RETINOID RECEPTOR FUNCTION IN SKIN CANCER PROGRESSION

皮肤癌进展中的视黄醇受体功能

基本信息

批准号：
6802658
负责人：
JOHN L CLIFFORD
金额：
$ 6.43万
依托单位：
LOUISIANA STATE UNIV HSC SHREVEPORT
依托单位国家：
美国
项目类别：
财政年份：
1998
资助国家：
美国
起止时间：
1998-07-01 至 2004-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6802658
关键词：
athymic mouse cell differentiation cell line disease /disorder model electroporation gene mutation gene targeting keratinocyte neoplastic cell neoplastic process phenotype receptor expression retinoid binding proteins skin neoplasms transfection /expression vector

项目摘要

Squamous cell carcinoma (SCC) is the most clinically aggressive form of non-melanoma skin cancer and in spite of aggressive treatment, deeply invasive SCC lesions recur at a high rate (30 percent). Therefore there is an urgent need for the development of improved therapeutic and preventive treatments for this disease. Retinoids are important modulators of epithelial differentiation and proliferation. Retinoids are effective in the treatment and prevention of epithelial cancers, including cutaneous SCC. However the mechanism for this effect is not well understood. In order to better design chemopreventive therapies for cutaneous SCC, more information about the mechanism of retinoid action in this system is needed. Retinoids exert their effects primarily through nuclear receptors, retinoic acid receptors (RARalpha, beta and gamma) and retinoid X receptors (RXRalpha, beta and gamma), members of the steroid hormone receptor superfamily. Retinoid receptor loss has been correlated with malignancy in several systems, and one recent study has demonstrated a suppression of RARalpha, RARgamma and RXRalpha expression in SCCs of patients. This study is based on the hypothesis that retinoid receptor loss contributes to the malignant phenotype by rendering epithelial cells resistant to retinoids, which wold normally suppress carcinogenesis. To test this hypothesis, HaCaT cells, a spontaneously immortalized, nontumorigenic, keratinocyte- derived cell line was chose. These cells express the two predominant retinoid receptors normally found in skin, RARgamma and RXRalpha, and retain the same differentiation characteristics and response to retinoids as normal keratinocytes. The HaCaT cells, which are a model for premalignant cells, will be used to accomplish the following specific aims: 1.) To create RARgamma null, RXTalpha null and RARgamma/RXRalpha double null cells by homologous recombination-mediated gene targeting. 2.) To determine whether loss of receptor expression results in an altered cell phenotype, specifically with regard to tumorigenic potential, differentiation capacity and response to alterations in retinoic acid (RA) levels. 3.) To reexpress the missing receptor (RARgamma or RXRalpha) in the knockout cell lines by stable transfection in order to determine whether the putative phenotype observed is the direct result of the genetic lesion. A somatic cell gene targeting approach has been successfully by the principle investigator to analyze retinoid receptor function in F9 embryonal carcinoma cells. It is expected that the generation of receptor null HaCaT cells will provide an equally powerful tool for understanding the role of retinoid receptors in the development of cutaneous SCC, as well as their role in epidermal differentiation.

鳞状细胞癌（SCC）是临床上最具侵略性的形式非黑色素瘤皮肤癌，尽管进行了侵略性治疗，但侵入性SCC病变以高率（30％）复发。因此迫切需要开发改进的治疗性和预防这种疾病。视网膜类似很重要上皮分化和增殖的调节剂。视网膜类似有效地治疗和预防上皮癌，包括皮肤SCC。但是，这种效果的机制不是理解。为了更好地设计化学预防疗法对于皮肤SCC，更多有关类维生素机理的信息需要在此系统中进行操作。维生素类似于其作用主要通过核受体，视黄酸受体（raralpha， beta和伽马）和类维生素X受体（rxralpha，beta和伽马），类固醇激素受体超家族的成员。视网膜类动物受体损失与多种系统中的恶性肿瘤相关，一个最近的研究表明，Raralpha，Rargamma和患者SCC中的rxralpha表达。这项研究基于类视视感受体丧失有助于恶性肿瘤的假设表型通过渲染上皮细胞对类维生素的抗性 Wold通常抑制癌变。为了检验该假设，HACAT 细胞，一种自发永生的，非肿瘤的，角质形成细胞衍生的细胞系是选择的。这些细胞表达两个主要的类维生素类动物受体通常在皮肤，rargamma和rxralpha中发现，以及保留相同的分化特征和对类维生素类似于正常的角质形成细胞。 HACAT细胞，这是一个模型对于预启示性细胞，将用于完成以下内容具体目的：1。）创建rargamma null，rxtalpha null和通过同源重组介导的rargamma/rxralpha双重无效细胞基因靶向。 2.）确定受体表达的丧失导致细胞表型改变，特别是肿瘤势，分化能力和对视黄酸（RA）水平的改变。 3.）重新表达丢失稳定的敲除细胞系中的受体（rargamma或rxralpha）转染以确定推定表型是否观察到的是遗传病变的直接结果。体细胞基因靶向方法已通过原则成功研究者分析F9胚胎中类视视感受体功能癌细胞。预计受体无效 HACAT单元将提供同样强大的工具来理解性类维生素受体在皮肤SCC发展中的作用作为它们在表皮分化中的作用。