Polyoxazoline-Conjugated l-Asparaginase: An Antibody-Production-Free Therapeutic Agent for Acute Lymphoblastic Leukemia

l-asparaginase (ASNase), an enzyme that catalyzes the hydrolysis of l-asparagine into l-aspartic acid, is frequently used as a medication for acute lymphoblastic leukemia (ALL). However, when derived from bacterial sources, this enzyme can elicit side effects, including allergic or hypersensitivity reactions, owing to immune responses. Here, we describe the synthesis of polyoxazoline-conjugated ASNase (POx-ASNase) and investigate its enzyme activity, anticancer efficacy, immunogenicity, and retention in the bloodstream. The water-soluble POx was coupled with surface lysine residues of ASNase using a bifunctional cross-linker. The average number of polymers bound to each enzyme was determined as 10. Although the enzymatic activity of POx-ASNase decreased to 56% of that of native ASNase, its temperature and pH dependencies remained unaltered. Remarkably, the lyophilized powder form of POx-ASNase retained its catalytic ability for 24 months. POx-ASNase demonstrated nearly identical anticancer efficacy compared to naked ASNase against leukemia and lymphoma cells (MOLT-4, CLBL-1, and K562) while displaying no cytotoxicity toward normal cells. Animal experiments conducted using rats revealed that the POx decoration suppressed the generation of anti-ASNase IgM and IgG antibodies with no detection of anti-POx antibodies. The half-life within the bloodstream extended to 34 h, representing a 17-fold increase compared to unmodified ASNase. These findings suggest that POx-ASNase serves as an anticancer therapeutic agent, characterized by the absence of antibody production and notably extended circulation persistence.

Utility of ASNS gene methylation evaluated with the HPLC method as a pharmacogenomic biomarker to predict asparaginase sensitivity in BCP-ALL

Asparaginase is an important agent for the treatment of acute lymphoblastic leukaemia (ALL), but it is occasionally associated with severe adverse events. Thus, for safer and more efficacious therapy, a clinical biomarker predicting asparaginase sensitivity is highly anticipated. Asparaginase depletes serum asparagine by deaminating asparagine into aspartic acid, and ALL cells are thought to be sensitive to asparaginase due to reduced asparagine synthetase (ASNS) activity. We have recently shown that allele-specific methylation of the ASNS gene is highly involved in asparaginase sensitivity in B-precursor ALL (BCP-ALL) by using next-generation sequence (NGS) analysis of bisulphite PCR products of the genomic DNA. Here, we sought to confirm the utility of methylation status of the ASNS gene evaluated with high-performance liquid chromatography (HPLC) analysis of bisulphite PCR products for future clinical applications. In the global methylation status of 23 CpG sites at the boundary region of promoter and exon 1 of the ASNS gene, a strong positive correlation was confirmed between the mean percent methylation evaluated with the HPLC method and that with the NGS method in 79 BCP-ALL cell lines (R2 = 0.85, p = 1.3 × 10-33) and in 63 BCP-ALL clinical samples (R2 = 0.84, p = 5.0 × 10-26). Moreover, methylation status of the ASNS gene evaluated with the HPLC method was significantly associated with in vitro asparaginase sensitivities as well as gene and protein expression levels of ASNS. These observations indicated that the ASNS gene methylation status evaluated with the HPLC method is a reliable biomarker for predicting the asparaginase sensitivity of BCP-ALL.

NMR-based metabolomic analysis for the effects of moxibustion on imiquimod-induced psoriatic mice

ETHNOPHARMACOLOGICAL RELEVANCE

Moxibustion is a traditional medical intervention of traditional Chinese medicine. It refers to the direct or indirect application of ignited moxa wool made of mugwort leaves to acupuncture points or other specific parts of the body for either treating or preventing diseases. Moxibustion has been proven to be effective in treating skin lesions of psoriasis.

AIM OF THE STUDY

This study was performed to elucidate molecular mechanisms underlying the effects of moxibustion treatment on imiquimod-induced psoriatic mice.

