基于染色体22q13.1-13.31区域深度测序研究Gorlin综合征的新致病基因

Golin syndrome is an autosomal dominant disorder characterized by a predispostion to neoplasms and developmental abnormalities.Racial predilection in the phenotype and pathogenesis has been observed.Up to date, approximately 50% patients with Gorlin syndrome have mutations in the PTCH gene and mutations in the genes of PTCH2 and SUFU were also detected in one or two cases with this syndrome, which indicates other dominant gene or genes must be involved in causing Gorlin syndrome. Our group have performed mutation screening in 46 pedigrees with this syndrome and found no mutations in these three reported genes in 12 cases.Among these 12 families,a large family with five generations including 62 individuals was chosen as the object of study. A novel Gorlin syndrome locus at chromosome 22q13.1-q13.31 was identified and the genome sequencing for this region was finished. In this study, a candidated gene responsible for this syndrome will be identified by mutation analysis and mutation screening based on the previous data.Then mutations in the candidate gene will be detected in the rest pedigrees without mutations in the known genes responsible for Gorlin syndrome and sporadic cases for verification.After the causative gene is identified, its function and pathogenic mechanisms will be studied in vivo and in vitro systematically. In this project, hereditary pedigree study serves as an entry point to acquired independent intellectual property rights of a novel pathogenic gene for Chinese Han patients with Gorlin syndrome, to explore the phenotype and the molecular pathogenesis of this syndrome in Chinese Han patients, and to provide the basis of diagnosis and treatment for Gorlin sydrome.

Gorlin综合征属常染色体显性遗传性疾病，以发育异常和肿瘤易患性为主要特征。不同种族患者的表型和发病机制不尽相同，目前仅在约50%的患者中发现PTCH基因致病突变，偶见PTCH2及SUFU基因突变引发病变，提示该疾病存在其他致病基因。本课题组前期筛查46个患病家系，发现12个家系致病机制不明，遂以其中一个有5代62个成员的大家系为研究对象，定位了与该疾病连锁的染色体区段22q13.1-22q13.31；并完成了对该区段的基因组测序工作。本研究拟在前期研究基础上，通过突变分析及筛选，锁定候选基因，并在其余家系中和散发病例中测序检测、验证该基因的突变情况。在完成候选新致病基因验证后，将对其功能和致病机制开展体内、外系统研究。本项目以遗传家系研究为切入点，旨在获得具有自主知识产权的中国汉人Gorlin综合征新的致病基因，探求中国汉人该遗传病表型特点和分子发病机制，为该疾病的遗传学诊治提供基础。

口腔癌诊治效果的进一步提高，必须依托于对该类肿瘤致病基因的寻找和确定，进而发展新型的诊断和治疗技术。本课题选用遗传性口腔癌和散发口腔鳞癌为研究对象，寻找确定口腔癌致病相关候选基因，并分析其可能的临床应用价值。. 本课题通过中美国际合作，经过SNP 芯片、Merlin连锁分析及微卫星位点分型连锁分析，确定一个新的中国汉族人痣样基底细胞癌综合征致病基因所在的染色体区段为22q13.2-22q13.31；进一步对该区域完成了深度测序和分析，分析结果提示EP300及EGCAB6 作为新致病候选基因有一定可能性，这些为新致病基因寻找和研究提供条件。课题研究发现，中国汉族人口腔黏膜鳞癌中 NOTCH1 基因突变情况，该基因的突变较美国高加索人更为频繁、且功能更为复杂。NOTCH1 基因突变联合淋巴结转移可作为口腔鳞癌更好的预后指标；为以NOTCH1 信号通路作为诊治靶点，开发口腔鳞癌中诊治技术提供不可多得的实验资料。课题研究还证实， PTHLH在口腔癌中上调表达，该基因可促进口腔癌细胞的增殖、克隆形成、细胞周期等相关功能；研究分析证实，高表达PTHrP口腔癌患者的临床预后较差，其表达水平均可作为临床上判断口腔癌患者预后的独立指标。. 项目所取得成果为口腔癌致病基因的研究奠定了更坚实基础，部分研究成果为口腔癌诊治提供新的分子靶点。后续研究得到2016年国家精准医学重点专项-肿瘤分子分型项目资助。该课题已发表SCI收录论文5篇，参加国际会议交流论文3篇，申请专利2个，获得省、部级科技成果奖2项；培养研究生4名，其中中美联合培养2名。