Tsuneishi S, Sano K, Nakamura H
Department of Pediatrics, Kobe University School of Medicine, Japan.
Brain Res Mol Brain Res. 1993 Jan;17(1-2):119-28. doi: 10.1016/0169-328x(93)90080-9.
A human neuroblastoma cell line, GOTO, extends neurite-like processes upon withdrawal of serum from culture medium. This morphological change was accompanied by a 5-fold increase in the neurofilament (NF)-L and a 10-fold increase in the NF-M mRNA levels after 24 h. The addition of a protein kinase inhibitor, H-7 (1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride) also induced the extension of neurite-like processes; however, it did not increase the NF mRNA levels. Thrombin inhibited the extension of neurite-like processes in serum-free culture without affecting the increase in the NF mRNA levels. There was no difference in the number of cells progressing through the S phase between serum-containing and -free cultures at 24 h. This indicates that the increase in the NF mRNA levels upon withdrawal of serum was not preceded by the growth arrest. Treatment with actinomycin D and cycloheximide inhibited the increase in the NF mRNA levels. The half life of the NF gene transcripts was prolonged in the serum-free condition. These results indicate that the serum depletion-induced increase in the NF-L and -M mRNA levels was regulated by both transcriptional and post-transcriptional mechanisms, and the increase in the expression of the NF genes was not simply mediated by growth arrest but controlled by unknown regulator proteins.
人神经母细胞瘤细胞系GOTO在从培养基中去除血清后会延伸出类似神经突的突起。这种形态学变化伴随着24小时后神经丝（NF）-L增加5倍以及NF-M mRNA水平增加10倍。添加蛋白激酶抑制剂H-7（1-（5-异喹啉磺酰基）-2-甲基哌嗪二盐酸盐）也会诱导类似神经突的突起延伸；然而，它不会增加NF mRNA水平。凝血酶在无血清培养中抑制类似神经突的突起延伸，而不影响NF mRNA水平的增加。在24小时时，含血清和无血清培养中处于S期的细胞数量没有差异。这表明血清去除后NF mRNA水平的增加并非先于生长停滞。用放线菌素D和环己酰亚胺处理会抑制NF mRNA水平的增加。在无血清条件下，NF基因转录本的半衰期延长。这些结果表明，血清消耗诱导的NF-L和-M mRNA水平增加受转录和转录后机制调节，NF基因表达的增加并非简单地由生长停滞介导，而是受未知调节蛋白控制。
