (PH).
METHODS
We retrieved the safety and efficacy of macitentan treatment for PH using PubMed, the Cochrane Library, EMBASE databases and clinicaltrials.gov. The Cochrane Risk of Bias Tool was used for literature screening and quality assessment. Data analysis was conducted using RevMan 5.4.1 and Stata/SE 15.1 software. Results are presented as standardization mean differences (SMDs) and odds ratio (OR).
RESULTS
Meta-analysis of seven randomized controlled trial (RCT) studies and four non-RCT studies with 2769 patients was included, involving 723 in the macitentan group and 599 in the placebo group. The results of the study showed that macitentan had effectively decreased pulmonary vascular resistance (PVR) (SMD = -0.53, 95% CI: -0.77--0.29, p < 0.05), cardiac index (CI) (SMD = 0.60, 95% CI: 0.37-0.83, p < 0.05) and N-terminal pro-brain natriuretic peptide (NT-proBNP) (SMD = -0.22, 95% CI: -0.40--0.03, p < 0.05). Furthermore, macitentan also significantly reduced PVR (SMD = -0.58, 95% CI: -0.80--0.35, p < 0.05), 6-min walk distance (6WMD) (SMD = 0.33, 95% CI: 0.15-0.50, p < 0.05), CI (SMD = 0.48, 95% CI: 0.28-0.69, p < 0.05), mean pulmonary arterial pressure (mPAP) (SMD = -0.43, 95% CI: -0.64--0.23, p < 0.05) and NT-proBNP (SMD = -0.55, 95% CI: -1.07--0.03, p < 0.05) between baseline and follow-up. The adverse reactions to macitentan were mild, with headache, anaemia and bronchitis. Other efficacy and safety outcomes did not reach statistical differences.
CONCLUSION
Macitentan therapy for PH is effective and safe. The effectiveness on PVR, mPAP, mean right atrial pressure (mRAP), mortality and other indicators still needs to be further confirmed.
Topics: Humans; Hypertension, Pulmonary; Sulfonamides; Pyrimidines; Vascular Resistance
PubMed: 37427711
DOI: 10.1111/crj.13621 -
ESMO Open Dec 2023The JAVELIN Bladder 100 phase III trial led to the incorporation of avelumab first-line (1L) maintenance treatment into international guidelines as a standard of care... (Review)
Review
The JAVELIN Bladder 100 phase III trial led to the incorporation of avelumab first-line (1L) maintenance treatment into international guidelines as a standard of care for patients with advanced urothelial carcinoma (UC) without progression after 1L platinum-based chemotherapy. JAVELIN Bladder 100 showed that avelumab 1L maintenance significantly prolonged overall survival (OS) and progression-free survival in this population compared with a 'watch-and-wait' approach. The aim of this manuscript is to review clinical studies of avelumab 1L maintenance in patients with advanced UC, including long-term efficacy and safety data from JAVELIN Bladder 100, subgroup analyses in clinically relevant subpopulations, and 'real-world' data obtained outside of clinical trials, providing a comprehensive resource to support patient management. Extended follow-up from JAVELIN Bladder 100 has shown that avelumab provides a long-term efficacy benefit, with a median OS of 23.8 months measured from start of maintenance treatment, and 29.7 months measured from start of 1L chemotherapy. Longer OS was observed across subgroups, including patients who received 1L cisplatin + gemcitabine, patients who received four or six cycles of 1L chemotherapy, and patients with complete response, partial response, or stable disease as best response to 1L induction chemotherapy. No new safety signals were seen in patients who received ≥1 year of avelumab treatment, and toxicity was similar in those who had received cisplatin or carboplatin with gemcitabine. Other clinical datasets, including noninterventional studies conducted in Europe, USA, and Asia, have confirmed the efficacy of avelumab 1L maintenance. Potential subsequent treatment options after avelumab maintenance include antibody-drug conjugates (enfortumab vedotin or sacituzumab govitecan), erdafitinib in biomarker-selected patients, platinum rechallenge in suitable patients, nonplatinum chemotherapy, and clinical trial participation; however, evidence to determine optimal treatment sequences is needed. Ongoing trials of avelumab-based combination regimens as maintenance treatment have the potential to evolve the treatment landscape for patients with advanced UC.
Topics: Humans; Cisplatin; Carcinoma, Transitional Cell; Gemcitabine; Urinary Bladder Neoplasms; Deoxycytidine
PubMed: 37976999
DOI: 10.1016/j.esmoop.2023.102050 -
Nature Communications Aug 2023Purine-containing nucleotide second messengers regulate diverse cellular activities. Cyclic di-pyrimidines mediate anti-phage functions in bacteria; however, the...
