BRAF and RET polymorphism association with thyroid cancer risk, a preliminary study from Khyber Pakhtunkhwa population.

BACKGROUND: Thyroid cancer, originating in the neck's thyroid gland, encompasses various types. Genetic mutations, particularly in BRAF and RET genes are crucial in its development. This study investigates the association between BRAF (rs113488022) and RET (rs77709286) polymorphisms and thyroid cancer risk in the Khyber Pakhtunkhwa (KP) population. METHODS: Blood samples from 100 thyroid cancer patients and 100 healthy controls were genotyped using ARMS-PCR followed by gel electrophoresis and statistical analysis. RESULTS: Analysis revealed a significant association between the minor allele T of BRAF (rs113488022) and thyroid cancer risk (P = 0.0001). Both genotypes of BRAF (rs113488022) showed significant associations with thyroid cancer risk (AT; P = 0.0012 and TT; P = 0.045). Conversely, the minor allele G of RET (rs77709286) exhibited a non-significant association with thyroid cancer risk (P = 0.2614), and neither genotype showed significant associations (CG; P = 0.317, GG; P = 0.651). Demographic and clinical parameters analysis using SPSS showed a non-significant association between BRAF and RET variants and age group (P = 0.878 and P = 0.536), gender (P = 0.587 and P = 0.21), tumor size (P = 0.796 and P = 0.765), or tumor localization (P = 0.689 and P = 0.727). CONCLUSION: In conclusion, this study emphasizes the significant association between BRAF polymorphism and thyroid cancer risk, while RET polymorphism showed a less pronounced impact. Further validation using larger and specific datasets is essential to establish conclusive results.

In Silico Approach Triterpene Glycoside of H. atra Targeting Orotidine 5-Monophosphate Decarboxylase Protein (PfOMPDC) in P. falciparum Infection Mechanism.

This study accessed the potential antimalarial activity of triterpene glycoside of H. atra through targeting orotidine 5-monophosphate decarboxylase protein (PfOMPDC) in P. falciparum by molecular docking. Nine triterpene glycosides from H. atra extract modeled the structure by the Corina web server and interacted with PfOMPDC protein by using Hex 8.0.0. The docking results were visualized and analyzed by Discovery Studio version 21.1.1. 17-Hydroxyfuscocineroside B showed the lowest binding energy in PfOMPDC interaction, which was -1,098.13 kJ/mol. Holothurin A3, echinoside A, and fuscocineroside C showed low binding energy. Nine triterpene glycosides of H. atra performed interaction with PfOMPDC protein at the same region. Holothurin A1 posed interaction with PfOMPDC protein by 8 hydrogen bonds, 3 hydrophobic interactions, and 8 unfavorable bonds. Several residues were detected in the same active sites of other triterpene glycosides. Residue TYR111 was identified in all triterpene glycoside complexes, except holothurin A3 and calcigeroside B. In summary, the triterpene glycoside of H. atra is potentially a drug candidate for malaria therapeutic agents. In vitro and in vivo studies were required for further investigation.

Oral decitabine and cedazuridine plus venetoclax for older or unfit patients with acute myeloid leukaemia: a phase 2 study.

