| 1. |
- Apellániz-Ruiz, Maria, et al.
(författare)
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Targeted sequencing reveals low-frequency variants in EPHA genes as markers of paclitaxel-induced peripheral neuropathy.
- 2017
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Ingår i: Clinical Cancer Research. - : American Association of Cancer Research. - 1078-0432 .- 1557-3265. ; 23:5, s. 1227-1235
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Neuropathy is the dose limiting toxicity of paclitaxel and a major cause for decreased quality of life. Genetic factors have been shown to contribute to paclitaxel neuropathy susceptibility; however, the major causes for inter-individual differences remain unexplained. In this study we identified genetic markers associated with paclitaxel-induced neuropathy through massive sequencing of candidate genes.EXPERIMENTAL DESIGN: We sequenced the coding region of 4 EPHA genes, 5 genes involved in paclitaxel pharmacokinetics and 30 Charcot-Marie-Tooth genes, in 228 cancer patients with no/low neuropathy or high grade neuropathy during paclitaxel treatment. An independent validation series included 202 paclitaxel-treated patients. Variation-/ gene-based analyses were used to compare variant frequencies among neuropathy groups and Cox regression models were used to analyze neuropathy evolution along treatment.RESULTS: Gene-based analysis identified EPHA6 as the gene most significantly associated with paclitaxel-induced neuropathy. Low frequency non-synonymous variants in EPHA6 were present exclusively in patients with high neuropathy and all affected the ligand binding domain. Accumulated dose analysis in the discovery series showed a significantly higher neuropathy risk for EPHA5/6/8 low-frequency non-synonymous variant carriers (HR=14.60, 95%CI=2.33-91.62, P=0.0042) and an independent cohort confirmed an increased neuropathy risk (HR=2.07, 95%CI=1.14-3.77, P=0.017). Combining the series gave an estimated 2.50-fold higher risk of neuropathy (95%CI=1.46-4.31; P=9.1x10(-4)).CONCLUSION: This first study sequencing EPHA genes revealed that low frequency variants in EPHA6, EPHA5 and EPHA8 contribute to the susceptibility to paclitaxel-induced neuropathy. Furthermore, EPHAs neuronal injury repair function suggests that these genes might constitute important neuropathy markers for many neurotoxic drugs.
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| 2. |
- Bausch, Birke, et al.
(författare)
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Germline NF1 mutational spectra and loss-of-heterozygosity analyses in patients with pheochromocytoma and neurofibromatosis type 1.
- 2007
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 92:7, s. 2784-92
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Neurofibromatosis type 1 (NF1) is a pheochromocytoma-associated syndrome. Because of the low prevalence of pheochromocytoma in NF1, we ascertained subjects by pheochromocytoma that also had NF1 in the hope of describing the germline NF1 mutational spectra of NF1-related pheochromocytoma.MATERIALS AND METHODS: An international registry for NF1-pheochromocytomas was established. Mutation scanning was performed using denaturing HPLC for intragenic variation and quantitative PCR for large deletions. Loss-of-heterozygosity analysis using markers in and around NF1 was performed.RESULTS: There were 37 eligible subjects (ages 14-70 yr). Of 21 patients with corresponding tumor available, 67% showed somatic loss of the nonmutated allele at the NF1 locus vs. 0 of 12 sporadic tumors (P = 0.0002). Overall, 86% of the 37 patients had exonic or splice site mutations, 14% large deletions or duplications; 79% of the mutations are novel. The cysteine-serine rich domain (CSR) was affected in 35% but the RAS GTPase activating protein domain (RGD) in only 13%. There did not appear to be an association between any clinical features, particularly pheochromocytoma presentation and severity, and NF1 mutation genotype.CONCLUSIONS: The germline NF1 mutational spectra comprise intragenic mutations and deletions in individuals with pheochromocytoma and NF1. NF1 mutations tended to cluster in the CSR over the RAS-GAP domain, suggesting that CSR plays a more prominent role in individuals with NF1-pheochromocytoma than in NF1 individuals without this tumor. Loss-of-heterozygosity of NF1 markers in NF1-related pheochromocytoma was significantly more frequent than in sporadic pheochromocytoma, providing further molecular evidence that pheochromocytoma is a true component of NF1.