Purine-containing nucleotide second messengers regulate diverse cellular activities. Cyclic di-pyrimidines mediate anti-phage functions in bacteria; however, the synthesis mechanism remains elusive. Here, we determine the high-resolution structures of cyclic di-pyrimidine-synthesizing cGAS/DncV-like nucleotidyltransferases (CD-NTases) in clade E (CdnE) in its apo, substrate-, and intermediate-bound states. A conserved (R/Q)xW motif controlling the pyrimidine specificity of donor nucleotide is identified. Mutation of Trp or Arg from the (R/Q)xW motif to Ala rewires its specificity to purine nucleotides, producing mixed purine-pyrimidine cyclic dinucleotides (CDNs). Preferential binding of uracil over cytosine bases explains the product specificity of cyclic di-pyrimidine-synthesizing CdnE to cyclic di-UMP (cUU). Based on the intermediate-bound structures, a synthetic pathway for cUU containing a unique 2'3'-phosphodiester linkage through intermediate pppU[3'-5']pU is deduced. Our results provide a framework for pyrimidine selection and establish the importance of conserved residues at the C-terminal loop for the specificity determination of CD-NTases.
Topics: Pyrimidines; Nucleotidyltransferases; Nucleotides; Chromogranin A; Purine Nucleotides
PubMed: 37604815
DOI: 10.1038/s41467-023-40787-9 -
Nature Communications Mar 2024De novo synthesis of the pyrimidine, cytidine triphosphate (CTP), is crucial for DNA/RNA metabolism and depends on the CTP synthetases, CTPS1 and -2. Partial CTPS1...
De novo synthesis of the pyrimidine, cytidine triphosphate (CTP), is crucial for DNA/RNA metabolism and depends on the CTP synthetases, CTPS1 and -2. Partial CTPS1 deficiency in humans has previously been shown to lead to immunodeficiency, with impaired expansion of T and B cells. Here, we examine the effects of conditional and inducible inactivation of Ctps1 and/or Ctps2 on mouse embryonic development and immunity. We report that deletion of Ctps1, but not Ctps2, is embryonic-lethal. Tissue and cells with high proliferation and renewal rates, such as intestinal epithelium, erythroid and thymic lineages, activated B and T lymphocytes, and memory T cells strongly rely on CTPS1 for their maintenance and growth. However, both CTPS1 and CTPS2 are required for T cell proliferation following TCR stimulation. Deletion of Ctps1 in T cells or treatment with a CTPS1 inhibitor rescued Foxp3-deficient mice from fatal systemic autoimmunity and reduced the severity of experimental autoimmune encephalomyelitis. These findings support that CTPS1 may represent a target for immune suppression.
Topics: Female; Pregnancy; Humans; Animals; Mice; Cytidine Triphosphate; Embryonic Development; Autoimmunity; B-Lymphocytes; Cell Proliferation
PubMed: 38438357
DOI: 10.1038/s41467-024-45805-y -
Menopause (New York, N.Y.) Aug 2023Insomnia is common in midlife women. The efficacy and safety of lemborexant (LEM), a competitive dual orexin receptor antagonist, was assessed for 12 months in a... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
Insomnia is common in midlife women. The efficacy and safety of lemborexant (LEM), a competitive dual orexin receptor antagonist, was assessed for 12 months in a subgroup of midlife women (age, 40-58 y) from Study E2006-G000-303 (Study 303; SUNRISE-2).
METHODS
This was a randomized, double-blind, placebo (PBO)-controlled (first 6 mo) study of adults with insomnia disorder ( N = 949). During treatment period 1 (TP1), participants received PBO or LEM 5 mg (LEM5) or 10 mg (LEM10). During TP2 (second 6 mo), LEM participants continued their assigned dose; PBO participants were rerandomized to LEM5 or LEM10. Assessments included patient-reported sleep- and fatigue-related measures and treatment-emergent adverse events.
RESULTS
The midlife female subgroup comprised 280 of 949 participants (TP1: PBO, n = 90 of 318 [28.3%]; LEM5, n = 82 of 316 [25.9%]; LEM10, n = 108 of 315 [34.3%]). At 6 months, median changes from baseline in subjective sleep-onset latency (in minutes) were -17.9, -20.7, and - 30.4 for PBO, LEM5, and LEM10 (vs PBO: LEM5, P = not significant; LEM10, P = 0.0310). At 6 months, mean changes from baseline in subjective wake after sleep onset (in minutes) were -37.0 (59.6), -50.1 (74.5), and -54.5 (65.4) for PBO, LEM5, and LEM10 (vs PBO: LEM5 and LEM10, P = not significant), with benefits sustained through 12 months. Greater decreases from baseline (improvement) in Insomnia Severity Index total score and Fatigue Severity Scale total score were seen with LEM versus PBO at 6 months; benefits continued through 12 months. Most treatment-emergent adverse events were mild to moderate in severity.
CONCLUSIONS
Consistent with the total population, subjective sleep parameters improved, and improvement was sustained over time in midlife women. LEM was well tolerated, suggesting that LEM may be a potential treatment option for midlife women with insomnia.
Topics: Adult; Female; Humans; Middle Aged; Double-Blind Method; Pyridines; Pyrimidines; Sleep Initiation and Maintenance Disorders; Treatment Outcome; Menopause; Perimenopause
PubMed: 37339396
DOI: 10.1097/GME.0000000000002209 -
Journal of Inherited Metabolic Disease Nov 2023CAD is a large, 2225 amino acid multienzymatic protein required for de novo pyrimidine biosynthesis. Pathological CAD variants cause a developmental and epileptic...
