Abstract
Most models of tumorigenesis assume that the tumor grows by increased cell division. In these models, it is generally supposed that daughter cells behave as do their parents, and cell numbers have clear potential for exponential growth. We have constructed simple mathematical models of tumorigenesis through failure of programmed cell death (PCD) or differentiation. These models do not assume that descendant cells behave as their parents do. The models predict that exponential growth in cell numbers does sometimes occur, usually when stem cells fail to die or differentiate. At other times, exponential growth does not occur: instead, the number of cells in the population reaches a new, higher equilibrium. This behavior is predicted when fully differentiated cells fail to undergo PCD. When cells of intermediate differentiation fail to die or to differentiate further, the values of growth parameters determine whether growth is exponential or leads to a new equilibrium. The predictions of the model are sensitive to small differences in growth parameters. Failure of PCD and differentiation, leading to a new equilibrium number of cells, may explain many aspects of tumor behavior--for example, early premalignant lesions such as cervical intraepithelial neoplasia, the fact that some tumors very rarely become malignant, the observation of plateaux in the growth of some solid tumors, and, finally, long lag phases of growth until mutations arise that eventually result in exponential growth.
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- ARMITAGE P., DOLL R. A two-stage theory of carcinogenesis in relation to the age distribution of human cancer. Br J Cancer. 1957 Jun;11(2):161–169. doi: 10.1038/bjc.1957.22. [DOI] [PMC free article] [PubMed] [Google Scholar]
- ARMITAGE P., DOLL R. The age distribution of cancer and a multi-stage theory of carcinogenesis. Br J Cancer. 1954 Mar;8(1):1–12. doi: 10.1038/bjc.1954.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bakalkin G., Yakovleva T., Selivanova G., Magnusson K. P., Szekely L., Kiseleva E., Klein G., Terenius L., Wiman K. G. p53 binds single-stranded DNA ends and catalyzes DNA renaturation and strand transfer. Proc Natl Acad Sci U S A. 1994 Jan 4;91(1):413–417. doi: 10.1073/pnas.91.1.413. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cairns J. Mutation selection and the natural history of cancer. Nature. 1975 May 15;255(5505):197–200. doi: 10.1038/255197a0. [DOI] [PubMed] [Google Scholar]
- Clarke A. R., Purdie C. A., Harrison D. J., Morris R. G., Bird C. C., Hooper M. L., Wyllie A. H. Thymocyte apoptosis induced by p53-dependent and independent pathways. Nature. 1993 Apr 29;362(6423):849–852. doi: 10.1038/362849a0. [DOI] [PubMed] [Google Scholar]
- Donehower L. A., Bradley A. The tumor suppressor p53. Biochim Biophys Acta. 1993 Aug 23;1155(2):181–205. doi: 10.1016/0304-419x(93)90004-v. [DOI] [PubMed] [Google Scholar]
- Evan G. I., Wyllie A. H., Gilbert C. S., Littlewood T. D., Land H., Brooks M., Waters C. M., Penn L. Z., Hancock D. C. Induction of apoptosis in fibroblasts by c-myc protein. Cell. 1992 Apr 3;69(1):119–128. doi: 10.1016/0092-8674(92)90123-t. [DOI] [PubMed] [Google Scholar]
- FISHER J. C. Multiple-mutation theory of carcinogenesis. Nature. 1958 Mar 1;181(4609):651–652. doi: 10.1038/181651b0. [DOI] [PubMed] [Google Scholar]
- Fanidi A., Harrington E. A., Evan G. I. Cooperative interaction between c-myc and bcl-2 proto-oncogenes. Nature. 1992 Oct 8;359(6395):554–556. doi: 10.1038/359554a0. [DOI] [PubMed] [Google Scholar]
- Fisher D. E. Apoptosis in cancer therapy: crossing the threshold. Cell. 1994 Aug 26;78(4):539–542. doi: 10.1016/0092-8674(94)90518-5. [DOI] [PubMed] [Google Scholar]
- Kastan M. B., Canman C. E., Leonard C. J. P53, cell cycle control and apoptosis: implications for cancer. Cancer Metastasis Rev. 1995 Mar;14(1):3–15. doi: 10.1007/BF00690207. [DOI] [PubMed] [Google Scholar]
- Levine A. J., Momand J., Finlay C. A. The p53 tumour suppressor gene. Nature. 1991 Jun 6;351(6326):453–456. doi: 10.1038/351453a0. [DOI] [PubMed] [Google Scholar]
- Levine A. J. The tumor suppressor genes. Annu Rev Biochem. 1993;62:623–651. doi: 10.1146/annurev.bi.62.070193.003203. [DOI] [PubMed] [Google Scholar]
- Lowe S. W., Ruley H. E., Jacks T., Housman D. E. p53-dependent apoptosis modulates the cytotoxicity of anticancer agents. Cell. 1993 Sep 24;74(6):957–967. doi: 10.1016/0092-8674(93)90719-7. [DOI] [PubMed] [Google Scholar]
- Prives C. How loops, beta sheets, and alpha helices help us to understand p53. Cell. 1994 Aug 26;78(4):543–546. doi: 10.1016/0092-8674(94)90519-3. [DOI] [PubMed] [Google Scholar]
- QUASTLER H., SHERMAN F. G. Cell population kinetics in the intestinal epithelium of the mouse. Exp Cell Res. 1959 Jun;17(3):420–438. doi: 10.1016/0014-4827(59)90063-1. [DOI] [PubMed] [Google Scholar]
- Reed J. C. Bcl-2 and the regulation of programmed cell death. J Cell Biol. 1994 Jan;124(1-2):1–6. doi: 10.1083/jcb.124.1.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Symonds H., Krall L., Remington L., Saenz-Robles M., Lowe S., Jacks T., Van Dyke T. p53-dependent apoptosis suppresses tumor growth and progression in vivo. Cell. 1994 Aug 26;78(4):703–711. doi: 10.1016/0092-8674(94)90534-7. [DOI] [PubMed] [Google Scholar]
- Wyllie A. H. Apoptosis (the 1992 Frank Rose Memorial Lecture). Br J Cancer. 1993 Feb;67(2):205–208. doi: 10.1038/bjc.1993.40. [DOI] [PMC free article] [PubMed] [Google Scholar]