PHIP as a Biomarker of Triple-Negative Melanoma

描述(申请人提供)：最近在我们实验室进行的研究已经确定了Pleckstrin同源域相互作用蛋白(PhIP)基因作为黑色素瘤进展的标志和媒介的新角色。PhIP水平升高是黑色素瘤生存的独立预测因素。PhIP在三阴性黑色素瘤(含有野生型BRAF、NRAS和PTEN)中被激活，从而有助于描述这一鲜为人知的黑色素瘤分子亚群。此外，shRNA介导的PhIP下调显著抑制了小鼠和人类黑色素瘤的侵袭和转移潜力，包括在三阴性黑色素瘤细胞系中。在这项提案中，我们计划确认PhIP作为黑色素瘤生物标记物的重要作用，以及它作为黑色素瘤进展的媒介的作用。我们的具体目标是：(1)验证PhIP在黑色素瘤中的预后作用。我们将评估PhIP在250名来自不同人群的原发性黑色素瘤患者的不同队列中的预后作用。我们将使用免疫组织化学分析和荧光原位杂交来确定PhIP水平，并将PhIP水平与生存期相关联。我们还将评估200例黑色素瘤转移瘤的PhIP水平。这一目标将验证PhIP在黑色素瘤中的预后影响，并确定其作为黑色素瘤进展标志物的作用。(2)探讨PhIP在黑色素瘤分子分类中的作用。我们将检查450例记录有PhIP水平的黑色素瘤，以了解黑色素瘤中最常见的获得性突变，包括BRAF、NRAS和PTEN。这一目标将用于识别具有激活PhIP水平的黑色素瘤的分子亚型。它还将确定激活PhIP水平的三阴性黑色素瘤的比例。(3)验证PhIP在人类黑色素瘤发生发展中的作用。我们将研究PhIP在调节人类黑色素瘤进展中的作用。我们将评估shRNA介导的PhIP敲除以及PhIP过表达在具有明确BRAF突变状态的早期传代的人类黑色素瘤培养过程中的后果。如果成功，这些研究将验证PhIP作为一种新的黑色素瘤分子预后因子的作用，并确立其在黑色素瘤分子分类中的作用。最后，他们将验证PhIP在黑色素瘤进展中的功能作用，将其确立为可行的治疗靶点。

DESCRIPTION (provided by applicant): Recent studies performed in our laboratory have identified novel roles for the pleckstrin homology domain interacting protein (PHIP) gene as a marker and mediator of melanoma progression. Increased PHIP levels were an independent predictor of melanoma survival. PHIP was activated in triple-negative melanomas (harboring wild type BRAF, NRAS and PTEN), thereby helping to characterize this poorly understood molecular subset of melanoma. In addition, shRNA-mediated down regulation of PHIP significantly suppressed the invasiveness and metastatic potential of both murine and human melanoma, including in triple-negative melanoma cell lines. In this proposal, we plan to confirm the important role played by PHIP as a biomarker for melanoma and its role as a mediator of melanoma progression. Our specific aims are: (1) to validate the prognostic role of PHIP in melanoma. We will assess the prognostic role of PHIP in a distinct cohort of 250 patients with primary melanoma amassed from a different population. We will determine PHIP levels using both immunohistochemical analysis and fluorescence in situ hybridization and correlate PHIP levels with survival. We will also assess PHIP levels in 200 melanoma metastases. This aim will validate the prognostic impact of PHIP in melanoma, and determine its role as a melanoma progression marker. (2) To assess the role of PHIP in the molecular classification of melanoma. We will examine the 450 melanomas with documented PHIP levels for the most commonly acquired mutations in melanoma, including BRAF, NRAS, and PTEN. This aim will serve to identify the molecular subtypes of melanoma with activated PHIP levels. It will also determine the proportion of triple-negative melanomas that have activated PHIP levels. (3) To validate the functional role of PHIP in the progression of human melanoma. We will examine the role of PHIP in mediating human melanoma progression. We will assess the consequences of both shRNA-mediated PHIP knockdown as well as PHIP overexpression in the progression of early-passage human melanoma cultures with defined BRAF mutational status. If successful, these studies will validate the role of PHIP as a novel molecular prognostic factor for melanoma and establish its utility in the molecular classification of this disease. Finally, they will validate he functional role of PHIP in melanoma progression, establishing it as a viable target for therapy.