Identification of a Chromosome Carrying a Putative Tumor Suppressor gene in Human Choriocarcinoma by Microcell-Mediated Chromosome Transfer.

完全性葡萄胎有两种主要的起源机制：a)用单倍体精子受精空卵，然后进行复制；b)用两个单倍体精子受精。人们普遍认为，到目前为止，在所有不得不患绒毛膜癌的妊娠中，与葡萄胎相关的风险最高。葡萄胎隐性突变的纯合子表达被认为与这种恶性倾向有关。几个肿瘤抑制基因的改变和癌基因的激活被认为是绒毛膜癌发生所必需的。葡萄胎的遗传特征表明，前者的改变对于探索多步转化为恶性肿瘤特别重要。因此，来自正常细胞的单个染色体通过微细胞融合被导入绒毛膜癌细胞。微细胞杂交瘤的致瘤性评估表明，7号染色体携带一个可能的绒毛膜癌抑癌基因。基因印记或隐性突变可能是导致这种基因失活的原因。能够与鼹鼠的高度恶变倾向相对应。现在，可以生产出正常7号染色体特异的cDNA表达自由。利用从正常绒毛和CCI绒毛膜癌组织中获得的mRNA探针进行菌落杂交，除自杀选择克隆外，该突变株将能够克隆绒毛膜癌抑癌基因。

There are two main mechanisms of origin for complete hydatidiform mole ; a) fertilization of an empty egg by a haploid sperm followed by duplication and b) fertilization of such an egg by two haploid spermatozoa. It is widely accepted that of all forms of pregnancy that had to choriocarcinoma the risk associated with moles is by far the highest. Homozygous expression of a recessive mutation of moles has been assumed to associate with this propensity to malignancies.Alterations of several tumor suppressor genes together with activation of oncogenes are assumed to be necessary for choriocarcinogenesis. Genetic characteristics shown in the moles suggest that the former alterations are especially important to explore the multistep conversions to malignancies. Thus, individual chromosomes derived from normal cells were introduced into choriocarcinoma cells via microcell fusion. Evaluation of tumorigenicity in microcell hybrids suggested that chromosome #7 carried a putative tumor suppressor gene for choriocarcinoma. The gene imprinting or recessive mutation mmy be responsible for the inactivation of such a gene. Being able to correspond with the high propensity to malignancy of moles. Now, the cDNA expression liberaties specific to the normal #7 chromosome could be produced. Colony hybridization using mRNA probes obtained from normal villi and CCI choriarcinoma in addition to suicide selection cloning the revertant will be able to clone the tumor suppressor genes of choriocarcinoma.