BACKGROUND: Hypomethylating agents combined with venetoclax are effective regimens in patients with acute myeloid leukaemia who are ineligible for intensive chemotherapy. Decitabine and cedazuridine (ASTX727) is an oral formulation of decitabine that achieves equivalent area-under-curve exposure to intravenous decitabine. We performed a single centre phase 2 study to evaluate the efficacy and safety of ASTX727 plus venetoclax. METHODS: This study enrolled patients with newly diagnosed (frontline treatment group) acute myeloid leukaemia who were ineligible for intensive chemotherapy (aged ≥75 years, an Eastern Cooperative Oncology Group [ECOG] performance status of 2-3, or major comorbidities) or relapsed or refractory acute myeloid leukaemia. Being aged 18 years or older and having an ECOG performance status of 2 or less were requirements for the relapsed or refractory disease treatment cohort, without any limits in the number of previous lines of therapy. Treatment consisted of ASTX727 (cedazuridine 100 mg and decitabine 35 mg) orally for 5 days and venetoclax 400 mg orally for 21-28 days in 28-day cycles. The primary outcome was overall response rate of ASTX727 plus venetoclax. Living patients who have not completed cycle one were not evaluable for response. Safety was analysed in all patients who started treatment. This study was registered on ClinicalTrials.gov (NCT04746235) and is ongoing. The data cutoff date for this analysis was Sept 22, 2023. FINDINGS: Between March 16, 2021, and Sept 18, 2023, 62 patients were enrolled (49 frontline and 13 relapsed or refractory) with a median age of 78 years (IQR 73-82). 36 (58%) were male; 53 (85%) were White, 4 (6%) Black, 2 (3%) Asian and 3 (5%) other or did not answer. 48 (77%) of 62 patients were European LeukemiaNet 2022 adverse risk, 24 (39%) had antecedent myelodysplastic syndromes, 12 (19%) had previously failed a hypomethylating agent, ten (16%) had therapy-related acute myeloid leukaemia, and 11 (18%) had TP53 mutations. The median follow-up time was 18·3 months (IQR 8·8-23·3). The overall response rate was 30 (64%) of 47 patients (95% CI 49-77) in frontline cohort and six (46%) of 13 patients (19-75) in relapsed or refractory cohort. The most common grade 3 or worse treatment-emergent adverse events were febrile neutropenia in 11 (18%) of 62 patients, pneumonia in eight (13%), respiratory failure in five (8%), bacteraemia in four (6%), and sepsis in four (6%). Three deaths occurred in patients in remission (one sepsis, one gastrointestinal haemorrhage, and one respiratory failure) and were potentially treatment related. INTERPRETATION: ASTX727 plus venetoclax is an active fully oral regimen and safe in most older or unfit patients with acute myeloid leukaemia. Our findings should be confirmed in larger multicentric studies. FUNDING: MD Anderson Cancer Center Support Grant, Myelodysplastic Syndrome/Acute Myeloid Leukaemia Moon Shot, Leukemia SPORE, Taiho Oncology, and Astex Pharmaceuticals.

Exploration of the Diversity of Vicine and Convicine Derivatives in Faba Bean (Vicia faba L.) Cultivars: Insights from LC-MS/MS Spectra.

While numerous Fabaceae seeds are a good nutritional source of high-quality protein, the use of some species is hampered by toxic effects caused by exposure to metabolites that accumulate in the seeds. One such species is the faba or broad bean (Vicia faba L.), which accumulates vicine and convicine. These two glycoalkaloids cause favism, the breakdown of red blood cells in persons with a glucose-6-phosphate dehydrogenase deficiency. Because this is the most common enzyme deficiency worldwide, faba bean breeding efforts have focused on developing cultivars with low levels of these alkaloids. Consequently, quantification methods have been developed; however, they quantify vicine and convicine only and not the derivatives of these compounds that potentially generate the same bio-active molecules. Based on the recognition of previously unknown (con)vicine-containing compounds, we screened the fragmentation spectra of LC-MS/MS data from five faba bean cultivars using the characteristic fragments generated by (con)vicine. This resulted in the recognition of more than a hundred derivatives, of which 89 were tentatively identified. (Con)vicine was mainly derivatized through the addition of sugars, hydroxycinnamic acids, and dicarboxylic acids, with a group of compounds composed of two (con)vicine residues linked by dicarboxyl fatty acids. In general, the abundance profiles of the different derivatives in the five cultivars mimicked that of vicine and convicine, but some showed a derivative-specific profile. The description of the (con)vicine diversity will impact the interpretation of future studies on the biosynthesis of (con)vicine, and the content in potentially bio-active alkaloids in faba beans may be higher than that represented by the quantification of vicine and convicine alone.

Oral decitabine plus cedazuridine and venetoclax in patients with higher-risk myelodysplastic syndromes or chronic myelomonocytic leukaemia: a single-centre, phase 1/2 study.

