A Novel t(8;14)(q24;q11) Rearranged Human Cell Line as a Model for Mechanistic and Drug Discovery Studies of NOTCH1-Independent Human T-Cell Leukemia

Abstract

MYC-translocated T-lineage acute lymphoblastic leukemia (T-ALL) is a rare subgroup of T-ALL associated with CDKN2A/B deletions, PTEN inactivation, and absence of NOTCH1 or FBXW7 mutations. This subtype of T-ALL has been associated with induction failure and aggressive disease. Identification of drug targets and mechanistic insights for this disease are still limited. Here, we established a human NOTCH1-independent MYC-translocated T-ALL cell line that maintains the genetic and phenotypic characteristics of the parental leukemic clone at diagnosis. The University of Padua T-cell acute lymphoblastic leukemia 13 (UP-ALL13) cell line has all the main features of the above described MYC-translocated T-ALL. Interestingly, UP-ALL13 was found to harbor a heterozygous R882H DNMT3A mutation typically found in myeloid leukemia. Chromatin immunoprecipitation coupled with high-throughput sequencing for histone H3 lysine 27 (H3K27) acetylation revealed numerous putative super-enhancers near key transcription factors, including MYC, MYB, and LEF1. Marked cytotoxicity was found following bromodomain-containing protein 4 (BRD4) inhibition with AZD5153, suggesting a strict dependency of this particular subtype of T-ALL on the activity of super-enhancers. Altogether, this cell line may be a useful model system for dissecting the signaling pathways implicated in NOTCH1-independent T-ALL and for the screening of targeted anti-leukemia agents specific for this T-ALL subgroup.

The Physiopathology of T- Cell Acute Lymphoblastic Leukemia: Focus on Molecular Aspects

“…In a subgroup of about 6% of T-ALL, MYC translocations are secondary abnormalities, present in subclones, and are associated with induction failure, high rate of relapse, and with an aggressive clinical course (52). The genetic profile of these MYC-translocated T-ALL is characterized by concomitant abnormalities, including CDKN2A/B deletions, PTEN inactivation, and mutations typical of myeloid neoplasms, such as DNMT3A (54). Regarding MYB, it is activated in T-ALL harboring the t (6;7) translocation, which is common among children younger than 2 years of age, or as a result of duplications or amplification of 6q23 (45,55).…”

Crosstalk between Hedgehog pathway and the glucocorticoid receptor pathway as a basis for combination therapy in T-cell acute lymphoblastic leukemia

“…T-ALL cell lines (CUTLL1, DND41, HSB2, MOLT4, CCRF-CEM, JURKAT E6, RPMI 8402, ALL-SIL, KOPTK1, HPB-ALL) were cultured in complete RPMI-1640 medium (Euroclone, Pero, Italy) supplemented with 10% fetal bovine serum (FBS; Gibco, Thermo Fisher Scientific, Waltham, MA, USA) at 37 °C under 5% CO 2 . UP-ALL13 cells [49] were cultured in complete RPMI-1640 medium supplemented with 20% FBS. HEK-293T were cultured in complete DMEM medium (Euroclone), supplemented with 10% FBS.…”

Modern treatment approaches to adult acute T-lymphoblastic and myeloid/T-lymphoblastic leukemia: from current standards to precision medicine

“…The last is mainly related to deletions/mutations of its MYC translocations, leading to overexpression, occur in 5% of pediatric and adult cases and involve both TR@ and non-TR@ partners in a NOTCH1independent subset of T-ALL, which often has PTEN abnormalities [24,30]. High WBC count, poor response to glucocorticoid pretreatment, and poor response to standard chemotherapy suggest that MYC translocations are a negative prognostic marker, though they appear to confer sensitivity towards BET bromodomain inhibitors [30,31].…”