环六亚甲基双乙酰胺体外诱导胚胎性癌B7—2细胞分化对MS_3基因表达的影响

MS_3 cDNA是多潜能胚胎性癌细胞专一的顺序,HMBA可诱导B 7—2细胞分化为原始内胚层样细胞。用定量细胞质RNA点印迹杂交法分析了MS_3基因在小鼠胚胎性癌B 7—2细胞经HMBA诱导前和诱导后的表达水平。小鼠成纤维细胞NIH3T3被用作阴性对照,MS_3基因的表达水平在B 7—2细胞经HMBA诱导5天后下降了86％。鉴于HMBA对B 7—2细胞的诱导效率约为90％,这一实验结果表明在HMBA诱导分化中,MS_3基因的表达被抑制。

REPRESSION OF MS_3 GENE EXPRESSION DURING HMBA INDUCED DIFFERENTIATION OF AN EMBRYONAL CARCINOMA CELL LINE, B 7 - 2 IN VITRO

We have cloned a cDNA sequence comprising about 300 nucleotides. This cDNA sequence can detect a RNA species with a size of about 6 kb in the total cellular RNAs and the total poly (A+) RNAs of some mouse embryonal carcinoma (EC) cell lines such as F9, PCC3, PSAl, but not in several differentiated derivatives of EC cells examined so iar, i. e., TDM1 (trophoblastoma cell), PYS-2 (parietal york saclike cell), 3/A/1-D3 (embryonic fibroblast-like cell) and C17-S1-T384 (myoblast-like cell). Therefore we designate this cDNA sequence as multipotent cell specific sequence (MS3 sequence). The amount of MS3 RNA in B7 - 2 cells before and after induction with HMBA was estimated by the technique of dot blot hybridization. Mouse 3T3 cells were employed as a negative control. Induction with HMBA for 5 days brought about 86% reduction of the amount of MS3 RNA in B7-2 cells. Since the induction effeciency was about 90%, it is evident that the expression of MS3 gene was repressed in the induced differentiated derivatives of B7 - 2 cells.