Implementing Reverse Phase Protein Array Profiling as a Sensitive Method for the Early Pre-Clinical Detection of Off-Target Toxicities Associated with Sunitinib Malate

Proteomics Clin Appl. 2019 Jul;13(4):e1800159. doi: 10.1002/prca.201800159. Epub 2019 Mar 19.


Purpose: The tyrosine kinase inhibitor (TKI) sunitinib is a multi-targeted agent approved across multiple cancer indications. Nevertheless, since approval, data has emerged to describe a worrisome side effect profile including hypertension, hand-foot syndrome, fatigue, diarrhea, mucositis, proteinuria, and (rarely) congestive heart failure. It has been hypothesized that the observed multi-parameter toxicity profile is related to "on-target" kinase inhibition in "off-target" tissues.

Experimental design: To interrogate off-target effects in pre-clinical studies, a reverse phase protein array (RPPA) approach is employed. Mice are treated with sunitinib (40 mg kg-1 ) for 4 weeks, following which critical organs are removed. The Zeptosens RPPA platform is employed for protein expression analysis.

Results: Differentially expressed proteins associated with damage and/or stress are found in the majority of organs from treated animals. Proteins differentially expressed in the heart are associated with myocardial hypertrophy, ischaemia/reperfusion, and hypoxia. However, hypertrophy is not evidenced on histology. Mild proteinuria is observed; however, no changes in renal glomerular structure are visible via electron microscopy. In skin, proteins associated with cutaneous inflammation, keratinocyte hyper-proliferation, and increased inflammatory response are differentially expressed.

Conclusions and clinical relevance: It is posited that pre-clinical implementation of a combined histopathological/RPPA approach provides a sensitive method to mechanistically elucidate the early manifestation of TKI on-target/organ off-target toxicities.

Keywords: off-target toxicity; preclinical models; reverse phase protein arrays; sunitinib; tyrosine kinase inhibitors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Female
  • Mice
  • Mice, Inbred BALB C
  • Protein Array Analysis*
  • Protein Kinase Inhibitors / adverse effects*
  • Protein Kinase Inhibitors / pharmacology
  • Proteome / biosynthesis*
  • Sunitinib / adverse effects*
  • Sunitinib / pharmacology


  • Protein Kinase Inhibitors
  • Proteome
  • Sunitinib