Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1522102 (Melanoma)
 7,698 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Xiphophorus hybrid melanoma model represents one of the earliest reported cases of genetically regulated tumor susceptibility. Melanoma formation in Xiphophorus hybrids may be explained by the inheritance of two genes: a sex-linked oncogene, Xmrk, and a putative tumor suppressor locus, termed DIFF, located in Linkage Group V (LG V). Several genetic mapping procedures were used to produce a new Xiphophorus LG V map with 20 loci. All markers, particularly a recently cloned Xiphophorus CDKN2 gene family member, called CDKN2X, were tested for associations of genotype with degree of macromelanophore pigment pattern modification and susceptibility to melanoma formation in backcross hybrids of seven genetic types, involving 1,110 fish and three pigment patterns. Highly significant associations of CDKN2X genotypes with such phenotypic effects suggests that this gene is a strong candidate for the classically defined DIFF tumor suppressor gene. Because published results have documented the involvement of the CDKN2A (p16, MTS1, and INK4A) tumor suppressor gene in human melanoma formation, the possibility of CDKN2 genes acting as tumor suppressors in both man and Xiphophorus is likely.
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PMID:Localization of a CDKN2 gene in linkage group V of Xiphophorus fishes defines it as a candidate for the DIFF tumor suppressor. 962 32

The retinoblastoma protein (pRb) pathway is critical in regulating the G1 phase of the cell cycle and it is frequently disrupted in human cancers. Components of the pRb pathway which are often altered in tumour progression include the INK4 cyclin-dependent kinase (CDK) inhibitors p16INK4a/ CDKN2A and p15INK4b/CDKN2B, CDK4, D-type cyclins and pRb. Several of these components were studied in a series of cultured melanoma cell lines in order to determine the frequency and spectrum of genetic alterations and to define targets for potential gene transfer studies. Also studied were the p16INK4a alternate transcript (p14ARF) and the p21(waf1) CDK inhibitor. The majority of the melanoma cell lines tested (13 out of 17; 76%) carried mutated (two), deleted (nine) or silenced (two) p16(INK4a). CDK4 was mutated or overexpressed in two melanoma cell lines with homozygously deleted CDKN2A and CDKN2B genes. This suggests that the selective growth advantages afforded by CDKN2A inactivation and CDK4 insensitivity are distinct and may involve the mediation of other CDK inhibitors or CDKs.
Melanoma Res 1999 Feb
PMID:Multiple abnormalities of the p16INK4a-pRb regulatory pathway in cultured melanoma cells. 1033 30

The CDKN2A gene encodes the cell cycle inhibitor p16/ INK4A, which is involved in familial cutaneous melanoma. We have studied five Swedish familial melanoma kindreds characterized by germline mutations in CDKN2A and dysplastic naevus syndrome (DNS). We found significant correlations between germline CDKN2A mutations and melanoma and between DNS phenotype and melanoma, respectively. There was also a correlation between mutation status and the presence of DNS. In CDKN2A mutation carriers, all cases of early-onset melanoma occurred in DNS individuals, and the mean age at melanoma diagnosis was significantly lower in individuals with DNS than in those without a confirmed DNS phenotype. In one family where the proband had a P48L mutation in CDKN2A exon 1, the DNS phenotype was studied in detail. In vitro binding experiments established that the P48L mutant protein does not bind to cdk4 or cdk6 and thus is functionally abnormal. Furthermore, we demonstrated loss of heterozygosity at markers on chromosome 9p flanking the CDKN2A locus in a primary melanoma and a metastasis from the proband. Our results are consistent with the hypothesis that germline CDKN2A mutations and DNS both contribute to the predisposition to melanoma and may lead to the development of early-onset melanoma when present in the same individual.
Melanoma Res 1999 Feb
PMID:Melanoma development in relation to non-functional p16/INK4A protein and dysplastic naevus syndrome in Swedish melanoma kindreds. 1033 31

