Zheng Yichun, Ishiguro Hitoshi, Ide Hiroki, Inoue Satoshi, Kashiwagi Eiji, Kawahara Takashi, Jalalizadeh Mehrsa, Reis Leonardo O, Miyamoto Hiroshi
Department of Urology (Y.Z.), Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, China; Departments of Pathology and Urology (Y.Z., H.Is., H.Id., S.I., E.K., T.K., M.J., L.O.R., H.M.), Johns Hopkins University School of Medicine, Baltimore, Maryland 21287; Department of Pathology and Laboratory Medicine (Y.Z., H.Is., T.K., H.M.), University of Rochester Medical Center, Rochester, New York 14642; and Photocatalyst Group (H.Is.), Kanagawa Academy of Science and Technology, Kawasaki 210-0821, Japan.
Mol Endocrinol. 2015 Oct;29(10):1486-97. doi: 10.1210/me.2015-1128. Epub 2015 Aug 31.
Recent evidence indicates that glucocorticoids (GCs) suppress bladder cancer cell invasion through the GC receptor (GR) pathway, whereas androgen-mediated androgen receptor (AR) signals induce bladder tumor progression. In this study, we assessed the effects of 2-(4-acetoxyphenyl)-2-chloro-N-methyl-ethylammonium chloride (compound A [CpdA]), which was shown to function as not only a GR modulator but also an AR antagonist, on the growth of bladder cancer. In GR/AR-positive cells, CpdA strongly inhibited cell proliferation and colony formation as well as increased G1 phase-arrested cell population and apoptosis. Specifically, CpdA at 1μM decreased cell viability of TCCSUP/UMUC3-control-short hairpin RNA (shRNA), TCCSUP/UMUC3-GR-shRNA, and TCCSUP/UMUC3-AR-shRNA by 50%/67%, 25%/26%, and 38%/58%, respectively. CpdA also inhibited cell migration and invasion of GR/AR-positive (up to 61% decrease) and GR-positive/AR-silencing (up to 51% decrease) lines and, less strongly, those of GR-silencing/AR-positive lines (up to 35% decrease). Additionally, in UMUC3-control xenograft-bearing male mice, CpdA more strongly suppressed tumor growth than dexamethasone or hydroxyflutamide. In reporter gene assays, CpdA failed to induce GR transactivation, whereas it antagonized dihydrotestosterone-enhanced AR transactivation. In contrast, CpdA reduced nuclear factor (NF)-κB and activator protein 1 transcriptional activities, indicating induction of GR-mediated transrepression. Correspondingly, the expression of NF-κB-related molecules, matrix metalloproteinase-2, matrix metalloproteinase-9, interleukin-6, and vascular endothelial growth factor, was significantly down-regulated by CpdA in control lines but not in GR-silencing cells. Moreover, coimmunoprecipitation showed that CpdA promoted the interactions between GR and NF-κB. Thus, CpdA likely inhibits bladder cancer growth predominantly via inducing GR transrepression and at least partially mediated through the AR pathway, suggesting its effects more beneficial than GCs/pure GR ligands or AR antagonists.
近期证据表明，糖皮质激素（GCs）通过糖皮质激素受体（GR）途径抑制膀胱癌细胞侵袭，而雄激素介导的雄激素受体（AR）信号则诱导膀胱肿瘤进展。在本研究中，我们评估了2-（4-乙酰氧基苯基）-2-氯-N-甲基乙氯化铵（化合物A [CpdA]）对膀胱癌生长的影响，该化合物不仅可作为GR调节剂，还可作为AR拮抗剂。在GR/AR阳性细胞中，CpdA强烈抑制细胞增殖和集落形成，并增加G1期阻滞细胞群体和细胞凋亡。具体而言，1μM的CpdA分别使TCCSUP/UMUC3-对照短发夹RNA（shRNA）、TCCSUP/UMUC3-GR-shRNA和TCCSUP/UMUC3-AR-shRNA的细胞活力降低50%/67%、25%/26%和38%/58%。CpdA还抑制GR/AR阳性（降低高达61%）和GR阳性/AR沉默（降低高达51%）细胞系的细胞迁移和侵袭，对GR沉默/AR阳性细胞系的抑制作用较弱（降低高达35%）。此外，在携带UMUC3对照异种移植瘤的雄性小鼠中，CpdA比地塞米松或羟基氟他胺更强烈地抑制肿瘤生长。在报告基因测定中，CpdA未能诱导GR反式激活，而它拮抗二氢睾酮增强的AR反式激活。相反，CpdA降低了核因子（NF）-κB和激活蛋白1的转录活性，表明诱导了GR介导的反式抑制。相应地，在对照细胞系中，CpdA显著下调了NF-κB相关分子、基质金属蛋白酶-2、基质金属蛋白酶-9、白细胞介素-6和血管内皮生长因子的表达，但在GR沉默细胞中未下调。此外，免疫共沉淀显示CpdA促进了GR与NF-κB之间的相互作用。因此，CpdA可能主要通过诱导GR反式抑制来抑制膀胱癌生长，并且至少部分通过AR途径介导，这表明其效果比GCs/纯GR配体或AR拮抗剂更有益。
