1. |
- Artomov, Mykyta, et al.
(författare)
-
Rare variant, gene-based association study of hereditary melanoma using whole-exome sequencing
- 2017
-
Ingår i: Journal of the National Cancer Institute. - : Oxford University Press (OUP). - 0027-8874 .- 1460-2105. ; 109:12
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Extraordinary progress has been made in our understanding of common variants in many diseases, including melanoma. Because the contribution of rare coding variants is not as well characterized, we performed an exome-wide, gene-based association study of familial cutaneous melanoma (CM) and ocular melanoma (OM). Methods: Using 11 990 jointly processed individual DNA samples, whole-exome sequencing was performed, followed by largescale joint variant calling using GATK (Genome Analysis ToolKit). PLINK/SEQ was used for statistical analysis of genetic variation. Fourmodels were used to estimate the association among different types of variants. In vitro functional validation was performed using three humanmelanoma cell lines in 2D and 3D proliferation assays. In vivo tumor growth was assessed using xenografts of humanmelanoma A375melanoma cells in nudemice (eightmice per group). All statistical tests were two-sided. Results: Strong signals were detected for CDKN2A (Pmin = 6.16×10-8) in the CM cohort (n=273) and BAP1 (Pmin = 3.83×10-6) in the OM (n=99) cohort. Eleven genes that exhibited borderline association (P < 10-4) were independently validated using The Cancer Genome Atlas melanoma cohort (379 CM, 47 OM) and a matched set of 3563 European controls with CDKN2A (P = .009), BAP1 (P = .03), and EBF3 (P = 4.75×10-4), a candidate risk locus, all showing evidence of replication. EBF3 was then evaluated using germline data from a set of 132 familial melanoma cases and 4769 controls of UK origin (joint P = 1.37×10-5). Somatically, loss of EBF3 expression correlated with progression, poorer outcome, and high MITF tumors. Functionally, induction of EBF3 in melanoma cells reduced cell growth in vitro, retarded tumor formation in vivo, and reduced MITF levels. Conclusions: The results of this large rare variant germline association study further define the mutational landscape of hereditary melanoma and implicate EBF3 as a possible CM predisposition gene.
|
|
2. |
- Cirenajwis, Helena, et al.
(författare)
-
Molecular stratification of metastatic melanoma using gene expression profiling: prediction of survival outcome and benefit from molecular targeted therapy.
- 2015
-
Ingår i: Oncotarget. - : Impact Journals, LLC. - 1949-2553. ; 6:14, s. 12297-12309
-
Tidskriftsartikel (refereegranskat)abstract
- Melanoma is currently divided on a genetic level according to mutational status. However, this classification does not optimally predict prognosis. In prior studies, we have defined gene expression phenotypes (high-immune, pigmentation, proliferative and normal-like), which are predictive of survival outcome as well as informative of biology. Herein, we employed a population-based metastatic melanoma cohort and external cohorts to determine the prognostic and predictive significance of the gene expression phenotypes. We performed expression profiling on 214 cutaneous melanoma tumors and found an increased risk of developing distant metastases in the pigmentation (HR, 1.9; 95% CI, 1.05-3.28; P=0.03) and proliferative (HR, 2.8; 95% CI, 1.43-5.57; P=0.003) groups as compared to the high-immune response group. Further genetic characterization of melanomas using targeted deep-sequencing revealed similar mutational patterns across these phenotypes. We also used publicly available expression profiling data from melanoma patients treated with targeted or vaccine therapy in order to determine if our signatures predicted therapeutic response. In patients receiving targeted therapy, melanomas resistant to targeted therapy were enriched in the MITF-low proliferative subtype as compared to pre-treatment biopsies (P=0.02). In summary, the melanoma gene expression phenotypes are highly predictive of survival outcome and can further help to discriminate patients responding to targeted therapy.
|
|
3. |
- Goldstein, Alisa M, et al.
