Department of Obstetrics and Gynecology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA.
Mol Cancer Ther. 2012 Jul;11(7):1587-97. doi: 10.1158/1535-7163.MCT-11-1058. Epub 2012 May 2.
The hedgehog pathway has been implicated in the formation and maintenance of a variety of malignancies, including ovarian cancer; however, it is unknown whether hedgehog signaling is involved in ovarian cancer chemoresistance. The goal of this study was to determine the effects of antagonizing the hedgehog receptor, Smoothened (Smo), on chemotherapy response in ovarian cancer. Expression of hedgehog pathway members was assessed in three pairs of parental and chemotherapy-resistant ovarian cancer cell lines (A2780ip2/A2780cp20, SKOV3ip1/SKOV3TRip2, HeyA8/HeyA8MDR) using quantitative PCR and Western blot analysis. Cell lines were exposed to increasing concentrations of two different Smo antagonists (cyclopamine, LDE225) alone and in combination with carboplatin or paclitaxel. Selective knockdown of Smo, Gli1, or Gli2 was achieved using siRNA constructs. Cell viability was assessed by MTT assay. A2780cp20 and SKOV3TRip2 orthotopic xenografts were treated with vehicle, LDE225, paclitaxel, or combination therapy. Chemoresistant cell lines showed higher expression (>2-fold, P < 0.05) of hedgehog signaling components compared with their respective parental lines. Smo antagonists sensitized chemotherapy-resistant cell lines to paclitaxel, but not to carboplatin. LDE225 treatment also increased sensitivity of ALDH-positive cells to paclitaxel. A2780cp20 and SKOV3TRip2 xenografts treated with combined LDE225 and paclitaxel had significantly less tumor burden than those treated with vehicle or either agent alone. Increased taxane sensitivity seems to be mediated by a decrease in P-glycoprotein (MDR1) expression. Selective knockdown of Smo, Gli1, or Gli2 all increased taxane sensitivity. Smo antagonists reverse taxane resistance in chemoresistant ovarian cancer models, suggesting combined anti-hedgehog and chemotherapies could provide a useful therapeutic strategy for ovarian cancer.
刺猬途径已被牵连到多种恶性肿瘤的形成和维持中，包括卵巢癌;然而，尚不清楚刺猬信号是否参与卵巢癌的化疗耐药性。本研究的目的是确定拮抗刺猬受体 smoothened (Smo) 对卵巢癌化疗反应的影响。使用定量 PCR 和 Western blot 分析评估了三对亲本和化疗耐药性卵巢癌细胞系 (A2780ip2/A2780cp20、SKOV3ip1/SKOV3TRip2、HeyA8/HeyA8MDR) 中刺猬途径成员的表达。细胞系单独或与卡铂或紫杉醇联合暴露于两种不同 Smo 拮抗剂 (环巴胺、LDE225) 的递增浓度下。使用 siRNA 构建体实现了 Smo、Gli1 或 Gli2 的选择性敲低。通过 MTT 测定评估细胞活力。用载体、LDE225、紫杉醇或联合治疗处理 A2780cp20 和 SKOV3TRip2 原位异种移植。与各自的亲本系相比，耐药细胞系显示出更高的刺猬信号成分表达 (>2 倍，P < 0.05)。Smo 拮抗剂使化疗耐药细胞系对紫杉醇敏感，但对卡铂不敏感。LDE225 处理还增加了 ALDH 阳性细胞对紫杉醇的敏感性。用联合的 LDE225 和紫杉醇治疗的 A2780cp20 和 SKOV3TRip2 异种移植物的肿瘤负担明显小于用载体或单独用任一药物治疗的异种移植物。紫杉醇敏感性的增加似乎是通过降低 P-糖蛋白 (MDR1) 表达介导的。Smo、Gli1 或 Gli2 的选择性敲低均增加了紫杉醇的敏感性。Smo 拮抗剂逆转了化疗耐药性卵巢癌模型中的紫杉醇耐药性，表明联合抗刺猬和化疗可能为卵巢癌提供有用的治疗策略。
