ROLE FOR ALKALINE CERAMIDASE 1 (ACER1) IN SKIN CANCER

碱性神经酰胺酶 1 (ACER1) 在皮肤癌中的作用

• 批准号: 8360387
• 负责人: CUNGUI MAO
• 金额: $ 10.84万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-01 至 2012-07-18
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8360387
• 关键词: Basal Cell; Cell Line; Cells; Centers of Research Excellence; Ceramidase; Ceramides; Data; Development; Diagnosis; Differentiation Antigens; Down-Regulation; Epidermal Growth Factor; Epidermis; Foundations; Funding; Goals; Grant; Growth; Human; Hydrolysis; Hyperplasia; In Situ Hybridization; Keratin; Malignant - descriptor; Malignant Epithelial Cell; Messenger RNA; Molecular; Mus; National Center for Research Resources; Natural regeneration; Nonesterified Fatty Acids; Physiological; Play; Prevention; Principal Investigator; Proliferating; Publishing; RNA Interference; Research; Research Infrastructure; Resources; Role; Severe Combined Immunodeficiency; Skin; Skin Cancer; Skin Neoplasms; Skin Papilloma; Skin Transplantation; Skin graft; Source; Sphingosine; Testing; Transgenes; Transgenic Mice; Tumor Suppressor Proteins; United States National Institutes of Health; Up-Regulation; cost; extracellular; keratinocyte; keratinocyte differentiation; mouse alkaline ceramidase; novel strategies; research study; response; skin squamous cell carcinoma

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The skin squamous cell carcinoma (SSCC), which is derived from malignant keratinocytes, is a major type of skin cancer, more than 1 million cases of which are diagnosed annually within the US. The long-term goals of this project are to define the role of the human alkaline ceramidase 1 (ACER1) in suppressing SSCC, and to develop this concept into novel approaches for the prevention and treatment of SSCC. ACER1 is our newly cloned ceramidase that catalyzes the hydrolysis of ceramide to generate free fatty acid and sphingosine (SPH). Our published data demonstrate that ACER1 is a skin-specific ceramidase that plays an important role in the growth arrest and differentiation of epidermal keratinocytes. In situ hybridization revealed that ACER1 mRNA is expressed at much higher levels in the differentiating and differentiated cell layers of the epidermis than the proliferating basal cell layer. ACER1 expression in cultured keratinocytes is markedly upregulated by extracellular Ca2+, a key physiological inducer of the growth arrest and differentiation of keratinocytes. This upregulation is inhibited by epidermal growth factor (EGF), which promotes keratinocyte proliferation but suppresses differentiation. ACER1 knockdown by RNA interference increases keratinocyte proliferation and suppresses keratinocyte differentiation in response to extracellular Ca2+ elevation. Our preliminary data suggest that ACER1 downregulation may contribute to both hyperproliferation and dedifferentiation of SSCC cells. ACER1 expression is suppressed in all SSCC cell lines that we examined. The expression of the mouse alkaline ceramidase 1 (Acer1) is also substantially down-regulated in chemically induced skin papillomas. Restored expression of ACER1 in SSCC cells not only inhibit the proliferation of SSCC cells but also induces the expression of differentiation markers, such as keratin 1. Our hypothesis is that ACER1 acts as a "tumor suppressor" to inhibit SSCC development and progression through its ability to induce the growth arrest and differentiation of keratinocytes. We will test this hypothesis with the following Specific Aims. Specific Aim 1 Establish that ACER1 downregulation leads to epidermal hyperplasia We will determine whether ACER1 knockdown by RNA interference in keratinocytes causes epidermal hyperplasia in regenerated human skin grafts on a severe combined immunodeficiency (SCID) mouse. Specific Aim 2 Establish that ACER1 plays a tumor suppressor role in SSCC development We will use ACER1 transgenic mice that express the human transgene ACER1 specifically in the epidermis and investigate whether the chemically induced formation of skin tumors is inhibited or reduced in ACER1 transgenic mice. The proposed research in this application is of great importance as the results generated from the experiments will provide an important molecular foundation for the prevention and treatment of SSCC.

该副本是利用资源的众多研究子项目之一 由NIH/NCRR资助的中心赠款提供。对该子弹的主要支持 而且，副投影的主要研究员可能是其他来源提供的 包括其他NIH来源。 列出的总费用可能 代表subproject使用的中心基础架构的估计量， NCRR赠款不直接向子弹或副本人员提供的直接资金。 来自恶性角质形成细胞的皮肤鳞状细胞癌（SSCC）是一种主要的皮肤癌，每年在美国室内被诊断出超过100万例。该项目的长期目标是定义人类碱性神经酶1（ACER1）在抑制SSCC中的作用，并将这一概念发展为预防和治疗SSCC的新方法。 ACER1是我们新的克隆神经酰胺酶，可催化神经酰胺的水解产生游离脂肪酸和鞘氨醇（SPH）。我们已发表的数据表明，ACER1是一种皮肤特异性神经酶，在表皮角质形成细胞的生长停滞和分化中起重要作用。原位杂交表明，与增殖的基底细胞层相比，在表皮的分化和分化细胞层中，ACER1 mRNA在更高的水平上表达。培养的角质形成细胞中的ACER1表达明显地上调了细胞外Ca2+，这是生长停滞和角质形成细胞分化的关键生理诱导剂。表皮生长因子（EGF）抑制了这种上调，该因子促进角质形成细胞增殖，但抑制了分化。 ACER1通过RNA干扰敲低会增加角质形成细胞的增殖并抑制角质形成细胞分化，以响应细胞外Ca2+升高。我们的初步数据表明，ACER1下调可能有助于SSCC细胞的过度增殖和去分化。 ACER1表达在我们检查的所有SSCC细胞系中都被抑制。在化学诱导的皮肤乳头状瘤中，小鼠碱性神经酶1（ACER1）的表达也基本下调。恢复了ACER1在SSCC细胞中的表达不仅抑制了SSCC细胞的增殖，而且还诱导分化标记物的表达，例如角蛋白1。我们的假设是ACER1充当“肿瘤抑制器”以抑制SSCC的发育，并通过其能力抑制其进展诱导角质形成细胞的生长停滞和分化。我们将以以下特定目的检验这一假设。 特定目标1确定ACER1下调导致表皮增生 我们将确定ACER1在角质形成细胞中的RNA干扰是否会导致重生的人类皮肤移植物在严重的合并免疫缺陷（SCID）小鼠上引起表皮增生。 具体目标2确定ACER1在SSCC发育中起抑制肿瘤的作用 我们将使用ACER1转基因小鼠，该小鼠在表皮中特别表达人类转基因ACER1，并研究ACER1转基因小鼠的化学诱导的皮肤肿瘤的形成是抑制还是减少。 该应用中提出的研究非常重要，因为实验产生的结果将为预防和治疗SSCC提供重要的分子基础。