(författare)
-
Features associated with germline CDKN2A mutations: a GenoMEL study of melanoma-prone families from three continents
- 2007
-
Ingår i: Journal of Medical Genetics. - : BMJ. - 0022-2593 .- 1468-6244. ; 44:2, s. 99-106
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The major factors individually reported to be associated with an increased frequency of CDKN2A mutations are increased number of patients with melanoma in a family, early age at melanoma diagnosis, and family members with multiple primary melanomas (MPM) or pancreatic cancer. METHODS: These four features were examined in 385 families with > or =3 patients with melanoma pooled by 17 GenoMEL groups, and these attributes were compared across continents. RESULTS: Overall, 39% of families had CDKN2A mutations ranging from 20% (32/162) in Australia to 45% (29/65) in North America to 57% (89/157) in Europe. All four features in each group, except pancreatic cancer in Australia (p = 0.38), individually showed significant associations with CDKN2A mutations, but the effects varied widely across continents. Multivariate examination also showed different predictors of mutation risk across continents. In Australian families, > or =2 patients with MPM, median age at melanoma diagnosis < or =40 years and > or =6 patients with melanoma in a family jointly predicted the mutation risk. In European families, all four factors concurrently predicted the risk, but with less stringent criteria than in Australia. In North American families, only > or =1 patient with MPM and age at diagnosis < or =40 years simultaneously predicted the mutation risk. CONCLUSIONS: The variation in CDKN2A mutations for the four features across continents is consistent with the lower melanoma incidence rates in Europe and higher rates of sporadic melanoma in Australia. The lack of a pancreatic cancer-CDKN2A mutation relationship in Australia probably reflects the divergent spectrum of mutations in families from Australia versus those from North America and Europe. GenoMEL is exploring candidate host, genetic and/or environmental risk factors to better understand the variation observed.
|
|
4. |
- Goldstein, Alisa M., et al.
(författare)
-
High-risk melanoma susceptibility genes and pancreatic cancer, neural system tumors, and uveal melanoma across GenoMEL
- 2006
-
Ingår i: Cancer Research. - 1538-7445 .- 0008-5472. ; 66:20, s. 9818-9828
-
Tidskriftsartikel (refereegranskat)abstract
- GenoMEL, comprising major familial melanoma research groups from North America, Europe, Asia, and Australia has created the largest familial melanoma sample yet available to characterize mutations in the high-risk melanoma susceptibility genes CDKN2A/alternate reading frames (ARF), which encodes p16 and p14ARF, and CDK4 and to evaluate their relationship with pancreatic cancer (PC), neural system tumors (NST), and uveal melanoma (UM). This study included 466 families (2,137 patients) with at least three melanoma patients from 17 GenoMEL centers. Overall, 41% (n = 190) of families had mutations; most involved p16 (n = 178). Mutations in CDK4 (n = 5) and ARF (n = 7) occurred at similar frequencies (2-3%). There were striking differences in mutations across geographic locales. The proportion of families with the most frequent founder mutation(s) of each locale differed significantly across the seven regions (P = 0.0009). Single founder CDKN2A mutations were predominant in Sweden (p.R112_L113insR, 92% of family's mutations) and the Netherlands (c.225_243del19, 90% of family's mutations). France, Spain, and Italy had the same most frequent mutation (p.G101W). Similarly, Australia and United Kingdom had the same most common mutations (p.M53I, cdVS2-105A > G, p.R24P, and p.L32P). As reported previously, there was a strong association between PC and CDKN2A mutations (P < 0.0001). This relationship differed by mutation. In contrast, there was little evidence for an association between CDKN2A mutations and NST (P = 0.52) or UM (P = 0.25). There was a marginally significant association between NST and ARF (P = 0.05). However, this particular evaluation had low power and requires confirmation. This GenoMEL study provides the most extensive characterization of mutations in high-risk melanoma susceptibility genes in families with three or more melanoma patients yet available.
|
|
5. |
- Harbst, Katja, et al.
(författare)
-
Molecular profiling reveals low- and high-grade forms of primary melanoma.
- 2012
-
Ingår i: Clinical cancer research : an official journal of the American Association for Cancer Research. - 1557-3265. ; 18:15, s. 4026-4036
-
Tidskriftsartikel (refereegranskat)abstract
- For primary melanomas, tumor thickness, mitotic rate, and ulceration are well-laid cornerstones of prognostication. However, a molecular exposition of melanoma aggressiveness is critically missing. We recently uncovered a four-class structure in metastatic melanoma, which predicts outcome and informs biology. This raises the possibility that a molecular structure exists even in the early stages of melanoma and that molecular determinants could underlie histophenotype and eventual patient outcome.We subjected 223 archival primary melanomas to a horizontally integrated analysis of RNA expression, oncogenic mutations at 238 lesions, histomorphometry, and survival data.Our previously described four-class structure that was elucidated in metastatic lesions was evident within the expression space of primary melanomas. Because these subclasses converged into two larger prognostic and phenotypic groups, we used the metastatic lesions to develop a binary subtype-based signature capable of distinguishing between "high" and "low" grade forms of the disease. The two-grade signature was subsequently applied to the primary melanomas. Compared with low-grade tumors, high-grade primary melanomas were significantly associated with increased tumor thickness, mitotic rate, ulceration (all P < 0.01), and poorer relapse-free (HR = 4.94; 95% CI, 2.84-8.59), and overall (HR = 3.66; 95% CI, 2.40-5.58) survival. High-grade melanomas exhibited elevated levels of proliferation and BRCA1/DNA damage signaling genes, whereas low-grade lesions harbored higher expression of immune genes. Importantly, the molecular-grade signature was validated in two external gene expression data sets.We provide evidence for a molecular organization within melanomas, which is preserved across all stages of disease.
|
|
6. |
- Ho, Allen, et al.