MATERIALS AND METHODS

We established an imiquimod (IMQ)-induced psoriatic mice (Model) and assessed the effects of moxibustion (Moxi) treatment on skin lesions of psoriatic mice by the PASI scores and expressions of inflammation-related factors relative to normal control mice (NC). We then performed nuclear magnetic resonance (NMR)-based metabolomic analysis on the skin tissues of the NC, Model and Moxi-treated mice to address metabolic differences among the three groups.

RESULTS

Moxi mice showed reduced PASI scores and decreased expressions of the pro-inflammatory cytokines IL-8, IL-17A and IL-23 relative to Model mice. Compared with the Model group, the NC and Moxi groups shared 9 characteristic metabolites and 4 significantly altered metabolic pathways except for taurine and hypotaurine metabolism uniquely identified in the NC group. To a certain extent, moxibustion treatment improved metabolic disorders of skin lesions of psoriatic mice by decreasing glucose, valine, asparagine, aspartate and alanine-mediated cell proliferation and synthesis of scaffold proteins, alleviating histidine-mediated hyperproliferation of blood vessels, and promoting triacylglycerol decomposition.

CONCLUSIONS

This study reveals the molecular mechanisms underlying the effects of moxibustion treatment on the skin lesions of psoriasis, potentially improving the clinical efficacy of moxibustion.

Targeting amino acid metabolism in cancer

Metabolic rewiring is a characteristic hallmark of cancer cells. This phenomenon sustains uncontrolled proliferation and resistance to apoptosis by increasing nutrients and energy supply. However, reprogramming comes together with vulnerabilities that can be used against tumor and can be applied in targeted therapy. In the last years, the genetic background of tumors has been identified thoroughly and new therapies targeting those mutations tested. Nevertheless, we propose that targeting the phenotype of cancer cells could be another way of treatment aiming to avoid drug resistance and non-responsiveness of cancer patients. Amino acid metabolism is part of the altered processes in cancer cells. Amino acids are building blocks and also sensors of signaling pathways regulating main biological processes. In this comprehensive review, we described four amino acids (asparagine, arginine, methionine, and cysteine) which have been actively investigated as potential targets for anti-tumor therapy. Asparagine depletion is successfully used for decades in the treatment of acute lymphoblastic leukemia and there is a strong implication to apply it to other types of tumors. Arginine auxotrophic tumors are great candidates for arginine-starvation therapy. Higher requirement for essential amino acids such as methionine and cysteine point out promising targetable weaknesses of cancer cells.

Efficacy of natural L-asparagine in the complex therapy for malignant tumors in experimental studies

AIM

To study the influence of natural L-asparagine on the efficacy of cytostatic therapy for malignant tumors in experimental investigations.

MATERIALS AND METHODS

Female C57B1/6 mice weighing 18-20 g were selected for the experiments. Lewis' lung carcinoma (LLC) and melanoma B16 cells were used in the study. Animals were inoculated with tumor cells intramuscularly. Solution of L-asparagine in a volume of 0.2 ml per mouse (in appropriate doses) was administered to the animals using gastric probe, daily, for 14 days. Cyclophosphane was administered intraperitoneally in total doses of 180 mg/kg and 90 mg/kg on days 3 and 7 after tumor implantation. The percentage of tumor growth inhibition was calculated and inhibition index and frequency of metastasis were assessed.

RESULTS

It has been shown that despite low activity of L-asparagine with regard to primary tumor, the level of metastasis inhibition is rather high (up to 91% depending on experimental model, therapy regimen and follow-up period). The analysis of previously obtained data and our studies indicate that L-asparagine derived from burdock (Arctium lappa) root has not only its own antimetastatic activity but it is also able to increase antimetastatic activity of cyclophosphane partially reducing toxic effect of cyclophosphane on the organism without decreasing its antitumor and antimetastatic activities.

CONCLUSION

L-asparagine derived from burdock (Arctium lappa) root can be effective in the complex anticancer therapy with the use of appropriate chemotherapy doses and regimens.

