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Cytotechnology

, Volume 62, Issue 3, pp 175–188 | Cite as

Cell death in mammalian cell culture: molecular mechanisms and cell line engineering strategies

  • Britta Krampe
  • Mohamed Al-RubeaiEmail author
Review

Abstract

Cell death is a fundamentally important problem in cell lines used by the biopharmaceutical industry. Environmental stress, which can result from nutrient depletion, by-product accumulation and chemical agents, activates through signalling cascades regulators that promote death. The best known key regulators of death process are the Bcl-2 family proteins which constitute a critical intracellular checkpoint of apoptosis cell death within a common death pathway. Engineering of several members of the anti-apoptosis Bcl-2 family genes in several cell types has extended the knowledge of their molecular function and interaction with other proteins, and their regulation of cell death. In this review, we describe the various modes of cell death and their death pathways at molecular and organelle level and discuss the relevance of the growing knowledge of anti-apoptotic engineering strategies to inhibit cell death and increase productivity in mammalian cell culture.

Keywords

Bcl-2 Apoptosis Autophagy Cell engineering Signalling pathways Cell death 

Abbreviations

A1

Apolipoprotein

AIF

Apoptosis-inducing factors

ANT

Adenine nucleotide translocator

Akt

Protein kinase B

Atgs

Autophagy-related proteins

Aven

Apoptosis, caspase activation inhibitor

Apaf1

Apoptotic protease activation factor 1

Ap1

Jun oncogene

Bad

Bcl-2-associated agonist of cell death

Bak

Bcl-2-antagonist/killer 1

Bax

Bcl-2-associated X protein

Bcl-2

B-cell lymphoma

Bcl-xL

Bcl-2 related gene, long isoform

Bid

BH3 interacting domain death agonist

Bim

Bcl-2-like 11

Bok

Bcl-2-related ovarian killer

c-MYC

v-myc myelocytomatosis viral oncogene homolog

Creb

AMP responsive element binding protein 1

ER

Endoplasmic reticulum

E2F4

Eukaryotic transcription factor 4

E2F1

Eukaryotic transcription factor 1

FADD

Fas-associated death domain

FasL

Fas ligand

Mcl-1

Myeloid cell leukemia sequence 1 (Bcl2-related)

mTOR

Target of rapamycin

MOMP

Mitochondrial outer membrane permeabilization

Noxa

PMA-induced protein

NUR77

Nuclear receptor subfamily 4

PI3K

Phosphoinositide 3-kinase

PKB

Protein kinase B

PT

Permeability transition pores

PUMA

p53-upregulated modulator of apoptosis

p27

Cyclin dependent kinase inhibitor protein 1B

SMAC/DIABLO

Second mitochondria-derived activator of caspases/direct IAP-bind protein with low pI