(författare)
-
Melanoma genetics and genomics
- 2017
-
Ingår i: Melanoma Development : Molecular Biology, Genetics and Clinical Application - Molecular Biology, Genetics and Clinical Application. - Cham : Springer International Publishing. - 9783319413198 - 9783319413174 ; , s. 63-93
-
Bokkapitel (refereegranskat)abstract
- Recent work has expanded our knowledge in somatic genetic events related to melanoma progression. It has become increasingly clear that multiple genetic events are required for melanoma to develop and that melanoma is a vastly heterogeneous disease. Signaling pathways that are essential for tumor progression have been pinpointed due to recent technological developments, which has led to the vigorous pursuit of small molecule kinase inhibitors and the eventual FDA approval of novel MAPK pathway inhibitors for the treatment of advanced melanoma (see Chaps. 7 and 16). As has been implicated in many other malignancies, molecular profiling is further anticipated to reveal prognostic, diagnostic, and predictive tools in the clinical setting of melanoma.Additionally, tumor genetic data have been interconnected with epidemiology of melanoma (see Chap. 3). Two etiological pathways have been postulated to trigger the formation of melanoma. The first pathway involves relatively young individuals with large numbers of nevi and who develop melanomas on locations (e.g., trunk) that are intermittently UV exposed. This pathway is further corroborated by the fact that BRAF mutations, which frequently occur in nevi, are also more common in melanomas of younger patients with larger number of moles. A second pathway, which is probably related to chronic UV exposure, leads to melanomas that develop among older individuals and on chronically sun-exposed sites. Additionally, genetic analyses have uncovered a previously undisclosed hidden molecular structure between subtypes of melanoma. Along translational lines, tumor genetic information has recently shown to be of enormous significance for personalizing therapeutic choice, e.g., Braf inhibitors that selectively target BrafV600E mutated melanomas and Mek inhibitors that target the MAPK pathway in metastatic melanoma; thus tumor genetic information is required prior to treatment. Moreover, molecular studies have also begun to shed light onto mechanisms of resistance that develop in the context of treatment with Braf and/or Mek inhibitors. In this chapter, we have screened current literature for an update of genetics and genomics within the field of melanoma tumor biology.
|
|
7. |
- Ji, Zhenyu, et al.
(författare)
-
MITF Modulates Therapeutic Resistance through EGFR Signaling.
- 2015
-
Ingår i: Journal of Investigative Dermatology. - : Elsevier BV. - 1523-1747 .- 0022-202X. ; 135:7, s. 1863-1872
-
Tidskriftsartikel (refereegranskat)abstract
- Response to targeted therapies varies significantly despite shared oncogenic mutations. Nowhere is this more apparent than in BRAF(V600E)-mutated melanomas where initial drug response can be striking and yet relapse is commonplace. Resistance to BRAF inhibitors have been attributed to the activation of various receptor tyrosine kinases (RTKs) though the underlying mechanisms have been largely uncharacterized. Here, we found that EGFR induced vemurafenib resistance is ligand dependent. We then employed whole-genome expression analysis and discovererd that vemurafenib resistance correlated with the loss of MITF, along with its melanocyte lineage program, and with the activation of EGFR signaling. An inverse relationship between MITF, vemurafenib resistance and EGFR was then observed in patient samples of recurrent melanoma and was conserved across melanoma cell lines and patients' tumor specimens. Functional studies revealed that MITF depletion activated EGFR signaling and consequently recapitulated the resistance phenotype. In contrast, forced expression of MITF in melanoma and colon cancer cells inhibited EGFR and conferred sensitivity to BRAF/MEK inhibitors. These findings indicate that an "autocrine drug resistance loop" is suppressed by melanocyte lineage signal(s), such as MITF. This resistance loop modulates drug response and could explain the unique sensitivity of melanomas to BRAF inhibition.Journal of Investigative Dermatology accepted article preview online, 19 March 2015. doi:10.1038/jid.2015.105.
|
|
8. |
- Ji, Zhenyu, et al.
