Department of General Surgery, Qianfoshan Hospital, Shandong University, Jinan, 250014, China,
Dig Dis Sci. 2014 Aug;59(8):1798-809. doi: 10.1007/s10620-014-3111-9. Epub 2014 Mar 27.
The purpose of this study was to investigate whether the therapeutic activity of gemcitabine (GCB) in hepatocellular carcinoma (HCC) could be increased by the down-regulation of secretory clusterin (sCLU), a glycoprotein that is considered to play a cytoprotective role in the resistance to chemotherapy.
The expression of sCLU was detected in HCC tumor tissues and cell lines. A cell viability and apoptosis assay were performed in parental HCC cells or the same cells transfected with sCLU shRNA and treated with or without GCB. The potential downstream pathways were investigated using the Human Apoptosis RT(2) Profiler™ PCR Array.
The expression levels of sCLU in HCC tissues were significantly higher than in adjacent non-tumor liver tissues and were associated with the histological grade and transarterial chemoembolization. sCLU overexpression was also found in three HCC cell lines and hepatocytes. The depletion of sCLU synergistically increased GCB sensitivity in Bel7402 and SMMC7721 cells and induced cell apoptosis. Based on the PCR array analysis, sCLU depletion also resulted in the up-regulation of BNIP1, GADD45A, TNFRSF10A, and TRADD and down-regulation of AKT1 in Bel7402 and SMMC7721 cells compared with the parental controls. These results were further supported by a Western blot analysis, which showed increased GADD45a protein expression and the decreased expression of phosphorylated AKT. GADD45a overexpression also increased the sensitivity to GCB in the Bel7402 and SMMC7721 cells.
Targeting sCLU may be a useful method to enhance the cytotoxic effect of GCB in hepatocellular carcinoma.
本研究旨在探讨下调分泌型簇蛋白（sCLU）是否可以增强吉西他滨（GCB）在肝细胞癌（HCC）中的治疗活性，sCLU 被认为在化疗耐药中发挥细胞保护作用。
检测 HCC 肿瘤组织和细胞系中 sCLU 的表达。在亲本 HCC 细胞或转染 sCLU shRNA 的相同细胞中进行细胞活力和细胞凋亡测定，并在有无 GCB 的情况下进行处理。使用 Human Apoptosis RT(2) Profiler™ PCR Array 研究潜在的下游途径。
HCC 组织中 sCLU 的表达水平明显高于相邻非肿瘤肝组织，与组织学分级和经动脉化疗栓塞相关。sCLU 在三种 HCC 细胞系和肝细胞中也过表达。sCLU 的耗竭在 Bel7402 和 SMMC7721 细胞中协同增强了 GCB 的敏感性，并诱导细胞凋亡。基于 PCR 阵列分析，与亲本对照相比，sCLU 耗竭还导致 Bel7402 和 SMMC7721 细胞中 BNIP1、GADD45A、TNFRSF10A 和 TRADD 的上调和 AKT1 的下调。Western blot 分析进一步证实了这一点，结果显示 GADD45a 蛋白表达增加，磷酸化 AKT 的表达减少。GADD45a 过表达也增加了 Bel7402 和 SMMC7721 细胞对 GCB 的敏感性。
靶向 sCLU 可能是增强 GCB 在肝细胞癌中细胞毒性作用的一种有用方法。
