Fig. 1.
Nuclear proteasomal activity measured by suc-LLVY-MCA degradation in U937 human myelomonocytic leukemia cells after treatment with different chemotherapeutics.
Nuclei from U937 cells treated with 10−7 M adriamycin (▪), 10−7 M AraC (●), or 10−6 M VP-16 (♦), were isolated and lysed and the degradation of lactacystin-senstive suc-LLVY-MCA was quantified as proteasomal activity. Data are given as mean ± SD (n = 4).