TNF

Tumour necrosis factor

TRAIL

TNF-related apoptosis-inducing ligand

VDAC

Voltage dependent anion channel

UPR

Unfolded protein response

References

  1. Al-Rubeai M, Singh RP (1998) Apoptosis in cell culture. Curr Opin Biotechnol 9:152–156CrossRefGoogle Scholar
  2. Al-Rubeai M, Mills D, Emery AN (1990) Electron microscopy of hybridoma cells with special regard to monoclonal antibody production. Cytotechnology 4:13–28CrossRefGoogle Scholar
  3. Al-Rubeai M, Emery AN, Chalder S, Jan DC (1992) Specific monoclonal antibody productivity and the cell cycle-comparisons of batch, continuous and perfusion cultures. Cytotech 9:85–97CrossRefGoogle Scholar
  4. Al-Rubeai M, Singh RP, Goldman MH, Emery AN (1995a) The death mechanism of animal cells in conditions of intensive agitation. Biotechnol Bioeng 45:463–472CrossRefGoogle Scholar
  5. Al-Rubeai, Singh R, Emery AN (1995b) The transfection of mammalian cells with the anti-apoptotic bcl-2 gene can enhance survivability and reduce the need for essential amino acids and nutrients. AIChE meeting, Miami, Nov, 12–17Google Scholar
  6. Arden N, Majors BS, Ahn SH, Oyler G, Betenbaugh M (2006) Inhibiting the apoptosis pathway using MDM2 in mammalian cell cultures. Biotechnol Bioeng 97:601–614CrossRefGoogle Scholar
  7. Ashkenazi A, Dixit VM (1998) Death receptors: signaling and modulation. Science 281:1305–1308CrossRefGoogle Scholar
  8. Astley K, Al-Rubeai M (2008) The role of Bcl-2 and its combined effect with p21CIP1 in adaptation of CHO cells to suspension and protein-free culture. Appl Microbiol Biotechnol 78:391–399CrossRefGoogle Scholar
  9. Bierau H, Perani A, Al-Rubeai M, Emery AN (1998) A comparison of intensive cell culture bioreactors operating with hybridomas modified for inhibited apoptotic response. J Biotech 62:195–207CrossRefGoogle Scholar
  10. Cheng EHYA, Wei MC, Weiler S, Flavell RA, Mak TW, Lindsten T, Korsmeyer SJ (2001) Bcl-2, Bcl-xL sequester BH3 domain-only molecules preventing Bax- and Bak-mediated mitochondrial apoptosis. Mol Cell 8:705–711CrossRefGoogle Scholar
  11. Chiang GG, Sisk WP (2005) Bcl-xL mediates increased production of humanized monoclonal antibodies in Chinese haster ovary cells. Biotechnol Bioeng 91:779–792CrossRefGoogle Scholar
  12. Chipuk JE, Green DR (2008) How do Bcl-2 proteins induce mitochondrial outer membrane permeabilization? Trend Cell Biol 18:157–164CrossRefGoogle Scholar
  13. Chisti Y (2000) Animal-cell damage in sparged bioreactors. Trends Biotechnol 18:420–432CrossRefGoogle Scholar
  14. Cohen JJ, Al-Rubeai M (1995) Apoptosis-targeted therapies: the ‘next big thing’ in biotechnology? Trends Biotechnol 13:281–283CrossRefGoogle Scholar
  15. Cory S, Adams JM (2002) The Bcl-2 family: regulators of the cellular life-or-death switch. Nat Rev Cancer 2:647–656CrossRefGoogle Scholar
  16. Cost GJ, Freyvert Y, Vafiadis A, Santiago Y, Miller JC, Rebar E, Collingwood TN, Snowden A, Gregory PD (2009) Bak and Bax deletion using zinc-finger nucleases yields apoptosis-resistant CHO cells. Biotechnol Bioeng 105:330–340CrossRefGoogle Scholar
  17. Cotter TG, Al-Rubeai M (1995) Cell death (apoptosis) in cell culture systems. Trends Biotechnol 13:150–155CrossRefGoogle Scholar
