Brain contains inhibiting factors specific to the large T-antigen gene.
Brain contains inhibiting factors specific to the large T-antigen gene.
复制标题
大脑中含有大 T 抗原基因特有的抑制因子。
DOI：
10.1016/s0304-3835(97)00367-4
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发表时间：
1998
期刊：
影响因子：
9.7
通讯作者：
Prasad,KN
中科院分区：
文献类型：
--
作者：
Clarkson,ED;LaRosa,FG;Edwards-Prasad,J;Kumar,S;Kumar,A;Cole,W;Freed,CR;Prasad,KN
SV 40大T抗原（LTa）基因诱导的永生化大鼠多巴胺产生神经细胞（1 RB 3AN 27），其在体外产生LTa蛋白并分裂，当移植到成年大鼠纹状体中时不分裂，也不产生LTa蛋白。这表明脑中存在LTa基因抑制因子。在这里，我们报告，大鼠脑可溶性部分（SF）含有因子，特异性抑制LTa基因的活性在体外。脑SF在体外可抑制LTa蛋白水平及1 RB 3AN 27细胞和2 RSG细胞（LTa基因诱导的永生化大鼠腮腺腺泡细胞）的生长，但可刺激自发永生化人腮腺腺泡细胞（2 HPC 8）的生长，对培养的小鼠神经母细胞瘤细胞（NBP 2）和大鼠胶质瘤细胞（C-6）的增殖无影响。相比之下，肝脏SF在不同程度上抑制了所有测试细胞系的生长，因此对LTa基因活性缺乏特异性。脑中特异性LTa基因抑制因子和肝脏中一般肿瘤生长抑制因子的存在可能提供了一些保护机制，以防止体内致癌。
SV40 large T-antigen (LTa) gene-induced immortalized rat dopamine-producing nerve cells (1RB3AN27), which produce LTa protein and divide in vitro, do not divide and do not produce LTa protein when transplanted into striatum of adult rats. This suggests the presence of LTa gene-inhibiting factors in brain. Here we report that rat brain soluble fraction (SF) contains factors which specifically inhibit LTa gene activity in vitro. The brain SF inhibited LTa protein levels and the growth of 1RB3AN27cells and 2RSG cells (LTa gene-induced immortalized rat parotid acinar cells) in vitro, but it stimulated the growth of spontaneously immortalized human parotid acinar cells (2HPC8) and had no effect on the proliferation of murine neuroblastoma cells (NBP2) and rat glioma cells (C-6) in culture. In contrast, the liver SF inhibited the growth of all cell lines tested at varying degrees and thus lacked specificity with respect to LTa gene activity. The presence of specific LTa gene-inhibiting factors in the brain and general tumor growth-inhibiting factors in the liver may provide some of the mechanisms of protection against in vivo carcinogenesis.