PTHrP Modulation of TRPV1 in Pain Associated with Breast Cancer Bone Metastasis

PTHrP 对 TRPV1 的调节在乳腺癌骨转移相关疼痛中的作用

• 批准号: 8397858
• 负责人: Aaron David Mickle
• 金额: $ 2.82万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8397858
• 关键词: Afferent Neurons; Analgesics; Behavior assessment; Biochemical; Body Temperature; Bone Pain; Bone neoplasms; Breast; Breast Cancer Cell; Case Study; Chronic; Coculture Techniques; Cytolysis; Development; Diagnosis; Dose-Limiting; Drops; Electrophysiology (science); Event; Fiber; Frequencies; Gait; Goals; Human; Image; Inflammation Mediators; Inflammatory; Injection of therapeutic agent; Intervention; Ions; Lead; Limb structure; MDA MB 231; Malignant Bone Neoplasm; Malignant Neoplasms; Mammary Neoplasms; Mediating; Membrane Proteins; Metastatic Neoplasm to the Bone; Modification; Molecular; Morbidity - disease rate; Morphine; Morphine Derivatives Including Cocaine; Mus; Neoplasm Metastasis; Nerve Fibers; Neurons; Nociceptors; Nutrient; Osteoblasts; Osteoclasts; Pain; Palliative Care; Parathyroid Hormone Receptor; Patients; Pelvis; Pharmacotherapy; Phosphorylation; Physiological; Protein Biochemistry; Protein Kinase C; Proteins; Quality of life; Regimen; Role; Sensory; Series; Side; Signal Transduction; Signaling Molecule; Spinal Ganglia; Temperature; Testing; Therapeutic; Time; United States; Up-Regulation; Vanilloid; Vertebral column; Weight-Bearing state; Woman; Xenograft procedure; afferent nerve; base; bisphosphonate; bone; cancer diagnosis; cancer pain; chronic pain; grasp; in vivo; in vivo Model; inflammatory pain; insight; limb bone; long bone; malignant breast neoplasm; neurobiological mechanism; novel; pain behavior; parathyroid hormone-related protein; patch clamp; receptor; spontaneous pain; tumor; tumor growth

DESCRIPTION (provided by applicant): Breast cancer is the most frequently diagnosed cancer among women in the United States with >200,000 new cases reported every year. Aggressive forms of breast cancers most commonly metastasize to bones, which constitutes the key factor for high morbidity rate and associated suffering. Metastatic breast tumor growth in bones leads to chronic pain in the limbs, pelvis and spines, which is undermanaged with existing pain medications, mainly morphine derivatives. As palliative care is the major therapeutic goal for patients with breast cancer bone metastasis, a better understanding of signaling crosstalk between metastatic bone tumor microenvironment and the adjacent sensory nerve fibers is necessary for the development of highly efficacious analgesics for chronic bone cancer pain. Metastatic breast cancer cells secrete high levels of parathyroid hormone-related peptide (PTHrP), which act on osteoblasts and osteoclasts to induce bone lysis/destruction and subsequent release of nutrients and cell signaling molecules that stimulate tumor growth. Here I propose a novel hypothesis that PTHrP, by acting through its receptor PTH1 on sensory afferents, induce constitutive nociceptor sensitization via upregulation of activity/expression of the transient receptor potential vanilloid-1 (TRPV1) channel, which might underlie a mechanism for chronic pain associated with metastatic breast/bone cancers. The TRPV1 channel is normally activated only at noxious temperatures (e43oC). However, PTHrP acting through the PTH1 receptor could induce phosphorylation of TRPV1 protein and lead to constitutive channel activation at body temperatures (d37oC), a mechanism that could underlie chronic pain in the absence of any overt stimulation. Aim 1 of my study will determine the specific cellular signaling events that underlie PTHrP-modulation of TRPV1 channel activity/expression in sensory neurons, and nociceptor sensitization. I will utilize patch-clamp electrophysiology, Ca2+ imaging, and membrane protein biochemistry to determine the molecular mechanisms underlying TRPV1 modulation by PTHrP. Aim 2 of my study will determine the role of PTHrP-modulation of TRPV1 in sensory afferents on chronic bone pain in vivo using scid mice xenografts of human breast cancer cells, MDA-MB231-BoM-1833, that metastasize to bones when injected intracardialy. I will use a series of un-evoked/spontaneous bone-related pain behavioral assessments in these mice with metastatic breast/bone tumors. I will also utilize pharmacological inhibition of PTHrP and TRPV1 in these mice, to further confirm the contribution of PTHrP-modulation of TRPV1 in chronic bone pain associated with metastatic breast/bone tumor growth. My proposed studies will advance our understanding of how the interplay between metastatic breast/bone tumors and sensory neurons mediate chronic pain. Findings from this study will significantly contribute to the development of effective pharmacotherapies for chronic pain associated with metastatic bone cancers. PUBLIC HEALTH RELEVANCE: Chronic pain associated with bone-metastasized breast cancers significantly diminishes the quality of life for women with this metastatic form of breast cancers. Breast cancers frequently metastasize to bones and cause chronic debilitating pain, which is undermanaged with the currently available analgesic regimen. Understanding the precise neurobiological mechanisms underlying this form of chronic pain is paramount for the development of novel and effective analgesic therapeutics. Specific modulation of the activity/expression of the key pain-transducing channel TRPV1 in sensory neurons that innervate bones, by PTHrP, which is secreted at elevated levels in bone-metastasized breast tumor microenvironment, is a potential neurobiological mechanism for chronic pain, and can be targeted for the development of pharmacotherapeutics for treating such pain.)

