Role of hyaluronan matrix in prostate cancer progression

描述（由申请方提供）：透明质酸（HA）是细胞外基质的一种分泌型多聚糖胺聚糖组分，在正常发育期间对细胞生长和迁移至关重要。 HA的产生升高与包括癌症在内的几种病理状态相关。 对人前列腺肿瘤活检的研究表明，HA在正常成人前列腺中不存在，但在前列腺癌患者中作为疾病严重程度的函数显著过量产生。 在大多数侵袭性癌症中观察到肿瘤细胞相关HA，并且与患者的预后降低相关。 细胞表面HA聚合物的过度产生和操纵受透明质酸合成酶（HAS）和透明质酸酶的作用调节。 透明质酸酶降解HA产生小的寡糖片段，其是活性血管生成刺激物。 实验室的长期目标是了解HA积累如何发生，以及HA酶和透明质酸酶如何协同作用以促进生理相关模型系统中的肿瘤进展。 提出了以下具体目标。 目的1：确定HA生物合成酶和HA前体在促进HA产生和肿瘤发生中的相对重要性。 HA激酶的过度表达促进肿瘤生长，并可能导致HA蓄积。 目前尚不清楚HA合成的升高是如何发生的，因为HA的产生直接与肿瘤细胞中的能量代谢竞争。 雄激素刺激基因UDP-葡萄糖脱氢酶为HA合酶提供限制性前体。 UDP-葡萄糖脱氢酶和HA合酶的共表达协同提高HA合成，因此我们将评估这些酶对肿瘤促进的独立和协同影响。 目的2：探讨前列腺肿瘤细胞中HA生物合成和降解之间的平衡如何调节表型。 预期HA合酶仅在透明质酸酶存在下促进最大肿瘤生长。 我们已经稳定地选择了HA合酶和透明质酸酶的差异表达和共表达的肿瘤细胞系。 我们将使用这些独特的工具来关联的数量和分子大小的HA产生的细胞与它们的致瘤性和转移性的潜力后，直接前列腺注射。 目的3：使用诱导系统评估HA在肿瘤生长、消退和凋亡中的作用。 四环素诱导型构建体将用于上调非致瘤性前列腺肿瘤细胞中的HA合成，并以实验控制的方式抑制高度侵袭性前列腺肿瘤细胞中的HA合成。 HA在肿瘤发生中的时间顺序重要性及其作用模式将通过消除已建立的原位肿瘤中的HA产生并确定肿瘤切片中的血管密度和增殖和凋亡细胞的相对百分比来评价。

DESCRIPTION (provided by applicant): Hyaluronan (HA), a secreted polymeric glycosaminoglycan component of extracellular matrices, is essential for cell growth and migration during normal development. Elevated production of HA is associated with several pathological states, including cancer. Studies of human prostate tumor biopsies have demonstrated that HA, not present in normal adult prostate, is dramatically overproduced as a function of disease severity in prostate cancer patients. Tumor cell associated HA is observed in the most invasive cancers and correlates to reduced prognosis for the patient. Overproduction and manipulation of cell surface HA polymers is regulated by the action of hyaluronan synthase enzymes (HAS) and hyaluronidases. Degradation of HA by hyaluronidases produces small oligosaccharide fragments, which are active angiogenic stimuli. The long term goals of the laboratory are to understand how HA accumulation occurs, and how HA synthases and hyaluronidases function in concert to facilitate tumor progression in a physiologically relevant model system. The following specific aims are proposed. Aim 1: Determine the relative importance of HA biosynthetic enzymes and HA precursors in promoting HA production and tumorigenesis. The overexpression of HA synthases promotes tumor growth and is likely responsible for HA accumulation. It is unclear how elevated HA synthesis occurs, since HA production directly competes with energy metabolism in the tumor cells. An androgen-stimulated gene, UDP-glucose dehydrogenase, provides the limiting precursor for HA synthase. Coexpression of UDP-glucose dehydrogenase and HA synthase synergistically elevates HA synthesis, so we will assess the independent and concerted impact of these enzymes on tumor promotion. Aim 2: Investigate how a balance between HA biosynthesis and degradation in prostate tumor cells regulates phenotype. HA synthase is expected to promote maximal tumor growth only in the presence of hyaluronidase. We have stably selected tumor cell lines for differential expression and coexpression of HA synthase and hyaluronidase. We will use these unique tools to correlate the amount and molecular size of HA produced by the cells with their tumorigenic and metastatic potential following direct prostatic injection. Aim 3: Use an inducible system to evaluate the role of HA in tumor growth, regression, and apoptosis. Tetracycline inducible constructs will be used to upregulate HA synthesis in non-tumorigenic prostate tumor cells and to inhibit HA synthesis in highly aggressive prostate tumor cells in an experimentally controlled fashion. The chronological importance of HA in tumorigenesis and its mode of action will be evaluated by eliminating HA production in an established orthotopic tumor and determining vascular density and relative percentages of proliferating and apoptotic cells in tumor sections.