Targeting Cancer Stem Cells in Castration-Resistant Prostate Cancer.
Targeting Cancer Stem Cells in Castration-Resistant Prostate Cancer.
复制标题
DOI：
10.1158/1078-0432.ccr-15-0190
复制
发表时间：
2016-02-01
期刊：
影响因子：
--
通讯作者：
Hsieh JT
中科院分区：
文献类型：
--
作者：
Yun EJ;Zhou J;Lin CJ;Hernandez E;Fazli L;Gleave M;Hsieh JT
临床证据表明，肿瘤组织中CSC的增加可能是传统治疗失败的原因之一，因为CSC似乎比分化的肿瘤细胞更具抵抗力。因此，揭示CSCs和候选靶分子的调控机制将为治疗患者提供新的策略。通过终止期实验和染料排斥实验确定干细胞样细胞特性。为了寻找关键的干细胞标记并揭示其调控机制，本研究采用了qRT-PCR、Western印迹、报告基因分析、染色质免疫沉淀等基本的生化和分子生物学方法。此外，为了确定CSCs及其后代的联合治疗效果，采用了体外四甲基偶氮唑盐比色法和体内异种移植模型。我们展示了永生化的正常人类前列腺上皮细胞，在体内看起来不会致癌，在敲除肿瘤抑制基因后成为致癌细胞并获得干细胞表型。此外，这些干细胞样细胞增加了对传统抗癌剂的化疗耐药性。从机制上，我们揭示了Wnt信号是通过直接与启动子相互作用来调节众所周知的干细胞标志物CD44的关键途径。因此，通过使用Wnt抑制剂靶向CSCs，可以协同增强传统药物的疗效。此外，体内异种移植小鼠模型在联合治疗后显示出对肿瘤生长的强烈抑制。总体而言，本研究提供了CRPC存在CSC的有力证据。这种针对CSC的新的联合治疗策略可以显著提高目前仅针对非CSC细胞的化疗方案的疗效。
Clinical evidence suggests an increased CSC in tumor mass may contribute to the failure of conventional therapies since CSCs seem to be more resistant than differentiated tumor cells. Thus, unveiling the mechanism regulating CSCs and candidate target molecules will provide new strategy to cure the patients. The stem-like cell properties were determined by a prostasphere assay, and dye exclusion assay. To find critical stem cell marker and reveal regulation mechanism, basic biochemical and molecular biological methods such as qRT-PCR, Western blot, reporter gene assay and chromatin immunoprecipitation assay were employed. In addition, to determine the effect of combination therapy targeting both CSCs and its progeny, in vitro MTT assay and in vivo xenograft model was used. We demonstrate immortalized normal human prostate epithelial cells, appeared non-tumorigenic in vivo, become tumorigenic and acquire stem cell phenotype after knocking down a tumor suppressor gene. Also, those stem-like cells increase chemoresistance to conventional anti-cancer reagent. Mechanistically, we unveil that Wnt signaling is a key pathway regulating well-known stem cell marker CD44 by directly interacting to the promoter. Thus, by targeting CSCs using Wnt inhibitors synergistically enhances the efficacy of conventional drugs. Furthermore, the in vivo mice model bearing xenografts showed a robust inhibition of tumor growth after combination therapy. Overall, this study provides strong evidence of CSC in CRPC. This new combination therapy strategy targeting CSC could significantly enhance therapeutic efficacy of current chemotherapy regimen only targeting non-CSC cells.