| 1. |
- Åkerström, Tobias, et al.
(författare)
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Comprehensive Re-Sequencing of Adrenal Aldosterone Producing Lesions Reveal Three Somatic Mutations near the KCNJ5 Potassium Channel Selectivity Filter.
- 2012
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Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 7:7
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Tidskriftsartikel (refereegranskat)abstract
- Aldosterone producing lesions are a common cause of hypertension, but genetic alterations for tumorigenesis have been unclear. Recently, either of two recurrent somatic missense mutations (G151R or L168R) was found in the potassium channel KCNJ5 gene in aldosterone producing adenomas. These mutations alter the channel selectivity filter and result in Na(+) conductance and cell depolarization, stimulating aldosterone production and cell proliferation. Because a similar mutation occurs in a Mendelian form of primary aldosteronism, these mutations appear to be sufficient for cell proliferation and aldosterone production. The prevalence and spectrum of KCNJ5 mutations in different entities of adrenocortical lesions remain to be defined.
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| 2. |
- Cromer, M. Kyle, et al.
(författare)
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Identification of Somatic Mutations in Parathyroid Tumors Using Whole-Exome Sequencing
- 2012
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 97:9, s. E1774-E1781
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Tidskriftsartikel (refereegranskat)abstract
- Context: The underlying molecular alterations causing sporadic parathyroid adenomas that drive primary hyperparathyroidism have not been thoroughly defined.Objective: The aim of the study was to investigate the occurrence of somatic mutations driving tumor formation and progression in sporadic parathyroid adenoma using whole-exome sequencing.Design: Eight matched tumor-constitutional DNA pairs from patients with sporadic parathyroid adenomas underwent whole-exome capture and high-throughput sequencing. Selected genes were analyzed for mutations in an additional 185 parathyroid adenomas.Results: Four of eight tumors displayed a frame shift deletion or nonsense mutation in MEN1, which was accompanied by loss of heterozygosity of the remaining wild-type allele. No other mutated genes were shared among the eight tumors. One tumor harbored a Y641N mutation of the histone methyltransferase EZH2 gene, previously linked to myeloid and lymphoid malignancy formation. Targeted sequencing in the additional 185 parathyroid adenomas revealed a high rate of MEN1 mutations (35%). Furthermore, this targeted sequencing identified an additional parathyroid adenoma that contained the identical, somatic EZH2 mutation that was found by exome sequencing.Conclusion: This study confirms the frequent role of the loss of heterozygosity of chromosome 11 and MEN1 gene alterations in sporadic parathyroid adenomas and implicates a previously unassociated methyltransferase gene, EZH2, in endocrine tumorigenesis.
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| 3. |
- Fonseca, Annabelle L, et al.
(författare)
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Comprehensive DNA methylation analysis of benign and malignant adrenocortical tumors
- 2012
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Ingår i: Genes, Chromosomes and Cancer. - : Wiley-Blackwell. - 1045-2257 .- 1098-2264. ; 51:10, s. 949-960
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Tidskriftsartikel (refereegranskat)abstract
- The molecular pathogenesis of benign and malignant adrenocortical tumors (ACT) is incompletely clarified. The role of DNA methylation in adrenocortical tumorigenesis has not been analyzed in an unbiased, systematic fashion. Using the Infinium HumanMethylation27 BeadChip, the DNA methylation levels of 27,578 CpG sites were investigated in bisulfite-modified DNA from 6 normal adrenocortical tissue samples, 27 adrenocortical adenomas (ACA), and 15 adrenocortical carcinomas (ACC). Genes involved in cell cycle regulation, apoptosis, and transcriptional regulation of known or putative importance in the development of adrenal tumors showed significant and frequent hypermethylation. Such genes included CDKN2A, GATA4, BCL2, DLEC1, HDAC10, PYCARD, and SCGB3A1/HIN1. Comparing benign versus malignant ACT, a total of 212 CpG islands were identified as significantly hypermethylated in ACC. Gene expression studies of selected hypermethylated genes (CDKN2A, GATA4, DLEC1, HDAC10, PYCARD, SCGB3A1/HIN1) in 6 normal and 16 neoplastic adrenocortical tissues (10 ACA and 6 ACC), displayed reduced gene expression in benign and malignant ACT versus normal adrenocortical tissue. Treatment with 5-aza-2-deoxycytidine of adrenocortical cancer H-295R cells increased expression of the hypermethylated genes CDKN2A, GATA4, DLEC1, HDAC10, PYCARD, and SCGB3A1/HIN1. In conclusion, the current study represents the first unbiased, quantitative, genome-wide study of adrenocortical tumor DNA methylation. Genes with altered DNA methylation patterns were identified of putative importance to benign and malignant adrenocortical tumor development.
