Figure 5. GAB2 enhances tumorigenesis and induces angiogenesis in vivo.

(a). 1×10⁶ melan-a melanocytes stably expressing vector, NRAS^G12D, GAB2^WT+NRAS^G12D were injected into nude mice subcutaneously (n=8 mice per group). Primary tumor growth was examined by measuring tumor volume every other day.

(b). At four weeks, xenograft tumors were analyzed histologically using hematoxylin and eosin staining as well as for GAB2, CD34, VEGFR2, and HIF1α, using immunohistochemistry. Representative micrographs of NRAS^G12D and NRAS^G12D+GAB2^WT expressing tumors are shown.

(c). CD34 or VEGFR2-staining vasculature was quantified by measuring the vessel areas (20× per field, 4 fields per section) using the Image J software. Error bars indicate ± standard error. *p<0.05, **p<0.01.

(d). Proteins were extracted from xenografts (left panel) or cells cultured in 2D conditions (right panel) expressing either NRAS^G12D or GAB2^WT+NRAS^G12D, and VEGF levels were measured by ELISA. Experiments were performed in duplicates. Error bars indicate ± standard error. **p<0.01, ***p,0.001.