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

Objective: To explore the prognostic factors of extracellular NK/T cell lymphoma (ENKTL) treated with pegaspargase/L-asparaginase. Methods: The clinical data of 656 ENKTL patients diagnosed at 11 medical centers in the Huaihai Lymphoma Working Group from March 2014 to April 2021 were retrospectively analyzed. The patients were randomly divided into two groups: a training set (460 cases) and a validation set (196 cases) at 7∶3, and the prognostic factors of the patients were analyzed. A prognostic scoring system was established, and the predictive performance of different models was compared. Results: Patients' median age was 46 (34, 57) years, with 456 males (69.5% ) and 561 nasal involvement (85.5% ). 203 patients (30.9% ) received a chemotherapy regimen based on L-asparaginase combined with anthracyclines, and the 5-year overall survival rate of patients treated with P-GEMOX regimen (pegaspargase+gemcitabine+oxaliplatin) was better than those treated with SMILE regimen (methotrexate+dexamethasone+cyclophosphamide+L-asparaginase+etoposide) (85.9% vs 63.8% ; P=0.004). The results of multivariate analysis showed that gender, CA stage, the Eastern Cooperative Oncology Group performance status (ECOG PS) score, HGB, and EB virus DNA were independent influencing factors for the prognosis of ENKTL patients (P<0.05). In this study, the predictive performance of the prognostic factors is superior to the international prognostic index, Korean prognostic index, and prognostic index of natural killer lymphoma. Conclusion: Gender, CA stage, ECOG PS score, HGB, and EB virus DNA are prognostic factors for ENKTL patients treated with pegaspargase/L-asparaginase.
Male ; Humans ; Middle Aged ; Asparaginase/therapeutic use* ; Prognosis ; Retrospective Studies ; Lymphoma, Extranodal NK-T-Cell/drug therapy* ; Antineoplastic Combined Chemotherapy Protocols/therapeutic use* ; Etoposide ; Cyclophosphamide ; Methotrexate/therapeutic use* ; DNA/therapeutic use* ; Treatment Outcome

OBJECTIVE: To investigate the clinical characteristics, diagnosis, and treatment of one patient with primary adrenal natural killer/T-cell lymphoma (PANKTCL), and to strengthen the understanding of this rare type of lymphoma. METHODS: The clinical manifestations, diagnosis and treatment process, and prognosis of the patient admitted in our hospital were retrospectively analyzed. RESULTS: Combined with pathology, imaging, bone marrow examination， etc, the patient was diagnosed with PANKTCL (CA stage, stage II; PINK-E score 3, high-risk group). Six cycles of "P-GemOx+VP-16" regimen（gemcitabine 1 g/m² d1 + oxaliplatin 100 mg/m² d 1 + etoposide 60 mg/m² d 2-4 + polyethylene glycol conjugated asparaginase 3 750 IU d 5） was performed, and complete response was assessed in 4 cycles. Maintenance therapy with sintilimab was administered after the completion of chemotherapy. Eight months after the complete response, the patient experienced disease recurrence and underwent a total of four courses of chemotherapy, during which hemophagocytic syndrome occurred. The patient died of disease progression 1 month later. CONCLUSION PANKTCL is rare, relapses easily, and has a worse prognosis. The choice of the "P-GemOx+VP-16" regimen combined with sintilimab help to improve the survival prognosis of patient with non-upper aerodigestive tract natural killer /T-cell lymphoma.
Humans ; Treatment Outcome ; Antineoplastic Combined Chemotherapy Protocols/therapeutic use* ; Retrospective Studies ; Etoposide ; Neoplasm Recurrence, Local/drug therapy* ; Asparaginase ; Deoxycytidine ; Lymphoma, T-Cell, Peripheral/drug therapy* ; Lymphoma, Extranodal NK-T-Cell/therapy* ; Oxaliplatin/therapeutic use*

