CANCER-RELATED GLYCOLYTIC GENE--REGULATION/TARGETING

本提案的长期目标是确定 这些分子事件导致了人类历史上最普遍，最深刻， 以及恶性组织的有趣表型，即，其升高 利用葡萄糖的能力，葡萄糖是一种重要的碳和能源 对细胞生长至关重要。 在早期的研究中，我们发现了己糖激酶， 葡萄糖催化剂的初始酶，作为主要参与者， 在它的四种主要同工酶中，只有II型是高度 在肿瘤中过度表达并与线粒体结合。 在这里，酶 是不受调节的，并产生关键的代谢前体Glu-6-P在高 rates.最近，在基因水平上工作时，我们已经做出了一些 非常新颖，明确，令人兴奋的进展，第一次 在超过60年的时间里，开始揭示了 许多人高糖酵解表型特征 癌的 因此，我们已经证明II型己糖激酶基因是 扩增，并在分离和详细表征其启动子后， 证明它不仅被葡萄糖，胰岛素， 胰高血糖素和cAMP，但也通过缺氧条件（常见于 高度恶性肿瘤），以及肿瘤抑制因子的突变形式 第53页。 这些初步研究为研究奠定了坚实的基础 这些建议的重点是更好地了解癌症是如何- 相关的II型己糖激酶基因的调节，以及它如何能够 成功抑制。 具体目标有四个方面，包括： 确定在许多正常细胞中沉默的II型己糖激酶基因， 例如，在一个实施例中，肝细胞，在肿瘤发生过程中被“打开”; 2）阐明 II型己糖激酶激活的分子基础 基因启动子; 3）获得更深入的了解分子 新发现的基础和意义，即在肿瘤细胞内， II型己糖激酶的启动子由以下突变形式激活： p53;和4）确定阻止高度生长的方法 通过选择性地抑制 使用反义RNA和靶向基因破坏的II己糖激酶基因 技术. 这些研究对于我们在基因水平上理解 是癌细胞最常见的表型之一， 导致控制高度恶性肿瘤生长的新方法， 肿瘤的

The long-term objective of this proposal is to characterize and target those molecular events responsible for one of the most common, profound, and intriguing phenotypes of malignant tissues, i.e., their elevated capacity to utilize glucose, a critical carbon and energy source essential for cell growth. In earlier studies we identified hexokinase, the initial enzyme of glucose catabolism, as a major player and showed that, of its four major isozymes,only Type II is both highly overexpressed in tumors and bound to the mitochondria. Here, the enzyme is unregulated and produces the key metabolic precursor Glu-6-P at high rates. More recently while working at the gene level, we have made some very novel, definitive, and exciting progress, which for the first time in more than 6 decades, begins to shed light on the underlying cause of the highly glycolytic phenotype characteristic of numerous human cancers. Thus, we have shown that the Type II hexokinase gene is amplified, and upon isolating and characterizing its promoter in detail, demonstrated that it is activated, not only by glucose, insulin, glucagon, and cAMP, but also by both hypoxic conditions (common within highly malignant tumors), and by a mutant form of the tumor suppressor p53. These preliminary studies form a firm foundation for the studies proposed here which are focused on better understanding how the cancer- related Type II hexokinase gene is regulated, and how it can be successfully inhibited. Specific aims are 4-fold and will be to: 1) Establish how the Type Il hexokinase gene, silent in many normal cells, e.g., hepatocytes, is "switched on" during tumorigenesis; 2) Elucidate the molecular basis underlying the activation of the Type II hexokinase gene promoter by glucose; 3) Gain greater insight into the molecular basis and significance of the novel finding, that within tumor cells, the promoter for Type II hexokinase is activated by a mutant form of p53; and 4) Identify methods for arresting the growth of highly malignant cancers by selectively inhibiting the expression of the Type II hexokinase gene using antisense RNA and targeted gene disruption techniques. These studies are fundamental to our understanding at the gene level of one of the most common phenotypes of cancer cells, and are likely to lead to novel approaches for controlling the growth of highly malignant tumors.