Molecular Regulation of Human Melanoma Metastasis

描述（由申请方提供）：本申请的长期目的是确定白细胞介素（IL）-8在恶性黑色素瘤发病机制中的分子机制。 IL-8是CXC趋化因子家族的成员，在恶性黑素瘤中组成性表达，并作为自分泌/旁分泌生长、侵袭和血管生成因子发挥作用。 IL-8的作用通过黑色素瘤细胞和内皮细胞上表达的两种高亲和力受体CXCR 1和CXCR 2介导。 IL-8与CXCR 1和CXCR 2的结合可引发多种细胞应答，然而，IL-8在恶性黑素瘤中激活CXCR 1和/或CXCR 2的确切作用尚不清楚。 因此，本申请的具体目的是确定CXCR 1和CXCR 2在介导IL-8诱导的细胞应答中的不同功能作用，所述细胞应答调节黑素瘤生长、侵袭、血管生成和转移。 我们假设IL-8与CXCR 1和CXCR 2的相互作用激活不同的下游信号通路，并在黑色素瘤生长、侵袭、血管生成和转移中发挥不同的作用。 1）确定IL-8对CXCR 1和/或CXCR 2的激活是否导致在调节与黑素瘤生长、侵袭和转移相关的细胞表型中的不同或重叠作用; 2）检查黑素瘤中IL-8诱导的血管生成应答中内皮细胞中CXCR 1和CXCR 2的不同作用;和3）鉴定参与IL-8诱导的CXCR 1和CXCR 2依赖性调节黑素瘤细胞生长、存活和侵袭性应答的信号转导机制。 我们将在体外和体内研究CXCR 1和CXCR 2依赖性IL-8介导的作用。 我们将在异种移植模型和mCXCR 2敲除裸鼠中使用小分子拮抗剂和腺病毒-siRNA载体在体内特异性靶向CXCR 1和/或CXCR 2。 使用途径特异性抑制剂，磷酸化特异性抗体，免疫印迹和免疫组织化学，我们将检查CXCR 1和/或CXCR 2体外和体内激活后的下游信号通路。 这些研究将确定CXCR 1和CXCR 2激活及其下游信号通路在介导IL-8诱导的恶性黑色素瘤生长、血管生成和转移反应中的不同和/或重叠作用。 我们预计，从这些研究中获得的知识将确定新的治疗靶点，抑制配体结合和/或信号转导事件和恶性黑色素瘤的治疗方法的发展。

DESCRIPTION (provided by applicant): The long-term objective of this application is to determine the molecular mechanism(s) of interleukin (IL)-8 in malignant melanoma pathogenesis. IL-8, a member of the CXC chemokine family is constitutively expressed in malignant melanoma and functions as an autocrine/paracrine growth, invasive and angiogenic factor. The effect of IL-8 is mediated through two high affinity receptors, CXCR1 and CXCR2, expressed on melanoma cells as well as endothelial cells. Binding of IL-8 to CXCR1 and CXCR2 can initiate diverse cellular responses, however, the precise role of activation of CXCR1 and/or CXCR2 by IL-8 in malignant melanoma is not known. Therefore, the specific objective of this application is to determine the distinct functional role of CXCR1 and CXCR2 in mediating IL-8-induced cellular responses that regulate melanoma growth, invasion, angiogenesis, and metastasis. We hypothesize that interaction of IL-8 with CXCR1 and CXCR2 activates different downstream signaling pathways and plays a diverse role in melanoma growth, invasion, angiogenesis, and metastasis. We will test this hypothesis and accomplish the objective of this application by: 1) Determining whether activation of CXCR1 and/or CXCR2 by IL-8 result in distinct or overlapping roles in regulating cellular phenotypes associated with melanoma growth, invasion and metastasis; 2) Examining the diverse roles of CXCR1 and CXCR2 in endothelial cells in an IL-8-induced angiogenic response in melanoma; and 3) Identifying the signal transduction mechanism(s) involved in IL-8-induced CXCR1- and CXCR2-dependent modulation of melanoma cell growth, survival and invasive response. We will examine the CXCR1 and CXCR2-dependent IL-8-mediated effects in vitro and in vivo. We will use specific targeting of CXCR1 and/or CXCR2 in vivo using small molecule antagonists and adenoviral-siRNA vectors in xenograft models and mCXCR2 knockout nude mice. Using pathways specific inhibitors, phospho-specific antibodies, immunoblotting and immunohistochemistry, we will examine the downstream signaling pathways following CXCR1 and/or CXCR2 activation in vitro and in vivo. These studies will identify distinct and/or overlapping roles for CXCR1 and CXCR2 activation and their downstream signaling pathways in mediating IL-8-induced responses in malignant melanoma growth, angiogenesis, and metastasis. We anticipate that the knowledge gained from these studies will identify new therapeutic targets for inhibiting the ligand binding and/or signal transduction events and the development of therapeutics for malignant melanoma.