BACKGROUND: Hypomethylating agents are approved in higher-riskmyelodysplastic syndromes. The combination of a hypomethylating agent with venetoclax is standard of care in acute myeloid leukaemia. We investigated the safety and activity of the first totally oral combination of decitabine plus cedazuridine and venetoclax in patients with higher-risk-myelodysplastic syndromes and chronic myelomonocytic leukaemia. METHODS: We did a single-centre, dose-escalation and dose-expansion, phase 1/2, clinical trial. Patients with treatment-naive higher-risk-myelodysplastic syndromes or chronic myelomonocytic leukaemia (risk level categorised as intermediate-2 or higher by the International Prognostic Scoring System) with excess blasts (>5%). Treatment consisted of oral decitabine 35 mg plus cedazuridine 100 mg on days 1-5 and venetoclax (variable doses of 100-400 mg, day 1 to 14, 28-day cycle). The primary outcomes were safety for the phase 1 part and the overall response for the phase 2 part of the study. The trial is ongoing and this analysis was not prespecified. This study is registered with ClinicalTrials.gov, NCT04655755, and is currently enrolling participants. FINDINGS: Between Jan 21, 2021, and Jan 20, 2023, we enrolled 39 patients (nine in phase 1 and 30 in phase 2). The median age was 71 years (range 27-94), 28 (72%) patients were male, and 11 (28%) were female. The maximum tolerated dose was not reached, and the recommended phase 2 dose was established as oral decitabine 35 mg plus cedazuridine 100 mg for 5 days and venetoclax (400 mg) for 14 days. The most common grade 3-4 adverse events were thrombocytopenia (33 [85%] of 39), neutropenia (29 [74%]), and febrile neutropenia (eight [21%]). Four non-treatment-related deaths occurred on the study drugs due to sepsis (n=2), lung infection (n=1), and undetermined cause (n=1). The median follow-up time was 10·8 months (IQR 5·6-16·4). The overall response rate was 95% (95% CI 83-99; 37/39). 19 (49%) patients proceeded to hematopoietic stem-cell transplantation. INTERPRETATION: This early analysis suggests that the combination of oral decitabine plus cedazuridine with venetoclax for higher-risk-myelodysplastic syndromes and chronic myelomonocytic leukaemia is safe in most patients, with encouraging activity. Longer follow-up will be needed to confirm these data. FUNDING: MD Anderson Cancer Center, MDS/AML Moon Shot, Genentech/AbbVie, and Astex Pharmaceuticals.

Protection-Free, Two-step Synthesis of C5-C Functionalized Pyrimidine Nucleosides.

A simple, reliable, and efficient method for the gram-scale chemical synthesis of pyrimidine nucleosides functionalized with C5-carboxyl, nitrile, ester, amide, or amidine, starting from unprotected uridine and cytidine, is described. The protocol involves the synthesis of 5-trifluoromethyluridine and 5-trifluoromethylcytidine with Langlois reagent (CF3 SO2 Na) in the presence of tert-butyl hydroperoxide and subsequent transformation of the CF3 group to the C5-C 'carbon substituents' under alkaline conditions. © 2024 Wiley Periodicals LLC. Basic Protocol 1: Synthesis and characterization of 5-trifluoromethyluridine (5-CF3 U) and 5-trifluoromethylcytidine (5-CF3 C) Basic Protocol 2: Conversion of 5-CF3 U and 5-CF3 C to several C5-substituted ribonucleosides.

Fragmentation of 5-fluorouridine induced by low energy (< 12 eV) electrons: insights into the radiosensitization of DNA.

5-Fluorouracil is now routinely used in chemo- and radiotherapy. Incorporated within DNA, the molecule is bound to the sugar backbone, forming the 5-fluorouridine sub-unit investigated in the present work. For the clinical usage of the latter, no information exists on the mechanisms that control the radiosensitizing effect at the molecular level. As low energy (< 12 eV) electrons are abundantly produced along the radiation tracks during cancer treatment using beams of high energy particles, we study how these ballistic secondary electrons damage the sensitizing molecule. The salient result from our study shows that the N-glycosidic bonds are principally affected with a cross-section of approximately two orders of magnitude higher than the canonical thymidine, reflecting to some degree the surviving factor of radiation-treated carcinoma cells with and without 5-fluorouracil incorporation. This result may help in the comprehension of the radiosensitizing effect of the fluoro-substituted thymidine in DNA.

N3-Methyluridine and 2'-O-Alkyl/2'-Fluoro-N3-methyluridine functionalized nucleic acids improve nuclease resistance while maintaining duplex geometry.

