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International Journal of Hematology Jun 2024Medications used to treat acute lymphoblastic leukemia (ALL), such as L-asparaginase, can cause blood lipid disturbances. These can also be associated with polymorphisms...
BACKGROUND
Medications used to treat acute lymphoblastic leukemia (ALL), such as L-asparaginase, can cause blood lipid disturbances. These can also be associated with polymorphisms of the lipoprotein lipase (LpL) and apolipoprotein E (APOE) genes.
PROCEDURE
We aimed to investigate the association between lipid profile, certain LpL and APOE gene polymorphisms (rs268, rs328, rs1801177 and rs7412, rs429358 respectively) as well as the risk subgroup in 30 pediatric patients being treated for ALL, compared with 30 pediatric ALL survivors and 30 healthy controls.
RESULTS
The only APOE gene polymorphism with significant allelic and genotypic heterogeneity was rs429358. Further analysis of this polymorphism showed that genotype (CC, CT, or TT) was significantly associated with (1) changes in the lipid profile at the end of consolidation (total cholesterol, LDL, apo-B100, and lipoprotein a) and during re-induction (total cholesterol and apo-B100), and (2) classification in the high risk-ALL subgroup (for CC genotype/C allele presence).
CONCLUSIONS
Lipid abnormalities in children being treated for ALL may be associated with the APOE genotype, which is also possibly associated with risk stratification. Further research is needed to confirm the potential prognostic value of these findings.
Topics: Humans; Apolipoproteins E; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Child; Male; Female; Lipoprotein Lipase; Child, Preschool; Lipids; Adolescent; Polymorphism, Single Nucleotide; Genotype; Alleles; Asparaginase; Polymorphism, Genetic
PubMed: 38507115
DOI: 10.1007/s12185-024-03748-6 -
Protein Science : a Publication of the... Apr 2024L-Asparaginases (ASNases) catalyze the hydrolysis of L-Asn to L-Asp and ammonia. Members of the ASNase family are used as drugs in the treatment of leukemia, as well as...
L-Asparaginases (ASNases) catalyze the hydrolysis of L-Asn to L-Asp and ammonia. Members of the ASNase family are used as drugs in the treatment of leukemia, as well as in the food industry. The protomers of bacterial ASNases typically contain 300-400 amino acids (typical class 1 ASNases). In contrast, the chain of ASNase from Rhodospirillum rubrum, reported here and referred to as RrA, consists of only 172 amino acid residues. RrA is homologous to the N-terminal domain of typical bacterial class 1 ASNases and exhibits millimolar affinity for L-Asn. In this study, we demonstrate that RrA belongs to a unique family of cytoplasmic, short-chain ASNases (scASNases). These proteins occupy a distinct region in the sequence space, separate from the regions typically assigned to class 1 ASNases. The scASNases are present in approximately 7% of eubacterial species, spanning diverse bacterial lineages. They seem to be significantly enriched in species that encode for more than one class 1 ASNase. Here, we report biochemical, biophysical, and structural properties of RrA, a member of scASNases family. Crystal structures of the wild-type RrA, both with and without bound L-Asp, as well as structures of several RrA mutants, reveal topologically unique tetramers. Moreover, the active site of one protomer is complemented by two residues (Tyr21 and Asn26) from another protomer. Upon closer inspection, these findings clearly outline scASNases as a stand-alone subfamily of ASNases that can catalyze the hydrolysis of L-Asn to L-Asp despite the lack of the C-terminal domain that is present in all ASNases described structurally to date.
Topics: Asparaginase; Rhodospirillum rubrum; Protein Subunits; Aspartic Acid; Catalytic Domain
PubMed: 38501449
DOI: 10.1002/pro.4920 -
Frontiers in Chemistry 2024L-Asparaginases, divided into three structural Classes, catalyze the hydrolysis of L-asparagine to L-aspartic acid and ammonia. The members of Class 3, ReAIV and ReAV,...
