Phosphorylation of PBK/TOPK Tyr74 by JAK2 promotes Burkitt lymphoma tumor growth

Cancer Lett. 2022 Sep 28:544:215812. doi: 10.1016/j.canlet.2022.215812. Epub 2022 Jun 30.

Abstract

Burkitt lymphoma (BL), which is characterized by high invasiveness, is a subgroup of non-Hodgkin lymphoma. Although BL is regarded as a highly curable disease, especially for children, some patients unfortunately still do not respond adequately. The understanding of the etiology and molecular mechanisms of BL is still limited, and targeted therapies are still lacking. Here, we found that T-LAK cell-derived protein kinase (TOPK) and phosphorylated Janus kinase 2 (p-JAK2) are highly expressed in the tissues of BL patients. We report that TOPK directly binds to and is phosphorylated at Tyr74 by JAK2. Histone H3, one of the downstream targets of TOPK, is also phosphorylated in vivo and in vitro. Furthermore, we report that the phosphorylation of TOPK at Tyr74 by JAK2 plays a vital role in the proliferation of BL cells and promotes BL tumorigenesis in vivo. Phosphorylation of TOPK at Tyr74 by JAK2 enhances the stability of TOPK. Collectively, our results suggest that the JAK2/TOPK/histone H3 axis plays a key role in the proliferation of BL cells and BL tumorigenesis in vivo.

Keywords: Burkitt lymphoma; JAK2; Phosphorylation; TOPK; Tumor growth.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Burkitt Lymphoma* / genetics
  • Cell Line, Tumor
  • Cell Transformation, Neoplastic
  • Child
  • Histones / metabolism
  • Humans
  • Janus Kinase 2 / genetics
  • Janus Kinase 2 / metabolism
  • Mitogen-Activated Protein Kinase Kinases / metabolism
  • Phosphorylation

Substances

  • Histones
  • JAK2 protein, human
  • Janus Kinase 2
  • Mitogen-Activated Protein Kinase Kinases
  • PDZ-binding kinase