Excessive sun exposure and family history are strong risk factors for the development of cutaneous melanoma. Inherited susceptibility to this type of skin cancer could therefore result from constitutively impaired capacity to repair ultraviolet (UV)-induced DNA lesions. While a proportion of familial melanoma kindreds exhibit germline mutations in the cell cycle regulatory gene CDKN2A (p16INK4a) or its protein target, cyclin-dependent kinase 4 (CDK4), the biochemical basis of most familial melanoma is unknown. We have examined lymphoblastoid cell lines from melanoma-affected and unaffected individuals from large hereditary melanoma kindreds which are not attributable to CDKN2A or CDK4 gene mutation. These lines were tested for sensitivity of clonogenic growth to UV radiation and for their ability to repair transfected UV-damaged plasmid templates (host cell reactivation). Two of seven affected-unaffected pairs differed in colony survival after exposure to UVB radiation; however, no significant differences were observed in the host-cell reactivation assays. These results indicate that melanoma susceptibility genes other than CDKN2A and CDK4 do not impair net capacity to repair UV-induced DNA damage.
Melanoma Res 1999 Apr
PMID:Normal repair of ultraviolet radiation-induced DNA damage in familial melanoma without CDKN2A or CDK4 gene mutation. 1038 Sep 35

The CDKN2A gene that encodes the cell cycle inhibitor p16 shows mutations in many but not all 9p21-linked melanoma families. Most Dutch melanoma families segregate for a unique founder mutation (p16-Leiden), encoding a truncated nonfunctional p16 protein. The highly variable risk for p16-Leiden carriers to develop melanoma suggests a role for other genetic and/or environmental factors. We hypothesized that a 9p21 gene other than CDKN2A may be relevant in the remaining 9p21-linked melanoma families without p16 mutations but may also act as a risk modifier in p16-Leiden carriers. Haplotype analysis for 9p21 was performed using microsatellite markers in six p16-Leiden families originating from a founder population. p16-Leiden carriers in two families shared an unexpectedly large founder haplotype ( approximately 20-cM) around CDKN2A, mostly in proximal direction. Melanoma-positive p16-Leiden carriers from these families showed this extensive proximal haplotype compared with melanoma-negative p16-Leiden carriers from the same families. Additional p16-Leiden families less heavily affected with melanoma showed shorter haplotypes sharing, excluding the region proximally of CDKN2A. The presence of a gene involved in melanoma susceptibility proximal of CDKN2A is corroborated by somatic deletions of 9p in tumors, which frequently do not include CDKN2A but a more proximal chromosomal area instead. Our results provide a candidate region for further gene mapping in p16-negative 9p21-linked melanoma families and guide the search for risk modifiers in melanoma development.
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PMID:A locus linked to p16 modifies melanoma risk in Dutch familial atypical multiple mole melanoma (FAMMM) syndrome families. 1040 Sep 25

Cutaneous malignant melanoma (CMM) is an aggressive tumour with a high metastatic potential. Deletions of chromosome 9p have been detected in CMM, some of which involve the CDKN2A/p14ARF genes. Loss of heterozygosity (LOH) of 16 microsatellite markers on 9p and mutations in the CDKN2A/p14ARF genes had been previously studied in 32 melanoma patients by our group. 9p deletions were detected in 15 primary tumours (45.5%) and are here correlated with the clinical outcome over 5 years and compared with classical prognostic factors. Eight of the 32 patients developed metastases (25%). The metastases were all detected within 768 days of the initial diagnosis. The patients without metastases were last monitored at least 1621 days after diagnosis. None of the 21 patients with more than eight microsatellites conserved developed metastases, whereas all of the eight patients who developed metastases had eight or more markers deleted. The sensitivity of this analysis to predict metastases was 100% (specificity 84%), whereas the sensitivity for the same sample using a Breslow thickness > 3 mm was 62.5% (specificity 68%). LOH of eight or more of the 9p microsatellite markers is therefore a useful prognostic factor to predict the development of metastases in the first 4.4-6.3 years (1621-2294 days).
Melanoma Res 2000 Jun
PMID:Large deletions of chromosome 9p in cutaneous malignant melanoma identify patients with a high risk of developing metastases. Hospital Clinic Malignant Melanoma Group, University of Barcelona. 1089 Mar 76

