MMP-3 expression and activity are increased by cmvIL-10. a MDA-MB-231 cells were cultured in the presence or absence of 10 ng/ml cmvIL-10 for the indicated times and then cell lysates were analyzed by ELISA. Error bars SEM, *p < 0.05. b MDA cells cultured with 100 ng/ml cmvIL-10 for the indicated times were harvested and lysates examined by western blotting with anti-MMP3 or anti-MAPK as a protein loading control. Lysates from cells receiving the same treatment were analyzed under non-reducing conditions on a 4–16% Zymogram gel (lower panel). Arrow indicates active MMP-3. These results are representative of three independent experiments