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ABSTRACT: In a seminal study by Harbour and colleagues somatic mutations of BAP1 (BRCA-1 associated protein 1) were found to occur in 84% of metastasizing uveal melanomas (Harbour et al., 2010). Additionally, this study reported one germline mutation. Subsequent studies have shown that germline mutations of BAP1 predispose to uveal and cutaneous melanoma as well as mesothelioma and a range of other tumour types (Abdel-Rahman et al., 2011; Testa et al., 2011; Wadt et al., 2012). To date there have been no studies assessing the contribution of BAP1 mutation to a population-based sample of uveal melanoma (UMM) cases, although Tsao and co-workers have shown that BAP1 contributes to a small proportion of selected UMM cases from a clinic-based sample (Njauw et al., 2012). Here, we sought to determine the prevalence of germline BAP1 mutations in a population-based sample of Australian UMM cases to gain a better understanding of the relative contribution of BAP1 mutation to UMM susceptibility. © 2012 John Wiley & Sons A/S.
Pigment Cell & Melanoma Research 11/2012; · 5.06 Impact Factor
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ABSTRACT: In a seminal study by Harbour and colleagues somatic mutations of BAP1 (BRCA-1 associated protein 1) were found to occur in 84% of metastasizing uveal melanomas (Harbour et al., 2010). Additionally, this study reported one germline mutation. Subsequent studies have shown that germline mutations of BAP1 predispose to uveal and cutaneous melanoma as well as mesothelioma and a range of other tumour types (Abdel-Rahman et al., 2011; Testa et al., 2011; Wadt et al., 2012). To date there have been no studies assessing the contribution of BAP1 mutation to a population-based sample of uveal melanoma (UMM) cases, although Tsao and co-workers have shown that BAP1 contributes to a small proportion of selected UMM cases from a clinic-based sample (Njauw et al., 2012). Here, we sought to determine the prevalence of germline BAP1 mutations in a population-based sample of Australian UMM cases to gain a better understanding of the relative contribution of BAP1 mutation to UMM susceptibility. © 2012 John Wiley & Sons A/S.
Pigment Cell & Melanoma Research 11/2012; · 5.06 Impact Factor
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Ken Dutton-Regester, Lauren G Aoude,
Derek J Nancarrow,
Mitchell S Stark,
Linda O'Connor,
Cathy Lanagan,
Gulietta M Pupo,
Varsha Tembe,
Candace D Carter,
Michael O'Rourke,
Richard A Scolyer,
Graham J Mann,
Christopher W Schmidt,
Adrian Herington,
Nicholas K Hayward
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ABSTRACT: High density SNP arrays can be used to identify DNA copy number changes in tumors such as homozygous deletions of tumor suppressor genes and focal amplifications of oncogenes. Illumina Human CNV370 Bead chip arrays were used to assess the genome for unbalanced chromosomal events occurring in 39 cell lines derived from stage III metastatic melanomas. A number of genes previously recognized to have an important role in the development and progression of melanoma were identified including homozygous deletions of CDKN2A (13 of 39 samples), CDKN2B (10 of 39), PTEN (3 of 39), PTPRD (3 of 39), TP53 (1 of 39), and amplifications of CCND1 (2 of 39), MITF (2 of 39), MDM2 (1 of 39), and NRAS (1 of 39). In addition, a number of focal homozygous deletions potentially targeting novel melanoma tumor suppressor genes were identified. Because of their likely functional significance for melanoma progression, FAS, CH25H, BMPR1A, ACTA2, and TFG were investigated in a larger cohort of melanomas through sequencing. Nonsynonymous mutations were identified in BMPR1A (1 of 43), ACTA2 (3 of 43), and TFG (5 of 103). A number of potentially important mutation events occurred in TFG including the identification of a mini mutation "hotspot" at amino acid residue 380 (P380S and P380L) and the presence of multiple mutations in two melanomas. Mutations in TFG may have important clinical relevance for current therapeutic strategies to treat metastatic melanoma.
Genes Chromosomes and Cancer 05/2012; 51(5):452-61. · 3.31 Impact Factor
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Mitchell S Stark,
Susan L Woods,
Michael G Gartside,
Vanessa F Bonazzi,
Ken Dutton-Regester, Lauren G Aoude,
Donald Chow,
Chris Sereduk,
Natalie M Niemi,
Nanyun Tang, [......],
Bradford R Brooks,
Catherine Lanagan,
Christopher W Schmidt,
Bostjan Kobe,
Jeffrey P MacKeigan,
Hongwei Yin,
Kevin M Brown,
Richard Gibbs,
Jeffrey Trent,
Nicholas K Hayward
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ABSTRACT: We sequenced eight melanoma exomes to identify new somatic mutations in metastatic melanoma. Focusing on the mitogen-activated protein (MAP) kinase kinase kinase (MAP3K) family, we found that 24% of melanoma cell lines have mutations in the protein-coding regions of either MAP3K5 or MAP3K9. Structural modeling predicted that mutations in the kinase domain may affect the activity and regulation of these protein kinases. The position of the mutations and the loss of heterozygosity of MAP3K5 and MAP3K9 in 85% and 67% of melanoma samples, respectively, together suggest that the mutations are likely to be inactivating. In in vitro kinase assays, MAP3K5 I780F and MAP3K9 W333* variants had reduced kinase activity. Overexpression of MAP3K5 or MAP3K9 mutants in HEK293T cells reduced the phosphorylation of downstream MAP kinases. Attenuation of MAP3K9 function in melanoma cells using siRNA led to increased cell viability after temozolomide treatment, suggesting that decreased MAP3K pathway activity can lead to chemoresistance in melanoma.