Objective: To investigate the clinical characteristics and treatment of pancreatic pseudocyst after pegaspargase treatment in children. Methods: The clinical data of 6 children with pancreatic pseudocyst after pegaspargase treatment in the Department of Pediatrics in Peking University Third Hospital from July 2018 to February 2021 were analyzed retrospectively. Results: There were 4 males and 2 females, and their age of onset was 9.5 (5.8, 13.0) years. The total number of pegaspargase applications was 2.5 (2.0, 3.5) times. The course from the last dose of pegaspargase to the onset of pancreatitis was 11.0 (9.0, 17.2) days, and 42.5 (35.0, 129.5) days from the onset of pancreatitis to the diagnosis of pancreatic pseudocyst. Abdominal pain was the most prominent manifestation of pancreatitis (6/6). All of the 6 children were asymptomatic when pancreatic pseudocyst was noted, and were treated conservatively at first, but one case later developed intermittent abdominal distension or nausea after eating. All the cases had pancreatic pseudocyst enlargement during the conservative treatment. Three children were treated with endoscopic ultrasound-guided transgastric drainage, and the cyst disappeared from 10 days to 4 months after the operation. The other 3 children received endoscopic retrograde cholangiopancreatography (ERCP)-guided transpapillary drainage, but one of them turned to surgery due to pancreatic duct stricture, and in the rest 2 children the cyst disappeared at 1 and 3 months after operation respectively. Regarding safety issues, 1 child who received ERCP-guided transpapillary drainage had acute postoperative pancreatitis, which were improved after treatment, and the other 5 had no complications. Conclusions: Pancreatic pseudocyst after pegaspargase chemotherapy can be asymptomatic in the early stage, and should be diagnosed with a history of pegaspargase treatment and timely imaging examination. Conservative treatment is the first choice for asymptomatic pseudocyst. When the pseudocyst enlarges, different endoscopic drainage treatments are required according to whether the pseudocyst is connected with the main pancreatic duct.
Female ; Male ; Humans ; Child ; Retrospective Studies ; Asparaginase ; Polyethylene Glycols/adverse effects* ; Pancreatitis

OBJECTIVE: To investigate the clinical characteristics of patients with extranodal NK/T-cell lymphoma (ENKL), and to analyze the factors that affecting the survival and prognostic of patients treated with pegaspargase based chemotherapy. METHODS: The clinical data of 61 ENKL patients treated in Peking Union Medical College Hospital from January 2015 to June 2019 were enrolled and retrospectively analyzed. The clinical characteristics, survival rate and influencing factors of prognostic in patients were investigated. RESULTS: The male and female ratio in the whole group was 2.8∶1. The median age was 46 years old (range, 17-67 years old). 30 patients were in stage I/II, while 31 patients were in stage III/IV. The ratio of nasal and non-nasal type was 4.1∶1. The common sites of extranodal involvement were skin and subcutaneous tissue (26.2%), liver (14.8%), lung (13.1%) and gastrointestinal tract (13.1%). 9.8% of patients showed central nervous system involvement and 11.5% showed bone marrow involvement. The median follow-up time was 22 months (range, 1-53 months). The 2-year PFS and OS rates of patients in the whole group were 51.6% and 53.2%, respectively. The 2-year OS rate of patients at stage I/II was 87.5%, while that of patients at stage III/IV was only 21.2%, the difference showed statistically significant (P<0.0001). Patients with non-nasal type disease showed a higher proportion in adverse factors of prognosis, of whom the median OS was only 3 months. Multivariate analysis showed that age>60 years old and Ann Arbor stage III-IV were the independent adverse factors that affecting the prognosis of PFS and OS (HR=3.681, 95% CI 1.322-10.250; HR=4.611, 95% CI 1.118-19.009). CONCLUSION The survival of ENKL patients has been significantly improved by pegaspargase based chemotherapy. Patients with stage I/II disease have achieved a relatively good 2-year OS rate of 87.5%, but the prognosis of stage III/IV and non-nasal type patients are still poor. Age>60 years old and Ann Arbor stage III/IV are independent adverse prognostic factors for ENKL patients.
Adolescent ; Adult ; Aged ; Antineoplastic Combined Chemotherapy Protocols ; Asparaginase ; Female ; Humans ; Lymphoma, Extranodal NK-T-Cell/pathology* ; Male ; Middle Aged ; Neoplasm Staging ; Polyethylene Glycols ; Prognosis ; Retrospective Studies ; Young Adult

