Department of Urology, Air Force General Hospital, Beijing, China.
PLoS One. 2013 Sep 23;8(9):e74922. doi: 10.1371/journal.pone.0074922. eCollection 2013.
Sodium butyrate, a histone deacetylase inhibitor, has emerged as a promising anticancer drug for multiple cancers. Recent studies have indicated that sodium butyrate could inhibit the progression of prostate cancer; however, the exact mechanism is still unclear. The aim of this study was to investigate the mechanism of sodium butyrate action in prostate cancer DU145 cells.
The inhibitory effects of NaB on cell growth were detected by the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrrazolium bromide assay. Cell apoptosis was determined by flow cytometric analysis of DU145 cells stained with annexin V and PI. Hoechst 33258 and fluorescence microscopes were used to observe the nuclear morphology of DU145 cells after treatment with NaB. ANXA1 knockdown cells were established through transfection with ANXA1 siRNA. ANXA1 mRNA levels were measured by qRT-PCR. Bcl-2, Bax, ANXA1, ERK1/2 and pERK1/2 were detected by western blot.
NaB significantly inhibited the growth and induction apoptosis of DU145 and PC3 cells in a dose-dependent manner. Expression of the anti-apoptosis gene Bcl-xl and Bcl-2 in DU145 cells are decreased and expression of the pro-apoptosis gene Bax and Bak increased after NaB treatment. Further studies have demonstrated that NaB up-regulated the expression of ANXA1 and that the tumor inhibition action of NaB was reduced markedly through knockdown of the ANXA1 gene in DU145 cells. Moreover, the siANXA1 cells showed that cell proliferation increased and cell apoptosis was induced by the inactivation of extracellular regulated kinase (ERK).
Our results support a significant correlation between NaB functions and ANXA1 expression in prostate cancer, and pave the way for further studying the molecular mechanism of NaB actions in cancers.
丁酸钠是一种组蛋白去乙酰化酶抑制剂，已成为多种癌症有前途的抗癌药物。最近的研究表明，丁酸钠可以抑制前列腺癌的进展；然而，确切的机制尚不清楚。本研究旨在探讨丁酸钠在前列腺癌细胞 DU145 中的作用机制。
通过 3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐测定法检测 NaB 对细胞生长的抑制作用。通过流式细胞术分析用 annexin V 和 PI 染色的 DU145 细胞来确定细胞凋亡。用 Hoechst 33258 和荧光显微镜观察 NaB 处理后 DU145 细胞的核形态。通过转染 ANXA1 siRNA 建立 ANXA1 敲低细胞。通过 qRT-PCR 测量 ANXA1 mRNA 水平。通过 Western blot 检测 Bcl-2、Bax、ANXA1、ERK1/2 和 pERK1/2。
NaB 显著抑制 DU145 和 PC3 细胞的生长并呈剂量依赖性诱导细胞凋亡。Bcl-xl 和 Bcl-2 的抗凋亡基因在 DU145 细胞中的表达降低，Bax 和 Bak 的促凋亡基因表达增加。进一步的研究表明，NaB 上调了 ANXA1 的表达，并且通过在 DU145 细胞中敲低 ANXA1 基因，NaB 的肿瘤抑制作用明显降低。此外，siANXA1 细胞显示细胞增殖增加，细胞凋亡通过细胞外调节激酶 (ERK) 的失活而诱导。
我们的结果支持 NaB 功能与前列腺癌中 ANXA1 表达之间存在显著相关性，并为进一步研究 NaB 在癌症中的作用分子机制铺平了道路。