Herein, we report the synthesis of 2'-O-alkyl/2'-fluoro-N3-methyluridine (2'-O-alkyl/2'-F-m3U) phosphoramidites and their incorporation in DNA and RNA oligonucleotides. The duplex binding affinity and base discrimination studies showed that all 2'-O-alkyl/2'-F-m3U modifications significantly decreased the thermal stability and base-pairing discrimination ability. Serum stability study of dT20 with 2'-O-alkyl-m3U modification exhibited excellent nuclease resistance when incubated with 3'-exonucleases (SVPD) or 5'-exonucleases (PDE-II) as compared to m3U, 2'-F, 2'-OMe modified oligonucleotides. MD simulation studies with RNA tetradecamer duplexes illustrated that the m3U and 2'-O-methyl-m3U modifications reduce the duplex stabilities by disrupting the Watson-Crick hydrogen bonding and base-stacking interactions. Further molecular modelling investigations demonstrated that the 2'-O-propyl-m3U modification exhibits steric interactions with amino acid residues in the active site of 3'- and 5'-exonuclease, leading to enhanced stability. These combined data indicate that the 2'-modified-m3U nucleotides can be used as a promising tool to enhance the stability, silencing efficiency, and drug-like properties of antisense/siRNA-based therapeutics.

A Simple High-Throughput Method for the Analysis of Vicine and Convicine in Faba Bean.

The faba bean is one of the earliest domesticated crops, with both economic and environmental benefits. Like most legumes, faba beans are high in protein, and can be used to contribute to a balanced diet, or as a meat substitute. However, they also produce the anti-nutritional compounds, vicine and convicine (v-c), that when enzymatically degraded into reactive aglycones can potentially lead to hemolytic anemia or favism. Current methods of analysis use LC-UV, but are only suitable at high concentrations, and thus lack the selectivity and sensitivity to accurately quantitate the low-v-c genotypes currently being developed. We have developed and fully validated a rapid high-throughput LC-MS method for the analysis of v-c in faba beans by optimizing the extraction protocol and assessing the method of linearity, limit of detection, limit of quantitation, accuracy, precision and matrix effects. This method uses 10-times less starting material; removes the use of buffers, acids and organic chemicals; and improves precision and accuracy when compared to current methods.

Synthesis of 2'-O-[3-(N-methylsulfamoyl)propan-1-yl]ribothymidine as a potentially applicable 2'-modified nucleoside for antisense oligonucleotides.

A synthetic scheme was developed to derive a modified ribothymidine bearing a 3-(N-methylsulfamoyl)propyl group on 2'-oxygen (TMSP). For synthesis initiation, a nucleophilic attack of 1,2-ethanediol on 5'-protected 2,2'-anhydro-ribothymidine was performed to selectively modify the 2'-position. After protection of the 3'-hydroxy group, the hydroxyethyl group was oxidized to the aldehyde, which was coupled with isobutyl (diethoxyphosphinyl)methanesulfonate through the Horner-Wadsworth-Emmons reaction to yield the sulfonate intermediate. The intermediate was further converted to the desired TMSP. Using the phosphoramidite units derived from nucleosides, we synthesized oligonucleotides incorporating TMSP. Oligonucleotides modified with TMSP were found to have duplex stability, resistance toward 3'-exonuclease digestion, and antisense activity comparable to that of the oligonucleotide modified with a previously reported 2'-O-methylcarbamoylethyl group. Based on these results and the generality of the synthetic scheme, 2'-O-sulfamoylalkyl modification is expected to be used for the modulation of the properties of oligonucleotides by changing the substituents on the nitrogen, enabling the oligonucleotides to possess suitable properties for antisense oligonucleotides.

Improving knowledge on genotoxicity dynamics in somatic and germ cells of crayfish (Procambarus clarkii).

The harmful effects of pesticides can be extended beyond the exposure time scale. Appraisals combining exposure and long-term post-exposure periods appear as an unavoidable approach in pesticide risk assessment, thus allowing a better understanding of the real impact of agrochemicals in non-target organisms. This study aimed to evaluate the progression of genetic damage in somatic and germ tissues of the crayfish Procambarus clarkii, also seeking for gender-specificities, following exposure (7 days) to penoxsulam (23 µg L-1 ) and a post-exposure (70 days) period. The same approach was applied to the model genotoxicant ethyl methanesulfonate (EMS; 5 mg L-1 ) as a complementary mean to improve knowledge on genotoxicity dynamics (induction vs. recovery). Penoxsulam induced DNA damage in all tested tissues, disclosing tissue- and gender-specificities, where females showed to be more vulnerable than males in the gills, while males demonstrated higher susceptibility in what concerns internal organs, that is, hepatopancreas and gonad. Crayfish were unable to recover from the DNA damage induced by EMS in gills and hepatopancreas (both genders) as well as in spermatozoa. The genotoxicity in the hepatopancreas was only perceptible in the post-exposure period. Oxidative DNA lesions were identified in hepatopancreas and spermatozoa of EMS-exposed crayfish. The spermatozoa proved to be the most vulnerable cell type. It became clear that the characterization of the genotoxic hazard of a given agent must integrate a complete set of information, addressing different types of DNA damage, tissue- and gender-specificities, as well as a long-term appraisal of temporal progression of damage.

