Differential miRNA expression & progression of arsenic induced skin cancers

 描述（由申请人提供）：基底细胞癌（BCC）和鳞状细胞癌（SCC）是由阳光和砷暴露引起的两种类型的皮肤癌。很明显，来自紫外线诱导的DNA损伤的突变驱动了阳光诱导的皮肤癌。相反，砷诱发皮肤癌的机制仍不清楚。该探索性项目将表征在体外长期暴露于砷的原代人类角质形成细胞中以及在砷诱导的皮肤病变（包括角化过度（砷诱导的BCC和SCC的癌前病变）、BCC和SCC）的独特样本集中的差异microRNA表达。将通过微阵列分析从体外暴露于和未暴露于亚砷酸盐的原代人角质形成细胞纯化的RNA，以及在激光捕获显微切割中从福尔马林固定的石蜡包埋的砷诱导的皮肤病变样品纯化的角质形成细胞来确定microRNA表达谱。将通过qRT-PCR确认比较组之间具有最大倍数变化的6种microRNA的差异microRNA表达。暴露和未暴露的原代人角质形成细胞之间的比较将确定砷暴露诱导的microRNA表达的变化，可能有助于细胞转化。HK与BCC和HK与SCC之间的比较将揭示与从癌前病变到恶性表型的进展相关的变化，而BCC与SCC之间的比较将揭示两种肿瘤类型之间的相似性和差异性。将砷诱导的BCC和SCC特有的microRNA表达谱与来自阳光诱导的BCC和SCC的已发表数据进行比较，将提供关于由不同环境致癌物诱导的这些表型相似的癌症的相似性或不相似性的关键分子信息。这些研究的完成将为砷诱导的原代人角质形成细胞中microRNA的变化和砷诱导的皮肤癌的进展提供新的数据。将来扩展这些研究，使用来自单个个体的多个病灶，并将数据与mRNA表达谱相结合，将提供关于肿瘤进展的详细分子信息。

 DESCRIPTION (provided by applicant): Basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) are two types of skin cancer caused by both sunlight and arsenic exposure. It is clear that mutations from UV-induced DNA damage drive sunlight induced skin cancers. In contrast, the mechanism of arsenic induced skin cancer remains unclear. This exploratory project will characterize the differential microRNA expression in primary human keratinocytes exposed long term to arsenic in vitro and in a unique sample set of arsenic induced skin lesions including hyperkeratosis (premalignant lesion to both arsenic induced BCC and SCC), BCC and SCC. MicroRNA expression profiles will be determined by microarray analyses of RNA purified from primary human keratinocytes exposed and unexposed to arsenite in vitro, and in laser capture microdissection purified keratinocytes from formalin fixed paraffin embedded samples of the arsenic induced skin lesions. Differential microRNA expression for the 6 microRNAs with greatest fold change between comparison sets will be confirmed by qRT-PCR. Comparisons between exposed and unexposed primary human keratinocytes will identify arsenic exposure induced changes in microRNA expression that may contribute to cellular transformation. Comparisons between HK vs BCC and HK vs SCC will reveal changes associated with progression from pre-malignant to malignant phenotype, and between BCC vs SCC will reveal similarities and dissimilarities between the two tumor types. Comparison of the microRNA expression profiles unique to arsenic induced BCC and SCC with the published data from sunlight induced BCC and SCC will provide critical molecular information on the similarity or dissimilarity of these phenotypically similar cancers induced by different environmental carcinogens. Completion of these studies will provide novel data on arsenic induced changes in microRNAs in primary human keratinocytes and in progression of arsenic induced skin cancers. Extension of these studies in the future using multiple lesions from single individuals and by combining data with mRNA expression profiles will provide detailed molecular information on tumor progression.