Identification of Melanoma Susceptibility Gene at 1p22

描述（由申请人提供）：尽管经过数十年的研究，转移性皮肤恶性黑色素瘤（CMM）仍然是一种不治之症，中位生存时间为9个月，5年生存率低于5%。 此外，在过去的20年中，CMM的发病率在世界范围内急剧增加。 对这项研究至关重要的是，该疾病的阳性家族史是CMM最确定的风险因素之一; 10%的CMM病例是由遗传易感性引起的。 虽然CDKN 2A和CDK 4两个基因突变会增加CMM的风险，但它们仅占多发性CMM病例家族的20% - 25%。 我们假设，有额外的CMM易感基因，这个应用程序提供了一个经验为基础的，技术创新的方法来确定这样一个基因。 我们对82个不涉及CDKN 2A或CDK 4的CMM激酶进行了全基因组连锁扫描，并在1号染色体（1 p22）上鉴定了一个新的CMM易感基因座。 为了确定黑色素瘤易感基因在这个位点（目标1），我们正在整合多种实验方法，旨在优先考虑候选基因的突变筛查。 具体而言，我们将：（B）设计代表1 p22关键区域内所有潜在编码序列的定制寡核苷酸微阵列，以鉴定新基因并表征组织特异性基因表达，用于候选基因优先化的目的;和（c）设计用于比较基因组杂交（CGH）的定制1 p22寡核苷酸微阵列，并寻找来自患者淋巴细胞以及在1 p22处具有半合子缺失的黑素瘤细胞系的DNA中的部分或全基因缺失。 根据这些数据，我们将优先考虑候选基因，并（d）使用DNA测序筛选基因突变。 在鉴定1 p22黑色素瘤易感基因后，我们将确定黑色素瘤细胞系、肿瘤和痣中1 p22基因突变/缺失（Aim 2）的患病率，并提出一种实验方法来了解其作用机制。 最后，我们将检验黑皮质素受体（MCIR）的低突变率易感性等位基因改变1 p22易感性基因突变的突变率（Aim 3）以及这些等位基因的1 p22突变阳性家族中受影响和未受影响的成员的基因型的假设。

DESCRIPTION (provided by applicant): Despite decades of research, metastatic cutaneous malignant melanoma (CMM) remains an incurable disease, demonstrating a median survival time of 9 months, with a 5-year survival rate of less than 5 percent. Further, over the past 20 years, the incidence of CMM has increased dramatically worldwide. Critical to this study, a positive family history of the disease is among the most established risk factors for CMM; 10% of CMM cases result from an inherited predisposition. Although mutations in two genes, CDKN2A and CDK4, confer an increased risk of CMM, they account for only 20% - 25% of families with multiple cases of CMM. We hypothesize that that there are additional CMM-predisposition genes, and this application provides an empirically based, technologically innovative approach to identify one such gene. We have performed a genome-wide linkage scan of 82 CMM kindreds with no involvement of CDKN2A or CDK4, and have identified a novel CMM susceptibility locus on chromosome 1 (1p22). To identify the melanoma susceptibility gene at this locus (Aim 1), we are integrating multiple experimental methods aimed at prioritizing candidate genes for mutation screening. Specifically, we will: (a) perform high-resolution SNP-typing and look for evidence of haplotype sharing between CMM families in order to further narrow the critical region; (b) design a custom oligonucleotide microarray representing all potential coding sequences within the 1p22 critical region in order to identify novel genes and to characterize tissue-specific gene expression for the purpose of candidate gene prioritization; and (c) design a custom 1p22 oligonucleotide microarray for comparative genomic hybridization (CGH) and look for partial- or whole-gene deletions in DNA from patient lymphocytes as well as melanoma cell lines with hemizygous loss at 1p22. Based on these data, we will prioritize our gene candidates and (d) screen genes for mutations using DNA sequencing. Following the identification of the 1p22 melanoma susceptibility gene, we will determine the prevalence of 1p22 gene mutation/loss (Aim 2) in a panel of melanoma cell lines, tumors, and nevi, and propose an experimental approach to understand its mechanism of action. Lastly, we will test the hypothesis that Iow-penetrance susceptibility alleles of the melanocortin receptor (MCIR) modify the penetrance of 1p22 susceptibility gene mutations (Aim 3) and genotype both affected and unaffected members of our 1p22-mutation positive families for these alleles.