  18. Crea F, Sarti D, Falciani F, Al-Rubeai M (2006) Over-expression of hTERT in CHO K1 results in decreased apoptosis and reduced serum dependency. J Biotech 121:109–123CrossRefGoogle Scholar
  19. Cummings MC, Winterford CM, Walker NI (1997) Apoptosis. Am J Surg Pathol 21:88–101CrossRefGoogle Scholar
  20. Danial NN, Gramm CF, Scorrano L, Zhang CY, Krauss S, Ranger AM, Datta SR, Greenberg ME, Licklider LJ, Lowell BB, Gygi SP, Korsmeyer SJ (2003) Bad and glucokinase reside in a mitochondrial complex that integrates glycolysis and apoptosis. Nature 424:952–956CrossRefGoogle Scholar
  21. Degterev A, Boyce M, Yuan JY (2003) A decade of caspases. Oncogene 22:8543–8567CrossRefGoogle Scholar
  22. Deng XM, Gao FQ, May WS (2003) Bcl-2 retards G1/S cell cycle transition by regulating intracellular ROS. Blood 102:3179–3185CrossRefGoogle Scholar
  23. Ding WX, Yin XM (2008) Sorting, recognition and activation of the misfolded protein degradation pathways through macroautophagy and the proteasome. Autophagy 16:141–150Google Scholar
  24. Enis DR, Dunmore B, Johnson N, Pober JS, Print CG (2008) Anti-apoptotic activities of Bcl-2 correlate with vascular maturation and transcriptional modulation of human endothelial cells. Endothelium J Endothelial Cell Res 15:59–71CrossRefGoogle Scholar
  25. Fassnacht D, Rossing S, Franek F, Al-Rubeai M, Portner R (1998) Effect of Bcl-2 expression on hybridoma cell growth in serum-supplemented, protein free and diluted media. Cytotech 26:219–225CrossRefGoogle Scholar
  26. Figueroa B Jr, Chen S, Oyler G, Hardwick JM, Betenbaugh MJ (2004) Aven and Bcl-xL enhance protection against apoptosis for mammalian cells exposed to various culture conditions. Biotechnol Bioeng 6:589–600CrossRefGoogle Scholar
  27. Figueroa B Jr, Ailor E, Osborne D, Hardwick JM, Reff M, Betenbaugh MJ (2007) Enhanced cell culture performance using inducible anti-apoptotic genes E1B–19K and Aven in the production of a monoclonal antibody with Chinese hamster ovary cells. Biotechnol Bioeng 97:877–892CrossRefGoogle Scholar
  28. Gammel P (2007) MicroRNA: recently discovered key regulators of proliferation and apoptosis in animal cells. Cytotechnology 53:55–63CrossRefGoogle Scholar
  29. Gonzuacik D, Kimchi A (2004) Autophagy as a cell death and tumor suppressor mechanism. Oncogene 23:2891–2906CrossRefGoogle Scholar
  30. Goswami J, Sinskey AJ, Stelle H, Stephanopoulos GN, Wang DIC (1999) Apoptosis in batch cultures of Chinese hamster ovary cells. Biotechnol Bioeng 62:632–640CrossRefGoogle Scholar
  31. Greider C, Chattopadhyay A, Parkhurst C, Yang E (2002) Bcl-xL and Bcl-2 delay Myc-induced cell cycle entry through elevation of p27 and inhibition of G1 cyclin-dependent kinases. Oncogene 21:7765–7775CrossRefGoogle Scholar
  32. Hanson CJ, Bootman MD, Distelhorst CW, Maraldi T, Roderick HL (2008) The cellular concentration of Bcl-2 determines its pro- or anti-apoptotic effect. Cell Calcium 44:243–258CrossRefGoogle Scholar
  33. Heath-Engel HM, Chang NC, Shore GC (2008) The endoplasmic reticulum in apoptosis and autophagy: role of the Bcl-2 protein family. Oncogene 27:6419–6433CrossRefGoogle Scholar
  34. Hockenbery DM, Oltvai ZN, Yin XM, Milliman CL, Korsmeyer SJ (1993) Bcl-2 functions in an antioxidant pathway to prevent apoptosis. Cell 75:241–251CrossRefGoogle Scholar
