Fig. 3.

Genetic deletion of β3 integrin abrogates activity of tumstatin peptide. (A) RT2 mice were implanted s.c. with Matrigel plugs at 9 wk of age and treated with tumstatin daily as described above for 1 wk. The Matrigel plugs were then harvested; six plugs were assayed in each group. (B) An intervention trial comparing tumstatin and endostatin peptides in RT2/β3 Integrin^−/− mice treated from 10 to 13.5 wk of age. The tumstatin peptide (control, n = 7; tumstatin peptide, n = 7) did not prevent tumor growth in the absence of β3 integrin, whereas the endostatin peptide (control, n = 3; endostatin peptide, n = 4) significantly inhibited tumor growth in RT2/β3 integrin^−/− mice. Results are shown as mean ± SEM; *P < 0.05.