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. 2007 Dec 13;118(1):64–78. doi: 10.1172/JCI33154

Figure 7. EphA2 deficiency does not affect tumorigenesis, microvascular density, or growth regulatory signaling pathways in MMTV–PyV-mT tumors.

Figure 7

(A) Loss of EphA2 protein expression was confirmed by immunohistochemical staining. Scale bar: 50 μm. (B) We detected no change in MMTV–PyV-mT tumor microvascular density based on vWF staining (arrows indicate vWF+ blood vessels). Scale bar: 100 μm. (C) We did not observe any change in levels of GTP-bound active Ras or p-Erk in EphA2–/– MMTV–PyV-mT whole tumor extracts relative to controls, nor did we observe any change in levels of RhoA. Uniform loading was confirmed by immunoblotting for total Ras, total Erk, and tubulin. (D) We observed EphA2 overexpression and elevated phosphorylation in MMTV-Neu and MMTV–PyV-mT tumors relative to normal mammary tissue isolated from control FVB mice, with the highest levels observed in MMTV-Neu tumors. We also observed overexpression of ErbB2 and ephrin-A1 in both tumor types, with comparable ephrin-A1 expression in both tumor types and higher ErbB2 levels in MMTV-Neu tumors. Uniform loading was confirmed by immunoblot for actin. (E) We confirmed EphA2 overexpression specifically in epithelium by comparing EphA2 levels in PMEC lysates versus PMTCs derived from MMTV-Neu and MMTV–PyV-mT mice.