Recent advancement in the research of malignant melanoma is reviewed. Among many gene alterations detected in human melanoma, defect of CDKN2A located at chromosome 9p21 seems to be most important in the earlier developmental phase, though significance of this gene in the evolution of melanoma in situ has not been confirmed yet. Deletions of PTEN/MMAC1 on 10q23.3 and AIM1 on 6q21 as well as mutations of ras gene are involved in the later progression stages of melanoma. Adhesion molecules relevant to development and progression of melanoma have been intensely investigated in recent years, revealing crucial roles of cadherins and alpha(v)beta(3) integrin in the biologic behaviors of melanoma cells. Melanoma is characterized by extremely high potential of developing metastases. Dynamic changes of matrix metalloproteinase activity during invasion and movement of melanoma cells may be a major concern in this field. Fragility of blood vessels in melanoma lesions is another important point related to hematogeneous metastases. Acral lentiginous melanoma is a unique subtype of melanoma, because, in contrast to other subtypes, ultraviolet irradiation is not a major factor in its development. Investigation of pathogenesis of acral lentiginous melanoma surely provides us with new information about mechanism of melanocyte transformation. Recent advances in the management of malignant melanoma are also briefly reviewed, such as biochemotherapy, immunotherapy, and gene therapy. Finally, the concept of molecular classification of melanoma by gene expression profile is introduced, which possibly enables us to give the tailor-made therapy for each melanoma patient in the near future.
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PMID:Recent advances in melanoma research. 1132 15

CDKN2A is thought to be the main candidate gene for melanoma susceptibility. Deletion or mutations in the CDKN2A gene may produce an imbalance between functional p16 and cyclin D, causing abnormal cell growth. We here describe a novel mutation consisting of a 1 bp deletion at nucleotide position 201 (codon 67) (CACGGcGCG) resulting in a truncated protein (stop codon 145). The patient, a female subject from a melanoma-prone family, presented at the age of 47 years with a superficial spreading melanoma of the trunk. Her father had colon cancer at the age of 43 years and melanoma at 63 years, her uncle suffered from gastric cancer, and her grandfather had laryngeal cancer.
Melanoma Res 2001 Oct
PMID:CDKN2A novel mutation in a patient from a melanoma-prone family. 1159 80

To date, two genes have been implicated in melanoma pathogenesis. The first, CDKN2A, is a tumour suppressor gene with germline mutations detected in 20% of melanoma-prone families. The second, CDK4, is an oncogene with co-segregating germline mutations detected in only three kindreds worldwide. We examined 16 American melanoma-prone families for mutations in all coding exons of CDK4 and screened additional members of two previously reported families with the Arg24Cys germline CDK4 mutation to evaluate the penetrance of the mutation. No new CDK4 mutations were identified. In the two Arg24Cys families, the penetrance was estimated to be 63%. Overall, 12 out of 12 invasive melanoma patients, none out of one in situ melanoma patient, five out of 13 dysplastic naevi patients, two out of 15 unaffected family members, and none out of 10 spouses carried the Arg24Cys mutation. Dysplastic naevi did not strongly co-segregate with the Arg24Cys mutation. Thus the phenotype observed in melanoma-prone CDK4 families appears to be more complex than just the CDK4 mutation. Both genetic and environmental factors are likely to contribute to the occurrence of melanoma and dysplastic naevi in these families. In summary, although CDK4 is a melanoma susceptibility gene, it plays a minor role in hereditary melanoma.
Melanoma Res 2002 Feb
PMID:Rarity of CDK4 germline mutations in familial melanoma. 1182 58

While mutations of CDKN2A are associated with melanoma predisposition, the precise role of its gene product p16 in the development of sporadic melanoma is less clearly understood. We sought to determine the prevalence of p16 expression using immunohistochemical analysis in a population-based sample of melanoma tumours, and also to identify histological, phenotypic and environmental factors associated with the presence or absence of p16 expression. We conducted face-to-face interviews with 108 patients newly diagnosed with melanoma to ascertain their history of sun exposure, and recorded various phenotypic parameters. Paraffin sections of tumours from these patients were stained with an anti-p16 monoclonal antibody following antigen retrieval. Overall, 52 (48%) tumours expressed p16; nodular melanomas had significantly lower levels of p16 immunoreactivity than superficial spreading melanomas (P = 0.015). While no association was found between p16 expression and host phenotype, loss of p16 staining was associated with thicker lesions (p = 0.084) and a high mitotic index (P = 0.013). Taken together, these findings are consistent with loss of p16 being a late event in the progression of sporadic primary melanomas, being associated with tumours of a more aggressive nature.
Melanoma Res 2002 Dec
PMID:Loss of p16 expression is associated with histological features of melanoma invasion. 1245 43


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