RESUMO
Constitutional LZTR1 or SMARCB1 pathogenic variants (PVs) have been found in â¼86% of familial and â¼40% of sporadic schwannomatosis cases. Hence, we performed massively parallel sequencing of the entire LZTR1, SMARCB1, and NF2 genomic loci in 35 individuals with schwannomas negative for constitutional first-hit PVs in the LZTR1/SMARCB1/NF2 coding sequences; however, with 22q deletion and/or a different NF2 PV in each tumor, including six cases with only one tumor available. Furthermore, we verified whether any other LZTR1/SMARCB1/NF2 (likely) PVs could be found in 16 cases carrying a SMARCB1 constitutional variant in the 3'-untranslated region (3'-UTR) c.*17C>T, c.*70C>T, or c.*82C>T. As no additional variants were found, functional studies were performed to clarify the effect of these 3'-UTR variants on the transcript. The 3'-UTR variants c.*17C>T and c.*82C>T showed pathogenicity by negatively affecting the SMARCB1 transcript level. Two novel deep intronic SMARCB1 variants, c.500+883T>G and c.500+887G>A, resulting in out-of-frame missplicing of intron 4, were identified in two unrelated individuals. Further resequencing of the entire repeat-masked genomics sequences of chromosome 22q in individuals negative for PVs in the SMARCB1/LZTR1/NF2 coding- and noncoding regions revealed five potential schwannomatosis-predisposing candidate genes, that is, MYO18B, NEFH, SGSM1, SGSM3, and SBF1, pending further verification.
Assuntos
Neurilemoma , Neurofibromatoses , Cromossomos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Neurilemoma/genética , Neurilemoma/patologia , Neurofibromatoses/genética , Proteína SMARCB1/genética , Fatores de Transcrição/genéticaRESUMO
On 19 January 2014 Rolf ('Roffe') Bernander passed away unexpectedly. Rolf was a dedicated scientist; his research aimed at unravelling the cell biology of the archaeal domain of life, especially cell cycle-related questions, but he also made important contributions in other areas of microbiology. Rolf had a professor position in the Molecular Evolution programme at Uppsala University, Sweden for about 8 years, and in January 2013 he became chair professor at the Department of Molecular Biosciences, The Wenner-Gren Institute at Stockholm University in Sweden. Rolf was an exceptional colleague and will be deeply missed by his family and friends, and the colleagues and co-workers that he leaves behind in the scientific community. He will be remembered for his endless enthusiasm for science, his analytical mind, and his quirky sense of humour.
Assuntos
Archaea/citologia , Ciclo Celular/fisiologia , História do Século XX , História do Século XXI , SuéciaRESUMO
Constitutional SMARCB1 mutations at 22q11.23 have been found in â¼50% of familial and <10% of sporadic schwannomatosis cases. We sequenced highly conserved regions along 22q from eight individuals with schwannomatosis whose schwannomas involved somatic loss of one copy of 22q, encompassing SMARCB1 and NF2, with a different somatic mutation of the other NF2 allele in every schwannoma but no mutation of the remaining SMARCB1 allele in blood and tumor samples. LZTR1 germline mutations were identified in seven of the eight cases. LZTR1 sequencing in 12 further cases with the same molecular signature identified 9 additional germline mutations. Loss of heterozygosity with retention of an LZTR1 mutation was present in all 25 schwannomas studied. Mutations segregated with disease in all available affected first-degree relatives, although four asymptomatic parents also carried an LZTR1 mutation. Our findings identify LZTR1 as a gene predisposing to an autosomal dominant inherited disorder of multiple schwannomas in â¼80% of 22q-related schwannomatosis cases lacking mutation in SMARCB1.
Assuntos
Cromossomos Humanos Par 22/genética , Predisposição Genética para Doença/genética , Mutação em Linhagem Germinativa/genética , Modelos Moleculares , Neurilemoma/genética , Conformação Proteica , Fatores de Transcrição/genética , Sequência de Bases , Proteínas Cromossômicas não Histona/genética , DNA Complementar/genética , Proteínas de Ligação a DNA/genética , Componentes do Gene , Genes Dominantes/genética , Humanos , Perda de Heterozigosidade , Repetições de Microssatélites/genética , Dados de Sequência Molecular , Neurofibromatose 2/genética , Linhagem , Proteína SMARCB1 , Análise de Sequência de DNA , Fatores de Transcrição/químicaRESUMO
Breast cancer is a major cause of morbidity and mortality in women and its metastatic spread is the principal reason behind the fatal outcome. Metastasis-related research of breast cancer is however underdeveloped when compared with the abundant literature on primary tumors. We applied an unexplored approach comparing at high resolution the genomic profiles of primary tumors and synchronous axillary lymph node metastases from 13 patients with breast cancer. Overall, primary tumors displayed 20% higher number of aberrations than metastases. In all but two patients, we detected in total 157 statistically significant differences between primary lesions and matched metastases. We further observed differences that can be linked to metastatic disease and there was also an overlapping pattern of changes between different patients. Many of the differences described here have been previously linked to poor patient survival, suggesting that this is a viable approach toward finding biomarkers for disease progression and definition of new targets useful for development of anticancer drugs. Frequent genetic differences between primary tumors and metastases in breast cancer also question, at least to some extent, the role of primary tumors as a surrogate subject of study for the systemic disease.