L-Asparaginases, divided into three structural Classes, catalyze the hydrolysis of L-asparagine to L-aspartic acid and ammonia. The members of Class 3, ReAIV and ReAV, encoded in the genome of the nitrogen fixing , have the same fold, active site, and quaternary structure, despite low sequence identity. In the present work we examined the biochemical consequences of this difference. ReAIV is almost twice as efficient as ReAV in asparagine hydrolysis at 37°C, with the kinetic K, k parameters (measured in optimal buffering agent) of 1.5 mM, 770 s and 2.1 mM, 603 s, respectively. The activity of ReAIV has a temperature optimum at 45°C-55°C, whereas the activity of ReAV, after reaching its optimum at 37°C, decreases dramatically at 45°C. The activity of both isoforms is boosted by 32 or 56%, by low and optimal concentration of zinc, which is bound three times more strongly by ReAIV then by ReAV, as reflected by the K values of 1.2 and 3.3 μM, respectively. We also demonstrate that perturbation of zinc binding by Lys→Ala point mutagenesis drastically decreases the enzyme activity but also changes the mode of response to zinc. We also examined the impact of different divalent cations on the activity, kinetics, and stability of both isoforms. It appeared that Ni, Cu, Hg, and Cd have the potential to inhibit both isoforms in the following order (from the strongest to weakest inhibitors) Hg > Cu > Cd > Ni. ReAIV is more sensitive to Cu and Cd, while ReAV is more sensitive to Hg and Ni, as revealed by IC50 values, melting scans, and influence on substrate specificity. Low concentration of Cd improves substrate specificity of both isoforms, suggesting its role in substrate recognition. The same observation was made for Hg in the case of ReAIV. The activity of the ReAV isoform is less sensitive to Cl anions, as reflected by the IC50 value for NaCl, which is eightfold higher for ReAV relative to ReAIV. The uncovered complementary properties of the two isoforms help us better understand the inducibility of the ReAV enzyme.
PubMed: 38456185
DOI: 10.3389/fchem.2024.1373312 -
Scientific Reports Mar 2024A dataset comprising metagenomes of outpatients (n = 28) with acute leukemia (AL) and healthy controls (n = 14) was analysed to investigate the associations...
A dataset comprising metagenomes of outpatients (n = 28) with acute leukemia (AL) and healthy controls (n = 14) was analysed to investigate the associations between gut microbiota composition and metabolic activity and AL. According to the results obtained, no significant differences in the microbial diversity between AL outpatients and healthy controls were found. However, significant differences in the abundance of specific microbial clades of healthy controls and AL outpatients were found. We found some differences at taxa level. The relative abundance of Enterobacteriaceae, Prevotellaceae and Rikenellaceae was increased in AL outpatients, while Bacteirodaceae, Bifidobacteriaceae and Lachnospiraceae was decreased. Interestingly, the abundances of several taxa including Bacteroides and Faecalibacterium species showed variations based on recovery time from the last cycle of chemotherapy. Functional annotation of metagenome-assembled genomes (MAGs) revealed the presence of functional domains corresponding to therapeutic enzymes including L-asparaginase in a wide range of genera including Prevotella, Ruminococcus, Faecalibacterium, Alistipes, Akkermansia. Metabolic network modelling revealed potential symbiotic relationships between Veillonella parvula and Levyella massiliensis and several species found in the microbiota of AL outpatients. These results may contribute to develop strategies for the recovery of microbiota composition profiles in the treatment of patients with AL.
