Determination of Chromasomal localization of Tumor Suppressing Genes Associted with Oncogenesis of Choriocarcinoma

1.应用PCR方法对6例绒毛膜癌进行了DNA多态性分析。从石蜡包埋、福尔马林固定的绒毛膜癌组织（2例）、裸鼠移植瘤（2例）和新鲜切片（1例）中提取绒毛膜癌DNA。6例绒毛膜癌中4例来源于葡萄胎。我们的分析发现了一个有趣的病例，该病例不是来自上次正常怀孕，而是来自之前的葡萄胎。这4颗痣中的一颗已经显示出染色体异质性。此外，我们的分析被证实是有用的鉴别诊断双胎妊娠与正常妊娠和葡萄胎。4例中1例为绒毛膜癌，其中葡萄胎表现为染色体不均一性。2. DNA多态性被证明具有显著的信息量和容易检测。因此，我们用PCR技术扩增了显示这种多态性的DNA序列，并分析了每个样品之间带型的差异。特别是3个碱基对以上重复序列的微卫星，其检测系统简单，可通过PCR、聚丙烯酰胺凝胶电泳和银染等方法进行检测; 3.在一定的研究期间内，我们未能收集到足够数量的绒毛膜癌标本进行统计学分析，也未能确定绒毛膜癌中持续纯合的染色体。这主要是由于本病本身发病率的迅速下降和手术治疗病例的减少所致。必须与其他组织合作收集样本。

1. The pregnancies responsible for 6 choriocarcinoma cases were successfully indenrified by DNA polymarphism analysis using PCR method. Choriocarcinoma DNA samples were extracted from formalin-fixed, paraffin-embedded tissue(2 cases), tumors implanted on nude mice(2 cases), fresh poerational specimen(1 case). Four out of 6 choriocarcinonmas were determinded to derive from hydatidiform moles. Ouranalysis revealed an interesting case which was not derived from the last normal pregnancy, but a preceeding hydatidform mole. One out of these 4 moles has been already shown to exhibit chromosomal heterogenity. Addidionally, our analysis was cofirmed to ve useful for the differntial diagnosis of twin pregnancies with a mormal pregnancy and hydatidiform mole. One out of4 cases caused a choriocarcinoma, in which the hydatidiform mole showed chrmosomal heterogenity. 2. TheDNA polymorphisims, were demonstrated to ve remarkably informative and easily detected. Therfore, we amplified DNAsequences showing this type of polymorphism by PCR rechnique and anallysed differences in band pattern betweeneach sample. In paticular, microsatellites derived form fmre than 3 base-pair repeats were most useful for our analysis in terms of 1) simple detection system consisting ofPCR, electrophoresis on polyacrylamide gel, and silver staining and 2) wide and multiple distribution on each chromosome. 3. Whithin a given study period we failed to collect enough numbers of choriocarcinoma samples for satistical analysis and to determine the chromosomes showing constantly homozygosity in herero-moles. This wa arised form the rapid decrease in morbidity of the disease inself and the cases treated with operation. It is shus snceassary collect samples in collabration with other organizations.