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| 4. |
- Starker, Lee F., et al.
(författare)
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Evidence of a stabilizing mutation of beta-catenin encoded by CTNNB1 exon 3 in a large series of sporadic parathyroid adenomas
- 2012
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Ingår i: Endocrine. - : Springer Science and Business Media LLC. - 1355-008X .- 1559-0100. ; 42:3, s. 612-615
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Tidskriftsartikel (refereegranskat)abstract
- Aberrant accumulation of beta-catenin plays an important role in a variety of human neoplasms. This can be caused by stabilizing mutation of beta-catenin (CTNNB1, exon 3) or by mutation or deregulated expression of other components of the WNT/beta-catenin signaling pathway. Accumulation of non-phosphorylated active beta-catenin has been reported to commonly occur in parathyroid adenomas from patients with primary hyperparathyroidism (pHPT), either due to the aberrantly spliced internally truncated WNT receptor LRP5 (LRP5 Delta) or to a stabilizing mutation of beta-catenin. The S37A mutation was reported to occur in 7.3 % in a single study of parathyroid adenomas, while in other studies no stabilizing mutations of beta-catenin exon 3 were identified. The aim of this study was to determine the mutational frequency of the CTNNB1 gene, specifically exon 3 in a large series of parathyroid adenomas. One hundred and eighty sporadic parathyroid adenomas were examined for mutations in exon 3 of CTNNB1 by direct DNA sequencing, utilizing previously published primer sequences. The mutation S33C (TCT > TGT) was detected by direct-DNA sequencing of PCR fragments in 1 out of 180 sporadic parathyroid adenomas (0.68 %). Like serine 37, mutations of serine 33 have been reported in many neoplasms with resulting beta-catenin stabilization, enhanced transcription, and oncogenic activities. Immunohistochemical analysis revealed an overexpression of the beta-catenin protein in the lone mutant tumor. Taking also previous studies into account we conclude that activating mutations of the regulatory GSK-3 beta phosphorylation sites serine 33 and 37, encoded by CTNNB1 exon 3, rarely occur in parathyroid adenomas from patients with pHPT.
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| 5. |
- Starker, Lee F., et al.
(författare)
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Frequent germ-line mutations of the MEN1, CASR, and HRPT2/CDC73 genes in young patients with clinically non-familial primary hyperparathyroidism
- 2012
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Ingår i: Hormones & Cancer. - : Springer Science and Business Media LLC. - 1868-8497 .- 1868-8500. ; 3:1-2, s. 44-51
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Tidskriftsartikel (refereegranskat)abstract
- Familial primary hyperparathyroidism (FPHPT) may occur due to an underlying germ-line mutation in the MEN1, CASR, or HRPT2/CDC73 genes. The disease may be undiagnosed in the absence of a history suggestive of FHPT. Young PHPT patients (≤45 years of age) are more likely to harbor occult FPHPT. A total of 1,161 (136 were ≤45 years of age) PHPT patients underwent parathyroidectomy from 2001 to 2009. Thirty-four patients declined participation. Sixteen patients were diagnosed in the clinical routine with FPHPT (11 MEN1, four MEN2A, and one HPT-JT) and were not included in the genetic analysis. Eighty-six young (≤45 years of age) patients with clinically non-syndromic PHPT underwent genetic analysis. Sanger sequencing of all coding regions of the MEN1, CASR, and the HRPT2/CDC73 genes was performed. Eight of 86 (9.3%) young patients with clinically non-familial PHPT displayed deleterious germ-line mutations in the susceptibility genes (4 MEN1, 3 CASR, and 1 HRPT2/CDC73). There was one insertion, one deletion, two nonsense, and four missense mutations, all predicted to be highly damaging to protein function and absent in 3,244 control chromosomes. Germ-line mutations in known susceptibility genes within young patients with PHPT, including those diagnosed in the clinical routine, was 24/102 (23.5%; 15 MEN1, four RET, three CASR, and two HRPT2/CDC73). We demonstrate that germ-line inactivating mutations in susceptibility genes are common in young patients with clinically non-familial PHPT. Thus, enhanced use of genetic analysis may be warranted in clinically non-familial young PHPT patients.
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