Topics: Humans; Gastrointestinal Microbiome; Feces; Bacteria; Microbiota; Leukemia, Myeloid, Acute; Bacteroidetes
PubMed: 38454103
DOI: 10.1038/s41598-024-56054-w -
Cell Communication and Signaling : CCS Mar 2024Asparagine, an important amino acid in mammals, is produced in several organs and is widely used for the production of other nutrients such as glucose, proteins, lipids,... (Review)
Review
Asparagine, an important amino acid in mammals, is produced in several organs and is widely used for the production of other nutrients such as glucose, proteins, lipids, and nucleotides. Asparagine has also been reported to play a vital role in the development of cancer cells. Although several types of cancer cells can synthesise asparagine alone, their synthesis levels are insufficient to meet their requirements. These cells must rely on the supply of exogenous asparagine, which is why asparagine is considered a semi-essential amino acid. Therefore, nutritional inhibition by targeting asparagine is often considered as an anti-cancer strategy and has shown success in the treatment of leukaemia. However, asparagine limitation alone does not achieve an ideal therapeutic effect because of stress responses that upregulate asparagine synthase (ASNS) to meet the requirements for asparagine in cancer cells. Various cancer cells initiate different reprogramming processes in response to the deficiency of asparagine. Therefore, it is necessary to comprehensively understand the asparagine metabolism in cancers. This review primarily discusses the physiological role of asparagine and the current progress in the field of cancer research.
Topics: Animals; Asparagine; Neoplasms; Leukemia; Amino Acids; Glucose; Mammals
PubMed: 38448969
DOI: 10.1186/s12964-024-01540-x -
Signal Transduction and Targeted Therapy Mar 2024Natural killer T cell lymphoma (NKTCL) is highly aggressive, with advanced stage patients poorly responding to intensive chemotherapy. To explore effective and safe...
Natural killer T cell lymphoma (NKTCL) is highly aggressive, with advanced stage patients poorly responding to intensive chemotherapy. To explore effective and safe treatment for newly diagnosed advanced stage NKTCL, we conducted a phase II study of anti-metabolic agent pegaspargase plus PD-1 antibody sintilimab (NCT04096690). Twenty-two patients with a median age of 51 years (range, 24-74) were enrolled and treated with induction treatment of pegaspargase 2500 IU/m intramuscularly on day 1 and sintilimab 200 mg intravenously on day 2 for 6 cycles of 21 days, followed by maintenance treatment of sintilimab 200 mg for 28 cycles of 21 days. The complete response and overall response rate after induction treatment were 59% (95%CI, 43-79%) and 68% (95%CI, 47-84%), respectively. With a median follow-up of 30 months, the 2 year progression-free and overall survival rates were 68% (95%CI, 45-83%) and 86% (95%CI, 63-95%), respectively. The most frequently grade 3/4 adverse events were neutropenia (32%, n = 7) and hypofibrinogenemia (18%, n = 4), which were manageable and led to no discontinuation of treatment. Tumor proportion score of PD-L1, peripheral blood high-density lipoprotein cholesterol, and apolipoprotein A-I correlated with good response, while PD-1 on tumor infiltrating lymphocytes and peripheral Treg cells with poor response to pegaspargase plus sintilimab treatment. In conclusion, the chemo-free regimen pegaspargase plus sintilimab was effective and safe in newly diagnosed, advanced stage NKTCL. Dysregulated lipid profile and immunosuppressive signature contributed to treatment resistance, providing an alternative therapeutic approach dual targeting fatty acid metabolism and CTLA-4 in NKTCL.
Topics: Humans; Antibodies, Monoclonal, Humanized; Asparaginase; Lymphoma; Natural Killer T-Cells; Polyethylene Glycols; Programmed Cell Death 1 Receptor; Adult; Middle Aged; Aged; Young Adult
PubMed: 38448403
DOI: 10.1038/s41392-024-01782-8 -
F1000Research 2023On the occasion of the 20th anniversary of the discovery of acrylamide in food, an analysis of patents related to the mitigation of this compound in food products... (Review)
Review
On the occasion of the 20th anniversary of the discovery of acrylamide in food, an analysis of patents related to the mitigation of this compound in food products obtained through immersion frying was carried out. For this purpose, a comprehensive search, compilation, and information analysis were conducted using free online databases such as Google Patents, Patenscope, and Lens. The search yielded a total of 79 patents within the considered time period (2002-2022). The countries with the highest number of granted patents were the United States, the European Union, and South Korea. The patents were classified into four main approaches: raw material modification (49%), application of pre-treatments (27%), process modification (16%), and measurement techniques (8%). Among the results, Frito-Lay, an American company, stands out as the food industry company with the highest number of granted patents, totaling 15. Based on this review, it is concluded that while a significant number of patents have been granted in recent years, there is still a lag in developing countries. Furthermore, more studies are needed to determine acrylamide in starchy food matrices subjected to immersion frying different from potatoes.
