| 1. |
- Azimi, Alireza, et al.
(author)
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Targeting CDK2 overcomes melanoma resistance against BRAF and Hsp90 inhibitors
- 2018
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In: Molecular Systems Biology. - : EMBO. - 1744-4292. ; 14:3
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Journal article (peer-reviewed)abstract
- Novel therapies are undergoing clinical trials, for example, the Hsp90 inhibitor, XL888, in combination with BRAF inhibitors for the treatment of therapy-resistant melanomas. Unfortunately, our data show that this combination elicits a heterogeneous response in a panel of melanoma cell lines including PDX-derived models. We sought to understand the mechanisms underlying the differential responses and suggest a patient stratification strategy. Thermal proteome profiling (TPP) identified the protein targets of XL888 in a pair of sensitive and unresponsive cell lines. Unbiased proteomics and phosphoproteomics analyses identified CDK2 as a driver of resistance to both BRAF and Hsp90 inhibitors and its expression is regulated by the transcription factor MITF upon XL888 treatment. The CDK2 inhibitor, dinaciclib, attenuated resistance to both classes of inhibitors and combinations thereof. Notably, we found that MITF expression correlates with CDK2 upregulation in patients; thus, dinaciclib would warrant consideration for treatment of patients unresponsive to BRAF-MEK and/or Hsp90 inhibitors and/or harboring MITF amplification/overexpression.
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| 2. |
- Barrett, Jennifer H., et al.
(author)
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Genome-wide association study identifies three new melanoma susceptibility loci
- 2011
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In: Nature Genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 43:11, s. 1108-1113
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Journal article (peer-reviewed)abstract
- We report a genome-wide association study for melanoma that was conducted by the GenoMEL Consortium. Our discovery phase included 2,981 individuals with melanoma and 1,982 study-specific control individuals of European ancestry, as well as an additional 6,426 control subjects from French or British populations, all of whom were genotyped for 317,000 or 610,000 single-nucleotide polymorphisms (SNPs). Our analysis replicated previously known melanoma susceptibility loci. Seven new regions with at least one SNP with P < 10(-5) and further local imputed or genotyped support were selected for replication using two other genome-wide studies (from Australia and Texas, USA). Additional replication came from case-control series from the UK and The Netherlands. Variants at three of the seven loci replicated at P < 10(-3): an SNP in ATM (rs1801516, overall P = 3.4 x 10(-9)), an SNP in MX2 (rs45430, P = 2.9 x 10-9) and an SNP adjacent to CASP8 (rs13016963, P = 8.6 x 10(-10)). A fourth locus near CCND1 remains of potential interest, showing suggestive but inconclusive evidence of replication (rs1485993, overall P = 4.6 x 10(-7) under a fixed-effects model and P = 1.2 x 10(-3) under a random-effects model). These newly associated variants showed no association with nevus or pigmentation phenotypes in a large British case-control series.
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| 3. |
- Das, Ishani, et al.
(author)
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Inhibiting insulin and mTOR signaling by afatinib and crizotinib combination fosters broad cytotoxic effects in cutaneous malignant melanoma
- 2020
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In: Cell Death and Disease. - : Springer Nature. - 2041-4889. ; 11:10
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Journal article (peer-reviewed)abstract
- Current treatment modalities for disseminated cutaneous malignant melanoma (CMM) improve survival, however disease progression commonly ensues. In a previous study we identified afatinib and crizotinib in combination as a novel potential therapy for CMM independent of BRAF/NRAS mutation status. Herein, we elucidate the underlying mechanisms of the combination treatment effect to find biomarkers and novel targets for development of therapy that may provide clinical benefit by proteomic analysis of CMM cell lines and xenografts using mass spectrometry based analysis and reverse phase protein array. Identified candidates were validated using immunoblotting or immunofluorescence. Our analysis revealed that mTOR/Insulin signaling pathways were significantly decreased by the afatinib and crizotinib combination treatment. Both in vitro and in vivo analyses showed that the combination treatment downregulated pRPS6KB1 and pRPS6, downstream of mTOR signaling, and IRS-1 in the insulin signaling pathway, specifically ablating IRS-1 nuclear signal. Silencing of RPS6 and IRS-1 alone had a similar effect on cell death, which was further induced when IRS-1 and RPS6 were concomitantly silenced in the CMM cell lines. Silencing of IRS-1 and RPS6 resulted in reduced sensitivity towards combination treatment. Additionally, we found that IRS-1 and RPS6KB1 expression levels were increased in advanced stages of CMM clinical samples. We could demonstrate that induced resistance towards combination treatment was reversible by a drug holiday. CD171/L1CAM, mTOR and PI3K-p85 were induced in the combination resistant cells whereas AXL and EPHA2, previously identified mediators of resistance to MAPK inhibitor therapy in CMM were downregulated. We also found that CD171/L1CAM and mTOR were increased at progression in tumor biopsies from two matched cases of patients receiving targeted therapy with BRAFi. Overall, these findings provide insights into the molecular mechanisms behind the afatinib and crizotinib combination treatment effect and leverages a platform for discovering novel biomarkers and therapy regimes for CMM treatment.
