Addiction to DUSP1 protects JAK2V617F-driven polycythemia vera progenitors against inflammatory stress and DNA damage, allowing chronic proliferation

Oncogene. 2019 Jul;38(28):5627-5642. doi: 10.1038/s41388-019-0813-7. Epub 2019 Apr 9.

Abstract

Inflammatory and oncogenic signaling converge in disease evolution of BCR-ABL-negative myeloproliferative neoplasms, clonal hematopoietic stem cell disorders characterized by gain-of-function mutation in JAK2 kinase (JAK2V617F), with highest prevalence in patients with polycythemia vera (PV). Despite the high risk, DNA-damaging inflammatory microenvironment, PV progenitors tend to preserve their genomic stability over decades until their progression to post-PV myelofibrosis/acute myeloid leukemia. Using induced pluripotent stem cells-derived CD34+ progenitor-enriched cultures from JAK2V617F+ PV patient and from JAK2 wild-type healthy control, CRISPR-modified HEL cells and patients' bone marrow sections from different disease stages, we demonstrate that JAK2V617F induces an intrinsic IFNγ- and NF-κB-associated inflammatory program, while suppressing inflammation-evoked DNA damage both in vitro and in vivo. We show that cells with JAK2V617F tightly regulate levels of inflammatory cytokines-induced reactive oxygen species, do not fully activate the ATM/p53/p21waf1 checkpoint and p38/JNK MAPK stress pathway signaling when exposed to inflammatory cytokines, suppress DNA single-strand break repair genes' expression yet overexpress the dual-specificity phosphatase (DUSP) 1. RNAi-mediated knock-down and pharmacological inhibition of DUSP1, involved in p38/JNK deactivation, in HEL cells reveals growth addiction to DUSP1, consistent with enhanced DNA damage response and apoptosis in DUSP1-inhibited parental JAK2V617F+ cells, but not in CRISPR-modified JAK2 wild-type cells. Our results indicate that the JAK2V617F+ PV progenitors utilize DUSP1 activity as a protection mechanism against DNA damage accumulation, promoting their proliferation and survival in the inflammatory microenvironment, identifying DUSP1 as a potential therapeutic target in PV.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line, Tumor
  • Cell Proliferation*
  • Cytokines / genetics
  • Cytokines / metabolism
  • DNA Damage*
  • Dual Specificity Phosphatase 1 / genetics*
  • Hematopoietic Stem Cells / pathology*
  • Humans
  • Induced Pluripotent Stem Cells / pathology*
  • Inflammation / metabolism*
  • Janus Kinase 2 / genetics*
  • Mutation
  • Oxidative Stress*
  • Polycythemia Vera / genetics*
  • Reproducibility of Results
  • STAT1 Transcription Factor / metabolism
  • Tumor Microenvironment

Substances

  • Cytokines
  • STAT1 Transcription Factor
  • STAT1 protein, human
  • JAK2 protein, human
  • Janus Kinase 2
  • DUSP1 protein, human
  • Dual Specificity Phosphatase 1