The personalized therapy using Annexin II as a gemcitabine-resistant factor for pancreatic cancer patients after surgery.

背景：尽管吉西他滨已被广泛用作胰腺癌患者的一线化疗试剂，但其有效率仍然很低。我们先前确定膜联蛋白II是参与吉西他滨对胰腺癌耐药的一个因素。本研究的目的是阐明膜联蛋白II诱导吉西他滨耐药的信号机制，并开发一种克服吉西他滨耐药的新疗法。材料和方法：我们利用Bio-Plex磷酸化蛋白测定系统全面研究并比较了吉西他滨耐药（GEM-MIA PaCa-2）和野生型（WT-MIA PaCa-2）胰腺癌细胞系中12种靶向磷酸化信号蛋白的特异性谱。我们还通过免疫组化的方法对两种不同细胞系Annexin II和两种磷酸化蛋白的表达水平进行了评价。结果：胰腺癌切除术患者吉西他滨辅助化疗后，肿瘤细胞中Annexin II过表达与快速复发显著相关（P=0.0118）。Bio-Plex分析显示，在Annexin II高表达的GEM-MIA PaCa-2细胞中，p-Akt表达上调。免疫组化结果显示，胰腺癌组织中p-Akt与p-mTOR表达水平显著相关。抑制mTOR磷酸化可消除GEM-MIA PaCa-2细胞对吉西他滨的耐药性。结论：Akt/mTOR通路参与了Annexin II诱导胰腺癌细胞吉西他滨耐药的机制。因此，作为选择吉西他滨耐药的指标，膜联蛋白II可以应用于胰腺癌治疗的新型定制方法的开发。

Background : Although gemcitabine has been widely used as a first-line chemo reagent for patients with pancreatic cancer, the response rate still remains low. We previously identified Annexin II as a factor involved in gemcitabine resistance against pancreatic cancer. The aim of this study was to elucidate the signaling mechanism by which Annexin II induces gemcitabine resistance and to develop a new therapy which overcomes the resistance against gemcitabine.Materials and methods : We comprehensively investigated and compared the specific profiles of 12 targeted phosphorylated signaling proteins in gemcitabine-resistant (GEM-MIA PaCa-2) and wild-type (WT-MIA PaCa-2) pancreatic cancer cell lines by the Bio-Plex phosphorylation protein assay system. We also evaluated the expression levels of Annexin II and two phosphoproteins, which showed different expression in these two cell lines, by immunohistochemistry of pancreatic cancer tissues.Results : Annexin II overexpression in cancer cells was significantly associated with rapid recurrence after gemcitabine-adjuvant chemotherapy in patients with resected pancreatic cancer (P=0.0118). Bio-Plex analysis showed upregulation of p-Akt in GEM-MIA PaCa-2 cells in which Annexin II is highly expressed. On immunohistochemistry, the expression level of p-Akt was significantly correlated with that of p-mTOR in pancreatic cancer tissues. Inhibition of mTOR phosphorylation canceled gemcitabine resistance in GEM-MIA PaCa-2 cells.Conclusion : The Akt/mTOR pathway is involved in the mechanisms of gemcitabine resistance induced by Annexin II in pancreatic cancer cells. Annexin II as an indicator for selection of gemcitabine resistance could thus be applied to the development of novel tailor-made approaches for pancreatic cancer treatment.