Tributyltin or triphenyltin inhibits aromatase activity in the human granulosa-like tumor cell line KGN
Tributyltin or triphenyltin inhibits aromatase activity in the human granulosa-like tumor cell line KGN
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DOI：
10.1006/bbrc.2001.5952
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发表时间：
2001-11-23
影响因子：
3.1
通讯作者：
Nawata, H
中科院分区：
文献类型：
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作者：
Saitoh, M;Yanase, T;Nawata, H
雌性腹足动物的雄性性器官（阴茎和输精管）重叠，称为性畸变，这被广泛归因于接触三丁基锡化合物，三丁基锡化合物在世界范围内用于船舶油漆。已经假设TBT诱导的性畸变是由相对于雌激素水平增加的雄激素水平介导的，即雄激素向雌激素的转化减少（即，芳构化）。在本研究中，我们通过研究TBT或三苯基锡（TPT）对培养的人粒层细胞样肿瘤细胞系KGN中芳香化酶活性的影响来验证这一假设。用超过1000 ng/ml的TBT化合物处理对细胞具有很强的毒性，并在24 h内引起细胞立即死亡，而发现200 ng/ml引起细胞凋亡。用20 ng/ml TBT或TPT处理KGN细胞超过48 h，这是一种据报道会引起海洋物种性畸变的浓度水平，不影响细胞增殖，但显著抑制了由[H-3]H2O释放测定确定的芳香化酶活性。用20 ng/ml TBT化合物处理7天也导致由db-cAMP刺激的Δ 4-雄烯二酮产生的E2减少。TBT化合物引起的芳香化酶活性的变化与RT-PCR法测定的P450 arom mRNA的变化相当。在转染的KGN细胞中加入20 ng/ml TBT化合物后，P450 arom启动子II（1 kb）的荧光素酶活性下降，无论是在碱性状态下还是在由db-cAMP刺激的状态下。P450 arom启动子II的荧光素酶活性的Ad 4 BP依赖性增加也被这样的处理下调。这些结果表明，TBT化合物抑制芳香化酶的活性，并在转录水平上降低了KGN细胞中P450 arom mRNA的水平。因此，三丁基锡化合物对芳香化酶活性的直接抑制作用可以部分解释这些化合物在雌性物种中诱导性畸变的原因。(C)北京：科学出版社.
The superimposition of male sex organs (penis and vas deferens) in a female gastropod, called imposex, is widely attributed to the exposure to tributyltin (TBT) compounds, used world-wide in antifouling paints for ships. It has been hypothesized that the TBT-induced imposex is mediated by an increasing androgen level relative to the estrogen level, namely a decreased conversion of androgens to estrogens (i.e., aromatization). In the present study, we tested this hypothesis by examining the effects of TBT or triphenyltin (TPT) on the aromatase activity in a cultured human granulosa-like tumor cell line, KGN, which was recently established by our group. Treatment with more than 1000 ng/ml TBT compounds was very toxic to the cells and caused immediate cell death within 24 h, while 200 ng/ml was found to cause apoptosis of the cells. Treatment of the KGN cells for more than 48 h with 20 ng/ml TBT or TPT, which is a concentration level reported to cause imposex in marine species, did not affect cell proliferation but significantly suppressed the aromatase activity determined by a [H-3]H2O release assay. Treatment with 20 ng/ml TBT compounds for 7 days also resulted in a reduction of the E2 production from Delta4-androstenedione stimulated by db-cAMP. The changes in the aromatase activity by TBT compounds were associated with comparable changes in P450arom mRNA assessed by RT-PCR. The luciferase activity of the P450arom promoter II (1 kb) decreased after the addition of 20 ng/ml TBT compounds in transfected KGN cells either in a basic state or in states stimulated by db-cAMP. The Ad4BP-dependent increase in the luciferase activity of P450arom promoter II was also downregulated by such treatments. These results indicate that TBT compounds inhibited the aromatase activity and also decreased the P450arom mRNA level at the transcriptional level in KGN cells. The direct inhibitory effect of TBT compounds on the aromatase activity may therefore partly explain the induction of imposex by these compounds in female species. (C) 2001 Academic Press.