Multiple resistance mechanisms to penoxsulam in Echinochloa crus-galli from China.

Penoxsulam is an important herbicide for the control of Echinochloa crus-galli (L.) P. Beauv. Two resistant populations 17GA (R1) and 16NXB (R2) showed 17- and 3-fold resistance to penoxsulam, respectively. A known resistance mutation of Trp-574-Leu in ALS gene and enhanced rates of penoxsulam metabolism likely involving GST contribute to penoxsulam resistance in R1 population. This population had resistance to the ALS-inhibitors pyribenzoxim and bispyribac­sodium and the auxin herbicide quinclorac, but was susceptible to ACCase-inhibitors quizalofop-p-ethyl and cyhalofop-butyl. No known mutations in the ALS gene conferring target site resistance to ALS-inhibiting herbicides were presented in R2 population. However, penoxsulam metabolism in R2 plants was about 4-fold greater than in susceptible population 14YC (S0) plants. The enzyme inhibitors piperonyl butoxide, malathion and 4-chloro-7-nitrobenzoxadiazole reversed penoxsulam resistance in this population. GST and P450 enzyme activities and the genes of GST1-1, GST1-2, GST1-3, CYP81A18, CYP81A12, CYP81A21 were increased significantly in R2 population. These results indicate that multiple resistance mechanisms had occurred in E. crus-galli populations in central China and resistance needs to be managed effectively by diverse chemical and non-chemical methods.

Effects of ecotoxicity of penoxsulam single and co-exposure with AgNPs on Eisenia fetida.

Penoxsulam (PNX) and silver nanoparticles (AgNPs) are likely to coexist in soils due to continuous use. However, the ecotoxicity of PNX in earthworms and the effect of AgNPs on PNX toxicity are unknown. Therefore, the toxicity of PNX (0.05, 0.5, and 2.5 mg/kg) single and co-exposure with AgNPs (10 mg/kg) after 28 and 56 days on Eisenia fetida (E. fetida) was investigated from biochemical, genetic, histopathological, and transcriptomic aspects. The results showed that the low concentration of PNX (0.05PNX) had almost no effect on the biochemical level of E. fetida. However, the addition of AgNPs resulted in 0.05PNX causing E. fetida to produce excessive reactive oxygen species, and the activity of antioxidant and detoxification enzymes were interfered, resulting in lipid peroxidation and DNA damage. From the genetic level, even the lowest concentration of PNX can significantly interfere with the expression of functional genes, thus inducing oxidative stress and apoptosis and inhibited reproductive behavior in E. fetida. The integrated biomarker response results at the biochemical and genetic levels showed that the comprehensive toxicity of PNX and PNX + AgNPs on E. fetida was PNX dose-dependent. And the toxicity of all co-exposure groups was greater than that of the PNX only exposure groups. Furthermore, the addition of AgNPs significantly increased the damage of PNX on E. fetida intestinal tissue. Meanwhile, transcriptomic analysis showed that PNX + AgNPs had a greater effect on E. fetida than PNX single, and multiple pathways related to oxidative stress, inflammation, and cellular process regulation were disturbed. These results provide a basis for comprehensive evaluation of the ecotoxicity of PNX and confirm that the AgNPs does increase the ecotoxicity of PNX in soil environment.

Synthesis of an Atom-Specifically 2 H/13 C-Labeled Uridine Ribonucleoside Phosphoramidite.

