This study was purposed to explore the relationship between asparagine synthetase (AsnS) mRNA expression level and the sensitivity of leukemic cell lines to L-asparaginase. The AsnS mRNA expression level in 8 cell lines (Jurkat, HL-60, U937, NB4, THP-1, Namalwa, Karpas299 and K562) was determined by real-time quantitative PCR (RQ-PCR) based on fluorescence dye Eva Green before and after treatment with L-Asp, and the cell proliferation rates were analyzed by CCK-8 assay. The results showed that there was a significant disparity of AsnS expression level in 8 cell lines, and there were significant increases of AsnS expression level in cells co-cultured with L-Asp (p < 0.05). Of all these eight cell lines, cells sensitive to L-asparaginase had lower AsnS expression level and cells resistant to L-asparaginase had higher AsnS expression. U937 which was the most sensitive to L-asparaginase had the lowest AsnS expression level, while K562 was natural resistant to L-asparaginase and possessed of the highest AsnS level. It is concluded that the AsnS plays a critical role in regulating cellular biological behavior after depletion of asparagine, the AsnS mRNA expression level in cells reflects the sensitivity of cells to L-Asp. The results may imply the possibility for the use of L-asparaginase in leukemia with lower AsnS expression level.
Asparaginase ; metabolism ; pharmacology ; Aspartate-Ammonia Ligase ; metabolism ; Cell Line, Tumor ; Humans ; Leukemia ; enzymology

Objective: To summarize the adverse effects of pegaspargase in the treatment of lymphoid malignancies and management experience. Methods: Clinical data of patients who received chemotherapy including pegaspargase in the Department of Hematology of Beijing Tongren hospital during August 2011 to December 2015 were retrospective analyzed, and the adverse effects of pegaspargase and the management experience was summarized. Results: A total of 129 patients with 443 times of pegaspargase used during this period. The common adverse reactions included allergic reactions in 2 cases (1.6%), acute pancreatitis in 19 (14.7%) including 6 acute symptomatic pancreatitis and 13 chemical pancreatitis with elevated pancreatin, hypertriglyceridemia in 15 cases(11.6%), hyperglycemia in 85 (65.9%), hypoglycemia in 7 (5.4%), elevated aminotransferase in 25 (19.4%), hyperbilirubinemia in 21 (15.5%), hypoalbuminemia in 62 (48.1%), prolonged APTT in 61 (47.3%), prolonged PT in 22 (17.1%), prolonged TT in 15 (11.6%), hypofibrinogen in 75 (58.1%), thrombus in 11 (8.5%) and bleeding in 3 (2.3%). The above adverse reactions were improved by symptomatic treatment of anti allergy, inhibition of secretion of pancreatic juice, lipid lowering, hypoglycemic, liver preservation, supplementation of plasma and hemostasis, respectively. Some serious adverse reactions affected the application of pegaspargase, even lead to discontinuation of the aspartate. Conclusion: Though adverse effects associated with pegaspargase are extensive, most patients can successfully complete the chemotherapy containing the pegaspargase with close monitoring and timely treatment.
Asparaginase/metabolism* ; Humans ; Polyethylene Glycols/metabolism* ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; Retrospective Studies

L-asparaginase (L-ASN) is widely applied in the treatment of malignant tumor and low-acrylamide food production, however, the low expression level hampers its application. Heterologous expression is an effective strategy to increase the expression level of target enzymes, and Bacillus is generally used as the host for efficient production of enzymes. In this study, the expression level of L-asparaginase in Bacillus was enhanced through optimization of expression element and host. Firstly, five signal peptides (SP_SacC, SP_AmyL, SP_AprE, SP_YwbN and SP_WapA) were screened, among which SP_SacC showed the best performance, reaching an activity of 157.61 U/mL. Subsequently, four strong promoters (P43, P_ykzA-P43, P_Ubay and P_bacA) from Bacillus were screened, and tandem promoter P_ykzA-P43 showed the highest yield of L-asparaginase, which was 52.94% higher than that of control strain. Finally, three Bacillus expression hosts (B. licheniformis Δ0F3 and BL10, B. subtilis WB800) were investigated, and the maximum L-asparaginase activity, 438.3 U/mL, was reached by B. licheniformis BL10, which was an 81.83% increase compared with that of the control. This is also the highest level of L-asparaginase in shake flask reported to date. Taken together, this study constructed a B. licheniformis strain BL10/P_ykzA-P43-SP_SacC-ansZ capable of efficiently producing L-asparaginase, which laid the foundation for industrial production of L-asparaginase.
Bacillus licheniformis/metabolism* ; Asparaginase/genetics* ; Bacillus/genetics* ; Protein Sorting Signals ; Promoter Regions, Genetic/genetics* ; Bacillus subtilis/genetics* ; Bacterial Proteins

