Pancreatic Cancer Cells Resistant to Chemoradiotherapy Rich in "Stem-Cell-Like" Tumor Cells
Pancreatic Cancer Cells Resistant to Chemoradiotherapy Rich in "Stem-Cell-Like" Tumor Cells
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DOI：
10.1007/s10620-010-1340-0
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发表时间：
2011-03-01
影响因子：
3.1
通讯作者：
Peng, Chenghong
中科院分区：
文献类型：
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作者：
Du, Zhiyong;Qin, Renyi;Peng, Chenghong
肿瘤对放化疗的抵抗部分归因于抗凋亡肿瘤干细胞(CSCs)的存在。我们的初步研究表明，放化疗抵抗的胰腺癌细胞具有一定的CSC特性，并经历上皮-间充质转化(EMT)；我们的目的是验证这项研究的含义，即放化疗抵抗的亚群中富含可能与EMT相关的干细胞样肿瘤细胞。显微镜下观察细胞形态变化，Transwell法检测细胞迁移能力和侵袭力。免疫印迹法检测蛋白表达。用荧光激活的细胞分选分析研究胰腺CSC标志物。通过克隆形成实验、肿瘤球体形成实验和BALB/C裸鼠移植瘤实验来评估耐药细胞的干性。耐药细胞表达更多的抗凋亡蛋白Bcl2、凋亡抑制蛋白Survivin和干细胞标记物Oct4、ABCG2、CD24和CD133，在体外和体内更具致瘤性，并显示出与EMT一致的表型和分子变化，包括波形蛋白上调和E-钙粘蛋白下调。我们发现耐受放化疗的胰腺癌细胞与CSCs相似，可以进行EMT，这表明放化疗抵抗诱导的EMT与CSC的产生有关。
Tumor resistance to chemoradiation therapy is partly attributed to the presence of apoptosis-resistant cancer stem cells (CSCs). Chemoradiation therapy can enrich CSCs by killing apoptosis-susceptible cancer cells.Our preliminary study showed chemoradiation-resistant pancreatic cancer cells to have some CSC characteristics, and to undergo epithelial-mesenchymal transition (EMT); we aimed to verify that study's implication that chemoradiation-resistant subpopulations are enriched with "stem-cell-like" tumor cells, which may be linked to EMT.Four pancreatic cancer cell lines were cultured in gemcitabine with synchronous radiotherapy to obtain resistant subpopulations. Morphological changes were observed under microscope; migration and invasiveness were assessed by Transwell tests. Protein expression was determined by immunoblotting. Pancreatic CSC markers were studied using fluorescence-activated cell sorting analyses. Colony-formation tests, tumor sphere formation assays, and tumor xenografts in BALB/C nude mice were used to evaluate "stemness" in resistant cells.Resistant cells expressed more antiapoptotic protein Bcl-2, apoptosis-inhibitory protein survivin, and stem cell markers Oct4, ABCG2, CD24, and CD133, were more tumorigenic in vitro and in vivo, and showed phenotypic and molecular changes consistent with EMT, including upregulation of vimentin and downregulation of E-cadherin. They were also more invasive and migratory.We found chemoradiation-resistant pancreatic cancer cells to be similar to CSCs and to undergo EMT, suggesting that chemoradiation resistance-induced EMT is linked to CSC generation.