DISCOVERY OF NEW SECRETED PROTEINS OF PANCREATIC CANCER

血清肿瘤标志物的检测可显著提高肿瘤的早期诊断、疗效评估和复发的早期发现能力。 前列腺特异性抗原（PSA）的发现最有力地证明了这一潜力，PSA显著地促进了前列腺癌的筛查和监测。 我们已经开发出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，以筛选分泌的蛋白质的肿瘤，可用作标记物的早期检测癌症。 胰腺癌的一个或几个标志物的鉴定可能对这种疾病的管理具有深远的意义。 如果我们成功的话，血清标记物将首次提供一种简单、快速、廉价的胰腺癌筛查方法。在治疗过程中对疾病的监测和管理将得到显着加强，当肿瘤负荷较低时，可以快速检测到早期复发。 具体目标1：确认使用信号序列捕获技术的修改的初步实验，利用编码酵母分泌蛋白的SUC2基因。 在该系统中，只有用含有分泌信号序列的cDNA转化的酵母才能在含有蔗糖作为唯一糖源的平板上生长成菌落。 具体目标二：我们将构建一个人胰腺癌cDNA文库，该文库已经富集了胰腺特异性基因，并且该文库将被置于我们的基于酵母的信号序列捕获载体中，以鉴定编码分泌蛋白的基因。 具体目标3：在确定候选cDNA后，我们将进一步通过斑点印迹和DNA测序来选择新的胰腺特异性基因，并且我们将克隆全长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性的抗体（并且理想地，胰腺癌选择性蛋白），将开发ELISA以检查来自胰腺癌患者以及正常个体的血清样品中胰腺特异性分泌蛋白的存在。

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.