Human pathology

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melanomas

malignant melanoma

Melanoma, in its advanced stages, is the most deadly form of skin cancer due to its high metastatic potential and drug resistance. Alterations in expression or activity of various genes and signaling pathways promote melanoma development.

Epidemiology

- A positive family history of the disease is among the most established risk factors for CMM; it is estimated that 10% of CMM cases result from an inherited predisposition. Mutations in CDKN2A and CDK4 genes have been shown to confer an increased risk of CMM and account for only 20%-25% of families with multiple cases.

Physiopathology

Most melanomas arise within the epidermis (melanoma in situ) and then invade across the basement membrane.

These melanoma cells escape from control by keratinocytes through five major mechanisms:

- (1) downregulation of receptors important for communication with keratinocytes such as E-cadherin, P-cadherin, and desmoglein, which is achieved through growth factors such as hepatocyte growth factor, platelet-derived growth factor, and endothelin-1 produced by fibroblasts or keratinocytes;
- (2) upregulation of receptors and signaling molecules important for melanoma cell-melanoma cell and melanoma cell-fibroblast interactions such as N-cadherin, Mel-CAM, and zonula occludens protein-1;
- (3) deregulation of morphogens such as Notch receptors and their ligands;
- (4) loss of anchorage to the basement membrane because of an altered expression of cell-matrix adhesion molecules;
- (5) increased elaboration of metal-loproteinases.

Variants

- myxoid melanoma (11807440, 9711669)
- desmoplastic melanoma
- melanoma with ganglioneuroblastic differentiation (10328091)

Tumoral predisposition

- melanoma-prone families with germline mutations of CDKN2A (17492760)

Susceptibility loci

- CDKN2A mutations
- CDK4 mutations
- 1p22 (12844286)

LOH

- 9p21: CDKN2A or p16(INK4) inactivation (MIM.600160)

Gene amplifications

- CDK4 and MDM2 amplification by 12q14 amplification (16419059)

Prognosis

- tumor thickness

  • Clark level system
    - ulcerative state

Animal model

- Xiphophorus (17034900)

See also

- melanocytic tumors

Reviews

- Miller AJ, Mihm MC Jr. Melanoma. N Engl J Med. 2006 Jul 6;355(1):51-65. PMID: 16822996

- Smalley KS, Herlyn M. Towards the targeted therapy of melanoma. Mini Rev Med Chem. 2006 Apr;6(4):387-93. PMID: 16613575

- Smalley KS, Herlyn M. Targeting intracellular signaling pathways as a novel strategy in melanoma therapeutics. Ann N Y Acad Sci. 2005 Nov;1059:16-25. PMID: 16382039

- Meierjohann S, Schartl M. From Mendelian to molecular genetics: the Xiphophorus melanoma model. Trends Genet. 2006 Oct 9; PMID: 17034900

- Chudnovsky Y, Khavari PA, Adams AE. Melanoma genetics and the development of rational therapeutics. J Clin Invest. 2005 Apr;115(4):813-24. PMID: 15841168

- Chin L. The genetics of malignant melanoma: lessons from mouse and man. Nat Rev Cancer. 2003 Aug;3(8):559-70. PMID: 12894244

- Merlino G, Noonan FP. Modeling gene-environment interactions in malignant melanoma. Trends Mol Med. 2003 Mar;9(3):102-8. PMID: 12657431

- Satyamoorthy K, Bogenrieder T, Herlyn M. No longer a molecular black box—new clues to apoptosis and drug resistance in melanoma. Trends Mol Med. 2001 May;7(5):191-4. PMID: 11325619

Articles

- Kannengiesser C, Dalle S, Leccia MT, Avril MF, Bonadona V, Chompret A, Lasset C, Leroux D, Thomas L, Lesueur F, Lenoir G, Sarasin A, Bressac-de Paillerets B. New founder germline mutations of CDKN2A in melanoma-prone families and multiple primary melanoma development in a patient receiving levodopa treatment. Genes Chromosomes Cancer. 2007 Aug;46(8):751-60. PMID: 17492760

- Muthusamy V, Hobbs C, Nogueira C, Cordon-Cardo C, McKee PH, Chin L, Bosenberg MW. Amplification of CDK4 and MDM2 in malignant melanoma. Genes Chromosomes Cancer. 2006 May;45(5):447-54. PMID: 16419059