L-Asparaginase Toxicity in the Treatment of Children and Adolescents with Acute Lymphoblastic Leukemia

Effect of apolipoprotein E (APOE) gene polymorphisms on the lipid profile of children being treated for acute lymphoblastic leukemia

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.

Hyperlipidemia in children and adolescents with acute lymphoblastic leukemia: A systematic review and meta-analysis

BACKGROUND

The established association between acute lymphoblastic leukemia (ALL) and hyperlipidemia has, in some studies, been linked to toxicities such as pancreatitis, thrombosis, and osteonecrosis. However, a systematic review investigating the incidence, management, and clinical implications of hyperlipidemia during childhood ALL treatment is lacking.

OBJECTIVES

Systematically assess the incidence of hyperlipidemia during ALL treatment, explore associations with risk factors and severe toxicities (osteonecrosis, thrombosis, and pancreatitis), and review prevalent management strategies.

METHODS

A systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Data synthesis was descriptive, and a meta-analysis of hypertriglyceridemia and risk of severe toxicities was performed.

RESULTS

We included 13 studies with 3,425 patients. Hyperlipidemia incidence varied widely (6.7%-85%) but with inconsistent definitions and screening strategies across studies. Evidence regarding risk factors was conflicting, but age (> 10 years) and treatment with asparaginase and glucocorticosteroids seem to be associated with hyperlipidemia. Hypertriglyceridemia (grade 3/4) increased the risk for osteonecrosis (odds ratio (OR): 4.27, 95% confidence interval (CI): 2.77-6.61). No association could be established for pancreatitis (OR: 1.60, 95% CI: 0.53-4.82) or thrombosis (OR: 2.45, 95% CI: 0.86-7.01), but larger studies are needed to confirm this.

CONCLUSION

The overall evidence of this systematic review is limited by the small number of studies and risk of bias. Our review suggests that hypertriglyceridemia increases the risk for osteonecrosis. However, larger studies are needed to explore the clinical implications of hyperlipidemia and randomized trials investigating hyperlipidemia management and its impact on severe toxicities.

Long-term effects of asparaginase-associated pancreatitis

Pancreatitis is a common and severe toxicity that occurs during asparaginase treatment for acute lymphoblastic leukemia, and has received increasing attention during the last decades. However, no consensus regarding follow-up exists. In this commentary, we highlight potential long-term health-related effects following asparaginase-associated pancreatitis, thereby providing clinicians with a framework when following these patients during and after cessation of therapy.

Amino acids in hematologic malignancies: Current status and future perspective

In recent years, growing emphasis has been placed on amino acids and their role in hematologic malignancies. Cancer cell metabolism is altered during tumorigenesis and development to meet expanding energetic and biosynthetic demands. Amino acids not only act as energy-supplying substances, but also play a vital role via regulating key signaling pathways, modulating epigenetic factors and remodeling tumor microenvironment. Targeting amino acids may be an effective therapeutic approach to address the current therapeutic challenges. Here, we provide an updated overview of mechanisms by which amino acids facilitate tumor development and therapy resistance. We also summarize novel therapies targeting amino acids, focusing on recent advances in basic research and their potential clinical implications.

In vivo stabilization of a less toxic asparaginase variant leads to a durable antitumor response in acute leukemia

Asparagine is a non-essential amino acid since it can either be taken up via the diet or synthesized by asparagine synthetase. Acute lymphoblastic leukemia (ALL) cells do not express asparagine synthetase or express it only minimally, which makes them completely dependent on extracellular asparagine for their growth and survival. This dependency makes ALL cells vulnerable to treatment with L-asparaginase, an enzyme that hydrolyzes asparagine. To date, all clinically approved L-asparaginases have significant L-glutaminase co-activity, associated with non-immune related toxic side effects observed during therapy. Therefore, reduction of L-glutaminase co-activity with concomitant maintenance of its anticancer L-asparaginase effect may effectively improve the tolerability of this unique drug. Previously, we designed a new alternative variant of Erwinia chrysanthemi (ErA; Erwinaze) with decreased L-glutaminase co-activity, while maintaining its L-asparaginase activity, by the introduction of three key mutations around the active site (ErA-TM). However, Erwinaze and our ErA-TM variant have very short half-lives in vivo. Here, we show that the fusion of ErA-TM with an albumin binding domain (ABD)-tag significantly increases its in vivo persistence. In addition, we evaluated the in vivo therapeutic efficacy of ABD-ErA-TM in a B-ALL xenograft model of SUP-B15. Our results show a comparable long-lasting durable antileukemic effect between the standard-of-care pegylated-asparaginase and ABD-ErA-TM L-asparaginase, but with fewer co-glutaminase-related acute side effects. Since the toxic side effects of current L-asparaginases often result in treatment discontinuation in ALL patients, this novel ErA-TM variant with ultra-low L-glutaminase co-activity and long in vivo persistence may have great clinical potential.

L-asparaginase mediated therapy in L-asparagine auxotrophic cancers: A review

Microbial L-asparaginase is the most effective first-line therapeutic used in the treatment protocols of paediatric and adult leukemia. Leukemic cell's auxotrophy for L-asparagine is exploited as a therapeutic strategy to mediate cell death through metabolic blockade of L-asparagine using L-asparaginase. Escherichia coli and Erwinia chrysanthemi serve as the major enzyme deriving sources accepted in clinical practise and the enzyme has bestowed improvements in patient outcomes over the last 40 years. However, an array of side effects generated by the native enzymes due to glutamine co-catalysis and short serum stays augmenting frequent dosages, intended a therapeutic switch towards the development of biobetter alternatives for the enzyme including the formulations resulting in sustained local depletion of L-asparagine. In addition, the treatment with L-asparaginase in few cancer types has proven to elicit drug-induced cytoprotective autophagy mechanisms and therefore warrants concern. Although the off-target glutamine hydrolysis has been viewed in contributing the drug-induced secondary responses in cells deficient with asparagine synthetase machinery, the beneficial role of glutaminase-asparaginase in proliferative regulation of asparagine prototrophic cells has been looked forward. The current review provides an overview on the enzyme's clinical applications in leukemia and possible therapeutic implications in other solid tumours, recent advancements in drug formulations, and discusses the aspects of two-sided roles of glutaminase-asparaginases and drug-induced cytoprotective autophagy mechanisms.