Role of hyaluronan matrix in prostate cancer progression

描述(申请人提供)：透明质酸(HA)是细胞外基质中的一种分泌型多聚糖胺多糖成分，对细胞正常发育过程中的生长和迁移是必不可少的。HA的产生增加与包括癌症在内的几种病理状态有关。对人类前列腺癌活检组织的研究表明，正常成人前列腺中不存在的透明质酸，在前列腺癌患者中显著过度产生，是疾病严重程度的函数。肿瘤细胞相关的透明质酸在最具侵袭性的癌症中被观察到，并与患者预后的降低相关。透明质酸合成酶(HAS)和透明质酸酶的作用调节细胞表面HA聚合物的过量生产和调控。透明质酸酶降解透明质酸会产生小的寡糖片段，这是一种活跃的血管生成刺激。该实验室的长期目标是了解HA积聚是如何发生的，以及HA合成酶和透明质酸酶如何在生理相关的模型系统中协同作用以促进肿瘤的进展。提出了以下具体目标。目的1：确定HA生物合成酶及其前体在促进HA合成和肿瘤发生中的相对重要性。HA合酶的过度表达促进了肿瘤的生长，可能是导致HA积聚的原因。目前尚不清楚HA合成增加是如何发生的，因为HA合成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合成酶提供限制前体。UDP-葡萄糖脱氢酶和HA合成酶的共同表达协同提高了HA的合成，因此我们将评估这些酶在促进肿瘤方面的独立和协同作用。目的2：研究前列腺癌细胞中HA生物合成和降解之间的平衡如何调节表型。透明质酸合成酶只有在透明质酸酶存在的情况下才能最大限度地促进肿瘤生长。我们已经稳定地选择了HA合成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细胞产生的HA的数量和分子大小与其在直接前列腺癌注射后的致瘤和转移潜力。目的：用诱导系统评价透明质酸在肿瘤生长、消退和凋亡中的作用。四环素可诱导构建物将被用来以实验控制的方式上调非致癌前列腺癌细胞的HA合成，并抑制高侵袭性前列腺癌细胞的HA合成。通过消除已建立的原位肿瘤中HA的产生，并测定肿瘤切片中血管密度和增殖和凋亡细胞的相对百分比，来评估HA在肿瘤发生中的时序重要性及其作用方式。

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.