Effect of Akt overexpression on programmed cell death in antibody-producing Chinese hamster ovary cells.
Upon nutrient deprivation, Chinese hamster ovary (CHO) cells are subjected to two types of programmed cell death, apoptosis and autophagy. CHO cell engineering, as a means to improve foreign protein production, has focused mainly on anti-apoptosis. In this study, to determine the effect of Akt, which is known to regulate both apoptosis and autophagy, on cell survival and foreign protein production, constitutively active Akt was overexpressed in antibody-producing cells. Compared with the control cells, Akt overexpressing cells showed delayed onset of apoptosis and autophagy during batch culture. The inhibition of apoptosis was demonstrated by reduced amount of cleaved poly(ADP-ribose) polymerase and caspase 3 proteins and less fragmentation of chromosomal DNA. Moreover, under nutrient-limiting conditions, decreased level of autophagosome accumulation was observed in Akt overexpressing cells by the less accumulation of the 16kDa form of LC3-II and autophagic vacuoles. Taken together, the overexpression of constitutively active Akt in CHO cells could delay the onset of both types of programmed cell death during batch culture.
Hwang
Sun Ok
SO
Department of Biological Sciences, KAIST, 335 Gwahangno, Yuseong-gu, Daejeon, 305-701, Republic of Korea.
Lee
Gyun Min
GM
D000818:Animals; D017209:Apoptosis; D001343:Autophagy; D015153:Blotting, Western; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D053938:DNA Fragmentation; D004587:Electrophoresis, Agar Gel; D015870:Gene Expression; D046529:Microscopy, Electron, Transmission; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000502:physiology*
D051057:Proto-Oncogene Proteins c-akt