Figure 5.

Integrin αvβ3 activation controls metastatic potential in the MDA-MB 435 breast carcinoma cell model. (A) Lungs of female C.B17/lcrTac scid mice 42 days after i.v. injection of 1 × 10⁶ tumor cells. The β3 integrin lacking cell variant and its transfectants expressing either αvβ3_WT or αvβ3_D723R were compared. The β3_D723R-expressing variant had the platelet-interactive phenotype and showed increased metastatic activity. (B) Number of metastatic foci at the lung surface. Data points are numbers of lung surface metastases for each animal; horizontal lines are median numbers of metastases per group (n = 8). Cells expressing activated αvβ3_D723R produced a significantly larger number of metastases than cells lacking β3 or expressing nonactivated αvβ3_WT (P < 0.0001 by the Kruskal–Wallis test).