Figure 3
From: Protein tyrosine kinase 6 promotes ERBB2-induced mammary gland tumorigenesis in the mouse
PTK6 is induced throughout ERBB2-induced tumors, but it is activated primarily at the invading edges. (a) Protein lysates from ERBB2 transgenic mammary gland tumors were subjected to immunoblotting. Expression of total and active PTK6 was detected only in B2;Ptk6+/+ lysates. Active P-STAT3 levels were not significantly different between B2;Ptk6+/+ and B2;Ptk6−/− animals. (b) Cells with active P-STAT3 were detected in B2;Ptk6+/+ and B2;Ptk6−/− tumors. Although heterogeneous staining could be detected within tumors, a significant difference in the number of P-STAT3-positive cells was not observed. (c) Total PTK6 is ubiquitously expressed in ERBB2 mammary gland tumors as shown by immunohistochemistry, but active PTK6 was primarily localized to the invading edges of the tumors but not in the center. Panels on the right are controls that demonstrate mammary gland tumors that developed in B2;Ptk6−/−mice are negative for total and active PTK6. (d) BrdU incorporation in breast tumors from B2;Ptk6+/+ and B2;Ptk6−/− animals with similar tumor burden was examined by immunohistochemistry. The size bars represent 50 μm
