Figure 6.

MCB contain actin fragments similar to those obtained following cleavage with granzyme B. Western blots of tumor lysate obtained from fresh-frozen MCB tumors (lanes 1 and 2) or purified nonmuscle actin either uncut (lane 3), cleaved with 50 mM granzyme B in the presence (lane 4) or absence (lane 5) of iodoacetamide, or caspase-3 (lane 6) were stained for actin. Caspase-3 in the absence of actin (lane 7) yielded some higher molecular weigh background staining, whereas no staining was observed for granzyme B in the absence of actin (lane 8).