A combined enzymatic and chemical synthesis of a 2'-O-cyanoethoxymethyl (CEM) protected [1',6-13 C2 , 5-2 H]-uridine phosphoramidite is described herein. This is the first report of an atom-specific nucleobase and ribose labeled 2'-O-CEM protected ribonucleoside phosphoramidite. Importantly, the CEM 2'-OH protecting group permits the efficient solid-phase synthesis of large (>60 nucleotides) RNAs with good yield and purity. The new isotope-labeled phosphoramidite can therefore be applied to nuclear magnetic resonance (NMR) spectroscopy studies. Specifically, the [1',6-13 C2 , 5-2 H]-uridine phosphoramidite can be used to make position-specifically labeled RNAs for NMR analysis without complications from resonance overlap and scalar and dipolar couplings. © 2022 Wiley Periodicals LLC. Basic Protocol 1: Synthesis of the ribonucleoside 6 Basic Protocol 2: Synthesis of the ribonucleoside phosphoramidite 11.

2-Selenouridine, a Modified Nucleoside of Bacterial tRNAs, Its Reactivity in the Presence of Oxidizing and Reducing Reagents.

The 5-substituted 2-selenouridines are natural components of the bacterial tRNA epitranscriptome. Because selenium-containing biomolecules are redox-active entities, the oxidation susceptibility of 2-selenouridine (Se2U) was studied in the presence of hydrogen peroxide under various conditions and compared with previously reported data for 2-thiouridine (S2U). It was found that Se2U is more susceptible to oxidation and converted in the first step to the corresponding diselenide (Se2U)2, an unstable intermediate that decomposes to uridine and selenium. The reversibility of the oxidized state of Se2U was demonstrated by the efficient reduction of (Se2U)2 to Se2U in the presence of common reducing agents. Thus, the 2-selenouridine component of tRNA may have antioxidant potential in cells because of its ability to react with both cellular ROS components and reducing agents. Interestingly, in the course of the reactions studied, we found that (Se2U)2 reacts with Se2U to form new 'oligomeric nucleosides' as linear and cyclic byproducts.

Physicochemical properties calculated using DFT method and changes of 5-methyluridine hemihydrate crystals at high temperatures.

5-methyluridine hemihydrate (5 mU) single crystals were synthesized by the slow solvent evaporation method. The physicochemical properties, such as frontier molecular orbitals, global reactivity indices and vibrational were computationally studied through density functional theory (DFT). In addition, structural, vibrational, and thermal properties were obtained by powder X-ray diffraction (PXRD), Raman spectroscopy, thermogravimetric (TG) analysis and differential scanning calorimetry (DSC). PXRD evaluated the structural behavior of 5 mU crystal in the temperature range of 300-460 K. The high-temperature PXRD results suggested that the crystal undergoes two dehydration processes, being a first occurring from the orthorhombic structure (P21212) to triclinic (P1), in which the water losses occurred around 380 K. A second dehydration triggers the change from the triclinic structure to monoclinic (P21) within the 420-435 K temperature range. Furthermore, after this temperature, the anhydrous 5 mU suffers a melting process near 460 K, which is remarkably characterized as an irreversible process. Raman spectroscopy was carried out to identify the vibrational modes linked to the water molecule and the noticeable changes in these bands due to high-temperature effects around 380 K and 410 K. Indeed, changes on Raman bands, such as intensity inversion, the disappearance of bands associated with the hydrogen bonds formed from the water molecules and uracil group, and the ribose group were observed. Finally, this study provided details on the structural and vibrational changes caused by the dehydration of 5 mU crystals and the importance of hydrogen bonds for understanding the intermolecular interactions of the 5 mU, a methylated nucleoside with important biological functions.

Characterization of the Oxazinomycin Biosynthetic Pathway Revealing the Key Role of a Nonheme Iron-Dependent Mono-oxygenase.

Oxazinomycin is a C-nucleoside natural product with antibacterial and antitumor activities. In addition to the characteristic C-glycosidic linkage shared with other C-nucleosides, oxazinomycin also features a structurally unusual 1,3-oxazine moiety, the biosynthesis of which had previously been unknown. Herein, complete in vitro reconstitution of the oxazinomycin biosynthetic pathway is described. Construction of the C-glycosidic bond between ribose 5-phosphate and an oxygen-labile pyridine heterocycle is catalyzed by the C-glycosidase OzmB and involves formation of an enzyme-substrate Schiff base intermediate. The DUF4243 family protein OzmD is shown to catalyze oxygen insertion and rearrangement of the pyridine C-nucleoside intermediate to generate the 1,3-oxazine moiety along with the elimination of cyanide. Spectroscopic analysis and mutagenesis studies indicate that OzmD is a novel nonheme iron-dependent enzyme in which the catalytic iron center is likely coordinated by four histidine residues. These results provide the first example of 1,3-oxazine biosynthesis catalyzed by an unprecedented iron-dependent mono-oxygenase.

