A novel role for carcinoembryonic antigen-related cell adhesion molecule 6 as a determinant of gemcitabine chemoresistance in pancreatic adenocarcinoma cells
A novel role for carcinoembryonic antigen-related cell adhesion molecule 6 as a determinant of gemcitabine chemoresistance in pancreatic adenocarcinoma cells
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DOI：
10.1158/0008-5472.can-04-0424
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发表时间：
2004-06-01
期刊：
影响因子：
11.2
通讯作者：
Whang, EE
中科院分区：
文献类型：
--
作者：
Duxbury, MS;Ito, H;Whang, EE
大多数胰腺癌患者患有手术无法治愈的疾病。吉西他滨是治疗此类患者的主要药物，对结局影响不大。癌胚抗原相关细胞粘附分子（CEACAM）6的过度表达是这种恶性肿瘤的一个特征，与抗失巢凋亡和转移增加有关。本研究的目的是确定CEACAM 6在细胞对吉西他滨的化学抗性中的作用。CEACAM 6在Capan 2细胞中稳定过表达，Capan 2细胞固有地表达非常低水平的蛋白质。通过稳定转染产生CEACAM 6小干扰RNA的载体，在固有地过表达CEACAM 6的BxPC 3细胞中实现CEACAM 6表达的抑制。通过3-（4，5-二甲基噻唑-2-基）-2，5-二苯基四唑溴化物细胞毒性测定、流式细胞术凋亡定量、半胱天冬酶谱分析和细胞质细胞色素c释放的Western分析来确定调节CEACAM 6表达对吉西他滨诱导的细胞毒性的影响。研究了Akt和c-Src激酶作为CEACAM 6信号传导的下游靶标的作用。CAPAN 2中CEACAM 6的稳定过表达增加了吉西他滨的化学抗性，而BxPC 3中CEACAM 6基因沉默显著增加了这些细胞对吉西他滨的敏感性。CEACAM 6的差异表达以c-Src依赖性方式调节Akt活性，CEACAM 6过表达似乎保护细胞免受细胞色素c诱导的caspase 3激活和凋亡。
Most patients with pancreatic adenocarcinoma present with surgically incurable disease. Gemcitabine, the principal agent used to treat such patients, has little impact on outcome. Overexpression of carcinoembryonic antigen-related cell adhesion molecule (CEACAM) 6, a feature of this malignancy, is associated with resistance to anoikis and increased metastasis. The purpose of this study was to determine the role of CEACAM6 in cellular chemoresistance to gemcitabine. CEACAM6 was stably overexpressed in Capan2 cells, which inherently express very low levels of the protein. Suppression of CEACAM6 expression was achieved in BxPC3 cells, which inherently overexpress CEACAM6, by stable transfection of a CEACAM6 small interfering RNA-generating vector. The effects of modulating CEACAM6 expression on gemcitabine-induced cytotoxicity were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cytotoxicity assay, flow cytometric apoptosis quantification, caspase profiling, and Western analysis of cytoplasmic cytochrome c release. The roles of Akt and c-Src kinases as downstream targets of CEACAM6 signaling were examined. Stable overexpression of CEACAM6 in Capan2 increased gemcitabine chemoresistance, whereas CEACAM6 gene silencing in BxPC3 markedly increased the sensitivity of these cells to gemcitabine. Differential expression of CEACAM6 modulates Akt activity in a c-Src-dependent manner, and CEACAM6 overexpression appears to protect cells from cytochrome c-induced caspase 3 activation and apoptosis.