Oncogene Research Unit/Cancer Prevention Unit, Tochigi Cancer Center Research Institute, 4-9-13 Yonan, Utsunomiya-shi, Tochigi 320-0834, Japan.
J Pharmacol Exp Ther. 2010 Mar;332(3):795-802. doi: 10.1124/jpet.109.162768. Epub 2009 Dec 2.
Activating mutation of the fibroblast growth factor receptor-3 (FGFR3) gene is known as a key molecular event in both oncogenesis and cell proliferation of low-grade noninvasive human bladder urothelial carcinoma (UC), which is characterized by frequent intravesical recurrence. In this study, we investigated the antitumor potentiality of 1-tert-butyl-3-[6-(3,5-dimethoxy-phenyl)-2-(4-diethylamino-butylamino)-pyrido[2,3-d]pyrimidin-7-yl]-urea (PD173074), a small-molecule FGFR3-selective tyrosine kinase inhibitor (TKI), as a therapeutic modality using eight UC cell lines. In our in vitro cell proliferation assay, PD173074 suppressed cell proliferation remarkably in two cell lines, namely, UM-UC-14 and MGHU3, which expressed mutated FGFR3 protein. In contrast, the other six cell lines expressing wild-type FGFR3 or without FGFR3 expression were resistant to PD173074 treatment. Cell cycle analysis revealed the growth inhibitory effect of PD173074 was associated with arrest at G(1)-S transition in a dose-depending manner. Furthermore, we observed an inverse relationship between Ki-67 and p27/Kip1 expression after PD173074 treatment, suggesting that up-regulation of p27 recruited UC cells harboring activating FGFR3 mutations in G(1) that was analogous with the other receptor TKIs acting on the epidermal growth factor receptors. In the mouse xenograft models using subcutaneously transplanted UM-UC-14 and MGHU3, orally administered PD173074 suppressed tumor growth and induced apoptotic changes comparable with the results of our in vitro assay. These findings elucidated the effectiveness of molecular targeted approach for bladder UC harboring FGFR3 mutations and the potential utility to decrease the intravesical recurrence of nonmuscle invasive bladder UC after transurethral surgical resection.
成纤维细胞生长因子受体-3（FGFR3）基因的激活突变被认为是低级别非浸润性人膀胱尿路上皮癌（UC）发生和细胞增殖的关键分子事件，其特征是频繁的膀胱内复发。在这项研究中，我们使用 8 种 UC 细胞系研究了 1-叔丁基-3-[6-（3,5-二甲氧基-苯基）-2-（4-二乙氨基丁基氨基）-吡啶并[2,3-d]嘧啶-7-基]-脲（PD173074）作为一种治疗方法的抗肿瘤潜力，这是一种小分子 FGFR3 选择性酪氨酸激酶抑制剂（TKI）。在我们的体外细胞增殖测定中，PD173074 显著抑制了两种表达突变 FGFR3 蛋白的细胞系，即 UM-UC-14 和 MGHU3 的细胞增殖。相比之下，另外六种表达野生型 FGFR3 或没有 FGFR3 表达的细胞系对 PD173074 治疗具有抗性。细胞周期分析显示 PD173074 的生长抑制作用与剂量依赖性地 G1-S 期转变阻滞有关。此外，我们观察到 PD173074 治疗后 Ki-67 和 p27/Kip1 表达之间存在反比关系，表明在表皮生长因子受体上作用的其他受体 TKI 类似地募集携带激活 FGFR3 突变的 UC 细胞，将 p27 上调到 G1 期。在皮下移植 UM-UC-14 和 MGHU3 的小鼠异种移植模型中，口服给予 PD173074 抑制肿瘤生长并诱导与体外试验结果相当的凋亡变化。这些发现阐明了针对携带 FGFR3 突变的膀胱 UC 的分子靶向方法的有效性，并有可能降低经尿道切除术后非肌肉浸润性膀胱癌的膀胱内复发率。