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| 4. |
- Falkenius, Johan, et al.
(author)
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High expression of glycolytic and pigment proteins is associated with worse clinical outcome in stage III melanoma
- 2013
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In: Melanoma research. - 0960-8931 .- 1473-5636. ; 23:6, s. 452-460
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Journal article (peer-reviewed)abstract
- There are insufficient numbers of prognostic factors available for prediction of clinical outcome in patients with stage III malignant cutaneous melanoma, even when known adverse pathological risk factors, such as macrometastasis, number of lymph node metastases, and ulceration are taken into consideration. The aim of this study was therefore to identify additional prognostic factors to better predict patients with a high risk of relapse, thus enabling us to better determine the need for adjuvant treatment in stage III disease. An RNA oligonucleotide microarray study was performed on first regional lymph node metastases in 42 patients with stage III melanoma: 23 patients with short-term survival (13 months) and 19 with long-term survival (60 months), to identify genes associated with clinical outcome. Candidate genes were validated by real-time PCR and immunohistochemical analysis. Several gene ontology (GO) categories were highly significantly differentially expressed including glycolysis (GO: 0006096; P<0.001) and the pigment biosynthetic process (GO: 0046148; P<0.001), in which overexpression was associated with short-disease-specific survival. Three overexpressed glycolytic genes, GAPDHS, GAPDH, and PKM2, and two pigment-related genes, TYRP1 and OCA2, were selected for validation. A significant difference in GAPDHS protein expression between short- and long-term survivors (P=0.021) and a trend for PKM2 (P=0.093) was observed in univariate analysis. Positive expression of at least two of four proteins (GAPDHS, GAPDH, PKM2, TYRP1) in immunohistochemical analysis was found to be an independent adverse prognostic factor for disease-specific survival (P=0.011). Our results indicate that this prognostic panel in combination with established risk factors may contribute to an improved prediction of patients with a high risk of relapse.
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| 5. |
- Helgadottir, Hildur, et al.
(author)
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Cancer risks and survival in patients with multiple primary melanomas : Association with family history of melanoma and germline CDKN2A mutation status
- 2017
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In: Journal of the American Academy of Dermatology. - : Elsevier BV. - 0190-9622 .- 1097-6787. ; 77:5, s. 893-901
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Journal article (peer-reviewed)abstract
- Background Worse outcomes have been noted in patients with multiple primary melanomas (MPMs) than in patients with single primary melanomas. Objective We investigated how family history of melanoma and germline CDKN2A mutation status of MPM patients affects risks of developing subsequent melanomas and other cancers and survival outcomes. Methods Comprehensive data on cancer diagnoses and deaths of MPM patients, their first-degree relatives, and matched controls were obtained through Swedish national health care and population registries. Results Familial MPM cases with germline CDKN2A mutations were youngest at the diagnosis of their second melanoma (median age 42 years) and had among the MPM cohorts the highest relative risks (RR) compared to controls of developing >2 melanomas (RR 238.4, 95% CI 74.8-759.9). CDKN2A mutated MPM cases and their first-degree relatives were the only cohorts with increased risks of nonskin cancers compared to controls (RR 3.6, 95% CI 1.9-147.1 and RR 3.2, 95% CI 1.9-5.6, respectively). In addition, CDKN2A mutated MPM cases had worse survival compared with both cases with familial (HR 3.0, 95% CI 1.3-8.1) and sporadic wild-type MPM (HR 2.63, 95% CI 1.3-5.4). Limitations Our study examined outcomes in subgroups of MPM patients, which affected the sample size of the study groups. Conclusion This study demonstrates that CDKN2A mutation status and family history of melanoma significantly affects outcomes of MPM patients.
