中文摘要：

NGX6基因是我室利用定位候选克隆策略，在鼻咽癌的高频杂合性缺失区9p21-22克隆的新基因．前期研究结果提示，它与鼻咽癌细胞的侵袭转移密切相关．为了进一步阐明其作用的结构基础，本研究成功构建了含NGX6基因及突变体的pCMV-myc瞬时和pcDNA3．1-his-myc（-）B稳定表达载体．通过脂质体转染技术，构建了NGX6及突变体的稳定表达细胞系5-8F．用免疫荧光试验和免疫电镜观察了NGX6在5—8F细胞中的亚细胞定位主要位于胞膜、核膜以及胞浆中的膜质结构。缺失突变的功能域对其定位没有明显的影响．基质胶侵袭试验和划痕试验研究了NGX6及突变体对细胞运动的影响．NGX6能抑制高转移潜能的鼻咽癌细胞5．8F的运动和侵袭能力，缺失胞内区（CYTO）后NGX6不能抑制5—8F细胞的运动和侵袭，提示CYTO可能是其发挥作用的重要功能域．

英文摘要：

Nasopharyngeal carcinoma associated gene 6（NGX6） is a novel candidate suppressor gene located at the high frequent loss of heterozygosity（LOH） region 9p21-22 in nasopharyngeal carcinoma（NPC） by using positional candidate cloning strategy. Our previous study showed that NGX6 is associated with metastasis of nasopharyngeal carcinoma and mRNA level is reduced in nasopharyngeal carcinoma patients with node metastasis. In the present study, a series of deletion mutants of NGX6 were constructed successfully and transfected into nasopharyngeal carcinoma cell line 5-8F with lipofectamine 2000. NGX6 and mutants are located at plasma membrane, nuclear membrane, endoplasmic reticulum membrane and other membrane structure in cytosol by immunofluorescence staining and immune electron microscopic analysis. The deleted domains didn＇t affect the subcellular location. NGX6 could inhibit the mobility and migration of 5-8F cells. The cytoplasm region were found to be critical for NGX6 to modulate cell migration.