论文部分内容阅读
从人食管癌细胞系（ＥＣ８７１２）分离到一个维甲酸激活的全长ｃＤＮＡ（ＲＡ５３８）。将该ｃＤＮＡ的表达质粒（ｐＲＡ５３８）同ｎｅｏ基因（ｐＤＯＲｎｅｏ）共同移到亲本肿瘤细胞系ＥＣ８７１２。经含Ｇ４１８的培养液筛选后获得的克隆生长缓慢，３Ｈ－ＴｄＲ掺入率下降了６８％～７６％，并表现出终末分化和程序性细胞死亡的形态学改变。用ＲＡ５３８的片段作原位杂交，在细胞质内显示ＲＡ５３８ｍＲＮＡ的表达。只用ｐＤＯＲｎｅｏ转染的细胞，经Ｇ４１８筛选后表现出正常生长，且没有ＲＡ５３８的表达。在相同条件下，对照细胞ＥＣ８７１２在Ｇ４１８筛选后无一存活。这说明ＲＡ５３８的表达对食管癌细胞ＥＣ８７１２具有同维甲酸类似的作用。
An retinoic acid activated full-length cDNA (RA538) was isolated from a human esophageal cancer cell line (EC8712). The cDNA expression plasmid (pRA538) was co-transfected with the neo gene (pDORneo) into the parent tumor cell line EC8712. The colonies obtained after screening with the culture medium containing G418 grew slowly, the 3H-TdR incorporation rate decreased by 68% to 76%, and showed morphological changes of terminal differentiation and programmed cell death. The RA538 fragment was used for in situ hybridization to show the expression of RA538 mRNA in the cytoplasm. Cells transfected with pDORneo only showed normal growth after screening by G418, and there was no expression of RA538. Under the same conditions, none of the control cells EC8712 survived after G418 screening. This shows that the expression of RA538 has a similar effect to eretinoic acid on esophageal cancer EC8712.