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Sarcomas are rare mesenchymal malignancies whose pathogenesis is poorly understood; both environmental and genetic risk factors could contribute to their aetiology.We performed whole-exome sequencing (WES) in a familial aggregation of three individuals affected with soft-tissue sarcoma (STS) without TP53 mutation (Li-Fraumeni-like, LFL) and found a shared pathogenic mutation inGermline mutations in

Tumors often display unrestricted cell cycling attributable to a dysfunctional G(1)-S checkpoint. One of the mechanisms leading to such a defect is the inactivation of the cyclin-dependent kinase inhibitor p16(INK4a). Although inactivation of p16(INK4a) is observed in a wide range of tumors, including cutaneous melanoma, genetic alteration of p16(INK4a) is reportedly uncommon in uveal melanoma. Here we show that the p16(INK4a) promoter is hypermethylated in 6 of 12 uveal melanoma cell lines and in 7 of 22 primary uveal melanomas analyzed. Five of seven patients with a methylated primary tumor died of metastatic disease compared with 2 of 15 patients with a nonmethylated primary tumor. We also show that all uveal melanoma cell lines with a hypermethylated p16(INK4a) promoter have lost p16(INK4a) expression but have maintained the expression of p14(ARF). Treatment of uveal melanoma cell lines with 5-aza-2'-deoxycytidine results in demethylation of p16(INK4a) and in reexpression of p16(INK4a) mRNA, which is maintained upon withdrawal of the 5-aza-2'-deoxycytidine. In conclusion, p16(INK4a) promoter methylation appears to be a common event in uveal melanoma and is accompanied by the loss of p16(INK4a) expression.

Familial atypical multiple mole-melanoma (FAMMM) syndrome is characterized by the familial occurrence of malignant melanoma of the skin in combination with multiple atypical precursor naevi. In the present study we performed linkage analysis in seven Dutch FAMMM families to define the relationship between the ultimate phenotype melanoma and the postulated precursors, atypical (dysplastic) naevi. Various models were defined, varying from melanoma only to various combinations of melanoma and atypical naevi, reflecting the FAMMM phenotype. Using 124 microsatellite markers spread across all autosomes, hints for linkage were obtained between several chromosome 9p markers and a melanoma locus (D9S171; odds for linkage, 275:1). In a model including melanoma and a florid manifestation of atypical naevi a considerably higher lod score was obtained with D9S171 (odds for linkage, 4365:1); models including milder manifestations yielded less support. We conclude that, also in the Dutch FAMMM families, a melanoma gene is located on the short arm of chromosome 9 and that multiple atypical naevi, at least in certain cases, seems to be a component of the FAMMM phenotype.