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| 6. |
- Helgadottir, Hildur, et al.
(author)
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CDKN2a mutation-negative melanoma families have increased risk exclusively for skin cancers but not for other malignancies.
- 2015
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In: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 137:9, s. 2220-2226
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Journal article (peer-reviewed)abstract
- Germline CDKN2A mutations are found in 5-20% of melanoma families. Numerous studies have shown that carriers of CDKN2A mutations have increased risks of non-melanoma cancers, but so far there have been no studies investigating cancer risks in CDKN2A wild type (wt) melanoma families. In this prospective cohort study, index melanoma cases (n = 224) and their first-degree relatives (n = 944) were identified from 154 confirmed CDKN2A wt melanoma families. Cancer diagnoses in family members and matched controls were obtained from the Swedish Cancer Registry. Relative risks (RR), odds ratios (OR) and two-sided 95% confidence intervals (95% CI) were calculated. In index cases and first-degree relatives, the prospective RR for melanoma was 56.9 (95% CI 31.4-102.1) and 7.0 (95% CI 4.2-11.4), respectively, and for squamous cell skin cancers 9.1 (95% CI 6.0-13.7) and 3.4 (95% CI 2.2-5.2), respectively. In neither group, elevated risks were seen for non-skin cancers. In a subgroup analysis, CDKN2A wt melanoma families with young (<40 years) melanoma cases were found to have increased risk of non-skin cancers (RR 1.5, 95% CI 1.0-1.5). Further, MC1R gene variants were increased in familial melanoma cases compared to controls (OR 2.4, 95% CI 1.6-3.4). Our findings suggest that in the majority of CDKN2A wt melanoma families, a segregation of variants in low-risk melanoma genes such as MC1R causes increased skin cancer susceptibility, rather than mutations in high-risk cancer predisposing genes, such mutations are more probable to be found in melanoma families with young melanoma cases. This study further supports an implication of CDKN2A mutation screening as a clinical test that determines counseling and follows up routines of melanoma families.
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| 7. |
- Helgadottir, Hildur, et al.
(author)
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Germline CDKN2A Mutation Status and Survival in Familial Melanoma Cases
- 2016
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In: Journal of the National Cancer Institute. - : Oxford University Press (OUP). - 1460-2105 .- 0027-8874. ; 108:11
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Journal article (peer-reviewed)abstract
- BACKGROUND: Germline mutations in CDKN2A have been associated with increased risk of melanoma and tobacco-related cancers in respiratory and upper digestive tissues. In CDKN2A wild-type (wt) melanoma families, other known high-risk, melanoma-predisposing mutations are rare, and no increased risk has been observed for nonskin cancers in this group. This study is the first to compare survival in germline CDKN2A mutated (mut) and nonmutated melanoma cases.METHODS: Melanoma-prone families participating in this study were identified through a nationwide predictive program starting in 1987. Information on cancer diagnoses (types, stages, and dates) and deaths (causes and dates) were obtained through the Swedish Cancer Registry and Cause of Death Registry. Kaplan Meier and Cox proportional hazards regression models were used to assess survival in CDKN2A(mut) (n = 96) and CDKN2A(wt) (n = 377) familial melanoma cases and in matched sporadic melanoma cases (n = 1042). All statistical tests were two-sided.RESULTS: When comparing CDKN2A(mut) and CDKN2A(wt) melanoma cases, after adjusting for age, sex, and T classification, CDKN2A(mut) had worse survival than melanoma (hazard ratio [HR] = 2.50, 95% confidence interval [CI] = 1.49 to 4.21) and than nonmelanoma cancers (HR = 7.77, 95% CI = 3.65 to 16.51). Compared with matched sporadic cases, CDKN2A(mut) cases had statistically significantly worse survival from both melanoma and nonmelanoma cancers while no differences in survival were seen in CDKN2A(wt) compared with sporadic cases.CONCLUSIONS: CDKN2A(mut) cases had statistically significantly worse survival than nonmelanoma cancers and, intriguingly, also from melanoma, compared with melanoma cases with no CDKN2A mutations. Further studies are required to elucidate possible mechanisms behind increased carcinogen susceptibility and the more aggressive melanoma phenotype in CDKN2A mutation carriers.