  35. Hwang SO, Lee GM (2008) Nutrient deprivation induces autophagy as well as apoptosis in Chinese hamster ovary cell culture. Biotechnol Bioeng 99:678–685CrossRefGoogle Scholar
  36. Hwang SO, Lee GM (2009) Effect of Akt overexpression on programmed cell death in antibody-producing Chinese hamster ovary cells. J Biotech 139:89–94CrossRefGoogle Scholar
  37. Ifandi V, Al-Rubeai M (2005) Regulation of cell proliferation and apoptosis in CHO-K1 cells by the coexpression of c-Myc and Bcl-2. Biotech Prog 21:671–677CrossRefGoogle Scholar
  38. Imahashi K, Schneider MD, Steenbergen C, Murphy E (2003) Transgenic expression of Bcl-2 modulates energy metabolism and prevents cytosolic acidification during ischemia and reduces ischemia-reperfusion injury. Circulation 95:734–741Google Scholar
  39. Ishaque A, Al-Rubeai M (1999) Role of Ca, Mg and K ions in determining apoptosis and extent of suppression afforded by bcl-2 during hybridoma cell culture. Apoptosis 5:335–355CrossRefGoogle Scholar
  40. Ishaque A, Al-Rubeai M (2002) Role of vitamins in determining apoptosis and extent of suppression by bcl-2 during hybridoma cell culture. Apoptosis 7:231–239CrossRefGoogle Scholar
  41. Ishaque A, Thrift J, Murphy J, Konstantinov K (2007) Over-expression of Hsp70 in BHK-21 cells engineered to produce recombinant Factor VIII promotes resistance to apoptosis and enhances secretion. Biotechnol Bioeng 81:496–504Google Scholar
  42. Itoh Y, Ueda H, Suzuki E (1995) Overexpression of Bcl-2, apoptosis suppressing gene: prolonged viable culture period of hybridoma and enhanced antibody production. Biotechnol Bioeng 48:118–122CrossRefGoogle Scholar
  43. Janumyam YM, Sansam CG, Chattopadhyay A, Cheng NL, Soucie EL, Penn LZ, Andrews D, Knudson CM, Yang E (2003) Bcl-xL/Bcl-2 co-ordinately regulates apoptosis, cell cycle arrest and cell cycle entry. EMBO J 22:5459–5470CrossRefGoogle Scholar
  44. Jayapal KP, Wlaschin KF, Hu WS, Yap M (2006) Recombinant protein therapeutics from CHO cells—20 years and counting. CHO Consortium. SBE Special Section. Ref Type: reportGoogle Scholar
  45. Jin ZY, El Deiry WS (2005) Overview of cell death signalling pathways. Cancer Biol Ther 4:139–163CrossRefGoogle Scholar
  46. Juanola S, Vives J, Milian E, Prats E, Cairo JJ, Godia F (2009) Expression of Bhrf1 improves survival of murine hybridoma cultures in batch and continuous. Appl Microbiol Biotechnol 83:43–57CrossRefGoogle Scholar
  47. Kerr JFR, Wyllie AH, Currie AR (1972) Apoptosis: a basic biological phenomenon with wide-ranging implications in tissure kinetics. Br J Cancer 26:239Google Scholar
  48. Kim NS, Lee GM (2002) Response at recombinant Chinese hamster ovary cells to hyperosmotic pressure:effect of Bcl-2 overexpression. J Biotech 95:237–248CrossRefGoogle Scholar
  49. Kim YG, Lee GM (2009) Bcl-xL overexpression does not enhance specific erythropoietin productivity of recombinant CHO cells grown at 33C and 37C. Biotech Prog 25:252–256CrossRefGoogle Scholar
  50. Kim YG, Kim JY, Mohan C, Lee GM (2009) Effect of Bcl-xL over-expression on apoptosis and autophagy in recombinant chinese hamster ovary cells under nutrient deprived condition. Biotechnol Bioeng 4:757–766CrossRefGoogle Scholar
