Ectopic Auto-Stimulation of Growth
According to dogma nearly every cell in a mammal has the same genes encoded in its DNA and differentiation involves the selective derepression of a different and small proportion of these genes in the cells of different tissues. The gene for a hormone-like growth factor will be present in all cells but only expressed in a source cell from which the factor will be transported in the circulation to a target cell whose growth it regulates. If, by mutation, translocation, or teratogeny (mis-differentiation) the gene becomes expressed in the target cell, then the target cell will stimulate its own proliferation (auto-stimulation) and escape the normal growth regulation controls. Although the normal factor will be acting on the normal receptor to produce a normal response the cell will behave like a tumour cell. An auto-stimulating cell will also grow in culture independently of added growth factor. It has been possible to demonstrate the production of growth factors by tumour cells in tissue culture and that these factors partially explain the reduced requirement of transformed cells for serum in tissue culture.
KeywordsTarget Cell Source Cell Laryngeal Carcinoma Baby Hamster Kidney Agar Growth
Unable to display preview. Download preview PDF.
- 2.Gey, G.O., Coffman, W.D., and Kubicek, M.T. (1952) Cancer Res. 12, 264.Google Scholar
- 3.Moore, A.E., Sabachewsky, L., and Toolan, H.W. (1952) Cancer Re. 15, 598.Google Scholar
- 10.Jimenez de Asua, L., Clingan, D., and Rudland, P.S. (1975) Proc. Natl. Acad. Sci. USA 72, 2724.Google Scholar
- 14.Bürk, R.R., and Williams, C.A. (1971) in Ciba Foundation Symp.Growth Control in Cell Cultures, eds. G.E.W. Wolstenholme and J. Kniqht. Churchill Livingstone, London, p. 107.Google Scholar
- 15.Bürk, R.R. (1980) in Control Mechanisms in Animal Cells, eds. L. Jimenez de Asua et al., Raven Press, New York, p. 245.Google Scholar
- 19.Bürk, R.R. (1973) Proc. Natl. Acad. Sci. USA 70., 369.Google Scholar
- 21.Leuthard, P., Steck, G., Bürk, R.R., and Otto, A. (1980) in Control Mechanisms in Animal Cells, eds. L. Jimenez de Asua et al. Raven Press, New York, p. 259.Google Scholar