三个鼠源性肿瘤细胞系的RAPD分析

目的：探讨鼠源性肿瘤细胞系基因组不稳定程度或基因组损伤与肿瘤发生的关系。方法：用145条RAPD引物对鼠源性Lewis肺癌、SCC891乳腺癌及B16黑色素瘤及其相应正常组织基因组DNA进行RAPD扩增，扩增产物在含溴化乙锭的1．5％琼脂糖凝胶中电泳，紫外透射仪上观察照相。结果：145条引物绝大多数能扩增出清晰、明显的条带。多数引物扩增出的条带呈单态性，在肿瘤及其相应正常组织之间无差异。部分引物扩增出的DNA序列在肿瘤组织与其相应正常组织间存在差异，表现为多态性，即肿瘤组织与其相应正常组织的DNA片段相比，出现带的缺失、增加、移动和强度变化。扩增Lewis肺癌的105条引物中有25条表现多态性；扩增B16黑色素瘤的105条引物中有24条表现出多态性；扩增SCC891乳腺癌的120条引物中有18条表现出多态性。结论：RAPD扩增结果表明三个恶性度较高的瘤株，其基因组损伤程度亦较高，表现为基因拷贝数的增加或等位基因的丢失，进步证实了细胞的癌变与基因组某些改变密切相关。

Analysis of three mouse tumor cell lines by RAPD

Objective To evaluate the effects of genomic instability or genomic damage in mouse tumorigenesis. Methods Genomic DNAs from cancer and corresponding normal tissues were amplified by RAPD with 145 10 bp random primers. PCR products from RAPD were electrophoretically separated in agarose gels and banding profiles were visualized by ethidium bromide staining. Results Amplification products produced in most of primers were monomorphic. Some of the primers generated polymorphic profile when tumor RAPD profile was compared to that of its normal tissue DNA. The alterations exhibited in tumor DNA included the loss of a normal band, appearance of a new band and intensity changes. Twenty five of the 105 primers in Lewis lung cancer, 24 of the 105 primers in B 16 melanoma, 18 of the 100 primers in SCC891 mammary carcinoma generated polymorphic profile. Conclusion The higher level of random genomic damage in the three tumor cell lines have been detected by RAPD. Increased band intensity in tumor tissue DNA reflects the presence of extra copies of these sequences; loss and decrease in the intensity of RAPD bands in tumor tissue may reflect allelic losses. It is further certified that tumor is the result of some genomic changes.