  51. Klionsky DJ (2007) Autophagy: from phenomenology to molecular understanding in less than a decade. Nat Rev Mol Cell Biol 8:931–937CrossRefGoogle Scholar
  52. Krajewski S, Tanaka S, Takayama S, Schibler MJ, Fenton W, Reed JC (1993) Investigation of the subcellular-distribution of the Bcl-2 oncoprotein—residence in the nuclear-envelope, endoplasmic-reticulum, and outer mitochondrial-membranes. Cancer Res 53:4701–4714Google Scholar
  53. Krampe B, Al-Rubeai M (2009) Cellular and molecular analysis of NS0 cell line in batch, chemostat and perfusion cultures. PhD Thesis, University College Dublin, IrelandGoogle Scholar
  54. Ku B, Woo JS, Lian C, Lee KH, Hong HS, Xiaoefei E, Kim KS, Jung JU, Oh BH (2008) Structural and biochemical bases for the inhibition of autophagy and apoptosis by viral bcl-2 of murine y-herpesvirus 68. PLoS Pathog 4:e25CrossRefGoogle Scholar
  55. Kuystermans D, Krampe B, Swiderek H, Al-Rubeai M (2007) Using cell engineering and omic tools for the improvement of cell culture processes. Cytotech 53:3–22CrossRefGoogle Scholar
  56. Lam M, Dubyak G, Chen L, Nunez G, Miesfeld RL, Distelhorst CW (1994) Evidence that Bcl-2 represses apoptosis by regulating endoplasmic Reticulum-Associated Ca2+ Fluxes. Proc Natl Acad Sci USA 91:6569–6573CrossRefGoogle Scholar
  57. Lasunskaia EB, Fridlianskaia II, Darieva ZA, Da Silva MS, Kanashiro MM, Margulis BA (2003) Transfection of NS0 myeloma fusion partner cells with HSP70 gene results in higher hybridoma yield by improving cellular resistance to apoptosis. Biotech Bioeng 8:496–504CrossRefGoogle Scholar
  58. Lee YY, Wong KTK, Tan J, Toh PC, Mao Y, Brusic V, Yap MGS (2009) Overexpression of heat shock proteins (HSPs) in CHO cells for extended culture viability and improved recombinant protein production. J Biotech 143:34–43CrossRefGoogle Scholar
  59. Leist M, Single B, Castoldi AF, Kuhnle S, Nicotera P (1997) Intracellular adenosine triphosphate (ATP) concentrations: a switch in the decision between apoptosis and necrosis. J Exp Med 185:1481–1486CrossRefGoogle Scholar
  60. Levine B, Klionsky DJ (2004) Development by self-digestion: molecular mechanisms and biological functions of autophagy. Dev Cell 6:463–477CrossRefGoogle Scholar
  61. Levine B, Sinha S, Kroemer G (2008) Blc-2 family members: dual regulators of apoptosis and autophagy. Autophagy 4:600–606Google Scholar
  62. Lim SF, Chuan KH, Liu S, Loh SOH, Chung BYF, Ong CC, Song ZW (2006) RNAi suppression of Bax and Bak enhances viability in fed-batch cultures of CHO cells. Metab Eng 8:509–522CrossRefGoogle Scholar
  63. Lin BZ, Kolluri SK, Lin F, Liu W, Han YH, Cao XH, Dawson MI, Reed JC, Zhang XK (2004) Conversion of Bcl-2 from protector to killer by interaction with nuclear orphan receptor Nur77/TR3. Cell 116:527–540CrossRefGoogle Scholar
  64. Majid FAA, Butler M, Al-Rubeai M (2007) Glycosylation of an immunoglobulin produced from a murine hybridoma cell line: the effect of culture mode and the anti-apoptotic gene, bcl-2. Biotechnol Bioeng 97:156–169CrossRefGoogle Scholar
  65. Major BS, Betenbaugh MJ (2009) Mcl-1 overexpression leads to higher viabilities and increased production of humanized monoclonal antibody in Chinese hamster ovary cells. Biotech Prog 25:1161–1168CrossRefGoogle Scholar