Epidural spinal lipomatosis with acute onset of paraplegia in an HIV-positive patient treated with corticosteroids and protease inhibitor: case report

STUDY DESIGN

Case report.

OBJECTIVE

To report a case of HIV-related lipodystrophy with a rapid onset of symptoms from epidural lipomatosis in the wake of protease inhibitor and steroid treatment.

SUMMARY OF BACKGROUND DATA

Symptomatic spinal epidural lipomatosis is considered to be a rare condition usually presenting with slowly progressive cord or nerve root compression. Only 2 cases of spinal lipomatosis in HIV-related lipodystrophy have been reported.

METHODS

We describe the case of a 41-year-old male with HIV who received protease inhibitor medication and had neurologic deficits rapidly develop.

RESULTS

The patient had complete paraplegia develop within 12 hours from admission following a 1-day history of unsteady gait and a 3-day history of leg numbness. After diagnosis of epidural lipomatosis on magnetic resonance imaging, the patient underwent decompressive thoraco-laminectomy. He recovered well and was able to walk by postoperative day 4.

CONCLUSION

It is important to maintain an awareness for the possible association between HIV lipodystrophy and symptomatic epidural lipomatosis.

Childhood blastic NK cell leukemia successfully treated with L-asparagenase and allogeneic bone marrow transplantation

Blastic NK cell lymphoma/leukemia is a rare and highly malignant neoplasia in both adults and children. It is characterized by lymphoblastoid morphology without cytoplasmic granules and immature NK cell immunophenotypes (CD56+, CD57-, CD16-). It has predilection for extranodal organ involvement, and the prognosis of affected patients is extremely poor under the current chemotherapy. We present a 14-year-old girl who was diagnosed as having blastic NK cell leukemia with mediastinal, pleural, and pericardial involvement. Immunophenotyping of her leukemic cells showed positive for CD2, CD5, CD7, CD34, CD56, HLA-DR, and cytoplasmic CD3. T cell receptor (TCR) and Immunoglobulin heavy chain genes were not rearranged. She received chemotherapy for acute lymphoblastic leukemia incorporating L-asparaginase (L-asp) which successfully induced complete remission. Bone marrow transplantation (BMT) from her HLA-identical sibling was conducted after two courses of consolidation therapy. Expression of aspargine synthetase (AS) protein in the leukemic cells at diagnosis was examined by an immunocytochemical method. She remains in hematological remission for over 36 months after BMT. The expression of AS protein was negative, suggesting that the leukemic cells were sensitive to L-asp. Induction and consolidation therapy incorporating L-asp followed by allo-BMT might be a promising treatment for child hood blastic NK cell leukemia, but more samples of the rare leukemia need to be studied before any definitive conclusions can be drawn.

[Iatrogenic hyperlipidemia after l-asparaginase and glucocorticoid treatment in two children with acute lymphoblastic leukemia]

L-asparaginase and glucocorticosteroides are the main drugs used in the first-line treatment in children with acute lymphoblastic leukaemia. One of the observed side effects in the increase of serum level of triglycerides is synergistic manner. The paper describes two children with acute lymphoblastic leukaemia. In these patients we could observe remarkable hypertriglyceridemia, and hypercholesterolaemia with the increase of LDL-cholesterol after applying high doses of L-asparaginase and glucocorticosteroids simultaneously. The above-mentioned disorders were transient. In the analysis of the possible reasons of this pathology we took into consideration family predispositions, the transient deficit of lipoprotein lipase induced by L-asparaginase, improper diet and hyperthyroidismus.

