Wang J D, Takahara S, Nonomura N, Ichimaru N, Toki K, Azuma H, Matsumiya K, Okuyama A, Suzuki S
Department of Urology, Osaka University Medical School, Suita-city, Japan.
Prostate. 1999 Jun 15;40(1):50-5. doi: 10.1002/(sici)1097-0045(19990615)40:1<50::aid-pros6>3.0.co;2-n.
We previously reported that FTY720, a metabolite from Isaria sinclairii, induced some cancer cells to undergo apoptosis, and that FTY720-induced apoptosis was not related to Fas-antigens. In this study we investigated whether FTY720 was able to induce apoptosis in an androgen-independent prostate cancer cell line, DU145, which is not only resistant to androgen-withdrawal-induced apoptosis but also Fas- and TNF-alpha-mediated apoptosis.
Cell survival and morphological change were examined and apoptosis was confirmed by DNA isolation and analysis of DNA fragmentation. Caspase activation was studied by using anti-caspase-1 and anti-caspase-3 antibodies. To determine whether caspase activation is central to FTY720-induced apoptosis, caspase inhibitor was added to the media 24 hr prior to the addition of FTY720.
We found that FTY720 rapidly induced apoptosis in DU145 cells, and that caspase-3 was activated during FTY720-induced apoptosis. In contrast, normal human prostate stromal cells were resistant to FTY720. Furthermore, FTY720-induced apoptosis was prevented by caspase-3 inhibitor.
The data in this report show that FTY720 is a potential strong antitumor agent for cell line DU145, and provide the first evidence for involvement of caspase-3 in apoptosis of an androgen-independent prostate cancer cell line. Activation of such caspases may provide a means for eliminating androgen-independent prostate cancer in humans.
我们之前报道过，来自蝉拟青霉的代谢产物FTY720可诱导某些癌细胞发生凋亡，且FTY720诱导的凋亡与Fas抗原无关。在本研究中，我们调查了FTY720是否能够诱导雄激素非依赖性前列腺癌细胞系DU145发生凋亡，该细胞系不仅对雄激素撤除诱导的凋亡具有抗性，而且对Fas和肿瘤坏死因子-α介导的凋亡也具有抗性。
检测细胞存活情况和形态变化，并通过DNA分离和DNA片段分析来确认凋亡。使用抗半胱天冬酶-1和抗半胱天冬酶-3抗体研究半胱天冬酶激活情况。为了确定半胱天冬酶激活是否是FTY720诱导凋亡的关键，在添加FTY720前24小时向培养基中加入半胱天冬酶抑制剂。
我们发现FTY720可迅速诱导DU145细胞凋亡，且在FTY720诱导凋亡过程中半胱天冬酶-3被激活。相比之下，正常人类前列腺基质细胞对FTY720具有抗性。此外，半胱天冬酶-3抑制剂可阻止FTY720诱导的凋亡。
本报告中的数据表明，FTY720是DU145细胞系潜在的强效抗肿瘤药物，并首次提供了半胱天冬酶-3参与雄激素非依赖性前列腺癌细胞系凋亡的证据。此类半胱天冬酶的激活可能为消除人类雄激素非依赖性前列腺癌提供一种方法。
