Fulda S, Sieverts H, Friesen C, Herr I, Debatin K M
Division of Hematology/Oncology, University Children's Hospital, German Cancer Research Center, Heidelberg.
Cancer Res. 1997 Sep 1;57(17):3823-9.
Anticancer agents have been shown to trigger apoptosis in chemosensitive tumors such as neuroblastomas. We previously identified activation of the CD95 system as one of the key mechanisms for doxorubicin-induced apoptosis in leukemic T cells. Here, we report that therapeutic concentrations of doxorubicin, cisplatinum, and VP-16 led to induction of CD95 receptor and CD95 ligand (CD95-L) that mediated cell death in chemosensitive neuroblastoma cells. Using F(ab')2 anti-CD95 antibody fragments to interfere with CD95-L-receptor interaction markedly reduced apoptosis induced by those drugs in vitro. Cyclosporin A inhibited induction of CD95 mRNA and CD95-L mRNA and blocked drug-mediated apoptosis. Drug-induced apoptosis involved activation of caspases (interleukin 1beta-converting enzyme/Ced-3-like proteases) and processing of the prototype caspase substrate PARP and was completely blocked by benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone, a peptide inhibitor of caspases. In addition, neuroblastoma cells that were resistant to CD95-triggered apoptosis also displayed cross-resistance to chemotherapeutic agents. These data provide new clues for understanding the molecular requirements for drug-induced apoptosis in chemosensitive neuroblastoma cells by demonstrating that cell death was mediated via the CD95-L-receptor system and may open new avenues for targeting drug resistance of neuroblastoma.
抗癌药物已被证明可在诸如神经母细胞瘤等化疗敏感肿瘤中引发细胞凋亡。我们之前已确定CD95系统的激活是阿霉素诱导白血病T细胞凋亡的关键机制之一。在此，我们报告，治疗浓度的阿霉素、顺铂和依托泊苷可诱导CD95受体和CD95配体（CD95-L）的产生，它们介导了化疗敏感神经母细胞瘤细胞的死亡。使用F(ab')2抗CD95抗体片段干扰CD95-L-受体相互作用，可显著降低这些药物在体外诱导的细胞凋亡。环孢菌素A抑制CD95 mRNA和CD95-L mRNA的诱导，并阻断药物介导的细胞凋亡。药物诱导的细胞凋亡涉及半胱天冬酶（白细胞介素1β转换酶/Ced-3样蛋白酶）的激活以及典型半胱天冬酶底物PARP的加工，并且被半胱天冬酶的肽抑制剂苄氧羰基-Val-Ala-Asp-氟甲基酮完全阻断。此外，对CD95触发的细胞凋亡具有抗性的神经母细胞瘤细胞对化疗药物也表现出交叉抗性。这些数据通过证明细胞死亡是通过CD95-L-受体系统介导的，为理解化疗敏感神经母细胞瘤细胞中药物诱导细胞凋亡的分子要求提供了新线索，并可能为针对神经母细胞瘤的耐药性开辟新途径。