OBJECTIVETo study the antileukemic activity of L-asparaginase through determining the changes of 4 kinds of amino acids (Asn, Aspa, Glu and Gln) in cell culture medium.

METHODSFollowing L-Asp treatment with designed concentrations and duration, the IC50 (inhibitory concentration 50%) of 8 kinds of common leukemia cell lines (U937, HL-60, Jurkat, NB4, THP-1, Namalwa, Karpass299, K562) were determined by CCK-8 assay. The changes of the 4 kinds of amino acids mentioned above were detected by high performance liquid chromatography (HPLC).

RESULTSThe asparagines in cell culture medium were rapidly exhausted when treated with 0.01 U/mL L-Asp for 4 hrs or 1 U/mL L-Asp for 5 minutes. There were significant differences in the sensitivities to L-Asp of different leukemia cell lines. The sensitivities to L-Asp of various cell lines were dose-dependent. Low concentration of L-Asp resulted in a low IC50 and the IC50 increased following the L-Asp concentration increased.

CONCLUSIONSDifferent leukemia cell lines have different sensitivities to L-Asp, suggesting that exhaustion of asparagines around leukemia cells could not reflect the treatment efficacy of L-Asp. L-Asp antileukemic activity is dose-dependent, which suggests the importance of high-dose L-Asp on childhood acute lymphoblastic leukemia.

Asparaginase ; pharmacology ; Asparagine ; analysis ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Chromatography, High Pressure Liquid ; Humans ; Leukemia ; drug therapy ; metabolism ; pathology ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; drug therapy

OBJECTIVETo study the cellular activity of asparagine synthetase in different types of childhood acute lymphoblastic leukemia (ALL).

METHODSThe cellular activity of asparagine synthetase was detected by HPLC-FLD and Protein measurement in 28 ALL children (7 cases of T-ALL and 21 cases of B-lymphoid lineage ALL) before chemotherapy.

RESULTSThe asparagines synthetase activity levels in T-ALL children were significantly higher than those of the B-lymphoid lineage ALL patients, with the median activity level of 9.3 nM Asn/mg protein/hr vs 5.2 nM Asn/mg protein/hr (P < 0.05). The distribution of the asparagine synthetase activity demonstrated a polymorphism in either T-ALL or B-lymphoid lineage ALL patients.

CONCLUSIONSThe cellular activity of asparagines synthetase in ALL patients is presented with a polymorphism distribution. The asparagines synthetase activity levels in T-ALL are significantly higher than in B-lymphoid lineage ALL.

Asparaginase ; therapeutic use ; Aspartate-Ammonia Ligase ; genetics ; metabolism ; Child ; Core Binding Factor Alpha 2 Subunit ; genetics ; Female ; Humans ; Male ; Oncogene Proteins, Fusion ; genetics ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; drug therapy ; enzymology ; RNA, Messenger ; analysis

OBJECTIVETo confirm the responses and function of hALP, a telomerase-regulation associated gene, in DNA damage.

METHODSHeLa and Hep2 cells were treated by genotoxic agents H2O2 and cisplatin, and the induced expression of hALP was measured by quantitative RT-PCR and immunofluorescent histochemistry. The alterations in transcriptional activity of hALP promoter were estimated by luciferase reporter assays. The effects of genotoxic agents on cells in different status of hALP expression were analyzed by MTT method.

