高转移人胃癌裸鼠移植细胞系SY86B癌基因活化表达和肿瘤抗原表型特征分析

IDENTIFICATION OF EXPRESSION OF ACTIVATED ONCOGEN AND PHENOTYPE OF TUMOR ANTIGENS IN HIGH METASTATIC GASTRIC CANCER CELL LINE SY86B

本研究对我们已建立的具有高转移特点人胃癌裸鼠移植细胞系SY86B,从癌基因活化表达和肿瘤抗原表型特征进行了解析。结果发现,此株细胞中C-H-ras癌基因的BamHⅠ酶切片段呈现多态性,表明该基因具有重排;RNA转录水平上C-H-ras和C-myc癌基因有明显的过表达,提示C-H-ras基因重排可能是导致其过表达的基础。抗原表型特征检测发现,正常成熟抗原HLA-A、B、C和血型A和B表达丧失;随着传代增加血型前体表达有所减弱;肿瘤相关抗原CEA和单抗识别的胃癌抗原呈稳定地过表达。此株细胞癌基因重排和过表达与肿瘤相关抗原过量出现是构成其高转移特征的分子生物学基础。

The expression of activated oncogen and phenotype of tumor antigenswere further studied for high metastatic human gastric cancer cell line SY86Bin nude mice. The results showed that the fragements of BamHI endonucleasefor C-H-ras oncogen were as RFLP, 2.2kb, 6.6kb and 8.0kt fragements, whichindicated the rearrangement of this oncogen, co-expression of C-H-ras andC-myc cncogen in RNA transoription level were also found. The phenotype of tumor antigens expressed as the loss of normal antigens which were HLA-A,B and C antigen and blood group subsance A and B, the lower of precursorof blood group antigen, Y hapten and H type-2 and the over-expression oftumor associated antigen including CEA, CMU_(15a) (200kd glycoprotein) andCMU_(7a)(large molecular mucin antigen). These results suggested that therearrangement of C-H-ras oncogen, co-expression of C-H-ras and C-myc andover-expression of tumor-associated antigens were the basis of molecular biologyof high metastatic characteristics for this cancer cell line.