CANCER-RELATED GLYCOLYTIC GENE--REGULATION/TARGETING

这项提议长期目标是描述和确定目标 这些分子事件导致了最常见、最深刻、 以及耐人寻味的恶性组织表型，即它们升高的 利用葡萄糖的能力，葡萄糖是关键的碳和能源 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， 葡萄糖分解代谢的起始酶，作为主要的参与者而表现出来 在它的四种主要同工酶中，只有II型既是高度 在肿瘤中过度表达，并与线粒体结合。在这里，酶 是不受调控的，在高水平产生关键的代谢前体Glu-6-P 费率。最近，当我们在基因水平上工作时，我们做了一些 非常新颖、明确和令人兴奋的进展，这是第一次 在60多年的时间里，开始揭示 许多人类的高度糖酵解表型特征 癌症。因此，我们已经证明了II型己糖激酶基因是 并对其启动子进行了详细的分离和鉴定， 证明它不仅被葡萄糖、胰岛素激活， 和cAMP一样，也受两种缺氧条件的影响(常见于 高度恶性的肿瘤)，以及肿瘤抑制因子的突变形式 P53。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型己糖激酶基因被调控，以及它如何被 成功地阻止了。具体目标有4个，将是：1) 确定Il型己糖激酶基因是如何在许多正常细胞中沉默的， 例如，肝细胞，在肿瘤发生过程中被“开启”；2)阐明 II型己糖激酶激活的分子基础 通过葡萄糖启动基因；3)更深入地了解分子 这一新发现的基础和意义是，在肿瘤细胞内， II型己糖激酶的启动子被突变形式的 P53；以及4)找出阻止高度恶性肿瘤生长的方法 选择性抑制T型蛋白表达的恶性肿瘤 使用反义RNA和靶向基因干扰的II己糖激酶基因 技巧。 这些研究是我们在基因水平上理解的基础。 是癌细胞最常见的表型之一，很可能 导致控制高度恶性肿瘤生长的新方法 肿瘤。

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.