RESULTSThe level of hALP mRNA could be increased when treated by 0.2 - 1.6 mmol/L H2O2 and reach a peak in concentration of 0.4 mmol/L. The induction could be observed after 6 h in the treatment of 0.4 mmol/L H2O2 and the higher level can be retained for 36 h. Similarly, cisplatin induced hALP mRNA expression is also dose and time dependent. The immunofluorescent staining showed that the treatment of 0.2 or 0.4 mmol/L H2O2, 0.2 or 0.5 micromol/L cisplatin increased the intensity of hALP protein in cellular nuclei. The luciferase assays demonstrated that both H2O2 and cisplatin could up-regulate hALP promoter activity through its upstream - 705 - +20 nt region. In cell survivor assay, the HeLa cells expressing sense hALP gene could grow continuously in the presence of 0.4 mmol/L H2O2 or 0. 5 micromol/L cisplatin while cells with antisense hALP or control cells were slower in growth.

CONCLUSIONSThe expression of hALP gene could be up-regulated by DNA damage through activating transcription of its promoter, and increase cellular resistance to genotoxic agents.

Antineoplastic Agents ; administration & dosage ; pharmacology ; Asparaginase ; biosynthesis ; genetics ; Autoantigens ; biosynthesis ; genetics ; Cell Proliferation ; Cells, Cultured ; Cisplatin ; administration & dosage ; pharmacology ; DNA Damage ; physiology ; Dose-Response Relationship, Drug ; Gene Expression Regulation, Enzymologic ; HeLa Cells ; metabolism ; Humans ; Hydrogen Peroxide ; administration & dosage ; pharmacology ; RNA, Messenger ; biosynthesis ; genetics ; Telomerase ; genetics ; physiology ; Up-Regulation

BACKGROUND AND OBJECTIVEPrecursor T lymphoblastic lymphoma (T-LBL) is a highly aggressive lymphoma. Myeloid antigen expression was found in some of the patients, and its clinical significance is worth studying. This study was to compare the clinical features, short-term efficacy and survival of T-LBL patients with or without myeloid antigen expression so as to evaluate its prognostic significance.

METHODSForty-five T-LBL patients, with a median age of 14 years, were treated at Sun Yet-sen University Cancer Center between January 2000 and July 2008. These patients were divided into myeloid antigen-positive group (My(+) group) and myeloid antigen-negative group (My(-) group) based on the flow cytometric (FCM) analysis in bone marrow or pleural fluid. Myeloid antigen expression and its correlation with the short-term efficacy and overall survival were assessed in the two groups.

RESULTSThere were 18 patients (40.0%) in the My(+) group and 27 (60.0%) in the My(-) group. The myeloid antigen expression was negatively correlated with the initial level of lactate dehydrogenase (LDH), but not with other clinical features. The remission rate was lower in the My(+) group than in the My(-) group (38.8% vs. 70.3%, P = 0.028). The 2-year overall survival rate was lower in the My(+) group than in the My(-) group (51.9% vs. 78.7%, P = 0.036). By age subgroup analysis, there were no differences in response and survival rate among children and adolescents with or without myeloid antigen expression. But the remission rate and the 2-year overall survival rate were significantly lower in adult patients with myeloid antigen expression than in patients without it. Univariate and multivariate analysis demonstrated that age and myeloid antigen expression were adverse prognostic factors.

CONCLUSIONMyeloid antigen expression is a predictor of a poor response to chemotherapy, and adverse prognostic factor in adult T-LBL, but not in children with T-LBL.

Adolescent ; Adult ; Age Factors ; Aged ; Antigens, CD7 ; metabolism ; Antigens, Differentiation, Myelomonocytic ; metabolism ; Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Asparaginase ; therapeutic use ; Child ; Cyclin D3 ; metabolism ; Cyclophosphamide ; therapeutic use ; Cytarabine ; therapeutic use ; Daunorubicin ; therapeutic use ; Doxorubicin ; therapeutic use ; Etoposide ; therapeutic use ; Female ; Follow-Up Studies ; Humans ; Male ; Mercaptopurine ; therapeutic use ; Methotrexate ; therapeutic use ; Middle Aged ; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma ; drug therapy ; immunology ; Prednisone ; therapeutic use ; Proportional Hazards Models ; Remission Induction ; Survival Rate ; Transcription Factors ; metabolism ; Vincristine ; therapeutic use ; Young Adult