  66. Massaad CA, Portier BP, Taglialatela G (2004) Inhibition of transcription factor activity by nuclear compartment-associated Bcl-2. J Biol Chem 279:54470–54478CrossRefGoogle Scholar
  67. Mastrangelo AJ, Hardwick JM, Zou S, Betenbaugh MJ (2000) Part II. Overexpression of bcl-2 family members enhances survival of mammalian cells in response to various cultures insults. Biotechnol Bioeng 67:555–564CrossRefGoogle Scholar
  68. Mazel S, Burtrum D, Petrie HT (1996) Regulation of cell division cycle progression by bcl-2 expression: a potential mechanism for inhibition of programmed cell death. J Exp Med 183:2219–2226CrossRefGoogle Scholar
  69. Meents H, Enenkel B, Eppenberger HM, Werner RG, Fussenegger M (2002) Impact of coexpression and coamplification of sICAM and antiapoptosis determinants Bcl-2/Bcl-x(L) on productivity, cell survival, and mitochondria number in CHO-DG44 grown in suspension and serum-free media. Biotechnol Bioeng 80:706–716CrossRefGoogle Scholar
  70. Mercille S, Massie B (1994) Induction of apoptosis in nutrient-deprived cultures of hybridoma and myeloma cells. Biotechnol Bioeng 44:1140–1154CrossRefGoogle Scholar
  71. Mercille S, Massie B (1999) Apoptosis-resistant E1B-19K-expressing NS/0 myeloma cells exhibit increased viability and chimeric antibody productivity under perfusion culture conditions. Biotech Bioeng 63(5):529–593CrossRefGoogle Scholar
  72. Mercille S, Johnson M, Lanthier S, Kamen AA, Massie B (2000) Understanding factors that limit the productivity of suspension-based perfusion cultures operated at high medium renewal rates. Biotechnol Bioeng 67:435–450CrossRefGoogle Scholar
  73. Mohan C, Kim Y-G, Lee GM (2009) Apoptosis and autophagy cell engineering. Book Series Cell Line Development, Cell Engineering, vol 6. pp 195–216Google Scholar
  74. Murphy E, Imahashi K, Steenbergen C (2005) Bcl-2 regulation of mitochondrial energetics. Trends Cardiovasc Med 15:283–290CrossRefGoogle Scholar
  75. Murray K, Ang CE, Gull K, Hickman JA, Dickson AJ (1996) NSO myeloma cell death: influence of bcl-2 overexpression. Biotechnol Bioeng 51:298–304CrossRefGoogle Scholar
  76. Ogata M, Hino SI, Saito A, Morikawa K, Kondo S, Kanemoto S, Murakami T, Taniguchi M, Tanii I, Yoshinaga K, Shiosaka S, Hammarback JA, Urano F, Imaizumi K (2006) Autophagy is activated for cell survival after endoplasmic reticulum stress. Mol Cell Biol 26:9220–9231CrossRefGoogle Scholar
  77. Pattingre S, Tassa A, Qu X, Garuti R, Liang X, Misushima N, Packer M, Schneider M, Levine B (2005) Apoptosis and autophagy after mitochondrial or endoplasmic reticulum photodamage. Cell 122:927–939CrossRefGoogle Scholar
  78. Perani A, Singh RP, Chauhan R, Al-Rubeai M (1998) Variable functions of Bcl-2 in mediating bioreactor stress-induced apoptosis in hybridoma cells. Cytotech 28:177–188CrossRefGoogle Scholar
  79. Reggiori F, Klionsky DJ (2002) Autophagy in the eukariotic cell. Eukaryotic Cell 2:11–21CrossRefGoogle Scholar
  80. Remillard CV, Yuan JXJ (2004) Activation of K+ channels: an essential pathway in programmed cell death. Am J Physiol Lung Cell Mol Physiol 286:L49–L67CrossRefGoogle Scholar
  81. Ryu JS, Lee GM (1999) Application of hypoosmolar medium to fed-batch culture of hybridoma cells for improvement of culture longevity. Biotechnol Bioeng 62:120–123CrossRefGoogle Scholar
