An Inv(16)(p13.3q24.3)-encoded CBFA2T3-GLIS2 fusion protein defines an aggressive subtype of pediatric acute megakaryoblastic leukemia.

To define the mutation spectrum in non-Down syndrome acute megakaryoblastic leukemia (non-DS-AMKL), we performed transcriptome sequencing on diagnostic blasts from 14 pediatric patients and validated our findings in a recurrency/validation cohort consisting of 34 pediatric and 28 adult AMKL samples. Our analysis identified a cryptic chromosome 16 inversion (inv(16)(p13.3q24.3)) in 27% of pediatric cases, which encodes a CBFA2T3-GLIS2 fusion protein. Expression of CBFA2T3-GLIS2 in Drosophila and murine hematopoietic cells induced bone morphogenic protein (BMP) signaling and resulted in a marked increase in the self-renewal capacity of hematopoietic progenitors. These data suggest that expression of CBFA2T3-GLIS2 directly contributes to leukemogenesis.

Gruber TA ，Larson Gedman A ，Zhang J ，Koss CS ，Marada S ，Ta HQ ，Chen SC ，Su X ，Ogden SK ，Dang J ，Wu G ，Gupta V ，Andersson AK ，Pounds S ，Shi L ，Easton J ，Barbato MI ，Mulder HL ，Manne J ，Wang J ，Rusch M ，Ranade S ，Ganti R ，Parker M ，Ma J ，Radtke I ，Ding L ，Cazzaniga G ，Biondi A ，Kornblau SM ，Ravandi F ，Kantarjian H ，Nimer SD ，Döhner K ，Döhner H ，Ley TJ ，Ballerini P ，Shurtleff S ，Tomizawa D ，Adachi S ，Hayashi Y ，Tawa A ，Shih LY ，Liang DC ，Rubnitz JE ，Pui CH ，Mardis ER ，Wilson RK ，Downing JR ... -  《-》

Hh/Gli antagonist in acute myeloid leukemia with CBFA2T3-GLIS2 fusion gene.

Masetti R ，Bertuccio SN ，Astolfi A ，Chiarini F ，Lonetti A ，Indio V ，De Luca M ，Bandini J ，Serravalle S ，Franzoni M ，Pigazzi M ，Martelli AM ，Basso G ，Locatelli F ，Pession A ... -  《Journal of Hematology & Oncology》

Acute megakaryoblastic leukemia with trisomy 3 and CBFA2T3::GLIS2: A case report.

Non-Down-syndrome-related acute megakaryoblastic leukemia (non-DS-AMKL) is a rare form of leukemia that can present with a variety of initial symptoms, including fever, rash, bruising, bleeding, or other more clinically challenging symptoms. Herein, we describe a 19-month-old female patient who presented with left lower extremity pain and language regression who was diagnosed with AMKL, not otherwise specified (NOS), on the basis of peripheral blood and bone marrow analysis, as well as cytogenetic and molecular diagnostic phenotyping. Of note, in addition to this patient's karyotype showing trisomy 3, a fusion between CBFA2T3 (core-binding factor, alpha subunit 2, translocated to, 3) on chromosome 16 and GLIS2 (GLIS family zinc finger protein 2), also on chromosome 16, was observed. Patients with AMKL who have trisomy 3 with CBFA2T3::GLIS2 fusions are rare, and it is not known if the co-occurrence of these abnormalities is coincidental or biologically related. This highlights the continued need for further expansion of genetic testing in individuals with rare disease to establish the groundwork for identifying additional commonalities that could potentially be used to identify therapeutic targets or improve prognostication.

Gillam J ，Catic A ，Paulraj P ，Dalton J ，Lai G ，Jackson-Cook C ，Turner S ，Ferreira-Gonzalez A ，Barrie E ... -  《-》

CBFA2T3-GLIS2-positive acute myeloid leukaemia. A peculiar paediatric entity.

The scenario of paediatric acute myeloid leukaemia (AML), particularly non-Down syndrome acute megakaryoblastic leukaemia (non-DS-AMKL), has been recently revolutionized by the advent of large-scale, genomic sequencing technologies. In this changing landscape, a significantly relevant discovery has been represented by the identification of the CBFA2T3-GLIS2 fusion gene, which is the result of a cryptic inversion of chromosome 16. It is the most frequent chimeric oncogene identified to date in non-DS-AMKL, although it seems not to be exclusively restricted to the French-American-British M7 subgroup. The CBFA2T3-GLIS2 fusion gene characterizes a subtype of leukaemia that is specific to paediatrics, having never been identified in adults. It characterizes an extremely aggressive leukaemia, as the presence of this fusion is associated with a grim outcome in almost all of the case series reported, with overall survival rates ranging between 15% and 30%. Although the molecular basis that underlies this leukaemia subtype is still far from being completely elucidated, unique functional properties induced by CBFA2T3-GLIS2 in the leukaemogenesis driving process have been recently identified. We here review the peculiarities of CBFA2T3-GLIS2-positive AML, describing its intriguing clinical and biological behaviour and providing some challenging targeting opportunities.

Masetti R ，Bertuccio SN ，Pession A ，Locatelli F ... -  《-》

Prognostic impact of specific molecular profiles in pediatric acute megakaryoblastic leukemia in non-Down syndrome.

Pediatric acute megakaryoblastic leukemia in non-Down syndrome (AMKL) is a unique subtype of acute myeloid leukemia (AML). Novel CBFA2T3-GLIS2 and NUP98-KDM5A fusions recurrently found in AMKL were recently reported as poor prognostic factors. However, their detailed clinical and molecular characteristics in patients treated with recent improved therapies remain uncertain. We analyzed molecular features of 44 AMKL patients treated on two recent Japanese AML protocols, the AML99 and AML-05 trials. We identified CBFA2T3-GLIS2, NUP98-KDM5A, RBM15-MKL1, and KMT2A rearrangements in 12 (27%), 4 (9%), 2 (5%), and 3 (7%) patients, respectively. Among 459 other AML patients, NUP98-KDM5A was identified in 3 patients, whereas CBFA2T3-GLIS2 and RBM15-MKL1 were only present in AMKL. GATA1 mutations were found in 5 patients (11%). Four-year overall survival (OS) and event-free survival (EFS) rates of CBFA2T3-GLIS2-positive patients in AMKL were 41.7% and 16.7%, respectively. Three-year cumulative incidence of relapse in CBFA2T3-GLIS2-positive patients was significantly higher than that of CBFA2T3-GLIS2-negative patients (75.0% vs. 35.7%, P = 0.024). In multivariate analyses, CBFA2T3-GLIS2 was an independent poor prognostic factor for OS (HR, 4.34; 95% CI, 1.31-14.38) and EFS (HR, 2.95; 95% CI, 1.20-7.23). Furthermore, seven (54%) of 13 infant AMKL patients were CBFA2T3-GLIS2-positive. Notably, out of 7 CBFA2T3-GLIS2-positive infants, six (86%) relapsed and five (71%) died. Moreover, all of CBFA2T3-GLIS2-positive patients who experienced induction failure (n = 3) were infants, indicating worse prognosis of CBFA2T3-GLIS2-positive infants. These findings indicated the significance of CBFA2T3-GLIS2 as a poor prognostic factor in AMKL patients, particularly in infants.

Hara Y ，Shiba N ，Ohki K ，Tabuchi K ，Yamato G ，Park MJ ，Tomizawa D ，Kinoshita A ，Shimada A ，Arakawa H ，Saito AM ，Kiyokawa N ，Tawa A ，Horibe K ，Taga T ，Adachi S ，Taki T ，Hayashi Y ... -  《-》