Fig 2. (a) Caspase-3 cleavage after Staurosporine treatment: The left panel shows Caspase-3 cleavage in H2009 and its clones treated with 0.5μM Staurosporine for 3 hours. The right panel shows Caspase-3 cleavage after ABT-737 and Staurosporine treatment, where more caspase cleavage is observed in HB6 and HB1. Graph represents densitometric analysis of the cleaved caspase western blot in each panel. Data represents independent triplicate determinations ± SEM (standard error of mean). (b) TIMP-1 inhibits apoptosis induced by Staurosporine: TIMP-1 overexpression does not result in significant PARP-1 cleavage after 3 hrs of 0.5μM Staurosporine treatment, probably due to upregulation of Bcl-2, which plays an inhibitory role. Expression of Bcl-xL was unchanged. The side panel shows the graphical representation of cleaved PARP expression (p<0.0001, ANOVA). Data is representative of three independent experiments. C = control, S = Staurosporine treated. (c) Abrogating Bcl-2 by ABT-737 restores the PARP cleavage pattern: Treatment with 1μM ABT-737 for 24 hrs followed by 0.5μM Staurosporine from 21^st hour increased PARP cleavage in HB1 and HB6 cells. (d) Antiapoptotic function of TIMP-1 is independent of MMP activity: The T2G mutated TIMP-1 overexpressing clone showed similar pattern of PARP cleavage indicating that this activity of TIMP-1 was MMP independent.