Department of Urology, National Defense Medical College, Tokorozawa, Saitama, Japan.
Urology. 2010 Sep;76(3):764.e7-13. doi: 10.1016/j.urology.2010.04.042. Epub 2010 Jul 13.
To investigate the combined effect of the histone deacetylase (HDAC) inhibitor suberoylanilide hydroxamic acid (SAHA) and the protease inhibitor ritonavir on renal cancer cells.
Renal cancer cells (769P, 786O, A498, ACHN, Caki-1) and renal proximal tubule epithelial cells were treated with SAHA (0-5 μM) with or without ritonavir (0-50 μM). Cell viability, clonogenecity, and changes in cell cycle were evaluated. The expression of acetylated histone, retinoblastoma protein (Rb), phosphorylated Rb, histone deacetylases, X-linked inhibitor of apoptosis, survivin, and active caspase 3 was assessed using Western blot analysis.
SAHA induced histone acetylation and Rb dephosphorylation and inhibited cell growth in a time- and dose-dependent manner. SAHA and ritonavir combined inhibited cell proliferation effectively and promoted histone acetylation and Rb dephosphorylation but only slightly affected renal proximal tubule epithelial cell survival. The combination induced the accumulation of the sub-G(1) fraction, decreased the expression of X-linked inhibitor of apoptosis and survivin, and increased active caspase 3, thus inducing apoptosis. It also inhibited the expression of histone deacetylases.
Combination therapy using SAHA and ritonavir inhibited the proliferation of renal cancer cells effectively, perhaps by inhibiting both histone deacetylase function and expression. It might be a useful new regimen for treating renal cancer.
研究组蛋白去乙酰化酶（HDAC）抑制剂 SAHA 和蛋白酶抑制剂利托那韦联合对肾癌细胞的作用。
用 SAHA（0-5 μM）联合或不联合利托那韦（0-50 μM）处理肾癌细胞（769P、786O、A498、ACHN、Caki-1）和肾近端小管上皮细胞，检测细胞活力、集落形成能力和细胞周期变化。用 Western blot 分析评估乙酰化组蛋白、视网膜母细胞瘤蛋白（Rb）、磷酸化 Rb、组蛋白去乙酰化酶、X 连锁凋亡抑制蛋白、存活素和活性半胱氨酸天冬氨酸蛋白酶 3 的表达。
SAHA 诱导组蛋白乙酰化和 Rb 去磷酸化，呈时间和剂量依赖性抑制细胞生长。SAHA 和利托那韦联合有效抑制细胞增殖，促进组蛋白乙酰化和 Rb 去磷酸化，但对肾近端小管上皮细胞存活的影响较小。该联合诱导亚 G1 期细胞群积累，降低 X 连锁凋亡抑制蛋白和存活素的表达，增加活性半胱氨酸天冬氨酸蛋白酶 3，从而诱导细胞凋亡。它还抑制组蛋白去乙酰化酶的表达。
SAHA 和利托那韦联合治疗可有效抑制肾癌细胞的增殖，可能通过抑制组蛋白去乙酰化酶的功能和表达。它可能是治疗肾癌的一种有用的新方案。