(författare)
-
Vemurafenib Synergizes with Nutlin-3 to Deplete Survivin and Suppresses Melanoma Viability and Tumor Growth
- 2013
-
Ingår i: Clinical Cancer Research. - 1078-0432. ; 19:16, s. 4383-4391
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: For patients with advanced melanoma, primary and secondary resistance to selective BRAF inhibition remains one of the most critically compelling challenges. One rationale argues that novel biologically informed strategies are needed to maximally cripple melanoma cells up front before compensatory mechanisms emerge. As p53 is uncommonly mutated in melanoma, restoration of its function represents an attractive adjunct to selective BRAF inhibition. Experimental Design: Thirty-seven BRAF(V600E)-mutated melanoma lines were subjected to synergy studies in vitro using a combination of vemurafenib and nutlin-3 (Nt-3). In addition, cellular responses and in vivo efficacy were also determined. We also analyzed changes in the levels of canonical apoptotic/survival factors in response to vemurafenib. Results: Dual targeting of BRAF(V600E) and Hdm2 with vemurafenib and Nt-3, respectively, synergistically induced apoptosis and suppressed melanoma viability in vitro and tumor growth in vivo. Suppression of p53 in melanoma cells abrogated Nt-3's effects fully and vemurafenib's effects partially. A survey of canonical survival factors revealed that both vemurafenib and Nt-3 independently attenuated levels of the antiapoptotic protein, survivin. Genetic depletion of survivin reproduces the cytotoxic effects of the combination strategy. Conclusion: These results show preclinical feasibility for overcoming primary vemurafenib resistance by restoring p53 function. Moreover, it identifies survivin as one downstream mediator of the observed synergism and a potential secondary target. (C)2013 AACR.
|
|
9. |
- Kumar, Raj, et al.
(författare)
-
BAP1 Plays a Survival Role in Cutaneous Melanoma.
- 2015
-
Ingår i: Journal of Investigative Dermatology. - : Elsevier BV. - 1523-1747 .- 0022-202X. ; 135:4, s. 1089-1097
-
Tidskriftsartikel (refereegranskat)abstract
- Although the pattern of BAP1 inactivation in ocular melanoma specimens and in the BAP1 cutaneous/ocular melanoma (CM/OM) predisposition syndrome suggests a tumor suppressor function, the specific role of this gene in the pathogenesis of cutaneous melanoma is not fully understood. We thus set out to characterize BAP1 in cutaneous melanoma and discovered an unexpected pro-survival effect of this protein. Tissue and cell lines analysis showed that BAP1 expression was maintained, rather than lost, in primary melanomas compared to nevi and normal skin. Genetic depletion of BAP1 in melanoma cells reduced proliferation and colony forming capability, induced apoptosis and inhibited melanoma tumor growth in vivo. On the molecular level, suppression of BAP1 led to a concomitant drop in the protein levels of survivin a member of anti-apoptotic proteins and a known mediator of melanoma survival. Restoration of survivin in melanoma cells partially rescued the growth-retarding effects of BAP1 loss. In contrast to melanoma cells, stable overexpression of BAP1 into immortalized but non-transformed melanocytes did suppress proliferation and reduce survivin. Taken together, these studies demonstrate that BAP1 may play a growth-sustaining role in melanoma cells, but that its impact on ubiquitination underpins a complex physiology which is context and cell dependent.Journal of Investigative Dermatology accepted article preview online, 18 December 2014. doi:10.1038/jid.2014.528.
|
|
10. |
- Leachman, Sancy A., et al.
(författare)
-
Selection criteria for genetic assessment of patients with familial melanoma
- 2009
-
Ingår i: Journal of American Academy of Dermatology. - : Elsevier BV. - 0190-9622. ; 61:4, s. 677-684
-
Forskningsöversikt (refereegranskat)abstract
- Approximately 5% to 10% of melanoma may be hereditary in nature, and about 2% of melanoma can be specifically attributed to pathogenic germline mutations in cyclin-dependent kinase inhibitor 2A (CDKN2A). To appropriately identify the small proportion of patients Who benefit most from referral to a genetics specialist for consideration of genetic testing for CDKN2A, We have reviewed available published studies of CDKN2A mutation analysis in cohorts with invasive, cutaneous melanoma and found variability in the rate of CDKN2A mutations based on geography, ethnicity, and the type of study and eligibility criteria used. Except in regions of high melanoma incidence, such as Australia, we found higher rates of CDKN2A positivity in individuals with 3 or more primary invasive melanomas and/or families with at least one invasive melanoma and two or more other diagnoses of invasive melanoma and/or pancreatic cancer among first- or second-degree relatives on the same side of the family. The Work summarized in this review should help identify individuals who are appropriate candidates for referral for genetic consultation and possible testing. (J Am Acad Dermatol 2009;61:677-84.)
|
|