Constitutively activating MEK1 mutations drive treatment refractory histiocytic neoplasms but confer response to ERK inhibition
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PROVIDER: PRJNA1117906 | ENA |
REPOSITORIES: ENA
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Project description:Histiocytic neoplasms are clonal disorders of the monocyte/macrophage lineage defined by mutations activating MAP kinase signaling, including BRAFV600E mutations in ~50% of patients, which confer robust responses to BRAF inhibition. More recently, the MEK inhibitor cobimetinib was FDA-approved for BRAFV600-wild-type histiocytosis patients. Here following genomic analysis of 500 pediatric and adult patients with diverse histiocytoses, the most common alteration following BRAFV600E was MEK1E102_I103 in-frame deletion. MEK1E102_I103del and related RAF-independent MEK mutants were associated with an aggressive multi-system clinical phenotype with worse progression-free survival with MEK inhibition as compared to patients with other classes of MEK1/2 mutations. Given that cancer-associated MEK1/2 mutations have not been modeled in vivo and the clinical importance of MEK1 mutations in histiocytoses, we generated MEK1E102_I103del conditional knock-in mice. Using three distinct hematopoietic Cre drivers, these mice developed a 100% penetrant, lethal disorder by 6 weeks of age with expansion of classical and non-classical monocytes, macrophages, and Cd11b+ conventional dendritic cells which infiltrated hematopoietic organs, liver, and skin. MEK1-mutant mice were sensitive to single-agent treatment with the oral ERK inhibitor ulixertinib. We consequently treated five MEK1E102_I103del-mutant patients with ulixertinib on prospective IRB-approved Single Patient Use Expanded Access protocols, four of whom had disease refractory to MEK inhibition. Four of five patients experienced objective clinical and/or radiological responses to ulixertinib. These data reveal the impact of oncogenic MEK kinase mutations in vivo, identify patients with likelihood of resistance to MEK inhibition, and nominate ERK inhibition as a therapeutic approach to overcome resistance to MEK inhibition in histiocytoses.
2024-09-03 | GSE268618 | GEO
Project description:Histiocytic neoplasms are clonal, hematopoietic disorders characterized by an accumulation of abnormal, monocyte-derived dendritic cells or macrophages in Langerhans Cell (LCH) and non-Langerhans (non-LCH) histiocytoses, respectively. The discovery of BRAFV600E mutations in ~50% of these patients provided the first molecular therapeutic target in histiocytosis. However, recurrent driving mutations in the majority of BRAFV600E-wildtype, non-LCH patients are unknown, and recurrent cooperating mutations in non-MAP kinase pathways are undefined for the histiocytic neoplasms. Through combined whole exome and transcriptome sequencing, we identified recurrent kinase fusions involving BRAF, ALK, and NTRK1, as well as recurrent, activating MAP2K1 and ARAF mutations in BRAFV600E-wildtype, non-LCH patients. In addition to MAP kinase pathway lesions, recurrently altered genes involving diverse cellular pathways were identified. Treatment of MAP2K1- and ARAF-mutated, non-LCH patients using MEK and RAF inhibitors, respectively, resulted in clinical efficacy demonstrating the importance of detecting and targeting diverse kinase alterations in these disorders. 13 patient samples were analyzed by RNA-seq and had 2 replicates.
2015-11-11 | E-GEOD-74442 | biostudies-arrayexpress
Project description:Histiocytic neoplasms are clonal, hematopoietic disorders characterized by an accumulation of abnormal, monocyte-derived dendritic cells or macrophages in Langerhans Cell (LCH) and non-Langerhans (non-LCH) histiocytoses, respectively. The discovery of BRAFV600E mutations in ~50% of these patients provided the first molecular therapeutic target in histiocytosis. However, recurrent driving mutations in the majority of BRAFV600E-wildtype, non-LCH patients are unknown, and recurrent cooperating mutations in non-MAP kinase pathways are undefined for the histiocytic neoplasms. Through combined whole exome and transcriptome sequencing, we identified recurrent kinase fusions involving BRAF, ALK, and NTRK1, as well as recurrent, activating MAP2K1 and ARAF mutations in BRAFV600E-wildtype, non-LCH patients. In addition to MAP kinase pathway lesions, recurrently altered genes involving diverse cellular pathways were identified. Treatment of MAP2K1- and ARAF-mutated, non-LCH patients using MEK and RAF inhibitors, respectively, resulted in clinical efficacy demonstrating the importance of detecting and targeting diverse kinase alterations in these disorders.
2015-11-11 | GSE74442 | GEO
Project description:Beta-cell proliferation is enhanced in the mice treated with with adenovirus containing constitutively active mutant of MEK1 (CAM mice) than mice treated control adenovirus. This microarray anaslysis was performed for the purpose of exploring the molecular mechanism thereby beta-cell proliferation is enhanced in L-MEK mice.
