Identification of factors involving chemotherapy resistance in pancreatic cancer patients by Protein Chip system for developing prediction system of chemotherapy response.

用抗膜联蛋白II抗体测定血清膜联蛋白II水平我们采用二维凝胶电泳技术，比较了长期使用抗肿瘤药物吉西他滨建立的耐药胰腺癌细胞株与野生型细胞株的蛋白表达谱。我们发现膜联蛋白II在耐药细胞系中高表达，而在野生型细胞中不表达。这表明膜联蛋白II在癌细胞的耐药过程中起作用。这也提示胰腺癌患者血清膜联蛋白II水平的测定可能预示该药物治疗患者的预后。现在，我们建立了用蛋白芯片系统（CYPHAGEN）检测血清膜联蛋白II水平的系统。该系统利用激光光谱对样品中的多肽进行解析，实现了样品中多肽表达水平的测定。为了获得特异性的血清膜联蛋白II水平，我们在蛋白芯片表面修饰了抗膜联蛋白II抗体。使用该系统，抗体仅捕获血清中整个蛋白中的膜联蛋白II，即使表达水平很低，我们也能准确地评估该靶蛋白的浓度。我们目前正在尝试测定胰腺癌患者的血清Annexin II水平，并分析该血清水平是否与患者吉西他滨治疗后的预后相吻合。为此，我们已经收集了患者手术或化疗前后的血清样本。我们也在尝试用同样的系统测量尿中膜联蛋白II的水平。利用这些技术，我们现在期望我们可以选择吉西他滨将改善预后的胰腺癌患者，并避免对治疗无反应的患者使用该药。对于这些病人，我们会用其他疗法的另一种药物来治疗，比如放疗。该系统为患者的选择提供了便利，避免了患者宝贵的时间和费用的浪费。少

Measurement of serum Annexin II level using anti-Annexin II antibodyUsing 2-D gel electrophoresis, we compared the protein profiling expressed in pancreatic cancer cell line which is resistant against treatment with anti cancer drug, gemcitabine, established by treating cells with the drug for long time with wild type cell line. We identified Annexin II is highly expressed in cell line with chemo-resistance, but not in wild type cells. This indicated that Annexin II has a role in establishing chemo-resistance in cancer cells. This also suggested that measurement of serum Annexin II level in pancreatic cancer patients may indicate the prognosis of the patients with treatment of this medicine. We now established the system to measure the serum level of Annexin II using Protein Chip System (CYPHAGEN). This system resolve the peptide in the sample using laser spectrum and enable to measure the expression level in the sample. To obtain specifically the serum level of Annexin II, we modified … More the surface of the protein chip plate with anti-Annexin II antibody. Using this system, only Annexin II within the whole protein in the serum is captured with the antibody, and we are able to evaluate the concentration of this target protein with precise value even though the expression level is very low. We are now trying to measure Annexin II serum level of the pancreatic cancer patients and analyze whether this serum level is collate with patients prognosis after gemcitabine treatment. For this purpose, we already collected serum samples from patients before and after operation or chemotherapy.We also are trying to measure the urine levels of Annexin II using same system. Using these technique, we are now expecting that we can select the pancreatic cancer patients whose prognosis gemcitabine will improve and avoid the use of this medicine for patients who will not respond the therapy. To these patients, we will treat them with another medicine of other therapies, such as radiation. This system will provide the benefits for selecting the patients and will avoid the wasting precious time and cost of these patients. Less