Epigenetic control of skin homeostasis by the ULK3 nuclear kinase

摘要 野生性癌变是角质形成细胞和真皮成纤维细胞联合作用的一种主要临床症状。 改装。识别针对这两种细胞类型的改变的调节分子是非常有意义的。 我们认为，核激酶ULK3就是这样一个分子，我们以前研究过它在其中的作用。 成纤维细胞。在这里，我们将追求以下目标：(1)我们将检验ULK3撞击KEY的假设 转录调控网络决定角质形成细胞的自我更新和致癌潜能。ULK3已启动- 角质形成细胞来源的皮肤和头颈部鳞状细胞癌(SCCs)的调节和沉默 该基因抑制人角质形成细胞(HKCs)和SCC细胞的增殖和致瘤潜能。我们 我将探讨ULK3与p63和GLI转录网络在肿瘤生长/分化中的相互作用 这些细胞及其致瘤性，在皮肤癌扩张的原位模型中。2)我们将检验这一假设 ULK3在精氨酸甲基组和染色质组织的交叉点起作用。精氨酸 甲基化是SCCs发育过程中染色质调节的一种少见的研究模式。我们发现ULK3 与精氨酸甲基酶PRMT1和PRMT5(PRMTs)相关，并导致鳞癌细胞ULK3丢失 在组蛋白4(H4R3)的二甲基化形式的下调中，PRMTs活性的已知产物。 我们将测试ULK3是否控制PRMT1和5的活性和/或将这些酶与关键底物联系起来，如 P63、GLI2和组蛋白(特别是H4)。我们将进一步确定ULK3是否控制基因转录 在HKCs和SCC中，通过汇聚PRMT1-和5-，对染色质组织产生更广泛的影响 依赖机制。3)我们将测试ULK3是与皮肤相关的翻译目标的假设 野战癌变。我们将采取遗传和药理学双重方法。从基因上讲，我们有 培育出带有Ulk3flx等位基因和K14-Creer转基因的角质形成细胞特异性Ulk3缺失的小鼠。我们会 检查Ulk3缺失对正常皮肤动态平衡的影响，以及移植到白化无毛症患者后的影响 背景：评估UVB诱导的皮肤野癌变的后果。从药理上讲，我们发现 ULK3抑制物抑制鳞状细胞癌和癌细胞/间质细胞的增殖能力 扩张。我们将在培养细胞上扩展ULK3和PRMT1/5抑制剂的研究，并进一步测试 在皮肤癌/基质细胞增殖的体内原位模型中最有希望的化合物。

SUMMARY Field cancerization is a major clinical condition resulting from combined keratinocyte and dermal fibroblast alterations. Identification of regulatory molecules to target alterations of both cell types is of substantial interest. We propose that the nuclear kinase ULK3 is one such a molecule, which we previously studied for its role in fibroblasts. Here we will pursue the following aims: (1) We will test the hypothesis that ULK3 impinges on key transcription regulatory networks determining keratinocyte self-renewal and oncogenic potential. ULK3 is up- regulated in keratinocyte-derived skin and head/neck Squamous Cell Carcinomas (SCCs) and silencing of the gene suppresses proliferative and tumorigenic potential of both human keratinocytes (HKCs) and SCC cells. We will explore the interplay between ULK3 and the p63 and GLI transcription networks in growth/differentiation of these cells and their oncogenicity, in orthotopic models of skin cancer expansion. 2) We will test the hypothesis that ULK3 functions at the intersection between the arginine methylome and chromatin organization. Arginine methylation is a little investigated mode of chromatin regulation in SCCs development. We have found that ULK3 associates with the arginine methylases PRMT1 and PRMT5 (PRMTs) and that ULK3 loss in SCC cells results in down-modulation of di-methylated forms of Histone 4 (H4R3), well established products of PRMTs activity. We will test whether ULK3 controls PRMT1 and 5 activity and/or links these enzymes to key substrates such as p63, GLI2 and histones (specifically H4). We will further determine whether ULK3 control of gene transcription in HKCs and SCC involves a broader impact on chromatin organization through convergent PRMT1- and 5- dependent mechanisms. 3) We will test the hypothesis that ULK3 is a target of translational relevance for skin field cancerization. We will undertake a dual genetic and pharmacological approach. Genetically, we have developed mice with Ulk3flox alleles and K14- CreER transgene for keratinocyte-specific Ulk3 deletion. We will examine the impact of Ulk3 deletion on normal skin homeostasis and, after transfer into an albino hairless background, assess the consequences for UVB-induced skin field cancerization. Pharmacologically, we found that ULK3 inhibitory compounds suppress proliferative potential of SCC cells as well as cancer/stromal cell expansion. We will extend our studies with ULK3 and PRMT1/5 inhibitors on cultured cells and further test the most promising compounds in an in vivo orthotopic model of skin cancer/stromal cells expansion.