Genomic Scanning for Genetic and Epigenetic Alterations in head and neck cancer

描述（由申请人提供）：这是“头颈癌表观遗传和遗传改变的基因组扫描”资助的竞争性更新。先前的拨款已经成功完成，并产生了大量描述头颈部鳞状细胞癌（HNSCC）中DMA甲基化和DMA扩增改变的数据。其中一个新基因（转录因子21或tcf21），在染色体6q23-24上发现，这是一个在HNSCC和其他恶性肿瘤中经常丢失的区域，具有肿瘤抑制功能，以及转移抑制活性。TCF21是人类肿瘤中DMA甲基化改变的常见靶标，并被DMA甲基化转录沉默。我们提供的初步数据支持我们的假设，即TCF21是一种新的肿瘤/转移抑制基因。为了解决这一假设，我们提出了三个具体目标。(1)在目的1中，我们将研究TCF21在各种正常组织和癌细胞系中的表达模式和可能的替代剪接形式，并详细评估DMA甲基化如何导致DMA沉默。接下来，我们将评估HNSCC和肺癌中TCF21的突变谱，以确定TCF21沉默在每种肿瘤类型中的重要性。(2)在目标2中，我们提出了将有助于了解TCF21如何促进肿瘤发生的实验，并使用表达阵列、ChIP、酵母双杂交和荧光素酶检测的组合来识别不同组织特异性的结合伙伴和靶基因。(3)在目的3中，我们将利用小鼠模型进一步研究TCF21的作用。我们正在筹划裸鼠的致瘤性和转移性实验，我们建议用Tcf21杂合敲除小鼠进行癌变实验；并将在小鼠口腔癌和肺癌模型中研究Tcf21及其下游靶点。

DESCRIPTION (provided by applicant): This is a competitive renewal of grant "Genomic Scanning for Epigenetic and Genetic alterations in Head and neck cancer". The previous grant has been successfully completed and resulted in a wealth of data describing altered DMA methylation and DMA amplification in head and neck squamous cell carcinoma (HNSCC). One of the novel genes (transcription factor 21 orTCF21), identified on chromosome 6q23-24, a region frequently lost in HNSCC, as well as other malignancies has tumor suppressor function, as well as metastasis suppressing activity. TCF21 is a frequent target for altered DMA methylation in human tumors and is transcriptionally silenced by DMA methylation. We provide preliminary data supporting our hypothesis that TCF21 is a novel tumor/metastasis suppressor gene. To address this hypothesis, we propose three specific aims. (1) In aim 1 we will investigate expression patterns of TCF21 and possible alternative splice forms in various normal tissues and cancer cell lines and evaluate in detail how DMA methylation contributes to DMA silencing. We will next evaluate the mutational spectrum of TCF21 in HNSCC and lung cancer to determine the importance of TCF21 silencing in each tumor type. (2) In aim 2 we propose experiments that will help to understand how TCF21 contributes to tumorgenesis and identify binding partners and target genes specific for different tissues using a combination of expression array, ChIP, yeast two hybrid and luciferase assays. (3) In aim 3 we will utilize mouse models to further investigate the role of TCF21. We are planning nude mouse tumorigenicity and metastasis assays, we are proposing a carcinogenesis experiment with Tcf21 heterozygous knock out mice; and will investigate Tcf21 and downstream targets in a mouse model for oral cavity carcinogenesis and lung carcinogenesis.