Li Yan, Wang Kai, Jiang Yi-Zhou, Chang Xin-Wen, Dai Cai-Feng, Zheng Jing
Department of Obstetrics and Gynecology, University of Wisconsin, 202 S. Park St., Madison, WI, 53715, USA.
Cell Oncol (Dordr). 2014 Dec;37(6):429-37. doi: 10.1007/s13402-014-0206-4. Epub 2014 Nov 18.
The aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor, mediates a broad spectrum of biological processes, including ovarian growth and ovulation. Recently, we found that an endogenous AhR ligand (ITE) can inhibit ovarian cancer proliferation and migration via the AhR. Here, we tested whether 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, an exogenous AhR ligand) may exert similar anti-ovarian cancer activities using human ovarian cancer and non-cancerous human ovarian surface epithelial cells.
Two human ovarian cancer cell lines (SKOV-3 and OVCAR-3) and one human ovarian surface epithelial cell line (IOSE-385) were used. Cell proliferation and migration activities were determined using crystal violet and FluoroBlok insert system assays, respectively. AhR protein expression was assessed by Western blotting. Expression of cytochrome P450, family 1, member A1 (CYP1A1) and member B1 (CYP1B1) mRNA was assessed by qPCR. Small interfering RNAs (siRNAs) were used to knock down AhR expression.
We found that TCDD dose-dependently suppressed OVCAR-3 cell proliferation, with a maximum effect (~70% reduction) at 100 nM. However, TCDD did not affect SKOV-3 and IOSE-385 cell proliferation and migration. The estimated IC50 of TCDD for inhibiting OVCAR-3 cell proliferation was 4.6 nM. At 10 nM, TCDD time-dependently decreased AhR protein levels, while it significantly increased CYP1A1 and CYP1B1 mRNA levels in SKOV-3, OVCAR-3 and IOSE-385 cells, indicating activation of AhR signaling. siRNA-mediated AhR knockdown readily blocked TCDD-mediated suppression of OVCAR-3 cell proliferation.
Our data indicate that TCDD can suppress human ovarian cancer cell proliferation via the AhR signaling pathway and that TCDD exhibits an anti-proliferative activity in at least a subset of human ovarian cancer cells.
芳烃受体（AhR）是一种配体激活的转录因子，介导包括卵巢生长和排卵在内的广泛生物学过程。最近，我们发现一种内源性AhR配体（ITE）可通过AhR抑制卵巢癌的增殖和迁移。在此，我们使用人卵巢癌细胞和非癌性人卵巢表面上皮细胞，测试2,3,7,8-四氯二苯并对二恶英（TCDD，一种外源性AhR配体）是否可能发挥类似的抗卵巢癌活性。
使用两种人卵巢癌细胞系（SKOV-3和OVCAR-3）和一种人卵巢表面上皮细胞系（IOSE-385）。分别使用结晶紫和FluoroBlok插入系统测定法测定细胞增殖和迁移活性。通过蛋白质免疫印迹法评估AhR蛋白表达。通过定量聚合酶链反应（qPCR）评估细胞色素P450 1A1（CYP1A1）和1B1（CYP1B1）mRNA的表达。使用小干扰RNA（siRNA）敲低AhR表达。
我们发现TCDD剂量依赖性地抑制OVCAR-3细胞增殖，在100 nM时具有最大效应（约降低70%）。然而，TCDD不影响SKOV-3和IOSE-385细胞的增殖和迁移。TCDD抑制OVCAR-3细胞增殖的估计半数抑制浓度（IC50）为4.6 nM。在10 nM时，TCDD时间依赖性地降低AhR蛋白水平，同时显著增加SKOV-3、OVCAR-3和IOSE-385细胞中CYP1A1和CYP1B1 mRNA水平，表明AhR信号通路被激活。siRNA介导的AhR敲低很容易阻断TCDD介导的OVCAR-3细胞增殖抑制。
我们的数据表明，TCDD可通过AhR信号通路抑制人卵巢癌细胞增殖，并且TCDD在至少一部分人卵巢癌细胞中表现出抗增殖活性。
