Ubai Takanobu, Azuma Haruhito, Kotake Yatsugu, Inamoto Teruo, Takahara Kiyoshi, Ito Yuko, Kiyama Satoshi, Sakamoto Takeshi, Horie Shigeo, Muto Satoru, Takahara Shiro, Otsuki Yoshinori, Katsuoka Yoji
Department of Urology, Osaka Medical College, Takatsuki, Osaka 569-8686, Japan.
Anticancer Res. 2007 Jan-Feb;27(1A):75-88.
A unique immunosuppressant, FTY720, selectively induces apoptosis in activated lymphocytes, but not in other hematopoietic cells. The potential that this unique mechanism could provide anticancer potential by inducing apoptosis in the human renal cancer cell line, ACHN, which is resistant to cisplatin, and its molecular pathway was investigated.
The difference in drug susceptibility to FTY720 between cancer cells and non-cancer cells was examined by MTT assay and flow cytometry. Apoptosis assay, including TUNEL staining, electron microscopy and DNA electrophoresis, was performed and the molecular pathway of FTY720 was evaluated by real time RT-PCR and Western blot. The in vivo effect of FTY720 was evaluated using a murine zenograft model.
The susceptibility to FTY720 was significantly higher in ACHN cancer cells than in normal renal tubular cells (HK-2) at a concentration of less than 30 microM, while the susceptibility to cisplatin was even higher in HK-2 than in ACHN. Cancer cells treated with FTY720 showed findings typical of apoptosis with highly condensed nuclear chromatin and fragmented nuclei. The molecular analysis revealed that FTY720-induced apoptosis was mediated by a Fas-independent, Bcl-associated signal transduction pathway, and that inhibition of extracellular signal-regulated kinase (ERK) activity was involved in its underlying mechanism of action. FTY720 treatment significantly prevented in vivo tumor growth without any severe adverse reactions, while cisplatin treatment did not inhibit tumor growth despite exhibiting severe side-effects.
FTY720 may be a promising candidate for a new anticancer therapy of renal cancer.
一种独特的免疫抑制剂FTY720可选择性地诱导活化淋巴细胞凋亡，但不会诱导其他造血细胞凋亡。研究了这种独特机制通过诱导对顺铂耐药的人肾癌细胞系ACHN凋亡发挥抗癌作用的可能性及其分子途径。
通过MTT法和流式细胞术检测癌细胞与非癌细胞对FTY720的药物敏感性差异。进行凋亡检测，包括TUNEL染色、电子显微镜检查和DNA电泳，并通过实时RT-PCR和蛋白质免疫印迹法评估FTY720的分子途径。使用小鼠异种移植模型评估FTY720的体内作用。
在浓度低于30微摩尔时，ACHN癌细胞对FTY720的敏感性显著高于正常肾小管细胞（HK-2），而HK-2对顺铂的敏感性甚至高于ACHN。用FTY720处理的癌细胞表现出典型的凋亡特征，核染色质高度浓缩，细胞核碎片化。分子分析表明，FTY720诱导的凋亡由Fas非依赖性、Bcl相关信号转导途径介导，细胞外信号调节激酶（ERK）活性的抑制参与其潜在作用机制。FTY720治疗显著抑制体内肿瘤生长且无任何严重不良反应，而顺铂治疗尽管有严重副作用但未抑制肿瘤生长。
FTY720可能是一种有前景的肾癌新抗癌治疗候选药物。