  82. Sauerwald TM, Oyler GA, Betenbaugh MJ (2003) Study of caspase inhibitors for limiting death in mammalian cell culture. Biotechnol Bioeng 81:329–340CrossRefGoogle Scholar
  83. Schroder M, Kaufman RJ (2005) The mammalian unfolded protein response. Annu Rev Biochem 74:739–789CrossRefGoogle Scholar
  84. Shimizu S, Narita M, Tsujimoto Y (1999) Bcl-2 family proteins regulate the release of apoptogenic cytochrome c by the mitochondrial channel VDAC. Nature 399:483–487CrossRefGoogle Scholar
  85. Shimizu S, Ide T, Yanagida T, Tsujimoto Y (2000) Electrophysiological study of a novel large pore formed by Bax and the voltage-dependent anion channel that is permeable to cytochrome c. J Biol Chem 275:12321–12325CrossRefGoogle Scholar
  86. Shimuzu S, Kanaseki T, Mizushima N, Mizuta T, Arakawa-Kobayashi S, Thompson CB, Tsujimoto Y (2004) Role of Bcl-2 family proteins in a non-apoptotic programmed cell death dependent on autophagy genes. Nat Cell Biol 6:1221–1228CrossRefGoogle Scholar
  87. Simpson N, Milner AE, Al-Rubeai M (1997) Prevention of hybridoma cell death by bcl-2 during sub-optimal culture conditions. Biotechnol Bioeng 54:1–16CrossRefGoogle Scholar
  88. Simpson NH, Singh RP, Perani A, Goldenzon C, Al-Rubeai M (1998) In hybridoma cultures, deprivation of any single amino acid leads to apoptotic death, which is suppressed by the expression of the bcl-2 gene. Biotechnol Bioeng 59:90–98CrossRefGoogle Scholar
  89. Simpson NH, Singh RP, Emery AN, Al-Rubeai M (1999) Bcl-2 over-expression reduces growth rate and prolongs G1 phase in continuous chemostat cultures of hybridoma cells. Biotechnol Bioeng 64:174–186CrossRefGoogle Scholar
  90. Singh RP, Al-Rubeai M (1998) Apoptosis and bioprocess technology. Adv Biochem Eng Biotechnol 62:167–184Google Scholar
  91. Singh RP, Alrubeai M, Gregory CD, Emery AN (1994) Cell-death in bioreactors—a role for apoptosis. Biotechnol Bioeng 44:720–726CrossRefGoogle Scholar
  92. Singh RP, Emery AN, Al-Rubeai M (1996) Enhancement of survivability of mammalian cells by over-expression of the apoptosis-suppressor gene bcl-2. Biotech Bioeng 52:166–175CrossRefGoogle Scholar
  93. Sung YH, Hwang SJ, Lee GM (2005) Influence of down-regulation of caspase-3 by siRNAs on sodium butyrate-induced apoptotic cell death of Chinese hamster ovary cells producing thrombopoietin. Metab Eng 5–6:457–466CrossRefGoogle Scholar
  94. Terada S, Fukuoka K, Fujita T, Komatsu T, Takayaa S, Reed JC, Suzuki E (1997) Anti-apoptotic genes, bag-1 and bcl-2, enabled hybridoma cells to survive under treatment for arresting cell cycle. Cytotech 25:17–23CrossRefGoogle Scholar
  95. Tey BT, Al-Rubeai M (2005a) Effect of Bcl-2 over-expression on cell cycle and antibody productivity in chemostat cultures of myeloma NS0 cells. J Biosci Bioeng 100:303–310CrossRefGoogle Scholar
  96. Tey BT, Al-Rubeai M (2005b) Bcl-2 over-expression reduced the serum dependency and improved the nutrient metabolism in NS0 cell culture. Biotechnol Bioprocess Eng 10:254–261CrossRefGoogle Scholar
  97. Tey BT, Singh RP, Piredda L, Piacentini M, Al-Rubeai M (2000a) Bcl-2 mediated suppression of apoptosis in myeloma NS0 cultures. J Biotechnol 79:147–159CrossRefGoogle Scholar
