Figure 9. Effect of either leupeptin or ALLM on Ca_o²⁺-induced filamin A cleavage and cell migration.

DU145 (A) and PC-3 (B) cells were serum deprived overnight last hour with 20 μM leupeptin (Leu) or ALLM, and then stimulated with or without 3 mM CaCl₂ for 1 hr. The cells were lysed, and equal amounts of cellular proteins were processed for immunoblotting using the antibodies against filamin A and tubulin. Con, control; FL, full length of filamin A; 180 Fr, 180 kD fragment of filamin A; and Tub, tubulin. (C) The cells were seeded in 24-well plates with Transwell filters in the presence and absence of leupeptin or ALLM, and then analyzed cell migration in response to Ca_o²⁺. The data represent means of forty fields with duplicate samples in two experiments. *P < 0.05 and **P < 0.01.