Exome sequencing identifies highly recurrent somatic GATA2 and CEBPA mutations in acute erythroid leukemia

Abstract

Acute erythroid leukemia (AEL), characterized by a predominant erythroid proliferation, is a subtype of acute myelogenous leukemia. The genetic basis of AEL remains poorly defined. Through whole-exome sequencing, we identified high frequencies of mutations in CEBPA (32.7%), GATA2 (22.4%), NPM1 (15.5%), SETBP1 (12.1%) and U2AF1 (12.1%). Structure prediction analysis revealed that most of the GATA2 mutations were located at the DNA-binding N-terminal zinc-finger near the DNA-binding interface, suggesting that mutations could result in at least partial inactivation of GATA2 protein. On co-transfection of a GATA-responsive reporter construct together with plasmids expressing either GATA2 wild-type or GATA2 ZF1 mutants (P304H, L321P and R330X) in 293T cells, we found a reduced transcriptional activation in cells transfected with GATA2 mutants. To determine whether reduced GATA2 function is involved in leukemogenesis of AEL, we transfected 32D cells with GATA2 mutants and evaluated the impact of GATA2 mutations on erythroid differentiation. Our data revealed an increased expression of erythroid-related antigens Ter-119, β-globin and βh1-globin, as well as increased hemoglobin positivity in 32D cells transfected with GATA2 mutants compared with control cells. Our results suggest that the decline of GATA2 resulting from mutations contributes to the erythroid commitment, differentiation and the development of AEL.

Integrating Enhancer Mechanisms to Establish a Hierarchical Blood Development Program

“…Mutations in the DNA binding C-terminal zinc finger inhibit binding (Hahn et al, 2011), while +9.5 enhancer mutations reduce GATA2 expression (Hsu et al, 2013; Johnson et al, 2012). Mutations also occur in the N-terminal zinc finger that is not required for DNA binding (Ping et al, 2017). GATA-2 promotes AML cell proliferation (Katsumura et al, 2016) and mediates leukemogenic activity in a mouse model involving Tet2 deficiency and mutant Flt3(ITD) expression (Shih et al, 2015).…”

GATA2 mutations in myeloid malignancies: Two zinc fingers in many pies

“…They detected GATA2 mutations in 5.5% of non-AEL AML and in 15% of CML in blast crisis and reported that the frequency of GATA2 mutations in AEL (22.4%) is significantly higher than in non-AEL AML. 24 Iacobucci et al confirmed that these data with a cohort of 159 child and adult AEL cases presenting a mutational prevalence of 14.4%. 26 Tien et al analyzed GATA2 mutations in non-M3 AML patients and identified 44 GATA2 mutations in 43 (6.2%) of their 693 patients, two-thirds of those mutations located in the ZF1 domain.…”

“…The authors did not observe such a dominant‐negative effect in ZF1 mutants P304H and L321P. Additionally, in their study, the overexpression of GATA2 mutants in the mouse myeloid progenitor cell line 32D had no effect on proliferation or colony‐forming ability …”

“…Most of the observed mutations were missense and among them, 9 out of 12 were located in ZF1. They detected GATA2 mutations in 5.5% of non‐AEL AML and in 15% of CML in blast crisis and reported that the frequency of GATA2 mutations in AEL (22.4%) is significantly higher than in non‐AEL AML . Iacobucci et al confirmed that these data with a cohort of 159 child and adult AEL cases presenting a mutational prevalence of 14.4% …”

“…Somatic GATA2 mutations show overall reduced transactivation potential with a few exceptions and skew the differentiation of hematologic progenitors towards the granulocytic linage . So far, somatic mutations in GATA2 ZF1 have been shown to co‐occur with mutations in CEBPA and SF3B1 , FAB M1 subtype, AEL and t(3;3) AML and to be mutually exclusive with mutations in NPM1 , RUNX1 , and FLT3 ‐ITD and FAB M4 AML . The L359V mutant was earlier described to be exclusively associated with CML, whereas more recent studies show an association with BCR‐ABL‐negative AML .…”