Systematic Cellular Disease Models Reveal Synergistic Interaction of Trisomy 21 and GATA1 Mutations in Hematopoietic Abnormalities

Abstract

Chromosomal aneuploidy and specific gene mutations are recognized early hallmarks of many oncogenic processes. However, the net effect of these abnormalities has generally not been explored. We focused on transient myeloproliferative disorder (TMD) in Down syndrome, which is characteristically associated with somatic mutations in GATA1. To better understand functional interplay between trisomy 21 and GATA1 mutations in hematopoiesis, we constructed cellular disease models using human induced pluripotent stem cells (iPSCs) and genome-editing technologies. Comparative analysis of these engineered iPSCs demonstrated that trisomy 21 perturbed hematopoietic development through the enhanced production of early hematopoietic progenitors and the upregulation of mutated GATA1, resulting in the accelerated production of aberrantly differentiated cells. These effects were mediated by dosage alterations of RUNX1, ETS2, and ERG, which are located in a critical 4-Mb region of chromosome 21. Our study provides insight into the genetic synergy that contributes to multi-step leukemogenesis.

A Pair of Maternal Chromosomes Derived from Meiotic Nondisjunction in Trisomy 21 Affects Nuclear Architecture and Transcriptional Regulation

“…We previously generated a patient-derived trisomy 21 iPSC (‘Tri21-GATA1wt’ iPSC) line that contains one paternal and two maternal copies of chromosome 21 (Supplementary Fig. S1), and a partial trisomy 21 iPSC (‘Partial-Tri21-GATA1wt’ iPSCs) line (hereafter referred to as ‘Tri21’ iPSCs and ‘Partial-Tri21’ iPSCs, respectively) 17 . In this Partial-Tri21 iPSC line, a 4-Mb region on HSA21 was selectively deleted only from the paternal chromosome 21 in Tri21 iPSCs, so these genetically modified cells can be used to clarify the parental origin of chromosome 21.…”

“…Next, we differentiated the healthy control disomy 21 (Di21), trisomy 21 (Tri21) and corrected disomy 21 iPSC lines into haematopoietic lineages to evaluate their haematopoietic differentiation potential. Recently, we have reported that trisomy 21 augments foetal haematopoiesis through the acceleration of early haematopoietic commitment 17 . The proportion of CD43 + cells in the CD34 + CD38 − Lin − fraction, which represents committed haematopoietic progenitors, was significantly increased in the Tri21 iPSC line compared with that in the Di21 iPSC lines, as reported previously (Fig.…”

“…Human iPSCs (hiPSCs) were established and cultured as previously described 17 . In brief, iPSCs were generated from either cord blood cells, or dermal fibroblast, a kind gift from Dr. Toshiyuki Yamamoto (Tokyo Women’s Medical University Institute for Integrated Medical Science, Tokyo, Japan), using a Sendaivirus vector encoding tetracistronic factors ( OCT3/4, SOX2, KLF4 and c-Myc ) and maintained on mitomycin C (Sigma)-inactivated mouse embryonic fibroblasts in hES medium containing DMEM/F12 (Wako), 20% KnockOut Serum Replacement (Gibco), 2 mM L-alanyl-L-glutamine (Wako), 1% MEM nonessential amino acid solution (Wako), 0.1 mM 2-mercaptoethanol (Sigma) and 5 ng/mL basic fibroblast growth factor (Katayama Chemical).…”

Combinations of chromosome transfer and genome editing for the development of cell/animal models of human disease and humanized animal models

“…ES-sac-mediated in vitro hematopoietic differentiation analyses using the DS models revealed that Ts21 and the GATA1 mutations synergistically contributed to hematopoietic abnormalities. Although another group established isogenic cell lines via the spontaneous loss of chromosome 21 from induced pluripotent stem (iPS) cells derived from a DS patient, they reported the synergistic interaction of Ts21 and GATA1 mutations mainly from an assessment of nonisogenic cell lines with a different genotype [96]. It is crucial to establish isogenic cell lines for disease models harboring chromosome abnormalities.…”

Cytokine Profiles in Pericardial Effusion in a Down Syndrome Infant with Transient Abnormal Myelopoiesis

“…TAM is characterised by increased circulating blast cells that harbor acquired N-terminal truncating mutations in the key hematopoietic transcription factor gene GATA1 (Wechsler et al 2002;Groet et al 2003;Rainis et al 2003;Bhatnagar et al 2016). Furthermore, the interaction between DS, GATA1 mutations and TAM was reported, recently (Banno et al 2016). TAM is usually self-limiting and undergoes spontaneous regression, but 10-20% of neonates with TAM subsequently develop myeloid leukemia in the first 5 years of life.…”