Liu An, Hu Yun-shuang, Wang Zhao-hong, Tang Li-li, Ke Pin-yu, Lin Sheng-zhang
Second Affiliated Hospital of Wenzhou Medical College, Wenzhou 325027, China.
Yao Xue Xue Bao. 2011 Feb;46(2):146-52.
In view of gemcitabine resistance has limited clinical activity of gemcitabine as a cellulotoxic drug in pancreatic cancer patients, this study is designed to investigate the effect of emodin on the sensitivity of pancreatic cancer to gemcitabine as well as its mechanism. After gemcitabine-resistant pancreatic cancer cell line (SW1990/GZ) was established by escalating doses of gemcitabine serially in pancreatic cancer cell line (SW1990). The cellular proliferation was detected by cell counting kit-8 (CCK-8) assay. Flow cytometry (FCM) was used to determine apoptosis of pancreatic cancer cells. The activity of NF-kappaB in pancreatic cancer cells was measured by electrophoretic mobility shift assay (EMSA). Western blotting was used to detect the protein expression of Bcl-2 and Survivin in SW1990/GZ cells. Metastatic model simulating human pancreatic cancer was established by orthotopic implantation of histologically intact human tumor tissue into pancreatic wall of nude mice. Also, immunohistochemistry was used to detect the positive expression of Ki-67, NF-kappaB, Bcl-2 and Survivin in the tumors. The results show that pretreatment of cells with emodin followed by gemcitabine induced a higher percentage of growth inhibition and apoptosis of pancreatic cancer cells than that of gemcitabine alone. In addition to in vitro results, emodin in combination with gemcitabine is much more effective as an antitumor agent compared to either agent alone in the orthotopic tumor model. Further study showed that the emodin with or without gemcitabine significantly down-regulates NF-kappaB and its regulated molecules such as Bcl-2 and Survivin proteins both in vitro and in vivo. It is concluded that inactivation of NF-kappaB signaling pathway by emodin resulting in the chemosensitization of pancreatic cancer to gemcitabine, which is likely to be an important and novel strategy for the treatment of pancreatic cancer.
鉴于吉西他滨耐药性限制了吉西他滨作为细胞毒性药物在胰腺癌患者中的临床活性，本研究旨在探讨大黄素对胰腺癌对吉西他滨敏感性的影响及其机制。通过在胰腺癌细胞系（SW1990）中连续递增吉西他滨剂量建立吉西他滨耐药的胰腺癌细胞系（SW1990/GZ）。采用细胞计数试剂盒-8（CCK-8）法检测细胞增殖。流式细胞术（FCM）用于测定胰腺癌细胞的凋亡。采用电泳迁移率变动分析（EMSA）检测胰腺癌细胞中NF-κB的活性。蛋白质印迹法检测SW1990/GZ细胞中Bcl-2和Survivin的蛋白表达。通过将组织学完整的人肿瘤组织原位植入裸鼠胰腺壁建立模拟人胰腺癌的转移模型。此外，采用免疫组织化学法检测肿瘤中Ki-67、NF-κB、Bcl-2和Survivin的阳性表达。结果显示，大黄素预处理细胞后再用吉西他滨诱导的胰腺癌细胞生长抑制和凋亡百分比高于单独使用吉西他滨。除体外结果外，在原位肿瘤模型中，大黄素与吉西他滨联合使用作为抗肿瘤药物比单独使用任一药物更有效。进一步研究表明，无论有无吉西他滨，大黄素在体外和体内均能显著下调NF-κB及其调控分子如Bcl-2和Survivin蛋白。结论是大黄素使NF-κB信号通路失活，导致胰腺癌对吉西他滨的化疗增敏，这可能是治疗胰腺癌的一种重要且新颖的策略。
