TGF‐β1 inhibits DNA synthesis and phosphorylation of the retinoblastoma gene product in a rat liver epithelial cell line
TGF‐β1 inhibits DNA synthesis and phosphorylation of the retinoblastoma gene product in a rat liver epithelial cell line
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TGF-β1 抑制大鼠肝上皮细胞系中视网膜母细胞瘤基因产物的 DNA 合成和磷酸化
DOI：
--
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
K. Itakura
中科院分区：
文献类型：
--
作者：
R. Whitson;K. Itakura
在大鼠肝上皮细胞系WB中，TGF-β1抑制DNA合成的能力与其抑制视网膜母细胞瘤易感基因pRb蛋白产物磷酸化的能力相关。当WB细胞血清饥饿，然后再用含血清的培养基，DNA合成的高峰出现在约18小时。放射自显影显示，此时43.6%的细胞核可被3 H-胸苷标记。当TGF-β1与血清同时加入时，它阻断了DNA合成，并将标记的细胞核数量减少至6.3%。单独用血清处理18小时的细胞也显示出显著增加的高度磷酸化形式的pRb，如所示的迁移率变化在免疫印迹，并在活性磷酸化的pRb，如所示的32 P掺入。同时加入TGF-β1和血清可消除32 P掺入pRb及其在免疫印迹上的迁移率变化。如果在加入TGF-β1之前将细胞与血清孵育8 h（因此允许进入S），则在18 h时测量的TGF-β1对DNA合成的影响急剧降低。如果在血清处理8小时后加入TGF-β1，则其在18小时抑制pRb磷酸化的能力不变。如果在血清处理13 h后加入TGF-β1，其对pRb磷酸化的影响降低。因此，随着细胞群进入S期，TGF-β1抑制pRb磷酸化和DNA合成的能力丧失。在WB细胞的更高代次中，TGF-β1抑制DNA合成的剂量反应向右偏移。TGF-β1对pRb磷酸化的抑制作用在高传代WB细胞中也消失。因此，对DNA合成抑制的敏感性的传代依赖性丧失伴随着对pRb磷酸化抑制的敏感性丧失。由于pRb的磷酸化被认为是细胞从G1期进展到S期所必需的，因此pRb磷酸化的抑制可能是TGF-β1导致WB细胞G1期阻滞的原因或结果。
In the rat liver epithelial cell line, WB, the ability of TGF‐β1 to inhibit DNA synthesis was shown to correlate with its ability inhibit phosphorylation of the protein product of the retinoblastoma susceptibility gene, pRb. When WB cells were serum‐starved, then refed with serum‐containing medium, a peak of DNA synthesis occurred at about 18 h. Autoradiographs showed that 43.6% of cell nuclei could be labeled with 3H‐thymidine at this time. When TGF‐β1 was added simultaneously with serum, it blocked DNA synthesis and reduced the number of labeled nucleii to 6.3%. Cells treated with serum alone for 18 h also showed a pronounced increase in the highly phosphorylated form of pRb, as shown by mobility shifts in immunoblots, and in active phosphorylation of pRb, as shown by 32P incorporation. Simultaneous addition of TGF‐β1 with serum abolished both 32P incorporation into pRb and its mobility shift on immunoblots. The effect of TGF‐β1 on DNA synthesis measured at 18 h was sharply reduced if the cells were incubated with serum for 8 h (and thus allowed to enter S) before the addition of TGF‐β1. If TGF‐β1 was added after 8 h of serum treatment, its ability to inhibit pRb phosphorylation at 18 h was unchanged. If TGF‐β1 was added after 13 h of serum treatment, its effects on pRb phosphorylation were reduced. Thus, as the cell population moved into S, the ability of TGF‐β1 to inhibit both pRb phosphorylation and DNA synthesis was lost. In higher passages of WB cells the dose‐response for inhibition of DNA synthesis by TGF‐β1 was shifted to the right. Inhibition of pRb phosphorylation by TGF‐β1 was also lost in higher passage WB cells. Thus, the passage‐dependent loss of sensitivity to inhibition of DNA synthesis accompained the loss of sensitivity to inhibition of pRb phosphorylation. Since the phosphorylation of pRb is believed to be required for the progression of cells from G1 to S, inhibition of pRb phosphorylation may be either a cause or a consequence of the G1 arrest of WB cells by TGF‐β1.
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影响因子：
56.9
作者：
HUANG, HJS;YEE, JK;LEE, WH
通讯作者：
LEE, WH
DOI：
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发表时间：
1988
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Cheifetz,S;Bassols,A;Stanley,K;Ohta,M;Greenberger,J;Massagué,J
通讯作者：
Massagué,J
通过转化生长因子-β 抑制培养的大鼠肝上皮细胞在特定细胞周期阶段的增殖。
DOI：
10.1016/0006-291x(87)90624-3
发表时间：
1987
影响因子：
3.1
作者：
Lin,P;Liu,C;Tsao,MS;Grisham,JW
通讯作者：
Grisham,JW
人类乳腺癌中视网膜母细胞瘤基因的结构重排。
DOI：
10.1126/science.3175651
发表时间：
1988
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
T'Ang,A;Varley,JM;Chakraborty,S;Murphree,AL;Fung,YK
通讯作者：
Fung,YK
DOI：
--
发表时间：
1989-02
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Frederick T. Boyd;J. Massagué
通讯作者：
Frederick T. Boyd;J. Massagué