Mechanisms of bone invasion and tumor growth in models of head and neck cancer.

描述（由申请人提供）：头颈部鳞状细胞癌（HNSCC）通常侵犯骨骼，这与严重的发病率和患者生存率降低有关。本项目的主要目的是通过识别和靶向肿瘤诱导骨吸收的机制来抑制HNSCC的骨侵袭和生长。这些研究将利用骨侵袭性鳞状细胞癌的体外和体内模型，采用来自自发性鳞状细胞癌肿瘤的人类细胞系。以下假设将被检验：恶性恶性肿瘤细胞癌侵入骨是由肿瘤诱导的骨吸收和肿瘤源性细胞因子表达的恶性循环引起的。具体来说，hnscc衍生的甲状旁腺激素相关蛋白（PTHrP）和前列腺素E2 （PGE2）诱导破骨细胞骨吸收，从而从骨基质中释放转化生长因子- β (TGF-P)。TGF-J3诱导额外的肿瘤合成PTHrP和PGE2，已知它们支持肿瘤生长和骨吸收。此外，将骨吸收抑制剂唑来膦酸与环氧化酶-2抑制剂美洛昔康联合使用，可以阻断恶性循环，减少骨侵袭和肿瘤生长。提出了三个具体目标。首先，确定细胞因子阻断是否会抑制hnscc诱导的骨吸收。通过测量基质细胞中RANKL和OPG（破骨细胞活性的介质）的表达、破骨前细胞的分化和骨培养物中TGF-J3的释放来评估骨吸收。siRNA会降低PTHrP，美洛昔康会抑制PGE2。其次，研究骨吸收如何影响HNSCC增殖和PTHrP和COX-2的表达。将比较溶解性和非溶解性骨的条件培养基对TGF-p抗体中和的影响。第三，确定多模式治疗（唑来膦酸联合美洛昔康）对体外和体内肿瘤生长和骨侵袭的影响。共培养将用于确定在骨存在的情况下治疗对HNSCC增殖和凋亡的影响。使用表达荧光素酶的原位、异种移植HNSCC裸鼠模型测量体内肿瘤生长和骨侵袭，并使用体内生物发光成像和显微ct进行定量。HNSCC占头颈部癌症的90%以上，是世界上第六大常见癌症。在过去的30年里，患者的生存率没有显著提高。骨侵犯经常发生，预后较差。本研究将确定同时抑制骨吸收和COX-2活性是否能成功阻断骨侵袭并减少HNSCC模型中的肿瘤生长。

DESCRIPTION (provided by applicant): Squamous cell carcinoma of the head and neck (HNSCC) commonly invades bone, which is associated with severe morbidity and reduced patient survival. The primary objective of this project is to inhibit bone invasion and growth of HNSCC by identifying and targeting mechanisms of tumor-induced bone resorption. These investigations will utilize in vitro and in vivo models of bone-invasive HNSCC, employing human cell lines derived from spontaneous HNSCC tumors. The following overall hypothesis will be tested: HNSCC invasion into bone is caused by a vicious cycle of tumor-induced bone resorption and expression of tumor-derived cytokines. Specifically, HNSCC-derived parathyroid hormone-related protein (PTHrP) and prostaglandin E2 (PGE2) induce osteoclastic bone resorption which releases transforming growth factor-beta (TGF-P) from the bone matrix. TGF-J3 induces additional tumor-synthesis of PTHrP and PGE2 which are known to support tumor growth as well as bone resorption. Furthermore, combining a bone resorption inhibitor, zoledronic acid, with a cyclooxygenase-2 inhibitor, meloxicam, will block the vicious cycle and reduce bone invasion and tumor growth. Three specific aims are proposed. First, determine if cytokine blockade will inhibit HNSCC-induced bone resorption. Resorption will be evaluated by measuring stromal cell expression of RANKL and OPG (mediators of osteoclast activity), differentiation of pre-osteoclast cells, and TGF-J3 release from bone cultures. PTHrP will be reduced with siRNA, and PGE2 will be inhibited by meloxicam. Second, examine how bone resorption affects HNSCC proliferation and expression of PTHrP and COX-2. The effects of conditioned medium from lytic and non-lytic bone will be compared, with and without antibody neutralization of TGF-p. Third, determine the effect of multimodal therapy (zoledronic acid combined with meloxicam) on tumor growth and bone invasion in vitro and in vivo. Co-cultures will be used to determine the effect of treatment on HNSCC proliferation and apoptosis in the presence of bone. In vivo tumor growth and bone invasion will be measured using orthotopic, xenograft nude mouse models of luciferase-expressing HNSCC, quantitated with in vivo bioluminescent imaging and micro-CT. HNSCC represents over 90% of head and neck cancers, the 6th most common cancer in the world. Patient survival has not significantly improved over the past 30 years. Bone invasion frequently occurs and is associated with a poorer prognosis. This study will determine if simultaneous inhibition of bone resorption and COX-2 activity will successfully block bone invasion and reduce tumor growth in models of HNSCC.