Glycosaminoglycan-based inhibitors for treatment of prostate cancer

描述（由申请人提供）：本申请的总体目标是针对肿瘤相关透明质酸-透明质酸酶（HA-HAase）系统开发前列腺癌（CaP）的新疗法。透明质酸是一种促进肿瘤生长和转移的糖胺聚糖，而HAase是一种内糖苷酶，可将透明质酸降解为血管生成碎片。HYAL1是一种肿瘤来源的HAase，由CaP细胞分泌。HA-HYAL1在CaP组织中的联合表达是预测CaP进展的独立预后指标。通过反义cDNA转染阻断CaP细胞中HYAL1的表达，可降低异种移植物中肿瘤的生长、侵袭和血管形成。硫酸酸化HA （sHA）聚合物和小sHA寡糖是有效的HYAL1活性抑制剂，通过引起细胞周期阻滞和抑制CaP异种移植物的生长来抑制CaP细胞的生长。这些药物降低局灶黏附激酶的激活，下调雄激素受体的水平和活性。4-甲基-伞形酮（4-MU）作为治疗肝脏营养不良的膳食补充剂，可抑制HA的合成。4-MU通过阻断细胞周围HA的形成，激活caspase-8诱导CaP细胞凋亡，抑制CaP异种移植物的生长。sHA和4-MU都是口服生物可利用的，对雄激素依赖性和独立的CaP细胞都有活性，长期治疗后没有组织学或全身毒性。在提议的项目中要检验的主要假设是，sHA和4-MU，单独或组合，将废除CaP的增长及其进展。我们将在体外评价sHA化合物对细胞生长和侵袭的抑制作用。我们将在3种CaP异种移植模型（原位肿瘤移植、诱导转移和骨内生长模型）中检测肿瘤生长、转移和血管生成的抑制作用。sHA对HA-HYAL1介导的细胞内信号传导的影响也将被研究（目的1）。我们将在体外研究4-MU对CaP细胞生长、侵袭和运动的控制作用。4-MU单独或与sHA联合对肿瘤生长和转移的抑制作用将在上述三种CaP异种移植模型中进行研究。4-MU诱导细胞凋亡的机制和HA介导的细胞内信号通路的消除也将被研究（目的2）。将在两种转基因CaP模型中研究sHA和4-MU单独或联合治疗CaP生长和转移的分期特异性治疗效果（Aim 3）。相关性：这是首次提出评估HA-HYAL1系统抑制剂作为治疗CaP的治疗药物的研究。如果证明有效，sHA化合物和4-MU将成为一类新的基于糖胺聚糖的靶向特异性抗肿瘤药物。

DESCRIPTION (provided by applicant): The overall objective of this proposal is to target the tumor-associated hyaluronic acid-hyaluronidase (HA-HAase) system to develop novel therapeutics for prostate cancer (CaP). HA is a glycosaminoglycan that promotes tumor growth and metastasis and HAase is an endoglycosidase that degrades HA into angiogenic fragments. HYAL1 is a tumor-derived HAase, secreted by CaP cells. Combined HA-HYAL1 expression in CaP tissues is an independent prognostic indicator for predicting CaP progression. Blocking HYAL1 expression in CaP cells, by antisense cDNA transfection, decreases tumor growth, invasion and vascularization in xenografts. Sulfated HA (sHA) polymer and small sHA oligosaccharides are potent inhibitors of HYAL1 activity which inhibit CaP cell growth by causing cell-cycle arrest and inhibit the growth of CaP xenografts. These agents decrease activation of focal adhesion kinase and down regulate androgen receptor levels and activity. 4-methyl-umbelliferone (4-MU), used as a dietary supplement for the treatment of liver aliments, inhibits HA synthesis. By blocking pericellular HA formation, 4-MU induces apoptosis in CaP cells by caspase-8 activation and inhibits the growth of CaP xenografts. Both sHA and 4-MU are orally bioavailable, active against both androgen dependent and independent CaP cells and show no histologic or systemic toxicity upon long-term treatment. The main hypothesis to be tested in the proposed project is that, sHA and 4-MU, either alone or in combination, will abrogate CaP growth and its progression. The efficacy of sHA compounds to inhibit cell growth and invasion will be evaluated in vitro. Inhibition of tumor growth, metastasis and angiogenesis will be examined in 3 CaP xenograft models (i.e., orthotopic tumor implant, induced metastasis and intra-osseous growth models). Effect of sHA on HA-HYAL1 mediated intracellular signaling will also be investigated (Aim 1). Effect of 4-MU in controlling CaP cell growth, invasion and motility will be investigated in vitro. Inhibition of tumor growth and metastasis by 4-MU, either alone or in combination with sHA, will be examined in the three CaP xenograft models, as described above. Mechanism of 4-MU induced apoptosis and abrogation of HA- mediated intracellular signaling will also be investigated (Aim 2). Efficacy of sHA and 4-MU, either alone or in combination, as stage-specific treatments for CaP growth and metastasis will be investigated in two transgenic models of CaP (Aim 3). Relevance: This is the first study that proposes to evaluate inhibitors of the HA-HYAL1 system as therapeutic agents for the treatment of CaP. If proven efficacious, sHA compounds and 4-MU will be a novel class of glycosaminoglycan-based target-specific anti-tumor drugs.