Chemotherapy augments TRAIL-induced apoptosis in breast cell lines.
Chemotherapy augments TRAIL-induced apoptosis in breast cell lines.
复制标题
DOI：
--
复制
发表时间：
1999-02
期刊：
影响因子：
11.2
通讯作者：
M. Keane;S. Ettenberg;M. Nau;E. Russell;S. Lipkowitz
中科院分区：
文献类型：
--
作者：
M. Keane;S. Ettenberg;M. Nau;E. Russell;S. Lipkowitz
研究了TRAIL凋亡通路在正常和恶性乳腺上皮细胞中的表达和功能。制备谷胱甘肽- s -转移酶(GST)-TRAIL胞外结构域融合蛋白，分析trail诱导的细胞凋亡。只有含有Fas自结合域和配体结合域同源区域的GST-TRAIL构建体才能诱导细胞凋亡。GST-TRAIL仅在8个正常乳腺细胞系和8个恶性乳腺细胞系中的1个细胞系中诱导了显著的（约90%）凋亡。所有其他品系对trail诱导的细胞凋亡均有相对抗性。激活TRAIL受体DR4和DR5在所有正常和恶性乳腺细胞系中均有表达。抑制受体TRID在四个正常乳腺细胞系中的一个和七个恶性乳腺细胞系中的两个中高度表达。DR4、DR5或TRID的表达与trail诱导的细胞凋亡的敏感性无关。用阿霉素或5-氟尿嘧啶孵育细胞系可显著增强trail诱导的大多数乳腺细胞系的凋亡。通过分级抑制分析，与单独用药相比，TRAIL与阿霉素或5-氟尿嘧啶联用具有协同作用。相比之下，美法兰和紫杉醇在少数细胞系中增强了trail诱导的细胞凋亡，而甲氨蝶呤在任何细胞系中都没有增强。阿霉素或5-氟尿嘧啶通过caspase激活介导trail诱导的细胞凋亡的增强。与TRAIL协同的化疗药物（如阿霉素）本身引起caspase-3和聚（adp -核糖）聚合酶（PARP）的裂解，其毒性被caspase抑制剂Z-Val-Ala-Asp(OMe)-CH2 （ZVAD-fmk）阻断。TRAIL和阿霉素联合使用可显著增强caspase-3和PARP的裂解，zvd -fmk也能抑制联合毒性。相比之下，不增加trail诱导的细胞凋亡的化疗药物（如甲氨蝶呤）本身引起的caspase-3和PARP的分裂很小，并且它们的毒性不受ZVAD-fmk的抑制。当与TRAIL联合使用时，这些药物也不会增加caspase-3或PARP的切割。综上所述，很少有乳腺细胞系对trail诱导的细胞凋亡敏感，正常和恶性细胞系之间的敏感性没有差异。化疗提供了一种使乳腺癌细胞对trail诱导的细胞凋亡敏感的方法。
Expression and function of the TRAIL apoptotic pathway was investigated in normal and malignant breast epithelial cells. Glutathione-S-transferase (GST)-TRAIL extracellular domain fusion proteins were produced to analyze TRAIL-induced apoptosis. Only GST-TRAIL constructs containing regions homologous to the Fas self-association and ligand binding domains could induce apoptosis. GST-TRAIL induced significant (>90%) apoptosis in just one of eight normal and one of eight malignant breast cell lines. All other lines were relatively resistant to TRAIL-induced apoptosis. Activating TRAIL receptors DR4 and DR5 were expressed in all normal and malignant breast cell lines. The inhibitory receptor TRID was highly expressed in one of four normal and two of seven malignant breast cell lines. DR4, DR5, or TRID expression did not correlate with sensitivity to TRAIL-induced apoptosis. Incubation of cell lines with doxorubicin or 5-fluorouracil significantly augmented TRAIL-induced apoptosis in most breast cell lines. By fractional inhibition analysis, the toxicity of the combination of TRAIL and doxorubicin or 5-fluorouracil was synergistic compared with either agent alone. In contrast, melphalan and paclitaxel augmented TRAIL-induced apoptosis in few cell lines, and methotrexate did not augment it in any cell line. Augmentation of TRAIL-induced apoptosis by doxorubicin or 5-fluorouracil was mediated through caspase activation. This was evidenced by the fact that chemotherapy agents that synergized with TRAIL (e.g., doxorubicin) themselves caused cleavage of caspase-3 and poly(ADP-ribose) polymerase (PARP), and their toxicity was blocked by the caspase inhibitor Z-Val-Ala-Asp(OMe)-CH2 (ZVAD-fmk). The combination of TRAIL and doxorubicin caused significantly greater caspase-3 and PARP cleavage, and the combined toxicity also was inhibited by ZVAD-fmk. In contrast, chemotherapy agents that did not augment TRAIL-induced apoptosis (e.g., methotrexate) caused minimal caspase-3 and PARP cleavage by themselves, and their toxicity was not inhibited by ZVAD-fmk. These drugs also did not increase caspase-3 or PARP cleavage when combined with TRAIL. In summary, few breast cell lines are sensitive to TRAIL-induced apoptosis, and no difference in sensitivity is found between normal and malignant cell lines. Treatment with chemotherapy provides an approach to sensitize breast cancer cells to TRAIL-induced apoptosis.