Pharmacologic targeting of the P-TEFb complex as a therapeutic strategy for chronic myeloid leukemia

Cell Commun Signal. 2021 Aug 9;19(1):83. doi: 10.1186/s12964-021-00764-5.

Abstract

Background: The positive transcription elongation factor b (P-TEFb) kinase activity is involved in the process of transcription. Cyclin-dependent kinase 9 (CDK9), a core component of P-TEFb, regulates the process of transcription elongation, which is associated with differentiation and apoptosis in many cancer types. Wogonin, a natural CDK9 inhibitor isolated from Scutellaria baicalensis. This study aimed to investigate the involved molecular mechanisms of wogonin on anti- chronic myeloid leukemia (CML) cells.

Materials and methods: mRNA and protein levels were analysed by RT-qPCR and western blot. Flow cytometry was used to assess cell differentiation and apoptosis. Cell transfection, immunofluorescence analysis and co-immunoprecipitation (co-IP) assays were applied to address the potential regulatory mechanism of wogonin. KU-812 cells xenograft NOD/SCID mice model was used to assess and verify the mechanism in vivo.

Results: We reported that the anti-CML effects in K562, KU-812 and primary CML cells induced by wogonin were regulated by P-TEFb complex. We also confirmed the relationship between CDK9 and erythroid differentiation via knockdown the expression of CDK9. For further study the mechanism of erythroid differentiation induced by wogonin, co-IP experiments were used to demonstrate that wogonin increased the binding between GATA-1 and FOG-1 but decreased the binding between GATA-1 and RUNX1, which were depended on P-TEFb. Also, wogonin induced apoptosis and decreased the mRNA and protein levels of MCL-1 in KU-812 cells, which is the downstream of P-TEFb. In vivo studies showed wogonin had good anti-tumor effects in KU-812 xenografts NOD/ SCID mice model and decreased the proportion of human CD45+ cells in spleens of mice. We also verified that wogonin exhibited anti-CML effects through modulating P-TEFb activity in vivo.

Conclusions: Our study indicated a special mechanism involving the regulation of P-TEFb kinase activity in CML cells, providing evidences for further application of wogonin in CML clinical treatment. Video Abstract.

Keywords: CDK9; CML; Cell differentiation; P-TEFb; Wogonin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Cell Proliferation / drug effects
  • Cyclin-Dependent Kinase 9 / antagonists & inhibitors
  • Cyclin-Dependent Kinase 9 / genetics*
  • Flavanones / pharmacology*
  • GATA1 Transcription Factor / genetics
  • Gene Expression Regulation, Neoplastic / drug effects
  • Humans
  • K562 Cells
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / drug therapy*
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / genetics
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive / pathology
  • Mice
  • Molecular Targeted Therapy
  • Multiprotein Complexes / antagonists & inhibitors
  • Multiprotein Complexes / genetics
  • Nuclear Proteins / genetics
  • Phosphorylation / drug effects
  • Positive Transcriptional Elongation Factor B / antagonists & inhibitors
  • Positive Transcriptional Elongation Factor B / genetics*
  • Transcription Factors / genetics
  • Xenograft Model Antitumor Assays

Substances

  • Flavanones
  • GATA1 Transcription Factor
  • GATA1 protein, human
  • Multiprotein Complexes
  • Nuclear Proteins
  • Transcription Factors
  • ZFPM1 protein, human
  • Positive Transcriptional Elongation Factor B
  • CDK9 protein, human
  • Cyclin-Dependent Kinase 9
  • wogonin