Minimising the long-term adverse effects of childhood leukaemia therapy

Malignancies in childhood occur with an incidence of 13-14 per 100,000 children under the age of 15 years. Acute lymphoblastic leukaemia with an incidence of 29% is the most common paediatric malignancy, whereas acute myeloid leukaemias account for about 5%. The treatment of acute leukaemias consists of sequential therapy cycles (induction, consolidation, intensification, maintenance therapy) with different cytostatic drugs over a time period of up to 1.5-3 years. Over the last 25 years of clinical trials, a significant rise in the rate of complete remissions as well as an increase in long-term survival has been achieved. Therefore, growing attention is now focused on the long-term effects of antileukaemic treatment. Several cytostatic drugs administered in the treatment of acute leukaemia in childhood are known to cause long-term adverse effects. Anthracyclines may induce chronic cardiotoxicity, alkylating agents are likely to cause gonadal damage and secondary malignancies and the use of glucocorticoids may cause osteonecrosis. Most of the long-term adverse effects have not been analysed systematically. Approaches to minimising long-term adverse effects without jeopardising outcome have included: the design of new drugs such as a liposomal formulation of anthracyclines, the development of anthracycline-derivates with lower toxicity, the development of cardioprotective agents or, more recently, the use of targeted therapy;alternative administration schedules like continuous infusion or timed sequential therapy; and risk group stratification by the monitoring of minimal residual disease. Several attempts have been made to minimise the cardiotoxicity of anthracyclines: decreasing concentrations delivered to the myocardium by either prolonging infusion time or using liposomal formulated anthracyclines or less cardiotoxic analogues, or the additional administration of cardioprotective agents. The advantage of these approaches is still controversial, but there are ongoing clinical trials to evaluate the long-term effects. The use of new diagnostic methods, such as diagnosis of minimal residual disease, which allow reduction or optimisation of dose, offer potential advantages compared with conventional treatment in terms of reducing the risk of severe long-term adverse effects. Most options for minimising long-term adverse effects have resulted from theoretical models and in vitro studies, but only some of the modalities such as the use of dexrazoxane, the continuous infusion of anthracyclines or timed sequential therapy, have been evaluated in prospective, randomised studies in patients. Future approaches to predict severe toxicity may be based upon pharmacogenetics and gene profiling.

Design of a temporally and spatially controlled drug delivery system for the treatment of liver diseases in mice

Strict regulation of the distribution and degradation kinetics is the ultimate aim of drug delivery system. Regulation of drug delivery would increase the therapeutic efficacy and decrease the potential side effects. We encapsulated and used Z-Asp, a caspase inhibitor in poly-N-p-vinylbenzyl-D-lactonamide (PVLA) coated-poly (L-lactic acid) (PLA)-nanospheres in a mouse model of acute hepatitis. These nanospheres were internalized and accumulated in hepatocytes both in vitro and in vivo. Encapsulation significantly extended the intracellular retention time of the content in hepatocytes, which increased the bioavailability of the caspase inhibitor. In addition, the therapeutic effect was temporally controllable in vivo by modifying the component of the nanospheres. A cocktail of nanospheres with diverse degradation kinetics showed persistent therapeutic effects in acute hepatitis, and only nanospheres that targeted hepatocytes and controlled degradation rescued mice from lethal hepatic injury. This temporally and spatially controlled drug delivery system could be used in various liver diseases.

[The usefulness of Aspargin for supplementing potassium and magnesium in ethanol dependent patients]

Intoxication with many xenobiotics cause serious electrolyte abnormalities which require intravenous supplementation. In chronic and acute but not very severe intoxication an oral supplementation of ions can be sufficient. The aim of the study was to evaluate the usefulness of Aspargin for supplementation of potassium and magnesium in chronic alcoholics suffering from withdrawal syndrome. There were 46 study patients, dependent on ethanol treated at the Detoxification Unit of the Department of Clinical Toxicology in Krak w. A differently intensified symptoms of ethanol withdrawal syndrome were noted according to CIWA-A scale in all the patients. Concentration of potassium and magnesium was monitored through the hospitalisation. Except a basic treatment (fluid supplementation, benzodiazepines) also Aspargin (three times a 2 tablets per day) was administered to each of patient for 7 to 10 days. No respiratory, muscular and gastrointestinal symptoms due to hypopotassemia and hypomagnesemia have been noted while hospitalisation in any patient so it could be suspected, that oral supplementation with Aspargin was sufficient to keep these ions balanced. Administration of Aspargin was beneficial to patient and the treatment outcome.

