Association of allele-specific methylation of the ASNS gene with asparaginase sensitivity and prognosis in T-ALL

Abstract

Asparaginase therapy is a key component of chemotherapy for T-cell acute lymphoblastic leukemia (T-ALL) patients. Asparaginase depletes serum asparagine by deamination into aspartic acid. Normal hematopoietic cells can survive due to asparagine synthetase (ASNS) activity, while leukemia cells are supposed to undergo apoptosis due to silencing of the ASNS gene. Since the ASNS gene has a typical CpG island in its promoter, its methylation status in T-ALL cells may be associated with asparaginase sensitivity. Thus, we investigated the significance of ASNS methylation status in asparaginase sensitivity of T-ALL cell lines and prognosis of childhood T-ALL. Sequencing of bisulfite PCR products using next-generation sequencing technology in 22 T-ALL cell lines revealed a stepwise allele-specific methylation of the ASNS gene, in association with an aberrant methylation of a 7q21 imprinted gene cluster. T-ALL cell lines with ASNS hypermethylation status showed significantly higher in vitro l-asparaginase sensitivity in association with insufficient asparaginase-induced upregulation of ASNS gene expression and lower basal ASNS protein expression. A comprehensive analysis of diagnostic samples from childhood T-ALL patients in Japanese cohorts (n = 77) revealed that methylation of the ASNS gene was associated with an aberrant methylation of the 7q21 imprinted gene cluster. In childhood T-ALL patients in Japanese cohorts (n = 75), ASNS hypomethylation status was significantly associated with poor therapeutic outcome, and all cases with poor prognostic SPI1 fusion exclusively showed ASNS hypomethylation status. These observations demonstrate that ASNS hypomethylation status is associated with asparaginase resistance and is a poor prognostic biomarker in childhood T-ALL.

Ferroptosis-related biomarkers for Alzheimer’s disease: Identification by bioinformatic analysis in hippocampus

“…In the present study, ASNS and SESN2 were significantly related to AD compared with other ferroptosis-related genes. At present, most studies have focused on the role of ASNS in cancer-related studies, including studies on ovarian cancer, oral squamous cell carcinoma, colorectal cancer cell, T-cell acute lymphoblastic leukemia, and skull base chordoma ( Lorenzi et al, 2006 ; Du et al, 2019 ; Fu et al, 2021 ; Shen et al, 2021 ; Akahane et al, 2022 ). ASNS may be a predictive biomarker in those tumors or cancers; however, assays also indicate an association between ASNS and neurodegeneration diseases.…”

Possible mechanism of metabolic and drug resistance with L-asparaginase therapy in childhood leukaemia

“…The study by Akahane et focused on the significance of SPI1 fusion in the methylation status of ASNS. In their cohort study, all seven SPI1 fusion cases had an ASNS promoter hypomethylation status, and the ASNS gene expression levels were significantly higher than those of SPI1 fusion-negative cases (47). This suggests that genetic modifications may play an important role in the methylation status of the ASNS promoter region.…”

“…further confirmed that the hypomethylation status of the ASNS promoter region is associated with L-ASNase resistance. Their analysis of 75 Japanese children with T-ALL revealed an intermediate (33.3% < methylation <66.7%) or low (<33.3%) methylation status of the ASNS promoter region in 92% of refractory/relapsed cases ( 47 ). In addition, Touzart et al.…”

Treatment of extranodal NK/T-cell lymphoma: From past to future

“…The low expression of AsnS in ALL cells is due to hypermethylation of the AsnS gene. The CpG island methylation status of the AsnS gene promoter is associated with Asp sensitivity and its hypomethylation status correlates with Asp resistance and is an adverse prognosticator of patient survival ( 118 ). ENKTCL cells are even more sensitive to L-Asp than ALL cells ( 25 ).…”