Yu Chunrong, Friday Bret B, Lai Jin-Ping, McCollum Andrea, Atadja Peter, Roberts Lewis R, Adjei Alex A
Department of Oncology, Mayo Clinic, Rochester, Minnesota, USA.
Clin Cancer Res. 2007 Feb 15;13(4):1140-8. doi: 10.1158/1078-0432.CCR-06-1751.
To evaluate the effects of combining the multiple receptor tyrosine kinase inhibitor AEE788 and histone deacetylase (HDAC) inhibitors on cytotoxicity in a broad spectrum of cancer cell lines, including cisplatin-resistant ovarian adenocarcinoma cells.
Multiple cancer cell lines were treated in vitro using AEE788 and HDAC inhibitors (LBH589, LAQ824, and trichostatin A), either alone or in combination. Effects on cytotoxicity were determined by growth and morphologic assays. Effects of the combination on cell signaling pathways were determined by Western blotting, and the results were confirmed using pathway-specific inhibitors and transfection of constitutively active proteins.
Cell treatment with AEE788 and HDAC inhibitors (LBH589, LAQ824, and trichostatin A) in combination resulted in synergistic induction of apoptosis in non-small cell lung cancer (MV522, A549), ovarian cancer (SKOV-3), and leukemia (K562, Jurkat, and ML-1) cells and in OV202hp cisplatin-resistant human ovarian cancer cells. AEE788 alone or in combination with LBH589 inactivated mitogen-activated protein kinase (MAPK) and Akt cascades. Inhibition of either MAPK and/or Akt enhanced LBH589-induced apoptosis. In contrast, constitutively active MAPK or Akt attenuated LBH589 or LBH589 + AEE788-induced apoptosis. Increased apoptosis was correlated with enhanced reactive oxygen species (ROS) generation. The free radical scavenger N-acetyl-l-cysteine not only substantially suppressed the ROS accumulation but also blocked the induction of apoptosis mediated by cotreatment with AEE788 and LBH589.
Collectively, these results show that MAPK and Akt inactivation along with ROS generation contribute to the synergistic cytotoxicity of the combination of AEE788 and HDAC inhibitors in a variety of human cancer cell types. This combination regimen warrants further preclinical and possible clinical study for a broad spectrum of cancers.
评估多受体酪氨酸激酶抑制剂AEE788与组蛋白去乙酰化酶（HDAC）抑制剂联合使用对多种癌细胞系（包括顺铂耐药的卵巢腺癌细胞）细胞毒性的影响。
使用AEE788和HDAC抑制剂（LBH589、LAQ824和曲古抑菌素A）单独或联合对多种癌细胞系进行体外处理。通过生长和形态学检测确定对细胞毒性的影响。通过蛋白质印迹法确定联合用药对细胞信号通路的影响，并使用通路特异性抑制剂和组成型活性蛋白转染来确认结果。
用AEE788和HDAC抑制剂（LBH589、LAQ824和曲古抑菌素A）联合处理细胞，可协同诱导非小细胞肺癌（MV522、A549）、卵巢癌（SKOV-3）、白血病（K562、Jurkat和ML-1）细胞以及OV202hp顺铂耐药的人卵巢癌细胞凋亡。单独使用AEE788或与LBH589联合使用可使丝裂原活化蛋白激酶（MAPK）和Akt级联失活。抑制MAPK和/或Akt可增强LBH589诱导的凋亡。相反，组成型活性MAPK或Akt可减弱LBH589或LBH589 + AEE788诱导的凋亡。凋亡增加与活性氧（ROS）生成增强相关。自由基清除剂N-乙酰-L-半胱氨酸不仅可显著抑制ROS积累，还可阻断AEE788和LBH589联合处理介导的凋亡诱导。
总体而言，这些结果表明，MAPK和Akt失活以及ROS生成有助于AEE788和HDAC抑制剂联合使用对多种人类癌细胞类型产生协同细胞毒性。这种联合方案值得针对多种癌症进行进一步的临床前研究以及可能的临床研究。
