COX-2 Induces Breast Cancer Stem Cells via EP4/PI3K/AKT/NOTCH/WNT Axis
COX-2 Induces Breast Cancer Stem Cells via EP4/PI3K/AKT/NOTCH/WNT Axis
复制标题
DOI：
10.1002/stem.2426
复制
发表时间：
2016-09-01
期刊：
影响因子：
5.2
通讯作者：
Lala, Peeyush K.
中科院分区：
文献类型：
--
作者：
Majumder, Mousumi;Xin, Xiping;Lala, Peeyush K.
癌症干细胞样细胞（SLC）抵抗常规疗法，需要寻找SLC特异性靶点。我们证实环氧化酶（考克斯）-2的表达通过激活前列腺素（PG）E-2受体EP 4促进人乳腺癌的进展。目前的研究表明，考克斯-2通过EP 4介导的NOTCH/WNT信号通路诱导SLCs的形成。MCF-7和SKBR-3细胞系中异位考克斯-2过表达导致：迁移/侵袭/增殖增加、上皮-间充质转化（EMT）、SLC（球状体形成）升高、ALDH活性增加以及考克斯-2和SLC标志物（ALDH 1A、CD 44、β-连环蛋白、NANOG、OCT 3/4、SOX-2）在球状体中共定位。这些变化被考克斯-2-抑制剂或EP 4-拮抗剂（EP 4A）逆转，表明依赖于考克斯-2/EP 4活性。考克斯-2过表达或EP 4激动剂处理考克斯-2-低细胞引起NOTCH/WNT基因上调，用PI 3 K/AKT抑制剂阻断。NOTCH/WNT抑制剂也阻断考克斯-2/EP 4诱导的SLC诱导。微阵列分析显示许多SLC调控和EMT相关基因的上调。在有限细胞接种的连续几代NOD/SCID/IL-2 R γ缺陷小鼠中，MCF-7-考克斯-2细胞显示乳腺致瘤性和自发性多器官转移增加。这些肿瘤显示VEGF-A/C/D、波形蛋白和磷酸化AKT的上调，E-Cadherin的下调以及SLC标志物阳性和球状体形成细胞的富集。MCF-7-考克斯-2细胞在NOD/SCID/GUSB-无效小鼠中也显示出增加的肺定殖，该作用被MCF-7-考克斯-2细胞的EP 4敲除或EP 4A处理逆转。乳腺癌组织中考克斯-2/EP 4/ALDH 1A mRNA表达呈高度相关性，且在进展期更明显。人乳腺肿瘤组织的原位免疫染色显示SLC标记物与考克斯-2共定位，支持考克斯-2诱导SLC。高考克斯-2/EP 4 mRNA表达与生存率降低有关。因此，EP 4代表了人类乳腺癌中新的SLC消融靶点。
Cancer stem-like cells (SLC) resist conventional therapies, necessitating searches for SLC-specific targets. We established that cyclo-oxygenase(COX)-2 expression promotes human breast cancer progression by activation of the prostaglandin(PG) E-2 receptor EP4. Present study revealed that COX-2 induces SLCs by EP4-mediated NOTCH/WNT signaling. Ectopic COX-2 over-expression in MCF-7 and SKBR-3 cell lines resulted in: increased migration/invasion/proliferation, epithelial-mesenchymal transition (EMT), elevated SLCs (spheroid formation), increased ALDH activity and colocalization of COX-2 and SLC markers (ALDH1A, CD44, beta-Catenin, NANOG, OCT3/4, SOX-2) in spheroids. These changes were reversed with COX-2-inhibitor or EP4-antagonist (EP4A), indicating dependence on COX-2/EP4 activities. COX-2 over-expression or EP4-agonist treatments of COX-2-low cells caused up-regulation of NOTCH/WNT genes, blocked with PI3K/AKT inhibitors. NOTCH/WNT inhibitors also blocked COX-2/EP4 induced SLC induction. Microarray analysis showed up-regulation of numerous SLC-regulatory and EMT-associated genes. MCF-7-COX-2 cells showed increased mammary tumorigenicity and spontaneous multiorgan metastases in NOD/SCID/IL-2R gamma-null mice for successive generations with limiting cell inocula. These tumors showed up-regulation of VEGF-A/C/D, Vimentin and phospho-AKT, down-regulation of E-Cadherin and enrichment of SLC marker positive and spheroid forming cells. MCF-7-COX-2 cells also showed increased lung colonization in NOD/SCID/GUSB-null mice, an effect reversed with EP4-knockdown or EP4A treatment of the MCF-7-COX-2 cells. COX-2/EP4/ALDH1A mRNA expression in human breast cancer tissues were highly correlated with one other, more marked in progressive stage of disease. In situ immunostaining of human breast tumor tissues revealed colocalization of SLC markers with COX-2, supporting COX-2 inducing SLCs. High COX-2/EP4 mRNA expression was linked with reduced survival. Thus, EP4 represents a novel SLC-ablative target in human breast cancer.