L-asparaginase hydrolyzes L-asparagine to produce L-aspartic acid and ammonia. It is widely distributed in microorganisms, plants and serum of some rodents, and has important applications in the pharmaceutical and food industries. However, the poor thermal stability, low catalytic efficiency and low yield hampered the further application of L-asparaginase. In this paper, rational design and 5' untranslated region (5'UTR) design strategies were used to increase the specific enzyme activity and protein expression of L-asparaginase derived from Rhizomucor miehei (RmAsnase). The results showed that among the six mutants constructed through homology modeling combined with sequence alignment, the specific enzyme activity of the mutant A344E was 1.5 times higher than the wild type. Subsequently, a food-safe strain Bacillus subtilis 168/pMA5-A344E was constructed, and the UTR strategy was used for the construction of recombinant strain B. subtilis 168/pMA5 UTR-A344E. The enzyme activity of B. subtilis 168/pMA5 UTR-A344E was 7.2 times higher than that of B. subtilis 168/pMA5-A344E. The recombinant strain B. subtilis 168/pMA5 UTR-A344E was scaled up in 5 L fermenter, and the final yield of L-asparaginase was 489.1 U/mL, showing great potential for industrial application.
Asparaginase/genetics* ; Bacillus subtilis/genetics* ; Industrial Microbiology ; Protein Engineering ; Rhizomucor/enzymology* ; Sequence Alignment

Objective: To explore the clinical characteristics, the best treatment and prognostic factors of primary pulmonary NK/T-cell lymphoma. Methods: A total of 24 cases with primary pulmonary NK/T-cell lymphoma from April 2011 to May 2019 were analyzed retrospectively. Survival analysis was performed using the Kaplan-Meier method and groups were compared using the log-rank test. Multivariate analysis using Cox proportional hazard regression model was conducted to confirm independent prognostic factors for overall survival (OS) and progression-free survival (PFS) . Results: ①The cohort of 24 patients included 16 male and 8 female with a median age of 49 years (range, 4-76 years) old. ②Most patients initially presented with a fever (66.7%) , cough and dyspnea. Chest imaging manifestations were primarily unilateral (45.8%) or bilateral (54.2%) pulmonary consolidation, nodules or mass. ③20 patients received chemotherapy, radiotherapy or hematopoietic stem cell transplantation, the rest 4 cases palliative treatment. Median OS was 9.5 months (range, 0.1-26.0 months) . The estimated 1-year OS rate was 45.8%. Overall response rate of patients treated with asparaginase-based regimen was 88.2%. ④In univariate survival analysis, age≤60 was prognostic for longer OS and PFS, compared with age>60 (P=0.002 and 0.004, respectively) ; ECOG≤2 was prognostic for longer OS and PFS, compared with ECOG>2 (P=0.042 and 0.004, respectively) . In multivariate survival analysis, age>60 and ECOG>2 were significantly correlated with inferior OS and PFS (OS: P=0.024 and 0.024, respectively; PFS: P=0.035 and 0.024, respectively) . Conclusions: Primary pulmonary NK/T-cell lymphoma was a rare disease with poor prognosis. Asparaginase-based regimens appeared to be effective. Age and ECOG served as independent prognostic factors for primary pulmonary NK/T-cell lymphoma patients.
Adolescent ; Adult ; Aged ; Antineoplastic Combined Chemotherapy Protocols ; Asparaginase ; Child ; Child, Preschool ; Disease-Free Survival ; Female ; Humans ; Lymphoma, Extranodal NK-T-Cell ; Male ; Middle Aged ; Prognosis ; Retrospective Studies ; Young Adult

OBJECTIVE: To investigate the effects and its potential mechanism of asparaginase on proliferation, cell cycle and apoptosis of diffuse large B-cell lymphoma (DLBCL) cell lines. METHODS: CCK-8 assay was used to detect the effect of asparaginase on proliferation of DLBCL cell lines. Flow cytometry was used to analyze cell cycle and apoptosis. Western blot was used to analyze apoptosis and its potential mechanism. RESULTS: Asparaginase obviously inhibited the proliferation of multiple DLBCL cell lines and caused G/G cell arrest. Furtherly, asparaginase inhibited the expression of HIF-1α which related to poor prognosis of patients with DLBCL, up-regulated the expression of DR4 and caspase 8, reduce the expression of c-FLIP. Meanwhile, asparaginase induced the expression of pro-apoptotic protein BAX and inhibited the expression of anti-apoptotic protein MCL-1. CONCLUSION Asparaginase can inhibit the proliferation of DLBCL cell lines, cause the arrest of cells in G/G and induce apoptosis via the endogenous and exogenous apoptotic pathways.
Apoptosis ; Asparaginase ; Cell Line, Tumor ; Cell Proliferation ; Humans ; Lymphoma, Large B-Cell, Diffuse

