(A) Tumor sections were stained for apoptosis by TUNEL staining. Data shown are representative fields. (B) Quantitation of apoptotic cells indicated an increase in number of TUNEL-positive cells per microscopic field in Ad-MMP-2 treated cells. Bars represent the mean and standard error of the mean of three sections from three animals of the same treatment. (C) Processing of PARP and caspases-8, -9 and -3 was detected in total cell lysates from the subcutaneous tumors of mice, which received mock, Ad-SV and Ad-MMP-2. Representative results obtained from the tumor of one mouse per treatment condition are shown. (D) Immunohistochemical analysis of Fas, Fas-L, TIMP-3 and Bid showing increased expression of these proteins in Ad-MMP-2-treated tumors compared to mock and Ad-SV controls.