Non-genetic origins of cell-to-cell variability in TRAIL-induced apoptosis

In microorganisms, noise in gene expression gives rise to cell-to-cell variability in protein concentrations. In mammalian cells, protein levels also vary and individual cells differ widely in their responsiveness to uniform physiological stimuli. In the case of apoptosis mediated by TRAIL (tumour necrosis factor (TNF)-related apoptosis-inducing ligand) it is common for some cells in a clonal population to die while others survive—a striking divergence in cell fate. Among cells that die, the time between TRAIL exposure and caspase activation is highly variable. Here we image sister cells expressing reporters of caspase activation and mitochondrial outer membrane permeabilization after exposure to TRAIL. We show that naturally occurring differences in the levels or states of proteins regulating receptor-mediated apoptosis are the primary causes of cell-to-cell variability in the timing and probability of death in human cell lines. Protein state is transmitted from mother to daughter, giving rise to transient heritability in fate, but protein synthesis promotes rapid divergence so that sister cells soon become no more similar to each other than pairs of cells chosen at random. Our results have implications for understanding ‘fractional killing’ of tumour cells after exposure to chemotherapy, and for variability in mammalian signal transduction in general.

[1]  Berenbaum Mc,et al.  In vivo determination of the fractional kill of human tumor cells by chemotherapeutic agents. , 1972 .

[2]  M C Berenbaum,et al.  In vivo determination of the fractional kill of human tumor cells by chemotherapeutic agents. , 1972, Cancer chemotherapy reports.

[3]  E. Kandel,et al.  Proceedings of the National Academy of Sciences of the United States of America. Annual subject and author indexes. , 1990, Proceedings of the National Academy of Sciences of the United States of America.

[4]  AC Tose.  Cell , 1993, Cell.

[5]  L. Hood,et al.  Death receptor 5, a new member of the TNFR family, and DR4 induce FADD-dependent apoptosis and activate the NF-kappaB pathway. , 1997, Immunity.

[6]  S. Leibler,et al.  Robustness in simple biochemical networks , 1997, Nature.

[7]  A. Arkin,et al.  Stochastic mechanisms in gene expression. , 1997, Proceedings of the National Academy of Sciences of the United States of America.

[8]  Xiaodong Wang,et al.  Bid, a Bcl2 Interacting Protein, Mediates Cytochrome c Release from Mitochondria in Response to Activation of Cell Surface Death Receptors , 1998, Cell.

[9]  Junying Yuan,et al.  Cleavage of BID by Caspase 8 Mediates the Mitochondrial Damage in the Fas Pathway of Apoptosis , 1998, Cell.

[10]  D. Green,et al.  A Single Cell Analysis of Apoptosis: Ordering the Apoptotic Phenotype , 2000, Annals of the New York Academy of Sciences.

[11]  Ertugrul M. Ozbudak,et al.  Regulation of noise in the expression of a single gene , 2002, Nature Genetics.

[12]  D. Goeddel,et al.  TNF-R1 Signaling: A Beautiful Pathway , 2002, Science.

[13]  P. Swain,et al.  Stochastic Gene Expression in a Single Cell , 2002, Science.

[14]  Jayanta Debnath,et al.  Morphogenesis and oncogenesis of MCF-10A mammary epithelial acini grown in three-dimensional basement membrane cultures. , 2003, Methods.

[15]  Mads Kærn,et al.  Noise in eukaryotic gene expression , 2003, Nature.

[16]  R. Marciniak,et al.  Death receptor 4 (DR4) efficiently kills breast cancer cells irrespective of their sensitivity to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) , 2004, Cancer Gene Therapy.

[17]  Uri Alon,et al.  Dynamics of the p53-Mdm2 feedback loop in individual cells , 2004, Nature Genetics.

[18]  G. Salvesen,et al.  Activation of caspases-8 and -10 by FLIP(L). , 2004, The Biochemical journal.

[19]  G. Salvesen,et al.  The protein structures that shape caspase activity, specificity, activation and inhibition. , 2004, The Biochemical journal.

[20]  P. Swain,et al.  Gene Regulation at the Single-Cell Level , 2005, Science.

[21]  C. Pesce,et al.  Regulated cell-to-cell variation in a cell-fate decision system , 2005, Nature.

[22]  E. Cox,et al.  Real-Time Kinetics of Gene Activity in Individual Bacteria , 2005, Cell.

[23]  R. Milo,et al.  Variability and memory of protein levels in human cells , 2006, Nature.

[24]  R. Milo,et al.  Oscillations and variability in the p53 system , 2006, Molecular systems biology.

[25]  Jerome T. Mettetal,et al.  Heritable Stochastic Switching Revealed by Single-Cell Genealogy , 2007, PLoS biology.

[26]  G. Cavet,et al.  Death-receptor O-glycosylation controls tumor-cell sensitivity to the proapoptotic ligand Apo2L/TRAIL , 2007, Nature Medicine.

[27]  K. Verstrepen,et al.  Timescales of Genetic and Epigenetic Inheritance , 2007, Cell.

[28]  A. Strasser,et al.  The BCL-2 protein family: opposing activities that mediate cell death , 2008, Nature Reviews Molecular Cell Biology.

[29]  R. Germain,et al.  Variability and Robustness in T Cell Activation from Regulated Heterogeneity in Protein Levels , 2008, Science.

[30]  R. Milo,et al.  Dynamic Proteomics of Individual Cancer Cells in Response to a Drug , 2008, Science.

[31]  Hannah H. Chang,et al.  Transcriptome-wide noise controls lineage choice in mammalian progenitor cells , 2008, Nature.

[32]  D. Lauffenburger,et al.  Modeling a Snap-Action, Variable-Delay Switch Controlling Extrinsic Cell Death , 2008, PLoS biology.

[33]  R. Herbst,et al.  To kill a tumor cell: the potential of proapoptotic receptor agonists. , 2008, The Journal of clinical investigation.

[34]  D. Lauffenburger,et al.  Quantitative analysis of pathways controlling extrinsic apoptosis in single cells. , 2008, Molecular cell.

[35]  Philippe Bastiaens,et al.  Systems biology: When it is time to die , 2009, Nature.

[36]  R. Rosenfeld.  Nature , 2009, Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery.