• Background: VEGFA is the primary driver of angiogenesis (new blood vessel formation). It binds to endothelial cell receptors VEGFR-1, VEGFR-2 (predominant), and VEGFR-3, activating signaling pathways (e.g., PI3K/AKT, MAPK) that promote endothelial cell proliferation, migration, and tube formation. Tumor cells upregulate VEGFA to induce tumor angiogenesis, securing nutrient/oxygen supply and facilitating metastasis. VEGFA maintains its status as a "star" target in the field of angiogenesis, and its pharmaceutical development has achieved remarkable success, particularly in the fields of tumor and ophthalmic diseases.
• Target strategy: The exons 1-8 of mouse Vegfa gene that encode the whole molecule (ATG to STOP codon) were replaced by human counterparts in B-NDG hVEGFA mice.
• Validation: Human VEGFA was only detectable in lung tissue homogenate of homozygous B-NDG hVEGFA mice.
• Application: Humanization of the VEGFA gene in immunodeficient mice serves the core purpose of constructing preclinical research models that can more accurately evaluate the efficacy of anti-cancer drugs targeting human VEGFA, particularly anti-angiogenic agents

Gene targeting strategy for B-NDG hVEGFA mice. The exons 1-8 of mouse Vegfa gene that encode the whole molecule (ATG to STOP codon) were replaced by human counterparts in B-NDG hVEGFA mice. The promoter, 5’UTR and 3’UTR region of the mouse gene are retained. The human VEGFA expression is driven by endogenous mouse VEGFA promoter, while mouse VEGFA gene transcription and translation will be disrupted.

Strain specific VEGFA expression analysis in wild-type B-NDG mice and homozygous B-NDG hVEGFA mice by ELISA. Lung tissue homogenate was collected from wild-type B-NDG mice (+/+) (female, n=3, 6-week-old) and homozygous B-NDG hVEGFA mice (H/H) (female, n=3, 6-week-old). Expression level of mouse and human VEGFA were analyzed by ELISA (anti-mouse VEGFA ELISA kit: RD, MMV00-1; anti-human VEGFA ELISA kit: RD, DVE00). Mouse VEGFA was only detectable in wild-type B-NDG mice. Human VEGFA was only detectable in homozygous B-NDG hVEGFA mice. Values are expressed as mean ± SEM.