DISCOVERY OF NEW SECRETED PROTEINS OF PANCREATIC CANCER

血清肿瘤标志物的检测可以显著提高肿瘤的早期诊断、有效评估治疗和早期发现肿瘤复发的能力。前列腺特异性抗原(PSA)的发现极大地显示了这种潜力，它极大地促进了前列腺癌的筛查和监测。我们开发了一种分离新的癌症血清肿瘤标志物的方法。我们建议使用分子生物学技术来筛选肿瘤分泌蛋白，这些蛋白可以用作癌症早期检测的标记。确定胰腺癌的一个或几个标志物可能会对这种疾病的治疗产生深远的影响。如果我们成功了，血清标记物将为一种简单、快速、廉价的胰腺癌筛查方法提供第一次机会。在治疗过程中对疾病的监测和管理将得到显着加强，当肿瘤负担较低时，可以迅速发现早期复发。具体目标1：利用编码酵母分泌蛋白的SUC2基因，利用信号序列陷阱技术的改进，确认初步实验。在这个系统中，只有转化了含有分泌信号序列的cDNA的酵母才能在以蔗糖为唯一糖源的平板上形成菌落。具体目的2：构建人胰腺癌特异基因文库，并将该文库置于酵母信号序列捕获载体中，用于鉴定分泌蛋白基因。具体目标3：在确定候选cDNA后，我们将通过斑点杂交和DNA测序进一步筛选新的胰腺特异基因，并克隆全长cDNA以制备针对基因产物的抗体。具体目标4：对于似乎是胰腺特异的抗体(理想情况下是胰腺癌选择性蛋白)，将开发一种酶联免疫吸附试验，以检测胰腺癌患者和正常人的血清样本中胰腺特异的分泌蛋白的存在。

The identification of serum tumor markers can markedly enhance the ability for early diagnosis, efficient assessment of treatment and early discovery of recurrence of cancers. This potential has been most elegantly shown through the discovery of prostate-specific antigen (PSA) which has markedly advanced screening and monitoring of prostate cancer. We have developed an approach to isolate new serum tumor markers of cancer. We propose using molecular biology techniques in order to screen for secreted proteins of tumors that can be used as markers for early detection of cancer. Identification of one or several markers of pancreatic cancer could have profound implications for the management of this disease. If we are successful, the serum markers will provide the first opportunity for a simple, rapid, inexpensive method of screening for pancreatic cancer. Monitoring and management of the disease during therapy would be markedly enhanced and early recurrence could be rapidly detected when tumor burden is low. Specific Aim 1: Confirmation of preliminary experiments using a modification of the signal sequence trap technique, utilizing the SUC2 gene encoding a secreted protein of yeast. In this system only the yeast which have been transformed with cDNAs containing secretory signal sequences can grow into colonies on the plates which contain sucrose as the only source of sugar. Specific Aim 2: We will construct a human pancreatic cancer cDNA library which has been enriched for pancreatic-specific genes, and this library will be placed in our yeast based signal sequence trap vector in order to identify genes encoding secreted proteins. Specific Aim 3: After identifying candidate cDNAs, we will further select for novel pancreatic-specific genes by dot blotting and DNA sequencing, and we will clone full-length cDNAs to make antibodies against the gene products. Specific Aim 4: For antibodies that appear to be pancreatic-specific (and ideally, pancreatic cancer-selective protein), an ELISA will be developed to examine for the presence of the pancreatic-specific, secreted protein in serum samples from pancreatic cancer patients as well as normal individuals.