Kim Yeon-Gu, Lee Gyun Min
Dept. of Biological Sciences, KAIST, 373-1 Kusong-Dong, Yusong-Gu, Daejon 305-701, Korea.
Biotechnol Prog. 2009 Jan-Feb;25(1):252-6. doi: 10.1002/btpr.91.
Overexpression of bcl-xL in recombinant Chinese hamster ovary (rCHO) cells has been known to suppress apoptotic cell death and thereby extend culture longevity during batch culture. However, its effect on specific productivity (q) of rCHO cells is controversial. This study attempts to investigate the effect of bcl-xL overexpression on q of rCHO cells producing erythropoietin (EPO). To regulate the bcl-xL expression level, the Tet-off system was introduced in rCHO cells producing EPO (EPO-off-bcl-xL). The bcl-xL expression level was tightly controlled by doxycycline concentration. To evaluate the effect of bcl-xL overexpression on specific EPO productivity (q(EPO)) at different levels, EPO-off-bcl-xL cells were cultivated at the two different culture temperatures, 33 degrees C and 37 degrees C. The q(EPO) at 33 degrees C and 37 degrees C in the presence of 100 ng/mL doxycycline (without bcl-xL overexpression) were 4.89 +/- 0.21 and 3.18 +/- 0.06 microg/10(6)cells/day, respectively. In the absence of doxycycline, bcl-xL overexpression did not affect q(EPO) significantly, regardless of the culture temperature, though it extended the culture longevity. Taken together, bcl-xL overexpression showed no significant effect on the q(EPO) of rCHO cells grown at 33 degrees C and 37 degrees C.
已知在重组中国仓鼠卵巢（rCHO）细胞中过表达bcl-xL可抑制凋亡性细胞死亡，从而延长分批培养期间的培养寿命。然而，其对rCHO细胞比生产率（q）的影响存在争议。本研究旨在探讨bcl-xL过表达对产生促红细胞生成素（EPO）的rCHO细胞q的影响。为了调节bcl-xL表达水平，在产生EPO的rCHO细胞（EPO-off-bcl-xL）中引入了Tet-off系统。bcl-xL表达水平受强力霉素浓度严格控制。为了评估不同水平的bcl-xL过表达对EPO比生产率（q(EPO)）的影响，将EPO-off-bcl-xL细胞在33℃和37℃这两种不同的培养温度下培养。在存在100 ng/mL强力霉素（无bcl-xL过表达）的情况下，33℃和37℃时的q(EPO)分别为4.89±0.21和3.18±0.06 μg/10(6)细胞/天。在不存在强力霉素的情况下，尽管bcl-xL过表达延长了培养寿命，但无论培养温度如何，其对q(EPO)均无显著影响。综上所述，bcl-xL过表达对在33℃和37℃下生长的rCHO细胞的q(EPO)无显著影响。
