Computational-experimental approach to drug-target interaction mapping: A case study on kinase inhibitors

PLoS Comput Biol. 2017 Aug 7;13(8):e1005678. doi: 10.1371/journal.pcbi.1005678. eCollection 2017 Aug.

Abstract

Due to relatively high costs and labor required for experimental profiling of the full target space of chemical compounds, various machine learning models have been proposed as cost-effective means to advance this process in terms of predicting the most potent compound-target interactions for subsequent verification. However, most of the model predictions lack direct experimental validation in the laboratory, making their practical benefits for drug discovery or repurposing applications largely unknown. Here, we therefore introduce and carefully test a systematic computational-experimental framework for the prediction and pre-clinical verification of drug-target interactions using a well-established kernel-based regression algorithm as the prediction model. To evaluate its performance, we first predicted unmeasured binding affinities in a large-scale kinase inhibitor profiling study, and then experimentally tested 100 compound-kinase pairs. The relatively high correlation of 0.77 (p < 0.0001) between the predicted and measured bioactivities supports the potential of the model for filling the experimental gaps in existing compound-target interaction maps. Further, we subjected the model to a more challenging task of predicting target interactions for such a new candidate drug compound that lacks prior binding profile information. As a specific case study, we used tivozanib, an investigational VEGF receptor inhibitor with currently unknown off-target profile. Among 7 kinases with high predicted affinity, we experimentally validated 4 new off-targets of tivozanib, namely the Src-family kinases FRK and FYN A, the non-receptor tyrosine kinase ABL1, and the serine/threonine kinase SLK. Our sub-sequent experimental validation protocol effectively avoids any possible information leakage between the training and validation data, and therefore enables rigorous model validation for practical applications. These results demonstrate that the kernel-based modeling approach offers practical benefits for probing novel insights into the mode of action of investigational compounds, and for the identification of new target selectivities for drug repurposing applications.

MeSH terms

  • Algorithms
  • Computational Biology / methods*
  • Databases, Factual
  • Drug Discovery / methods*
  • Humans
  • Models, Statistical*
  • Protein Binding
  • Protein Kinase Inhibitors* / chemistry
  • Protein Kinase Inhibitors* / metabolism
  • Protein Kinase Inhibitors* / pharmacology
  • Reproducibility of Results

Substances

  • Protein Kinase Inhibitors

Grants and funding

This work was financially supported by the Helsinki Doctoral Education Network in Information and Communications Technology HICT to AC, Academy of Finland [295496 to JR, 269862, 272437, 295504 and 310507 to TA, 272577, 277293 to KW, 289903 to AA], Cancer Society of Finland to KW and TA, Sigrid Jusélius foundation to KW, and the Biocentrum Helsinki connecting scientists grant [794509103 to AC and BR]. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.