CAD is a large, 2225 amino acid multienzymatic protein required for de novo pyrimidine biosynthesis. Pathological CAD variants cause a developmental and epileptic encephalopathy which is highly responsive to uridine supplements. CAD deficiency is difficult to diagnose because symptoms are nonspecific, there is no biomarker, and the protein has over 1000 known variants. To improve diagnosis, we assessed the pathogenicity of 20 unreported missense CAD variants using a growth complementation assay that identified 11 pathogenic variants in seven affected individuals; they would benefit from uridine treatment. We also tested nine variants previously reported as pathogenic and confirmed the damaging effect of seven. However, we reclassified two variants as likely benign based on our assay, which is consistent with their long-term follow-up with uridine. We found that several computational methods are unreliable predictors of pathogenic CAD variants, so we extended the functional assay results by studying the impact of pathogenic variants at the protein level. We focused on CAD's dihydroorotase (DHO) domain because it accumulates the largest density of damaging missense changes. The atomic-resolution structures of eight DHO pathogenic variants, combined with functional and molecular dynamics analyses, provided a comprehensive structural and functional understanding of the activity, stability, and oligomerization of CAD's DHO domain. Combining our functional and protein structural analysis can help refine clinical diagnostic workflow for CAD variants in the genomics era.
Topics: Humans; Dihydroorotase; Mutation, Missense; Proteins; Uridine
PubMed: 37540500
DOI: 10.1002/jimd.12667 -
Current Oncology (Toronto, Ont.) Jul 2023Biliary tract cancers (BTC) are rare and aggressive tumors with poor prognosis. Radical surgery offers the best chance for cure; however, most patients present with...
Biliary tract cancers (BTC) are rare and aggressive tumors with poor prognosis. Radical surgery offers the best chance for cure; however, most patients present with unresectable disease, and among those receiving curative-intent surgery, recurrence rates remain high. While other locoregional therapies for unresectable disease may be considered, only select patients may be eligible. Consequently, systemic therapy plays a significant role in the treatment of BTC. In the adjuvant setting, capecitabine is recommended following curative-intent resection. In the neoadjuvant setting, systemic therapy has mostly been explored for downstaging in borderline resectable tumours, although evidence for its routine use is lacking. For advanced unresectable or metastatic disease, gemcitabine-cisplatin plus durvalumab has become the standard of care, while the addition of pembrolizumab to gemcitabine-cisplatin has also recently demonstrated improved survival compared to chemotherapy alone. Following progression on gemcitabine-cisplatin, several chemotherapy combinations and biomarker-driven targeted agents have been explored. However, the optimum regimen remains unclear, and access to targeted agents remains challenging in Canada. Overall, this article serves as a practical guide for the systemic treatment of BTC in Canada, providing valuable insights into the current and future treatment landscape for this challenging disease.
Topics: Humans; Biliary Tract Neoplasms; Canada; Capecitabine; Cisplatin; Gemcitabine
PubMed: 37622998
DOI: 10.3390/curroncol30080517 -
Veterinary Research Dec 2023Porcine reproductive and respiratory syndrome virus (PRRSV) infection has caused huge economic losses in global swine industry over the last 37 years. PRRSV commercial...
Porcine reproductive and respiratory syndrome virus (PRRSV) infection has caused huge economic losses in global swine industry over the last 37 years. PRRSV commercial vaccines are not effective against all epidemic PRRSV strains. In this study we performed a high-throughput screening (HTS) of an FDA-approved drug library, which contained 2339 compounds, and found vidofludimus (Vi) could significantly inhibits PRRSV replication in Marc-145 cells and primary porcine alveolar macrophages (PAMs). Compounds target prediction, molecular docking analysis, and target protein interference assay showed that Vi interacts with dihydroorotate dehydrogenase (DHODH), a rate-limiting enzyme in the de novo pyrimidine synthesis pathway. Furthermore, PRRSV infection was restored in the presence of excess uridine and cytidine which promote pyrimidine salvage, or excess orotate which is the product of DHODH in the de novo pyrimidine biosynthesis pathway, thus confirming that the antiviral effect of Vi against PRRSV relies on the inhibition of DHODH. In addition, Vi also has antiviral activity against Seneca virus A (SVA), encephalomyocarditis virus (EMCV), porcine epidemic diarrhea virus (PEDV), and pseudorabies virus (PRV) in vitro. These findings should be helpful for developing a novel prophylactic and therapeutic strategy against PRRSV and other swine viral infections.
Topics: Animals; Swine; Porcine respiratory and reproductive syndrome virus; Dihydroorotate Dehydrogenase; Porcine Reproductive and Respiratory Syndrome; Molecular Docking Simulation; Cell Line; Virus Replication; Antiviral Agents; Pyrimidines; Swine Diseases
PubMed: 38124181
DOI: 10.1186/s13567-023-01251-0