Topics: Acrylamide; Cooking; Food Analysis; Patents as Topic; Starch
PubMed: 38434634
DOI: 10.12688/f1000research.140948.1 -
Translational Oncology May 2024Escherichia coli l-asparaginase (EcA), an integral part of multi-agent chemotherapy protocols of acute lymphoblastic leukemia (ALL), is constrained by safety concerns...
INTRODUCTION
Escherichia coli l-asparaginase (EcA), an integral part of multi-agent chemotherapy protocols of acute lymphoblastic leukemia (ALL), is constrained by safety concerns and the development of anti-asparaginase antibodies. Novel variants with better pharmacological properties are desirable.
METHODS
Thousands of novel EcA variants were constructed using protein engineering approach. After preliminary screening, two mutants, KHY-17 and KHYW-17 were selected for further development. The variants were characterized for asparaginase activity, glutaminase activity, cytotoxicity and antigenicity in vitro. Immunogenicity, pharmacokinetics, safety and efficacy were tested in vivo. Binding of the variants to pre-existing antibodies in primary and relapsed ALL patients' samples was evaluated.
RESULTS
Both variants showed similar asparaginase activity but approximately 24-fold reduced glutaminase activity compared to wild-type EcA (WT). Cytotoxicity against Reh cells was significantly higher with the mutants, although not toxic to human PBMCs than WT. The mutants showed approximately 3-fold lower IgG and IgM production compared to WT. Pharmacokinetic study in BALB/c mice showed longer half-life of the mutants (KHY-17- 267.28±9.74; KHYW-17- 167.41±14.4) compared to WT (103.24±18). Single and repeat-doses showed no toxicity up to 2000 IU/kg and 1600 IU/kg respectively. Efficacy in ALL xenograft mouse model showed 80-90 % reduction of leukemic cells with mutants compared to 40 % with WT. Consequently, survival was 90 % in each mutant group compared to 10 % with WT. KHYW-17 showed over 2-fold lower binding to pre-existing anti-asparaginase antibodies from ALL patients treated with l-asparaginase.
CONCLUSION
EcA variants demonstrated better pharmacological properties compared to WT that makes them good candidates for further development.
PubMed: 38412663
DOI: 10.1016/j.tranon.2024.101909 -
EFSA Journal. European Food Safety... Feb 2024The food enzyme asparaginase (l-asparagine amidohydrolase; EC 3.5.1.1) is produced with the genetically modified strain AGN by DSM Food Specialties B.V. The genetic...
The food enzyme asparaginase (l-asparagine amidohydrolase; EC 3.5.1.1) is produced with the genetically modified strain AGN by DSM Food Specialties B.V. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and its DNA. It is intended to be used to prevent acrylamide formation in food processing. The dietary exposure to the food enzyme-total organic solids (TOS) was estimated to be up to 1.434 mg TOS/kg body weight (bw) per day in European populations. The toxicity studies were carried out with an asparaginase from (strain ASP). The Panel considered this food enzyme as a suitable substitute for the asparaginase to be used in the toxicological studies, because the genetic differences between the production strains are not expected to result in a different toxigenic potential, and the raw materials and manufacturing processes of both food enzymes are comparable. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 1038 mg TOS/kg bw per day, which, when compared with the estimated dietary exposure, resulted in a margin of exposure of at least 724. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panel considered that the risk of allergic reactions by dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.
PubMed: 38379730
DOI: 10.2903/j.efsa.2024.8617