Tumor Suppressor Genes


When functioning normally, a tumor suppressor gene prevents the formation of one or more types of cancer. Mutations in tumor suppressor genes that interfere with their function can be inherited in the germ line or can occur in somatic cells; the accumulation of such mutations can allow cancer to develop.

Keywords: disease; tumor; cancer; carcinogenesis; cancer genetics

Figure 1.

Mechanisms of loss of heterozygosity. A cell containing two copies of chromosome 13, one with the normal or wild‐type RB1 allele (+) and one with the mutant RB1 allele (m) is shown at the top (the remaining 44 chromosomes are not shown for clarity). Independent mutation of the wild‐type allele (i) is possible but relatively rare. Aberrant cell division in which segregation of chromosomes into daughter cells does not occur faithfully can lead to loss of the whole chromosome carrying the wild‐type allele (ii), and this may be combined with duplication of its homolog carrying the mutant allele (iii, iv). Alternatively, after DNA replication (v) exchange of material between chromatid arms can occur by mitotic recombination (vi). As the two copies of the mutant allele are now on different copies of the chromosome, they will segregate independently at the following cell division (vii), and some daughter cells will acquire two copies of the mutant allele and no wild‐type allele. These pathways lead to four possible genotypes (1–4), all of which have no remaining wild‐type allele. Not all of these pathways are important for all tumor suppressor genes; in particular, for some chromosomes genotype 2 may be inconsistent with cell survival because essential gene products are not produced in sufficient amounts.


Further Reading

DiCiommo D, Gallie BL and Bremner R (2000) Retinoblastoma: the disease, gene and protein provide critical leads to understand cancer. Seminars in Cancer Biology 10: 255–269.

Fishel R (2001) The selection for mismatch repair defects in hereditary nonpolyposis colorectal cancer: revising the mutator hypothesis. Cancer Research 61: 7369–7374.

Hanahan D and Weinberg RA (2000) The hallmarks of cancer. Cell 100: 55–70.

Heinrichs A, Hodges M and Eccleston A (2001) A Trends guide to cancer biology. Trends in Cell Biology 11: S1.

Hooper ML (1998) Tumour suppressor gene mutations in humans and mice: parallels and contrasts. EMBO Journal 17: 6783–6789.

Knudson AG (1971) Mutation and cancer: statistical study of retinoblastoma. Proceedings of the National Academy of Sciences of the United States of America 68: 820–823.

Knudson AG (1997) Hereditary predisposition to cancer. Annals of the New York Academy of Sciences 833: 58–67.

Lodish H, Berk A, Zipursky SL, et al. (2000) Cancer. Molecular Cell Biology, 4th edn, pp. 1055–1084 New York: WH Freeman.

Ponder BAJ (2001) Cancer genetics. Nature 411: 336–341.

Quon KC and Berns A (2001) Haplo‐insufficiency? Let me count the ways. Genes and Development 15: 2917–2921.

Vogelstein B and Kinzler KW (1998) The Genetic Basis of Human Cancer. New York: McGraw‐Hill.

Web Links

Cyclin‐dependent kinase 2A (CDKN2A); LocusID: 1029. LocusLink: http://www.ncbi.nlm.nih.gov/LocusLink/LocRpt.cgi?l=1029

Retinoblastoma 1 (RB1); LocusID: 5925. LocusLink: http://www.ncbi.nlm.nih.gov/LocusLink/LocRpt.cgi?l=5925

Tumor protein p53 (TP53); LocusID: 7157. LocusLink: http://www.ncbi.nlm.nih.gov/LocusLink/LocRpt.cgi?l=7157

Cyclin‐dependent kinase 2A (CDKN2A); MIM number: 600160. OMIM: http://www.ncbi.nlm.nih.gov/htbin‐post/Omim/dispmim?600160

Retinoblastoma 1 (RB1); MIM number: 180200. OMIM: http://www.ncbi.nlm.nih.gov/htbin‐post/Omim/dispmim?180200

Tumor protein p53 (TP53); MIM number: 191170. OMIM: http://www.ncbi.nlm.nih.gov/htbin‐post/Omim/dispmim?191170

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How to Cite close
Hooper, Martin L(Jan 2006) Tumor Suppressor Genes. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1038/npg.els.0006005]