Division of Urology, Albany Medical College, Albany, New York, USA.
J Urol. 2010 Jul;184(1):344-51. doi: 10.1016/j.juro.2010.03.007. Epub 2010 May 20.
Hedgehog signaling regulates Gli transcription factors. Aberrant hedgehog signaling can be oncogenic and drugs that block hedgehog are being tested as anticancer agents. We considered whether hedgehog/Gli signaling may be involved in human bladder transitional cell carcinoma proliferative or invasive behavior.
We stratified the human bladder transitional cell carcinoma lines RT4 (ATCC), 253JP, 253BV, UMUC6 and UMUC3 for relative growth rate by cell counting and for in vitro invasiveness by Matrigel invasion assay. Cells were tested for growth inhibition by the hedgehog blocking drug cyclopamine or the inactive mimic tomatidine. Cell RNA was characterized for hedgehog signaling component expression, including ligands, receptors and signaling mediators, by quantitative reverse transcriptase-polymerase chain reaction. Gli2 expression or activity was modified by Gli2 expression lentiviruses or the Gli inhibitor GANT61. We measured effects on proliferation and invasiveness.
Cell growth rates and invasiveness were stratified into an equivalent order (RT4 <243JP <253BV <UMUC6 <UMUC3). All cells were weakly growth inhibited by tomatidine and cyclopamine. Gli2 was the only hedgehog signaling molecule of which expression correlated with stratification. Manipulation of Gli2 expression or activity significantly affected cell invasiveness.
Weak growth suppression by cyclopamine suggests that hedgehog signaling is not involved in bladder cancer cell proliferation but Gli2 expression strongly correlated with invasive behavior. Increased Gli2 expression increased low Gli2 cell invasiveness while Gli inhibition by GANT61 decreased high Gli2 cell invasiveness. Results suggest that Gli2 expression by noncanonical signaling contributes to bladder cancer cell invasiveness.
刺猬信号通路调节 Gli 转录因子。异常的刺猬信号通路可能致癌，目前正在测试阻断刺猬信号通路的药物作为抗癌药物。我们考虑刺猬/Gli 信号通路是否参与人类膀胱移行细胞癌的增殖或浸润行为。
我们通过细胞计数对人膀胱移行细胞癌细胞系 RT4（ATCC）、253JP、253BV、UMUC6 和 UMUC3 进行相对生长率分层，并通过 Matrigel 侵袭试验进行体外侵袭性测试。用 Hedgehog 阻断药物环巴胺或无活性模拟物番茄红素测试细胞的生长抑制作用。通过定量逆转录聚合酶链反应对 Hedgehog 信号通路成分的表达进行细胞 RNA 特征分析，包括配体、受体和信号转导介质。通过 Gli2 表达慢病毒或 Gli 抑制剂 GANT61 修饰 Gli2 表达或活性。我们测量了对增殖和侵袭性的影响。
细胞生长率和侵袭性按相同顺序分层（RT4 <243JP <253BV <UMUC6 <UMUC3）。所有细胞的番茄红素和环巴胺的生长抑制作用都较弱。Gli2 是唯一与分层相关的 Hedgehog 信号分子的表达。Gli2 表达或活性的操纵显著影响细胞侵袭性。
环巴胺的弱生长抑制表明 Hedgehog 信号通路不参与膀胱癌细胞增殖，但 Gli2 表达与浸润行为密切相关。Gli2 表达增加会增加低 Gli2 细胞的侵袭性，而 GANT61 的 Gli 抑制会降低高 Gli2 细胞的侵袭性。结果表明，非典型信号通路的 Gli2 表达有助于膀胱癌细胞的侵袭性。
