title: Progress towards a unified theory of the mechanisms of carcinogenesis, III: Circumvention of proliferation controls.
abstract: Circumvention of part of the normal controls of proliferation permits the relatively autonomous proliferation of cells which is characteristic of tumors. Several different mechanisms exist which permit circumvention of proliferation controls. RNA tumor viruses probably induce carcinogenesis by producing a viral kinase which is similar to a cAMP independent tyrosine kinase that is activated by epidermal growth factor. Circumvention of proliferation controls is permitted by modification of gene expression induced by genetic and/or epigenetic mechanisms. There does not appear to be one single mechanism for circumventing proliferation controls present in all tumors. Circumvention of proliferation controls is the basic cause of carcinogenesis.
mesh_terms: D002454:Cell Differentiation; D002455:Cell Division / Q000187:drug effects; D002471:Cell Transformation, Neoplastic; D003260:Contact Inhibition; D006801:Humans; D009369:Neoplasms / Q000209:etiology* / Q000503:physiopathology; D011494:Protein Kinases / Q000378:metabolism; D011506:Proteins; D012328:RNA Viruses / Q000201:enzymology
chemical_list: D011506:Proteins; D011494:Protein Kinases