Harris Joseph C, Gilliam Andrew D, McKenzie Andrew J, Evans Sean A, Grabowska Anna M, Clarke Philip A, McWilliams Daniel F, Watson Sue A
Academic Unit of Cancer Studies, University of Nottingham, Nottingham, United Kingdom.
Cancer Res. 2004 Aug 15;64(16):5624-31. doi: 10.1158/0008-5472.CAN-04-0106.
The gastrin gene is expressed widely in pancreatic adenocarcinomas and the study aimed to assess its role in both the resistance of cancer cells to apoptosis and the sensitivity of cells to chemotherapeutic agents. Two human pancreatic cell lines, PAN1 and BXPC3, expressed gastrin at both the RNA and protein levels and are shown to be representative of human pancreatic adenocarcinomas in terms of gastrin expression. Inhibition of endogenous gastrin production by tumor cells was achieved with neutralizing gastrin antiserum and transfection with a gastrin antisense plasmid. Gastrin antiserum synergized with both taxotere and gemcitabine in inhibiting the in vitro growth of the PAN1 cell line with the inhibitory effect of the antiserum increasing from 12.7% to 70.2% with taxotere (P < 0.05) and 28.6% with gemcitabine (P < 0.01) after controlling for the effects of the cytotoxics. Synergy was only achieved with taxotere in BXPC3 cells with the inhibitory effect of gastrin antiserum increasing from 22.9% to 50.0% (P < 0.005). Cells transfected with gastrin antisense had reduced in vitro growth in low serum conditions and were poorly tumorigenic in nude mice at an orthotopic site. Gastrin antisense-transfected PAN1 cells had increased sensitivity to the antiproliferative effects of both gemcitabine (IC50 of > 100 microg/ml reduced to 0.1 microg/ml) and taxotere (IC50 of 20 microg/ml reduced to < 0.01 microg/ml) when compared with vector controls. The increased sensitivity of PAN1 antisense coincided with increased caspase-3 activity and reduced protein kinase B/Akt phosphorylation in response to both gemcitabine and taxotere. Gastrin gene circumvention may be an optimal adjunct to chemotherapeutic agents, such as taxotere and gemcitabine, in pancreatic adenocarcinoma.
胃泌素基因在胰腺腺癌中广泛表达，该研究旨在评估其在癌细胞抗凋亡及细胞对化疗药物敏感性方面的作用。两种人胰腺细胞系PAN1和BXPC3在RNA和蛋白质水平均表达胃泌素，且就胃泌素表达而言，它们代表了人胰腺腺癌。通过中和胃泌素抗血清及用胃泌素反义质粒转染实现了肿瘤细胞内源性胃泌素产生的抑制。胃泌素抗血清与多西他赛和吉西他滨协同抑制PAN1细胞系的体外生长，在控制细胞毒性药物的作用后，抗血清的抑制作用在多西他赛作用下从12.7%增至70.2%（P<0.05），在吉西他滨作用下从28.6%增至70.2%（P<0.01）。在BXPC3细胞中仅多西他赛实现了协同作用，胃泌素抗血清的抑制作用从22.9%增至50.0%（P<0.005）。用胃泌素反义转染的细胞在低血清条件下体外生长降低，在裸鼠原位位点成瘤性差。与载体对照相比，胃泌素反义转染的PAN1细胞对吉西他滨（IC50从>100μg/ml降至0.1μg/ml）和多西他赛（IC50从20μg/ml降至<0.01μg/ml）的抗增殖作用敏感性增加。PAN1反义转染细胞敏感性增加与对吉西他滨和多西他赛反应时半胱天冬酶-3活性增加及蛋白激酶B/Akt磷酸化降低一致。胃泌素基因规避可能是胰腺腺癌中多西他赛和吉西他滨等化疗药物的最佳辅助手段。