Nature Genetics 12/2011; 44(2):165-9. · 35.53 Impact Factor
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Satoru Yokoyama,
Susan L Woods,
Glen M Boyle, Lauren G Aoude,
Stuart MacGregor,
Victoria Zismann,
Michael Gartside,
Anne E Cust,
Rizwan Haq,
Mark Harland, [......],
Julia A Newton-Bishop,
Grant W Montgomery,
Nicholas G Martin,
Graham J Mann,
D Timothy Bishop,
Hensin Tsao,
Jeffrey M Trent,
David E Fisher,
Nicholas K Hayward,
Kevin M Brown
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ABSTRACT: So far, two genes associated with familial melanoma have been identified, accounting for a minority of genetic risk in families. Mutations in CDKN2A account for approximately 40% of familial cases, and predisposing mutations in CDK4 have been reported in a very small number of melanoma kindreds. Here we report the whole-genome sequencing of probands from several melanoma families, which we performed in order to identify other genes associated with familial melanoma. We identify one individual carrying a novel germline variant (coding DNA sequence c.G1075A; protein sequence p.E318K; rs149617956) in the melanoma-lineage-specific oncogene microphthalmia-associated transcription factor (MITF). Although the variant co-segregated with melanoma in some but not all cases in the family, linkage analysis of 31 families subsequently identified to carry the variant generated a log of odds (lod) score of 2.7 under a dominant model, indicating E318K as a possible intermediate risk variant. Consistent with this, the E318K variant was significantly associated with melanoma in a large Australian case-control sample. Likewise, it was similarly associated in an independent case-control sample from the United Kingdom. In the Australian sample, the variant allele was significantly over-represented in cases with a family history of melanoma, multiple primary melanomas, or both. The variant allele was also associated with increased naevus count and non-blue eye colour. Functional analysis of E318K showed that MITF encoded by the variant allele had impaired sumoylation and differentially regulated several MITF targets. These data indicate that MITF is a melanoma-predisposition gene and highlight the utility of whole-genome sequencing to identify novel rare variants associated with disease susceptibility.
Nature 11/2011; 480(7375):99-103. · 36.28 Impact Factor
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ABSTRACT: To identify microRNAs potentially involved in melanomagenesis, we compared microRNA expression profiles between melanoma cell lines and cultured melanocytes. The most differentially expressed microRNA between the normal and tumor cell lines was miR-211. We focused on this pigment-cell-enriched miRNA as it is derived from the microphthalmia-associated transcription factor (MITF)-regulated gene, TRPM1 (melastatin). We find that miR-211 expression is greatly decreased in melanoma cells and melanoblasts compared to melanocytes. Bioinformatic analysis identified a large number of potential targets of miR-211, including POU3F2 (BRN2). Inhibition of miR-211 in normal melanocytes resulted in increased BRN2 protein, indicating that endogenous miR-211 represses BRN2 in differentiated cells. Over-expression of miR-211 in melanoma cell lines changed the invasive potential of the cells in vitro through directly targeting BRN2 translation. We propose a model for the apparent non-overlapping expression levels of BRN2 and MITF in melanoma, mediated by miR-211 expression.
Pigment Cell & Melanoma Research 03/2011; 24(3):525-37. · 5.06 Impact Factor
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ABSTRACT: Epigenetic regulation of tumor suppressor genes (TSGs) has been shown to play a central role in melanomagenesis. By integrating gene expression and methylation array analysis we identified novel candidate genes frequently methylated in melanoma. We validated the methylation status of the most promising genes using highly sensitive Sequenom Epityper assays in a large panel of melanoma cell lines and resected melanomas, and compared the findings with those from cultured melanocytes. We found transcript levels of UCHL1, COL1A2, THBS1 and TNFRSF10D were inversely correlated with promoter methylation. For THBS1 and UCHL1 the effect of this methylation on expression was confirmed at the protein level. Identification of these candidate TSGs and future research designed to understand how their silencing is related to melanoma development will increase our understanding of the etiology of this cancer and may provide tools for its early diagnosis.
PLoS ONE 01/2011; 6(10):e26121. · 4.09 Impact Factor
