Wnt signalling pathway parameters for mammalian cells

• Published in: PloS one Vol. 7; no. 2; p. e31882
• Main Authors: Tan, Chin Wee, Gardiner, Bruce S, Hirokawa, Yumiko, Layton, Meredith J, Smith, David W, Burgess, Antony W
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 21-02-2012; Public Library of Science (PLoS)
• Subjects: Adenomatous polyposis coli; Adenoviruses; Animals; Arthritis; Axin Protein - metabolism; beta Catenin - metabolism; Biology; Calibration; Cancer; Cell adhesion & migration; Cell Compartmentation; Cell Count; Cell cycle; Cell Division; Cell Extracts; Cell fate; Cell Line; Cell proliferation; Cell Separation; Cell Size; Cell Survival; Cells (Biology); Colorectal cancer; Colorectal carcinoma; Computation; Computer applications; Computer simulation; Data processing; Digitization; Dogs; E-cadherin; Engineering; Epithelial cells; Gene expression; Genetic aspects; Growth factors; HEK293 Cells; Humans; Hypoxia; Imaging, Three-Dimensional; Intestine; Kidneys; Kinases; Lysates; Mammalian cells; Mammals; Mammals - metabolism; Mathematical models; Measurement techniques; Medical research; Microscopy, Confocal; Models, Biological; Mutation; Ovum - cytology; Parameters; Phosphorylation; Proteins; Signal transduction; Signaling; Subcellular Fractions - metabolism; Tcf gene; Transcription; Transcription (Genetics); Tumor cell lines; Wnt protein; Wnt Proteins - metabolism; Wnt Signaling Pathway; Xenopus; β-Catenin; Australia; Western Australia Australia; Victoria Australia
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0031882

Wnt/β-catenin signalling regulates cell fate, survival, proliferation and differentiation at many stages of mammalian development and pathology. Mutations of two key proteins in the pathway, APC and β-catenin, have been implicated in a range of cancers, including colorectal cancer. Activation of Wnt signalling has been associated with the stabilization and nuclear accumulation of β-catenin and consequential up-regulation of β-catenin/TCF gene transcription. In 2003, Lee et al. constructed a computational model of Wnt signalling supported by experimental data from analysis of time-dependent concentration of Wnt signalling proteins in Xenopus egg extracts. Subsequent studies have used the Xenopus quantitative data to infer Wnt pathway dynamics in other systems. As a basis for understanding Wnt signalling in mammalian cells, a confocal live cell imaging measurement technique is developed to measure the cell and nuclear volumes of MDCK, HEK293T cells and 3 human colorectal cancer cell lines and the concentrations of Wnt signalling proteins β-catenin, Axin, APC, GSK3β and E-cadherin. These parameters provide the basis for formulating Wnt signalling models for kidney/intestinal epithelial mammalian cells. There are significant differences in concentrations of key proteins between Xenopus extracts and mammalian whole cell lysates. Higher concentrations of Axin and lower concentrations of APC are present in mammalian cells. Axin concentrations are greater than APC in kidney epithelial cells, whereas in intestinal epithelial cells the APC concentration is higher than Axin. Computational simulations based on Lee's model, with this new data, suggest a need for a recalibration of the model.A quantitative understanding of Wnt signalling in mammalian cells, in particular human colorectal cancers requires a detailed understanding of the concentrations of key protein complexes over time. Simulations of Wnt signalling in mammalian cells can be initiated with the parameters measured in this report.