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| 3. |
- Leandro-Garcia, Luis J., et al.
(författare)
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Regulatory Polymorphisms in beta-Tubulin IIa Are Associated with Paclitaxel-Induced Peripheral Neuropathy
- 2012
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Ingår i: Clinical Cancer Research. - : American Association for Cancer Research. - 1078-0432 .- 1557-3265. ; 18:16, s. 4441-4448
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Peripheral neuropathy is the dose-limiting toxicity of paclitaxel, a chemotherapeutic drug widely used to treat several solid tumors such as breast, lung, and ovary. The cytotoxic effect of paclitaxel is mediated through beta-tubulin binding in the cellular microtubules. In this study, we investigated the association between paclitaxel neurotoxicity risk and regulatory genetic variants in beta-tubulin genes. Experimental Design: We measured variation in gene expression of three beta-tubulin isotypes (I, IVb, and IIa) in lymphocytes from 100 healthy volunteers, sequenced the promoter region to identify polymorphisms putatively influencing gene expression and assessed the transcription rate of the identified variants using luciferase assays. To determine whether the identified regulatory polymorphisms were associated with paclitaxel neurotoxicity, we genotyped them in 214 patients treated with paclitaxel. In addition, paclitaxel-induced cytotoxicity in lymphoblastoid cell lines was compared with beta-tubulin expression as measured by Affymetrix exon array. Results: We found a 63-fold variation in beta-tubulin IIa gene (TUBB2A) mRNA content and three polymorphisms located at -101, -112, and -157 in TUBB2A promoter correlated with increased mRNA levels. The -101 and -112 variants, in total linkage disequilibrium, conferred TUBB2A increased transcription rate. Furthermore, these variants protected from paclitaxel-induced peripheral neuropathy [HR, 0.62; 95% confidence interval (CI), 0.42-0.93; P = 0.021, multivariable analysis]. In addition, an inverse correlation between TUBB2A and paclitaxel-induced apoptosis (P = 0.001) in lymphoblastoid cell lines further supported that higher TUBB2A gene expression conferred lower paclitaxel sensitivity. Conclusions: This is the first study showing that paclitaxel neuropathy risk is influenced by polymorphisms regulating the expression of a beta-tubulin gene.
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| 4. |
- Toledo, Rodrigo A., et al.
(författare)
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Consensus Statement on next-generation-sequencing-based diagnostic testing of hereditary phaeochromocytomas and paragangliomas
- 2017
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Ingår i: Nature Reviews Endocrinology. - : NATURE PUBLISHING GROUP. - 1759-5029 .- 1759-5037. ; 13:4, s. 233-247
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Tidskriftsartikel (refereegranskat)abstract
- Phaeochromocytomas and paragangliomas (PPGLs) are neural-crest-derived tumours of the sympathetic or parasympathetic nervous system that are often inherited and are genetically heterogeneous. Genetic testing is recommended for patients with these tumours and for family members of patients with hereditary forms of PPGLs. Due to the large number of susceptibility genes implicated in the diagnosis of inherited PPGLs, next-generation sequencing (NGS) technology is ideally suited for carrying out genetic screening of these individuals. This Consensus Statement, formulated by a study group comprised of experts in the field, proposes specific recommendations for the use of diagnostic NGS in hereditary PPGLs. In brief, the study group recommends target gene panels for screening of germ line DNA, technical adaptations to address different modes of disease transmission, orthogonal validation of NGS findings, standardized classification of variant pathogenicity and uniform reporting of the findings. The use of supplementary assays, to aid in the interpretation of the results, and sequencing of tumour DNA, for identification of somatic mutations, is encouraged. In addition, the study group launches an initiative to develop a gene-centric curated database of PPGL variants, with annual re-evaluation of variants of unknown significance by an expert group for purposes of reclassification and clinical guidance.
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