Ji Xi-wei, Chen Guang-ping, Song Yan, Hua Ming, Wang Li-jie, Li Liang, Yuan Yin, Wang Si-yuan, Zhou Tian-yan, Lu Wei
Department of Pharmaceutics, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
Institute of Clinical Pharmacology, Peking University First Hospital, Beijing 100191, China.
Acta Pharmacol Sin. 2015 Oct;36(10):1246-55. doi: 10.1038/aps.2015.14. Epub 2015 May 4.
Sulfotransferase-catalyzed sulfation is the most important pathway for inactivating estrogens. Thus, activation of estrogen sulfotransferase (EST) may be an alternative approach for the treatment of estrogen-dependent breast cancer. In this study we investigated the involvement of EST in anti-breast cancer effects of the dithiocarbamate derivative TM208 in vitro and in vivo.
The viability of human breast cancer MCF-7 cells was determined using a SBB assay. Nude mice bearing MCF-7 cells were orally administered TM208 (50 and 150 mg·kg(-1)·d(-1)) for 18 days. The xenograft tumors and uteri were collected. The mRNA expression of EST was examined with real-time PCR. EST protein was detected with Western blot, ELISA or immunohistochemical staining assays. A radioactive assay was used to measure the EST activity. Uterotropic bioassay was used to examine the uterine estrogen responses.
Treatment with TM208 (10, 15 and 20 μmol/L) concentration-dependently increased EST expression in MCF-7 cells in vitro. Co-treatment with triclosan, an inhibitor of sulfonation, abolished TM208-induced cytotoxicity in MCF-7 cells. TM208 exhibited an apparent anti-estrogenic property: it exerted more potent cytotoxicity in E2-treated MCF-7 cells. In the nude mice bearing MCF-7 cells, TM208 administration time-dependently increased the expression and activity of EST, and blocked the gradual increase of E2 concentration in the xenograft tumors. Furthermore, TM208 administration blocked the estrogens-stimulated uterine enlargement. Tamoxifen, a positive control drug, produced similar effects on the expression and activity of EST in vitro and in vivo.
The induction of EST and reduction of estrogen concentration contribute to the anti-breast cancer action of TM208 and tamoxifen. TM208 may be developed as anticancer drug for the treatment of estrogen receptor-positive breast cancer.
硫酸转移酶催化的硫酸化作用是雌激素失活的最重要途径。因此，激活雌激素硫酸转移酶（EST）可能是治疗雌激素依赖性乳腺癌的一种替代方法。在本研究中，我们在体外和体内研究了EST在二硫代氨基甲酸盐衍生物TM208抗乳腺癌作用中的参与情况。
使用SBB测定法测定人乳腺癌MCF-7细胞的活力。给携带MCF-7细胞的裸鼠口服TM208（50和150 mg·kg(-1)·d(-1)），持续18天。收集异种移植肿瘤和子宫。用实时PCR检测EST的mRNA表达。用蛋白质免疫印迹法、酶联免疫吸附测定法或免疫组织化学染色法检测EST蛋白。用放射性测定法测量EST活性。用子宫生物测定法检测子宫雌激素反应。
用TM208（10、15和20 μmol/L）处理在体外浓度依赖性地增加了MCF-7细胞中EST的表达。与磺化抑制剂三氯生共同处理消除了TM208诱导的MCF-7细胞的细胞毒性。TM208表现出明显的抗雌激素特性：它在E2处理的MCF-7细胞中发挥更强的细胞毒性。在携带MCF-7细胞的裸鼠中，给予TM208时间依赖性地增加了EST的表达和活性，并阻断了异种移植肿瘤中E2浓度的逐渐升高。此外，给予TM208阻断了雌激素刺激的子宫增大。阳性对照药物他莫昔芬在体外和体内对EST的表达和活性产生了类似的影响。
EST的诱导和雌激素浓度的降低有助于TM208和他莫昔芬的抗乳腺癌作用。TM208可能被开发为治疗雌激素受体阳性乳腺癌的抗癌药物。
