FIGURE 8.

Induction of ZEB1 in response to Rb1 family mutation is required for Ras to initiated sarcoma formation, whereas Ras superinduction of ZEB1 is required for transition to invasive sarcoma. 50,000 cells were injected into nude mice, and tumors were harvested after 31 days. Representative H&E sections of the tumor-host border are shown at the top, and sections of the tumor interior are shown below. The yellow arrow denotes the tumor-host border in a Ras-TKO ZEB1 shRNA-2 MEF tumor. Red arrows indicate sites of invasion into host muscle and the green arrow invasion into adipose tissue in a Ras-TKO MEF tumor. Scale bars, 50 μm.