ZEBRAFISH AS MODELS OF TYROSINE KINASE‐DRIVEN CANCER

Abstract

The protein kinase gene family encodes proteins involved in several essential functions, with cell growth and migration being essential outcomes. Mutations in kinases underlie a broad range of diseases, primarily inflammation and cancer. Tyrosine kinase inhibitors (TKIs) in particular, are successfully used as a targeted therapy for cancer and inflammation‐driven disorders. Current unmet needs include addressing the adverse effects of TKIs, the emergence of resistance, and the necessity of newer TKIs. Experiments using accessible animal models such as zebrafish can help address these needs. Zebrafish studies can help in efficient characterization of toxicological and pharmacological effects of inhibition using known or potential TKIs, via the combination of phenotypic and molecular analysis. The recent application of CRISPR‐Cas9 further enables the development of genetically engineered cancer models in zebrafish. Following our previous work showing conservation of zebrafish tyrosine kinases compared to humans, we are now studying the effects of chemical or genetic tyrosine kinase modulation in zebrafish.To identify the phenotypic endpoints of tyrosine kinase inhibition in zebrafish, we selected a few drugs approved by the USFDA for treating cancer and inflammation‐related disorders in humans. We evaluated phenotypic effects including adverse effects to identify NOELs and detectable and consistent phenotypic endpoints of such compounds in zebrafish. These effects provide a basis to evaluate novel TKI compounds. Further, tyrosine kinase genes involved in inflammation and cancer were selected for targeted genetic modification in zebrafish using CRISPR Cas9. Our initial data demonstrate the development of MET (HGFR) homozygous mutant zebrafish and the phenotypes associated with this mutant. Detailed characterization of this mutant including molecular analysis is under way. The characteristics of this mutant provide the basis to identify MET‐specific inhibitors. Development of zebrafish models carrying oncogenic TK mutants, and detailed characterization of the effects of TKIs in zebrafish are ongoing.In summary, our work is focussed on identifying TKI treatment‐related phenotypes in zebrafish, and generation of TK‐crispant zebrafish as cancer models.Support or Funding InformationDepartment of Biotechnology and the Indian Council of Medical Research, Govt. of India