Development of Cell-based High Throughput Luminescence Assay for Drug
Discovery in Inhibiting OCT4 and MAPKAPK2 Interaction
Abstract
Overexpression of c-MYC protein without genomic amplification occurs in
multiple cancers, including neuroblastoma and small cell lung cancer. In
searching for the mechanisms of c-MYC protein overexpression, we
demonstrated that the transcription factor, OCT4 mediates c-MYC
transcriptional activation in progressive disease neuroblastoma.
Subsequently, we identified two kinases, MAPKAPK2 (MK2) and DNA-PK,
which are predicted to bind and phosphorylate OCT4 at S111 and S93
residues, respectively. Based on these novel observations, we developed
a cell-based luminescence assay to screen and identify compounds that
inhibit the interactions between MK2 and OCT4. By screening 79,671
compounds, we identified 65 compounds we designated as “hits”. Using a
two-step validation of co-immunoprecipitation and
pOCT4S111 detection, the compounds were further
narrowed down to three for further studies. The three compounds were
tested for their ability to inhibit kinase activity, in vitro cytotoxic
activity, and anti-inflammatory activity. In conclusion, we developed a
cell-based luminescence assay for the discovery of new agents targeting
the c-MYC transcriptional activation pathway. Screening and subsequent
validation identified a small number of compounds for further
development.