Inhibition of CSF1R and AKT by (±)-kusunokinin hinders breast cancer cell proliferation

Biomed Pharmacother. 2020 Sep:129:110361. doi: 10.1016/j.biopha.2020.110361. Epub 2020 Jun 11.

Abstract

Kusunokinin, a lignan compound, inhibits cancer cell proliferation and induces apoptosis; however, the role of kusunokinin is not fully understood. Here, we aimed to identify a target protein of (-)-kusunokinin and determine the protein levels of its downstream molecules. We found that (-)-kusunokinin bound 5 possible target proteins, including CSF1R, MMP-12, HSP90-α, CyclinB1 and MEK1 with ΔGbind less than -10.40 kcal/mol. MD simulation indicated (-)-kusunokinin and pexidartinib (P31, a specific CSF1R binding compound) shared some extents of functional similarity in which (-)-kusunokinin bound CSF1R at the juxtamembrane (JM) region with aromatic amino acids similar to pexidartinib using π-π interaction, as well as hydrogen bond. Both P31 and (-)-kusunokinin moved into the same CSF1R region and W7 was a mutual key residue. However, the P31 binding site differed from the (-)-kusunokinin binding site. For in vitro study, the synthetic (±)-kusunokinin exhibited stronger cytotoxicity than picropodophyllotoxin, silibinin and etoposide on MCF-7 cells and represented less toxicity than picropodophyllotoxin and doxorubicin on L-929 and MCF-12A cells. Knocking down CSF1R using a specific siRNA combination with (±)-kusunokinin demonstrated levels of cell proliferation proteins slightly higher than siRNA-CSF1R treatment. However, siRNA-CSF1R combination with P31 represented the number of cell viability and cell proliferation proteins, like in the control groups (Lipofectamine and siRNA-Luciferase). Moreover, (±)-kusunokinin suppressed CSF1R and its downstream proteins, including AKT, CyclinD1 and CDK1. Meanwhile, both P31 and siRNA-CSF1R dramatically suppressed CSF1R, MEK1, AKT, ERK, CyclinB1, CyclinD1 and CDK1. Our overall results indicate that the mechanism of (±)-kusunokinin differed fairly from P31. We have concluded that (±)-kusunokinin inhibited breast cancer cell proliferation partially through the binding and suppression of CSF1R, which consequently affected AKT and its downstream molecules.

Keywords: AKT; Breast cancer; CSF1R; Cell proliferation; Kusunokinin.

Publication types

  • Comparative Study

MeSH terms

  • Antineoplastic Agents, Phytogenic / chemistry
  • Antineoplastic Agents, Phytogenic / metabolism
  • Antineoplastic Agents, Phytogenic / pharmacology*
  • Binding Sites
  • Breast Neoplasms / drug therapy*
  • Breast Neoplasms / enzymology
  • Breast Neoplasms / genetics
  • Breast Neoplasms / pathology
  • CDC2 Protein Kinase / genetics
  • CDC2 Protein Kinase / metabolism
  • Cell Proliferation / drug effects*
  • Cyclin D1 / genetics
  • Cyclin D1 / metabolism
  • Female
  • Humans
  • Lignans / chemistry
  • Lignans / metabolism
  • Lignans / pharmacology*
  • MCF-7 Cells
  • Molecular Docking Simulation
  • Molecular Dynamics Simulation
  • Protein Binding
  • Protein Conformation
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Receptors, Granulocyte-Macrophage Colony-Stimulating Factor / antagonists & inhibitors*
  • Receptors, Granulocyte-Macrophage Colony-Stimulating Factor / chemistry
  • Receptors, Granulocyte-Macrophage Colony-Stimulating Factor / genetics
  • Receptors, Granulocyte-Macrophage Colony-Stimulating Factor / metabolism
  • Signal Transduction
  • Structure-Activity Relationship

Substances

  • Antineoplastic Agents, Phytogenic
  • CCND1 protein, human
  • CSF1R protein, human
  • Lignans
  • Receptors, Granulocyte-Macrophage Colony-Stimulating Factor
  • kusunokinin
  • Cyclin D1
  • Proto-Oncogene Proteins c-akt
  • CDC2 Protein Kinase
  • CDK1 protein, human