Role of hyaluronan matrix in prostate cancer progression

描述（申请人提供）：透明质酸（HA）是细胞外基质分泌的聚合糖胺聚糖成分，在正常发育过程中对细胞生长和迁移至关重要。血凝素的升高与包括癌症在内的几种病理状态有关。人类前列腺肿瘤活组织检查的研究表明，在正常成人前列腺中不存在的透明质酸，在前列腺癌患者中作为疾病严重程度的一种功能，显着过量产生。在大多数侵袭性癌症中观察到肿瘤细胞相关的HA，并与患者预后降低相关。细胞表面透明质酸聚合物的过量生产和操纵是由透明质酸合成酶（HAS）和透明质酸酶的作用调节的。透明质酸酶降解透明质酸产生小的寡糖片段，这是积极的血管生成刺激。实验室的长期目标是了解HA是如何积累的，以及HA合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进展。提出以下具体目标。目的1：确定透明质酸生物合成酶和透明质酸前体在促进透明质酸产生和肿瘤发生中的相对重要性。HA合成酶的过度表达促进肿瘤生长，可能是HA积累的原因。目前尚不清楚HA的合成是如何升高的，因为HA的产生直接与肿瘤细胞的能量代谢竞争。雄激素刺激的基因，udp -葡萄糖脱氢酶，为血凝素合成酶提供限制性前体。udp -葡萄糖脱氢酶和HA合成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：研究前列腺肿瘤细胞中HA生物合成和降解之间的平衡如何调节表型。只有在透明质酸酶存在的情况下，透明质酸合酶才能促进肿瘤的最大生长。我们稳定地选择肿瘤细胞系进行HA合酶和透明质酸酶的差异表达和共表达。我们将使用这些独特的工具将直接前列腺注射后细胞产生的HA的数量和分子大小与它们的致瘤性和转移潜力联系起来。目的3：利用诱导系统评估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侵袭性前列腺肿瘤细胞中的HA合成。通过消除原位肿瘤中HA的产生，并测定肿瘤切片中血管密度和增殖细胞和凋亡细胞的相对百分比，将评估HA在肿瘤发生中的时间重要性及其作用模式。

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.