  98. Tey BT, Singh RP, Piredda L, Piacentini M, Al-Rubeai M (2000b) Influence of bcl-2 on cell death during the cultivation of a Chinese hamster ovary cell line expressing a chimeric antibody. Biotechnol Bioeng 68:31–43CrossRefGoogle Scholar
  99. Tsukada M, Ohsumi Y (1993) Isolation and characterization of autophagy-defective mutants of Saccharomyces cerevisiae. FEBS Lett 25:169–174CrossRefGoogle Scholar
  100. Vairo G, Soos TJ, Upton TM, Zalvide J, DeCaprio JA, Ewen ME, Koff A, Adams JM (2000) Bcl-2 retards cell cycle entry through p27(Kip1), pRB relative p130, and altered E2F regulation. Mol Cell Biol 20:4745–4753CrossRefGoogle Scholar
  101. Vander Heiden MG, Chandel NS, Schumacker PT, Thompson CB (1999) Bcl-xL prevents cell death following growth factor withdrawal by facilitating mitochondrial ATP/ADP exchange. Mol Cell 3:159–167CrossRefGoogle Scholar
  102. Vander Heiden MG, Chandel NS, Li XX, Schumacker PT, Colombini M, Thompson CB (2000) Outer mitochondrial membrane permeability can regulate coupled respiration and cell survival. Proc Natl Acad Sci USA 97:4666–4671CrossRefGoogle Scholar
  103. Vaux DL, Cory S, Adams JM (1988) Bcl-2 gene promotes haemopoietic cell survival and cooperates with c-myc to immortalize pre-B cells. Nature 335:440–442CrossRefGoogle Scholar
  104. Walsh G (2006) Biopharmaceutical benchmarks 2006. Nat Biotechnol 24:769–776CrossRefGoogle Scholar
  105. Willis SN, Fletcher JI, Kaufmann T, van Delft MF, Chen L, Czabotar PE, Ierino H, Lee EF, Fairlie WD, Bouillet P, Strasser A, Kluck RM, Adams JM, Huang DCS (2007) Apoptosis initiated when BH3 ligands engage multiple Bcl-2 homologs, not Bax or Bak. Science 315:856–859CrossRefGoogle Scholar
  106. Wong DCF, Wong KTK, Nissom PM, Heng CK, Yap MGS (2006) Targeting early apoptotic genes in batch and fed-batch CHO cell cultures. Biotechnol Bioeng 95:350–361CrossRefGoogle Scholar
  107. Wu J, Kaufman RJ (2006) From acute ER stress to physiological roles of the unfolded protein response. Cell Death Differ 13:374–384CrossRefGoogle Scholar
  108. Youle RJ, Strasser A (2008) The Bcl-2 protein family: opposing activities that mediate cell death. Nat Rev Mol Cell Biol 9:47–59CrossRefGoogle Scholar
  109. Yun CY, Liu S, Lim SF, Wang T, Chung BY, Jiat Teo J, Chuan KH, Soon AS, Goh KS, Song Z (2007) Specific inhibition of caspase-8 and -9 in CHO cells enhances cell viability in batch and fed-batch cultures. Metab Eng 9:406–418Google Scholar
  110. Zhu Y, Cuenca JV, Zhou WC, Varma A (2008) NS0 cell damage by high gas velocity sparging in protein-free and cholesterol-free cultures. Biotechnol Bioeng 101:751–760CrossRefGoogle Scholar
  111. Zinkel S, Gross A, Yang E (2006) Bcl-2 family in DNA damage and cell cycle control. Cell Death Differ 13:1351–1359CrossRefGoogle Scholar
  112. Zustiak M, Pollack JK, Marten MR, Betenbaugh MJ (2008) Feast of famine: autophagy control and engineering in eukaryotic cell culture. Curr Optin Biotech 5:518–526CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2010

Authors and Affiliations

  1. 1.School of Chemical and Bioprocess Engineering, and Conway Institute of Biomolecular & Biomedical ResearchUniversity College DublinBelfield, Dublin 4Republic of Ireland

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