Kinome-level screening identifies inhibition of polo-like kinase-1 (PLK1) as a target for enhancing non-viral transgene expression

J Control Release. 2015 Apr 28:204:20-9. doi: 10.1016/j.jconrel.2015.01.036. Epub 2015 Feb 11.


Human cells contain hundreds of kinase enzymes that regulate several cellular processes, which likely include transgene delivery and expression. We identified several kinases that influence gene delivery and/or expression by performing a kinome-level screen in which, we identified small-molecule kinase inhibitors that significantly enhanced non-viral (polymer-mediated) transgene (luciferase) expression in cancer cells. The strongest enhancement was observed with several small-molecule inhibitors of Polo-like Kinase 1 (PLK 1) (e.g., HMN-214 and BI 2536), which enhanced luciferase expression up to 30-fold by arresting cells in the G2/M phase of the cell cycle and influencing intracellular trafficking of plasmid DNA. Knockdown of PLK 1 using an shRNA-expressing lentivirus further confirmed the enhancement of polymer-mediated transgene expression. In addition, pairwise and three-way combinations of PLK1 inhibitors with the histone deacetylase-1 (HDAC-1) inhibitor Entinostat and the JAK/STAT inhibitor AG-490 enhanced luciferase expression to levels significantly higher than individual drug treatments acting alone. These findings indicate that inhibition of specific intracellular kinases (e.g., PLK1) can significantly enhance non-viral transgene expression for applications in biotechnology and medicine.

Keywords: BI 2536; Cell cycle; HMN-214; Kinases; Polymer Gene Delivery; Transient protein expression.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Cell Culture Techniques
  • Cell Cycle / drug effects
  • Cell Cycle / genetics
  • Cell Cycle Proteins / antagonists & inhibitors*
  • Cell Cycle Proteins / genetics
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Cell Survival / genetics
  • Cyclic N-Oxides / pharmacology*
  • Dose-Response Relationship, Drug
  • Drug Carriers / chemistry
  • Gene Silencing
  • Gene Transfer Techniques*
  • Green Fluorescent Proteins / genetics
  • Humans
  • Luciferases / genetics
  • Male
  • Plasmids
  • Polo-Like Kinase 1
  • Protein Kinase Inhibitors / pharmacology*
  • Protein Serine-Threonine Kinases / antagonists & inhibitors*
  • Protein Serine-Threonine Kinases / genetics
  • Proto-Oncogene Proteins / antagonists & inhibitors*
  • Proto-Oncogene Proteins / genetics
  • Pteridines / pharmacology*
  • Pyridines / pharmacology*
  • Small Molecule Libraries / pharmacology*
  • Sulfonamides / pharmacology*
  • Transgenes / genetics*


  • (E)-4-(2-(2-(N-acetyl-N-(4-methoxybenzenesulfonyl)amino)stilbazole)) 1-oxide
  • BI 2536
  • Cell Cycle Proteins
  • Cyclic N-Oxides
  • Drug Carriers
  • Protein Kinase Inhibitors
  • Proto-Oncogene Proteins
  • Pteridines
  • Pyridines
  • Small Molecule Libraries
  • Sulfonamides
  • enhanced green fluorescent protein
  • Green Fluorescent Proteins
  • Luciferases
  • Protein Serine-Threonine Kinases