Functions of ZNF516 in embryonic development, health, and disease

Zinc finger protein 516, or ZNF516, is a largely understudied protein. Germline homozygous loss of the murine ortholog, ZFP516, has been previously reported to lead to embryonic lethality in mice. However, the cause of this lethality has not been investigated. With the aid of newly developed Zfp516 knock out mouse line in our laboratory I characterised the phenotypes of Zfp516 knock out animals and concluded that severe and 100% penetrant congenital heart defects were the most likely cause of embryonic lethality in Zfp516-/-. I reported that heart defects were not due to selective Zfp516 deletion in cardiomyocytes, and that only some defects were recapitulated when Zfp516 was deleted in Isl1-expressing cells. I further described spatiotemporal expression of Zfp516 during development and showed that Zfp516 ablation at E9.5 leads to upregulation of genes involved in neuronal migration, growth and synapsogenesis. Moreover, I found genetic synergy between Zfp516 and Sox10 during development. Next, I characterized phenotypes associated with deletions of and polymorphisms in human ZNF516 and adult heterozygous Zfp516 knock out mice. I discovered that manifestation of phenotypes in Zfp516+/- mice was largely gender dependent, and that our mouse model phenocopied some of the phenotypes seen in humans. Lastly, I reported that targeting ZNF516 in HCT116 with CRIPSR/Cas9 can result in chromosome arm truncations. I therefore suggested a screening method for future studies that could preselect clones with correct genotype and without arm truncations before further cell expansion for subsequent downstream experiments

The role of APOBEC3B in lung tumor evolution and targeted cancer therapy resistance

In this study, the impact of the apolipoprotein B mRNA-editing catalytic subunit-like (APOBEC) enzyme APOBEC3B (A3B) on epidermal growth factor receptor (EGFR)-driven lung cancer was assessed. A3B expression in EGFR mutant (EGFRmut) non-small-cell lung cancer (NSCLC) mouse models constrained tumorigenesis, while A3B expression in tumors treated with EGFR-targeted cancer therapy was associated with treatment resistance. Analyses of human NSCLC models treated with EGFR-targeted therapy showed upregulation of A3B and revealed therapy-induced activation of nuclear factor kappa B (NF-κB) as an inducer of A3B expression. Significantly reduced viability was observed with A3B deficiency, and A3B was required for the enrichment of APOBEC mutation signatures, in targeted therapy-treated human NSCLC preclinical models. Upregulation of A3B was confirmed in patients with NSCLC treated with EGFR-targeted therapy. This study uncovers the multifaceted roles of A3B in NSCLC and identifies A3B as a potential target for more durable responses to targeted cancer therapy.</p

The role of APOBEC3B in lung tumor evolution and targeted cancer therapy resistance

In this study, the impact of the apolipoprotein B mRNA-editing catalytic subunit-like (APOBEC) enzyme APOBEC3B (A3B) on epidermal growth factor receptor (EGFR)-driven lung cancer was assessed. A3B expression in EGFR mutant (EGFRmut) non-small-cell lung cancer (NSCLC) mouse models constrained tumorigenesis, while A3B expression in tumors treated with EGFR-targeted cancer therapy was associated with treatment resistance. Analyses of human NSCLC models treated with EGFR-targeted therapy showed upregulation of A3B and revealed therapy-induced activation of nuclear factor kappa B (NF-κB) as an inducer of A3B expression. Significantly reduced viability was observed with A3B deficiency, and A3B was required for the enrichment of APOBEC mutation signatures, in targeted therapy-treated human NSCLC preclinical models. Upregulation of A3B was confirmed in patients with NSCLC treated with EGFR-targeted therapy. This study uncovers the multifaceted roles of A3B in NSCLC and identifies A3B as a potential target for more durable responses to targeted cancer therapy