NKL Homeobox Genes NKX2-3 and NKX2-4 Deregulate Megakaryocytic-Erythroid Cell Differentiation in AML

• Published in: International journal of molecular sciences 2021-10, Vol.22 (21), p.11434
• Main Authors: Nagel, Stefan, Pommerenke, Claudia, Meyer, Corinna, MacLeod, Roderick A F
• Format: Article
• Language: English
• Subjects: Aberration; Acute myeloid leukemia; Basic Helix-Loop-Helix Transcription Factors - genetics; Cell activation; Cell Cycle Proteins - genetics; Cell differentiation; Cell Differentiation - genetics; Cell Line, Tumor; Cells (biology); Chromosome 19; Chromosomes; Datasets; Deregulation; Differentiation (biology); Ectopic expression; Endothelium - cytology; Erythroid Cells - cytology; Gene expression; Gene Expression Profiling; Gene Expression Regulation - genetics; Genes; Hematopoiesis; Hemopoiesis; Homeobox; Homeodomain Proteins - genetics; HOX-code; Humans; Interferon Regulatory Factors - genetics; Leukemia; Leukemia, Erythroblastic, Acute - genetics; Leukemia, Erythroblastic, Acute - pathology; Lymphoma; Megakaryocytes - cytology; Myeloid leukemia; Myelopoiesis; NKL-code; Nkx2.3 protein; Patients; Progenitor cells; Proteins; RNA Interference; RNA, Small Interfering - genetics; siRNA; SIX gene family; SOXF Transcription Factors - genetics; Stem cells; TALE-code; TBX-code; Transcription factors; Transcription Factors - genetics; Vascular Endothelial Growth Factor Receptor-1 - genetics
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms222111434

NKL homeobox genes encode transcription factors that impact normal development and hematopoietic malignancies if deregulated. Recently, we established an NKL-code that describes the physiological expression pattern of eleven NKL homeobox genes in the course of hematopoiesis, allowing evaluation of aberrantly activated NKL genes in leukemia/lymphoma. Here, we identify ectopic expression of NKL homeobox gene NKX2-4 in an erythroblastic acute myeloid leukemia (AML) cell line OCI-M2 and describe investigation of its activating factors and target genes. Comparative expression profiling data of AML cell lines revealed in OCI-M2 an aberrantly activated program for endothelial development including master factor ETV2 and the additional endothelial signature genes HEY1, IRF6, and SOX7. Corresponding siRNA-mediated knockdown experiments showed their role in activating NKX2-4 expression. Furthermore, the ETV2 locus at 19p13 was genomically amplified, possibly underlying its aberrant expression. Target gene analyses of NKX2-4 revealed activated ETV2, HEY1, and SIX5 and suppressed FLI1. Comparative expression profiling analysis of public datasets for AML patients and primary megakaryocyte-erythroid progenitor cells showed conspicuous similarities to NKX2-4 activating factors and the target genes we identified, supporting the clinical relevance of our findings and developmental disturbance by NKX2-4. Finally, identification and target gene analysis of aberrantly expressed NKX2-3 in AML patients and a megakaryoblastic AML cell line ELF-153 showed activation of FLI1, contrasting with OCI-M2. FLI1 encodes a master factor for myelopoiesis, driving megakaryocytic differentiation and suppressing erythroid differentiation, thus representing a basic developmental target of these homeo-oncogenes. Taken together, we have identified aberrantly activated NKL homeobox genes NKX2-3 and NKX2-4 in AML, deregulating genes involved in megakaryocytic and erythroid differentiation processes, and thereby contributing to the formation of specific AML subtypes.