ERα negative breast cancer cells restore response to endocrine therapy by combination treatment with both HDAC inhibitor and DNMT inhibitor
ERα negative breast cancer cells restore response to endocrine therapy by combination treatment with both HDAC inhibitor and DNMT inhibitor
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DOI：
10.1007/s00432-008-0354-x
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发表时间：
2008-08-01
影响因子：
3.6
通讯作者：
Shao, Zhi-Min
中科院分区：
文献类型：
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作者：
Fan, Jiang;Yin, Wen-Jin;Shao, Zhi-Min
目的 雌激素受体 α (ER α) 介导雌激素对乳腺癌细胞的生长刺激，是内分泌治疗反应的有用预测因素。据报道，DNA甲基转移酶1（DNMT1）抑制剂5-氮杂-2'-脱氧胞苷（AZA）和组蛋白脱乙酰酶（HDAC）抑制剂曲古抑菌素A（TSA）均可在ER α阴性乳腺癌细胞中诱导ER α。但诱导ERα的乳腺癌细胞是否恢复对内分泌治疗的反应还有待进一步研究。 患者及方法采用逆转录聚合酶链式反应(RT-PCR)方法探讨两种化学物质(AZA+TSA)处理ERα阴性乳腺癌细胞MDA-MB-435中ERα、PR和pS2 mRNA的变化。采用水溶性四唑盐-8（WST-8）法研究乳腺癌细胞的增殖率。使用流式细胞仪（FCW）分析这些乳腺癌细胞的细胞周期分布。使用一些裸鼠异种移植模型来进一步研究我们在体外发现的结果。 结果在本研究中，我们观察到ER α阴性乳腺癌细胞MDA-MB-435中ER α、PR和pS2的mRNA在AZA + TSA处理后重新表达。增殖测定分析显示AZA + TSA抑制MDA-MB-435细胞的增殖，添加4-OH他莫昔芬(4-OHT)进一步抑制MDA-MB-435细胞的增殖。相反，单独用4-OHT处理的细胞的增殖与载体对照相比没有显示出差异。细胞周期分析显示，AZA + TSA 处理的细胞出现 S 期停滞，通过添加雌二醇 (E2) 部分减弱这种停滞；此外，在诱导 ER α 处理的细胞中，E2 对细胞周期刺激的作用可以被 4-OHT 逆转。体内实验结果显示，AZA+TSA处理的MDA-MB-435细胞的异种移植体积小于对照（P<0.01），并且卵巢切除进一步抑制了AZA+TSA处理的细胞的异种移植体积（P<0.01）。结论我们的数据表明，DNMT1抑制剂AZA和HDAC抑制剂TSA在 恢复 ER α 阴性乳腺癌细胞对体外和体内内分泌治疗的敏感性。
Purpose Estrogen receptor alpha (ER alpha) mediates the growth stimulation of estrogen in breast cancer cells and is a useful predictive factor for response to endocrine therapy. It is reported that ER alpha was induced in ER alpha negative breast cancer cells by both DNA methyltransferase-1 (DNMT1) inhibitor 5-aza-2'-deoxycytidine (AZA) and histone deacetylase (HDAC) inhibitor trichostatin A (TSA). However, whether the breast cancer cells with induced ER alpha restore response to endocrine therapy requires to be further researched.Patients and methods Reverse transcriptase-polymerase chain reaction (RT-PCR) method was used to explore the change in the mRNA of ER alpha, PR and pS2 in the ER alpha negative breast cancer cells MDA-MB-435 treated with two chemicals (AZA + TSA). Water-soluble tetrazolium salt-8 (WST-8) method was used to study the proliferation rate of the breast cancer cells. Flow cytometer (FCW) was used to analyze the distribution of cell cycle of these breast cancer cells. Some xenograft models in nude mice were used to further study the results we found in vitro.Results In this study we observed that the mRNA of ER alpha, PR and pS2 in the ER alpha negative breast cancer cells MDA-MB-435 was re-expressed by treatment with AZA + TSA. The proliferation assay analysis showed AZA + TSA suppressed the proliferation of MDA-MB-435 cells, which were further suppressed by addition of 4-OH Tamoxifen (4-OHT). On the contrary, the proliferation of cells treated with 4-OHT alone showed no difference compared with the vehicle control. Cell cycle analysis showed AZA + TSA treated cells showed S phase arrest, which was partially attenuated by addition of estradiol (E2); furthermore, the effect of E2 on stimulation of cell cycle could be reversed by 4-OHT in the treated cells with induced ER alpha. In vivo experiment xenograft volume of MDA-MB-435 cells treated with AZA + TSA was smaller than that of the control (P < 0.01), and the xenograft of AZA + TSA treated cells was further suppressed by ovarectomy (P < 0.01).Conclusions Our data indicate that DNMT1 inhibitor AZA and HDAC inhibitor TSA play important roles in restoring sensitivity of the ER alpha negative breast cancer cells to endocrine therapy in vitro and in vivo.