Failure of mineral-vitamin supplements to prevent tansy ragwort (Senecio jacobaea) toxicosis in cattle

The efficacy of 2 mineral-vitamin supplements in preventing or alleviating initial pyrrolizidine alkaloid (PA) toxicosis in cattle was tested. Three groups of calves were fed 1 of the 2 supplements plus tansy ragwort (Senecio jacobaea) containing PA and 2 groups of calves were fed tansy ragwort without the supplement. Toxicity comparisons were based on differences in observed clinical signs, serum enzyme changes, survival time of calves, and histopathologic examination of hepatic tissue. Typical tansy ragwort toxicosis terminating in death developed in all calves. There were no marked differences in responses of the groups of calves. Seemingly, the supplements did not afford protection or alleviate tansy ragwort-related PA toxicosis in calves.

Effect of asparagine, glutamine and insulin on cerebral amino acid neurotransmitters

Treatment of rats with asparagine or glutamine caused substantial increases in glutamine concentrations in cerebellum and medulla oblongata. Insulin treatment caused a diminution of glutamate and GABA in these regions of brain. Since it is now well-established that glutamine is a very efficient precursor of the neurotransmitter pool of glutamate in mammalian brain, treatment with asparagine or glutamine could be of therapeutic (replacement) value in the treatment of neurological disorders such as Friedreich's ataxia, in which cerebral glutamate concentrations have been found to be diminished.

Potential inhibitors of L-asparagine biosynthesis. 4. Substituted sulfonamide and sulfonylhydrazide analogues of L-asparagine

Several N-substituted sulfonamides and N'-substituted sulfonylhydrazides have been prepared as sulfur analogues of L-asparagine with the potential of acting as inhibitors of L-asparagine synthetase (ASase, from Novikoff hepatoma). L-Cysteine was converted in known steps to N-carboxy-3-(sulfonylchloro)-L-alanine dibenzyl ester (1). Condensation of 1 with O-benzylhydroxylamine, p-(fluorosulfonyl)benzylamine, or monoethyl fumarylhydrazide (9), followed by deblocking with HF, gave 3-(hydroxysulfamoyl)-L-alanine (3a), 3-[p-(fluorosulfonylbenzyl)]sulfamoyl-L-alanine (3c), and 3-sulfo-L-alanine S-[2-[(E)-3-(ethoxycarbonyl)acryloyl]hydrazide] (3e), respectively. Similarly, 1 with 2-chloroethylamine and deblocking with H2-Pd gave 3-[(2-chloroethyl)sulfamoyl]-L-alanine (3b). tert-Butyl carbazate was allowed to react with 1 and the tert-butyl group was removed with HCl. The resulting sulfonylhydrazide 7 was condensed with p-(fluorosulfonyl)benzoyl chloride and then deblocked with HF to give 3-sulfo-L-alanine S-[2-[P-(fluorosulfonyl)benzoyl]hydrazide] (3d). The inhibition of ASase by 3a-e at 2 mM was 97, 0, 30, 43, and 37%, respectively, and 3a was competitive with L-aspartic acid. Neither 3a nor 3e was effective in increasing the life span of mice bearing P-388 lymphocytic leukemia.

Effect of asparagine and arginine on the repair of isoprenaline-damaged myocardium of rat

The effect of asparagine and arginine on the repair of isoprenaline-damaged myocardium was studied. In group I (treated with isoprenaline) the rats developed large foci of myocardial damage filled by connective tissue after 14 days. Similar changes were observed in group II (isoprenaline + asparagine). In group III of rats treated with isoprenaline and arginine the number of foci of injury and their size were smaller, and only a few small foci fibrosis were found after 14 days. Arginine seems to protect the rat myocardium from isoprenaline-induced damage. The repair by connective tissue is supplemented by compensatory hypertrophy of muscle fibers.