PURPOSE: The aim of this study was to compare asparaginase-related toxicities in two asparaginase preparations, namely native Escherichia coli L-asparaginase (L-ASP) and pegylated asparaginase (PEG-ASP) in combination with ifosfamide, methotrexate, etoposide, and prednisolone (IMEP) in natural killer (NK)/T-cell lymphoma (NTCL). MATERIALS AND METHODS: A total of 41 NTCL patients who received IMEP plus native E. coli L-ASP or PEG-ASP at Seoul National University Hospital were included in this study between January 2013 and March 2016. IMEP/ASP treatment consisted of ifosfamide, methotrexate, etoposide, plus native E. coli L-ASP (6,000 IU/m2 on days 1, 3, 5, 7, 9, and 11) or PEG-ASP (2,500 IU/m2 on day 1) every 3 weeks. ASP-related toxicities, toxicity patterns, length of hospital stay, and clinical outcomes were compared between the different treatment groups. RESULTS: The frequency of ASP-related toxicities was similar between the IMEP plus native E. coli L-ASP group and the PEG-ASP group apart from hypofibrinogenemia (native E. coli L-ASP vs. PEG-ASP group, 86.4% vs. 36.8%; p=0.001). Although post-treatment transaminase and albumin levels were significantly high and low, respectively, hepatotoxicity gradients before and after treatment did not differ significantly between the groups. Since PEG-ASP was given at an outpatient clinic in some patients, length of hospital stay was significantly shorter in the IMEP plus PEG-ASP group (median, 4.0 vs. 6.0 days; p=0.002). A favorable tendency of clinical outcomes was observed in NTCL patients treated with IMEP plus PEG-ASP (complete remission rate, 73.7% vs. 45.5%; p=0.067). CONCLUSION: IMEP plus PEG-ASP showed similar ASP-related toxicities, shorter length of hospital stay, and a trend towards improved clinical outcomes compared with IMEP plus native E. coli L-ASP in NTCL.
Ambulatory Care Facilities ; Asparaginase* ; Escherichia coli* ; Escherichia* ; Etoposide* ; Humans ; Ifosfamide* ; Length of Stay ; Lymphoma* ; Methotrexate* ; Prednisolone* ; Seoul

Objective: To analyze the efficacy and safety of asparaginase based chemotherapy bridging autologous hematopoietic stem cell transplantation (auto-HSCT) in the treatment of 16 patients with nasal type extranodal NK/T-cell lymphoma (ENKTL). Methods: From January 2012 to June 2017, 16 patients with nasal type extranodal NK/T-cell lymphoma reached complete remission by L-asparaginase based regimens, and then received auto-HSCT. Results: ①Of the 16 patients, 12 were males and 4 females, with a median age of 35.5 (14-61) years. There were 11 patients in the first complete remission (CR1) and 5 in the second CR (CR2) before transplantation, respectively. EB virus (EBV) DNA (EBV-DNA) was negative and positive in 13 and 3 cases respectively before transplantation. ②Hematopoietic reconstitution was achieved in all 16 cases. The median time for neutrophils implantation was 12 (8-17) days, and that of platelet implantation was 15.5 (12-24) days. ③To the last follow-up, there were no transplant related deaths, 3 patients died of disease progression. The median overall survival (OS) time and progression-free survival time (PFS) were not reached. Seven patients lived with no disease progression more than 2 years. ④The OS and PFS of patients at CR(1) before auto-HSCT are better than that of patients at CR(2), but there was no statistically significant difference (P=0.162, P=0.123). There was no significant difference in OS and PFS between EBV-DNA negative and positive patients before transplantation (P=0.280, P=0.244). Conclusions: L-asparaginase based regimens bridging auto-HSCT is a safe and highly effective for advanced-stage and relapsed ENKTL treatment.
Adolescent ; Adult ; Antineoplastic Combined Chemotherapy Protocols ; Asparaginase ; Female ; Hematopoietic Stem Cell Transplantation ; Humans ; Lymphoma, Extranodal NK-T-Cell ; Male ; Middle Aged ; Neoplasm Recurrence, Local ; Nose Neoplasms ; Transplantation, Autologous ; Young Adult