Molecular Targets - Colon Cancer

我们采用了一种新的策略来确定治疗和预防常见癌症的分子靶点，最初的重点是结肠癌。化学治疗剂的主要限制之一是相对狭窄的治疗：毒性比，这是由癌组织和正常组织中的治疗靶点的共同性引起的。因此，我们试图通过使用公共数据库中可用的基因表达信息，结合使用高通量基因表达阵列分析，来确定相对癌症特异性的潜在治疗靶点。使用数字基因表达显示器挖掘NCI癌症基因组解剖项目提供的表达文库，我们确定了665个在结肠癌文库中表达但在基本正常组织中不表达的序列。其中，356个基因在Affytron表达阵列上呈现，这允许比较这些基因在结肠癌组织和细胞系以及基本正常组织中的表达。这项调查加上随后的确认，使用定量RT-PCR导致两个以前未表征的基因，其表达是相对特异性的结肠癌样品的相当大的比例测试的鉴定。我们目前正在使用小干扰RNA（siRNA）来“敲除”这些基因。这些试验将用于验证每种试验在维持恶性表型中可能发挥的作用。 利用现有的数据库结合高通量技术鉴定相对癌症选择性基因靶点的方法可能构成一种快速有效的方法，用于开发活性和毒性较小的化疗药物。这些基因作为潜在靶点的鉴定完全基于其表达谱，而不是依赖于其细胞内功能的先验知识。除了为药物开发提供感兴趣的靶标之外，这些靶标还可以用于药物递送，作为疾病的分子标志物，或作为药物递送和药物有效性的替代标志物。

We have employed a novel strategy to identify molecular targets for the therapy and prevention of common cancers, with an initial focus on colon cancer. One of the major limitations of chemotherapeutic agents is the relatively narrow therapeutic: toxic ratio that results from the commonality of the therapeutic target in both the cancerous and normal tissues. Therefore, we sought to identify potential therapeutic targets that were relatively cancer specific by using gene expression information available in public databases coupled with the use of high-throughput gene expression array analysis. Using the Digital Gene expression Displayer to mine expression libraries available through the NCI's Cancer Genome Anatomy Project, we identified 665 sequences that were expressed in colon cancer libraries but not in essential normal tissues. Of these, 356 were represented on Affymetrix expression arrays and this allowed for a comparison of the expression of these genes in colon cancer tissues and cell lines, and essential normal tissues. This investigation coupled with subsequent confirmation using quantitative RT-PCR resulted in the identification of two previously uncharacterized genes whose expression was relatively specific to a substantial proportion of colon cancer samples tested. We are currently pursuing "knock out" of these genes using small interfering RNA (siRNA). These assays will be used to verify the role each may play in maintenance of the malignant phenotype. The approach of using available databases coupled with high-throughput technologies for the identification of relatively cancer selective gene targets may constitute a rapid and efficient method for the development of active and less toxic chemotherapeutic agents. The identification of these genes as potential targets was based entirely on their expression profile rather than dependent on prior knowledge of their intracellular function(s). In addition to providing targets of interest for drug development, such targets could also be exploited for drug delivery, as molecular markers of disease, or as surrogate markers for drug delivery and drug effectiveness.