描述（由申请人提供）：乳腺癌是美国女性中最常诊断的癌症，每年报告> 20万例新病例。侵袭性乳腺癌最常转移到骨骼，这是高发病率和相关痛苦的关键因素。转移性乳腺肿瘤在骨骼中的生长导致四肢、骨盆和脊柱的慢性疼痛，这是现有止痛药（主要是吗啡衍生物）治疗不足的。由于姑息治疗是乳腺癌骨转移患者的主要治疗目标，因此更好地了解转移性骨肿瘤微环境与邻近感觉神经纤维之间的信号串扰对于开发高效的慢性骨癌疼痛镇痛药是必要的。转移性乳腺癌细胞分泌高水平的甲状旁腺素相关肽（PTHrP），其作用于成骨细胞和破骨细胞以诱导骨溶解/破坏以及随后释放刺激肿瘤生长的营养物质和细胞信号分子。在这里，我提出了一个新的假设，PTHrP，通过其受体PTH 1的感觉传入，诱导组成性伤害感受器敏化通过上调瞬时受体电位香草酸-1（TRPV 1）通道的活性/表达，这可能是慢性疼痛与转移性乳腺癌/骨癌的机制。TRPV 1通道通常仅在有害温度（e43 ℃）下激活。然而，PTHrP通过PTH 1受体起作用，可以诱导TRPV 1蛋白磷酸化，并导致在体温（d37 ℃）下的组成性通道激活，这是一种在没有任何明显刺激的情况下可能导致慢性疼痛的机制。目的1我的研究将确定特定的细胞信号事件，PTHrP调制TRPV 1通道的活动/表达的感觉神经元，和伤害感受器敏化。我将利用膜片钳电生理学，钙离子成像，膜蛋白生物化学，以确定PTHrP的TRPV 1调制的分子机制。我的研究目的2将确定PTHrP调节TRPV 1在感觉传入中对体内慢性骨痛的作用，使用人乳腺癌细胞MDA-MB 231-BoM-1833的scid小鼠异种移植物，当心内注射时转移到骨骼。我将在这些转移性乳腺/骨肿瘤小鼠中使用一系列非诱发/自发性骨相关疼痛行为评估。我还将在这些小鼠中利用PTHrP和TRPV 1的药理学抑制，以进一步证实PTHrP调节TRPV 1在与转移性乳腺/骨肿瘤生长相关的慢性骨痛中的作用。我提出的研究将促进我们对转移性乳腺/骨肿瘤和感觉神经元之间的相互作用如何介导慢性疼痛的理解。这项研究的结果将大大有助于发展有效的药物治疗与转移性骨癌相关的慢性疼痛。 公共卫生相关性：与骨转移性乳腺癌相关的慢性疼痛显著降低了患有这种转移性乳腺癌的女性的生活质量。乳腺癌经常转移到骨骼并引起慢性衰弱性疼痛，目前可用的镇痛方案管理不足。了解这种形式的慢性疼痛背后的确切神经生物学机制对于开发新的有效的镇痛疗法至关重要。通过PTHrP（其在骨转移的乳腺肿瘤微环境中以升高的水平分泌）对支配骨骼的感觉神经元中的关键疼痛转导通道TRPV 1的活性/表达的特异性调节是慢性疼痛的潜在神经生物学机制，并且可以靶向用于治疗这种疼痛的药物治疗剂的开发。