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- Newell, Felicity, et al.
(author)
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Whole-genome landscape of mucosal melanoma reveals diverse drivers and therapeutic targets
- 2019
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 10:1
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Journal article (peer-reviewed)abstract
- Knowledge of key drivers and therapeutic targets in mucosal melanoma is limited due to the paucity of comprehensive mutation data on this rare tumor type. To better understand the genomic landscape of mucosal melanoma, here we describe whole genome sequencing analysis of 67 tumors and validation of driver gene mutations by exome sequencing of 45 tumors. Tumors have a low point mutation burden and high numbers of structural variants, including recurrent structural rearrangements targeting TERT, CDK4 and MDM2. Significantly mutated genes are NRAS, BRAF, NF1, KIT, SF3B1, TP53, SPRED1, ATRX, HLA-A and CHD8. SF3B1 mutations occur more commonly in female genital and anorectal melanomas and CTNNB1 mutations implicate a role for WNT signaling defects in the genesis of some mucosal melanomas. TERT aberrations and ATRX mutations are associated with alterations in telomere length. Mutation profiles of the majority of mucosal melanomas suggest potential susceptibility to CDK4/6 and/or MEK inhibitors.
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2. |
- Isaksson, Karolin, et al.
(author)
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Sentinel lymph node biopsy in patients with thin melanomas : Frequency and predictors of metastasis based on analysis of two large international cohorts
- 2018
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In: Journal of Surgical Oncology. - : Wiley. - 0022-4790 .- 1096-9098. ; 118:4, s. 599-605
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Journal article (peer-reviewed)abstract
- Background: Sentinel lymph node (SLN) metastasis in patients with thin melanomas (≤1 mm) is uncommon but adverse prognostic factors may indicate an increased risk. We sought to determine how often SLN biopsy (SLNB) was performed in patients with thin melanomas, establish the frequency of SLN metastasis and evaluate the predictive value of ulceration, tumor mitotic rate, and thickness for SLN involvement. Methods: Melanoma patients with a Breslow thickness greater than or equal to 0.5 to less than or equal to 1 mm, diagnosed 2009-2016, were identified in the Swedish Melanoma Register (SMR) and the Melanoma Institute Australia (MIA) Database. Results: In total 8165 patients were included from the SMR and 1603 from MIA. SLNB was performed in 9.5% and 16.2% of patients, respectively. Corresponding figures for T1b (American Joint Committee on Cancer [AJCC] 7th Edition) were 19.5% and 24.6%. The SLN positivity rate were 4.4% (Sweden) and 5.8% (MIA). SLN metastasis was more frequent in tumors with ulceration, mitoses, and Breslow thickness greater than or equal to 0.9 mm but none were statistically significant. Younger age was identified as a significant risk factor for SLN positivity at MIA. Conclusions: A minority of patients with thin melanomas had SLNB performed and the SLN positivity rate was low. This study did not confirm tumor ulceration, mitoses, or thickness as statistically significant predictors for SLN metastasis.
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3. |
- van Kempen, Leon C. L., et al.
(author)
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The protein phosphatase 2A regulatory subunit PR70 is a gonosomal melanoma tumor suppressor gene
- 2016
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In: Science Translational Medicine. - : American Association for the Advancement of Science (AAAS). - 1946-6234 .- 1946-6242. ; 8:369
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Journal article (peer-reviewed)abstract
- Male gender is independently and significantly associated with poor prognosis in melanoma of all clinical stages. The biological underpinnings of this sex difference remain largely unknown, but we hypothesized that gene expression from gonosomes (sex chromosomes) might play an important role. We demonstrate that loss of the inactivated X chromosome in melanomas arising in females is strongly associated with poor distant metastasis-free survival, suggesting a dosage benefit from two X chromosomes. The gonosomal protein phosphatase 2 regulatory subunit B, beta (PPP2R3B) gene is located on the pseudoautosomal region (PAR) of the X chromosome in females and the Y chromosome in males. We observed that, despite its location on the PAR that predicts equal dosage across genders, PPP2R3B expression was lower in males than in females and was independently correlated with poor clinical outcome. PPP2R3B codes for the PR70 protein, a regulatory substrate-recognizing subunit of protein phosphatase 2A. PR70 decreased melanoma growth by negatively interfering with DNA replication and cell cycle progression through its role in stabilizing the cell division cycle 6 (CDC6)-chromatin licensing and DNA replication factor 1 (CDT1) interaction, which delays the firing of origins of DNA replication. Hence, PR70 functionally behaves as an X-linked tumor suppressor gene.
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