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| 8. |
- Helgadottir, Hildur, et al.
(author)
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High risk of tobacco-related cancers in CDKN2A mutation-positive melanoma families.
- 2014
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In: Journal of Medical Genetics. - : BMJ. - 0022-2593 .- 1468-6244. ; 51:8, s. 545-552
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Journal article (peer-reviewed)abstract
- Germline mutations in the tumour suppressor gene CDKN2A occur in 5-20% of familial melanoma cases. A single founder mutation, p.Arg112dup, accounts for the majority of CDKN2A mutations in Swedish carriers. In a national program, carriers of p.Arg112dup mutation have been identified. The aim of this study was to assess cancer risks in p.Arg112dup carriers and their first degree relatives (FDRs) and second degree relatives (SDRs).
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| 9. |
- Hoiom, Veronica, et al.
(author)
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MC1R variation and melanoma risk in the Swedish population in relation to clinical and pathological parameters
- 2009
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In: Pigment Cell & Melanoma Research. - 1755-148X .- 1755-1471. ; 22:2, s. 196-204
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Journal article (peer-reviewed)abstract
- The genetic background of cutaneous malignant melanoma (CMM) includes both germ line aberrations in high-penetrance genes, like CDKN2A, and allelic variation in low-penetrance genes like the melanocortin-1 receptor gene, MC1R. Red-hair colour associated MC1R alleles (RHC) have been associated with red hair, fair skin and risk of CMM. We investigated MC1R and CDKN2A variation in relation to phenotype, clinical factors and CMM risk in the Swedish population. The study cohort consisted of sporadic primary melanoma patients, familial melanoma patients and a control group. An allele-dose dependent increase in melanoma risk for carriers of variant MC1R alleles (after adjusting for phenotype), with an elevated risk among familial CMM patients, was observed. This elevated risk was found to be significantly associated with an increased frequency of dysplastic nevi (DN) among familial patients compared to sporadic patients. MC1R variation was found to be less frequent among acral lentiginous melanomas (ALM) and dependent on tumour localisation. No association was found between CDKN2A gene variants and general melanoma risk. Two new variants in the POMC gene were identified in red haired individuals without RHC alleles.
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| 10. |
- Höiom, Veronica, et al.
(author)
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Hereditary uveal melanoma : A report of a germline mutation in BAP1
- 2013
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In: Genes, Chromosomes and Cancer. - : Wiley. - 1045-2257 .- 1098-2264. ; 52:4, s. 378-384
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Journal article (peer-reviewed)abstract
- Melanoma of the eye is a rare and distinct subtype of melanoma, which only rarely are familial. However, cases of uveal melanoma (UM) have been found in families with mixed cancer syndromes. Here, we describe a comprehensive search for inherited genetic variation in a family with multiple cases of UM but no aggregation of other cancer diagnoses. The proband is a woman diagnosed with UM at 16 years who within 6 months developed liver metastases. We also identified two older paternal relatives of the proband who had died from UM. We performed exome sequencing of germline DNA from members of the affected family. Exome-wide analysis identified a novel loss-of-function mutation in the BAP1 gene, previously suggested as a tumor suppressor. The mutation segregated with the UM phenotype in this family, and we detected a loss of the wild-type allele in the UM tumor of the proband, strongly supporting a causative association with UM. Screening of BAP1 germline mutations in families predisposed for UM may be used to identify individuals at increased risk of disease. Such individuals may then be enrolled in preventive programs and regular screenings to facilitate early detection and thereby improve prognosis.
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