Serum Orotidine: A Novel Biomarker of Increased CVD Risk in Type 2 Diabetes Discovered Through Metabolomics Studies.

OBJECTIVE: To identify novel biomarkers of cardiovascular disease (CVD) risk in type 2 diabetes (T2D) via a hypothesis-free global metabolomics study, while taking into account renal function, an important confounder often overlooked in previous metabolomics studies of CVD. RESEARCH DESIGN AND METHODS: We conducted a global serum metabolomics analysis using the Metabolon platform in a discovery set from the Joslin Kidney Study having a nested case-control design comprising 409 individuals with T2D. Logistic regression was applied to evaluate the association between incident CVD events and each of the 671 metabolites detected by the Metabolon platform, before and after adjustment for renal function and other CVD risk factors. Significant metabolites were followed up with absolute quantification assays in a validation set from the Joslin Heart Study including 599 individuals with T2D with and without clinical evidence of significant coronary heart disease (CHD). RESULTS: In the discovery set, serum orotidine and 2-piperidinone were significantly associated with increased odds of incident CVD after adjustment for glomerular filtration rate (GFR) (odds ratio [OR] per SD increment 1.94 [95% CI 1.39-2.72], P = 0.0001, and 1.62 [1.26-2.08], P = 0.0001, respectively). Orotidine was also associated with increased odds of CHD in the validation set (OR 1.39 [1.11-1.75]), while 2-piperidinone did not replicate. Furthermore, orotidine, being inversely associated with GFR, mediated 60% of the effects of declining renal function on CVD risk. Addition of orotidine to established clinical predictors improved (P < 0.05) C statistics and discrimination indices for CVD risk (ΔAUC 0.053, rIDI 0.48, NRI 0.42) compared with the clinical predictors alone. CONCLUSIONS: Through a robust metabolomics approach, with independent validation, we have discovered serum orotidine as a novel biomarker of increased odds of CVD in T2D, independent of renal function. Additionally, orotidine may be a biological mediator of the increased CVD risk associated with poor kidney function and may help improve CVD risk prediction in T2D.

Blockade of p38 MAPK overcomes AML stem cell line KG1a resistance to 5-Fluorouridine and the impact on miRNA profiling.

Most of the AML patients in remission develop multidrug resistance after the first-line therapy and relapse. AML stem cells have gained attention for their chemoresistance potentials. Chemoresistance is a multifactorial process resulting from altered survival signaling pathways and apoptosis regulators such as MAPK, NF-κB activation and ROS production. We targeted the survival pathway p38 MAPK, NF-κB and ROS generation in human chemoresistant AML stem cell line KG1a, susceptible to enhance cell sensitivity to the chemotherapy drug 5-Fluorouridine, compared to the chemosensitive AML cell line HL60. After confirming the phenotypic characterization of KG1a and HL60 cells using flow cytometry and transcriptomic array analyses, cell treatment with the NF-κB inhibitor IKKVII resulted in a complete induction of apoptosis, and a few p38 MAPK inhibitor SB202190-treated cells underwent apoptosis. No change in the apoptosis status was observed in the ROS scavenger N-acetylcysteine-treated cells. The p38 MAPK pathway blockade enhanced the KG1a cell sensitivity to 5-Fluorouridine, which was associated with the upregulation of microribonucleic acid-(miR-)328-3p, as determined by the microarray-based miRNA transcriptomic analysis. The downregulation of the miR-210-5p in SB202190-treated KG1a cells exposed to FUrd was monitored using RT-qPCR. The miR-328-3p is known for the enhancement of cancer cell chemosensitivity and apoptosis induction, and the downregulation of miR-210-5p is found in AML patients in complete remission. In conclusion, we highlighted the key role of the p38 MAPK survival pathway in the chemoresistance capacity of the AML stem cells and potentially involved miRNAs, which may pave the way for the development of a new therapeutic strategy targeting survival signaling proteins and reduce the rate of AML relapse.