Bortezomib promotes cytotoxicity of cytostatic agents. Control B-cell line L1309, control Jurkat T-cell line, and HL B-cell lines (untreated or pretreated with bortezomib, 5 nM, 48 hours) were treated with STS (0.5 μM), etoposide (50 μM), doxorubicin (1 μM), vinblastine (0.2 μM), or cisplatin (200 μM) and incubated for 24 hours. (A) Viability was assayed by XTT test. The means ±SD are from 3 individual experiments performed in triplicate. (B) PARP cleavage was detected in nuclear extracts by mouse anti-PARP antibody.