Growth/differentiation control of keratinocytes by ROR alpha

描述（由申请人提供）：分化与上皮肿瘤的发展呈负相关。我们最近发现叉头转录因子FOXN 1和Notch 1信号通路在功能上与抑制恶性皮肤肿瘤形成有关。我们的工作假设是维甲酸相关的核孤儿受体ROR 1是角质形成细胞中促分化网络的关键组成部分，作为FOXN 1/Notch 1基因和脂质代谢或稳态相关酶的上游调节因子发挥作用。ROR 1以前已经涉及许多过程，包括发育，炎症和昼夜节律。我们的初步结果指出ROR 1在角质形成细胞生长/分化和肿瘤发展中的关键作用。对于我们未来的工作，我们将解决以下具体目标：1）我们将评估ROR 1是否在控制角质形成细胞分化中发挥重要作用，FOXN 1和Notch 1基因作为下游效应子。我们将通过对传统和3D器官型培养物中的原代人角质形成细胞（HKC）以及ROR 1基因破坏的小鼠进行联合分析来验证这一假设。2)我们将评估ROR 1是否控制参与脂质代谢的酶的表达。我们将测试ROR 1的代谢功能通过ALOXE 3（一种强烈参与角质形成细胞分化的脂氧合酶）影响生长/分化控制和肿瘤发生的更一般方面的可能性。3)我们将评估ROR 1是否在控制角质形成细胞肿瘤形成中起重要作用。这一假设将通过遗传学和药理学双重方法进行检验。将测试具有杂合ROR 1基因突变的小鼠对DMBA-TPA诱导的皮肤癌发生的敏感性，并将测试具有ras癌基因表达加/减ROR 1敲低的HKC异种移植物的肿瘤形成。在药理学上，我们将测试用ROR 1特异性激动剂（CGP 52608）治疗是否可以影响化学诱导的和/或异种移植肿瘤形成。)

DESCRIPTION (provided by applicant): Differentiation is inversely related to development of epithelial tumors. We recently showed that the forkhead transcription factor FOXN1 and the Notch1 signaling pathways are functionally linked to suppression of malignant skin tumor formation. Our working hypothesis is that the retinoid-related nuclear orphan receptor ROR1 is a key integral element of the pro-differentiation network in keratinocytes, functioning as an upstream regulator of FOXN1/Notch1 genes and enzymes involved in lipid metabolism or homeostasis. ROR1 has been previously implicated in a number of processes, including development, inflammation and circadian rhythm. Our preliminary results point to a key role of ROR1 in keratinocyte growth/differentiation and tumor development. For our future work we will address the following specific aims: 1) We will assess whether ROR1 plays an important role in control of keratinocyte differentiation with the FOXN1 and Notch1 genes as downstream effectors. We will test this hypothesis by a combined analysis of primary human keratinocytes (HKCs) in conventional and 3D organotypic cultures, and mice with disruption of the ROR1 gene. 2) We will assess whether ROR1 controls the expression of enzymes involved in lipid metabolism. We will test the possibility that the metabolic function of ROR1 impinges on more general aspects of growth/differentiation control and tumorigenesis via ALOXE3, a lipoxygenase that is intensively involved in keratinocyte differentiation. 3) We will assess whether ROR1 plays an important role in control of keratinocyte tumor formation. This hypothesis will be tested by a dual genetic and pharmacological approach. Mice with heterozygous ROR1 gene mutation will be tested for their sensitivity to DMBA-TPA-induced skin carcinogenesis, and xenografts of HKCs with ras oncogene expression plus/minus ROR1 knockdown will be tested for tumor formation. Pharmacologically, we will test whether treatment with a ROR1 specific agonist (CGP 52608) can affect chemical- induced and/or xenograft tumor formation. )