2017-09-26 | E-MTAB-5799 | biostudies-arrayexpress
Project description:Molecular Genetics of Histiocytic Sarcomas
| PRJNA507681 | ENA
Project description:Molecular Genetics of Histiocytic Sarcomas
| PRJNA507682 | ENA
Project description:Background: The determination of altered expression of genes in specific tumor types and their effect upon cellular processes may create insight in tumorigenesis and help to design better treatments. The Flatcoated retriever is a dog breed with an exceptionally high incidence of histiocytic sarcomas. The breed develops two distinct entities of histiocytic neoplasia, a soft tissue form and a visceral form. Gene expression studies of these tumors has value for comparable human diseases such as histiocytic/dendritic cell sarcoma for which knowledge is difficult to accrue due to their rare occurrence. In addition, such studies may help in the search for genetic aberrations underlying the genetic predisposition in this dog breed. Methods: Microarray analysis and pathway analyses were performed on fresh-frozen tissues obtained from Flatcoated retrievers with localized, soft tissue histiocytic sarcomas (STHS) and disseminated, visceral histiocytic sarcomas (VHS) and on normal canine spleens from various breeds. Expression differences of nine genes were validated with quantitative real-time PCR (qPCR) analyses. Results: QPCR analyses identified the significantly altered expression of nine genes; PPBP, SpiC, VCAM1, ENPEP, ITGAD (down-regulated), and GTSF1, Col3a1, CD90 and LUM (up-regulated) in the comparison of both the soft tissue and the visceral form with healthy spleen. DAVID pathway analyses revealed 24 pathways that were significantly involved in the development of HS in general, most of which were involved in the DNA repair and replication process. Conclusions: This study identified altered expression of nine genes not yet implicated in histiocytic sarcoma manifestations in the dog nor in comparable human histiocytic/dendritic sarcomas. Extraploration of this downside effect of canine inbreeding strategies for the study of similar sarcomas in humans might also lead to the identification of genes related to these rare malignancies in the human. Microarray expression dataset including STHS: Soft Tissue (localized) Histiocytic Sarcoma; VHS: Visceral (disseminated)Histiocytic Sarcoma; together with normal spleen (NS) samples. Comparisons were analysed in dyeswap on a 2-color platform against a common reference sample, consisting of a multitude of canine organs, including liver, spleen, kidney, lung, hart, intestine and bone.
2013-08-07 | E-GEOD-45832 | biostudies-arrayexpress
Project description:Background: The determination of altered expression of genes in specific tumor types and their effect upon cellular processes may create insight in tumorigenesis and help to design better treatments. The Flatcoated retriever is a dog breed with an exceptionally high incidence of histiocytic sarcomas. The breed develops two distinct entities of histiocytic neoplasia, a soft tissue form and a visceral form. Gene expression studies of these tumors has value for comparable human diseases such as histiocytic/dendritic cell sarcoma for which knowledge is difficult to accrue due to their rare occurrence. In addition, such studies may help in the search for genetic aberrations underlying the genetic predisposition in this dog breed. Methods: Microarray analysis and pathway analyses were performed on fresh-frozen tissues obtained from Flatcoated retrievers with localized, soft tissue histiocytic sarcomas (STHS) and disseminated, visceral histiocytic sarcomas (VHS) and on normal canine spleens from various breeds. Expression differences of nine genes were validated with quantitative real-time PCR (qPCR) analyses. Results: QPCR analyses identified the significantly altered expression of nine genes; PPBP, SpiC, VCAM1, ENPEP, ITGAD (down-regulated), and GTSF1, Col3a1, CD90 and LUM (up-regulated) in the comparison of both the soft tissue and the visceral form with healthy spleen. DAVID pathway analyses revealed 24 pathways that were significantly involved in the development of HS in general, most of which were involved in the DNA repair and replication process. Conclusions: This study identified altered expression of nine genes not yet implicated in histiocytic sarcoma manifestations in the dog nor in comparable human histiocytic/dendritic sarcomas. Extraploration of this downside effect of canine inbreeding strategies for the study of similar sarcomas in humans might also lead to the identification of genes related to these rare malignancies in the human.
2013-08-07 | GSE45832 | GEO
Project description:Saccharomyces cerevisiae Mek1 is a CHK2/Rad53-family kinase that regulates meiotic recombination and progression upon its activation in response to DNA double-strand breaks (DSBs). The full catalog of direct Mek1 phosphorylation targets remains unknown. Here, we show that phosphorylation of histone H3 on threonine 11 (H3 T11ph) is induced by meiotic DSBs in S. cerevisiae and Schizosaccharomyces pombe. Molecular genetic experiments in S. cerevisiae confirmed that Mek1 is required for H3 T11ph and revealed that phosphorylation is rapidly reversed when Mek1 kinase is no longer active. Reconstituting histone phosphorylation in vitro with recombinant proteins demonstrated that Mek1 directly catalyzes H3 T11 phosphorylation. Mutating H3 T11 to nonphosphorylatable residues conferred no detectable meiotic defects, indicating that H3 T11ph is dispensable for Mek1 functions in controlling recombination. However, H3 T11ph provides an excellent marker of ongoing Mek1 kinase activity in vivo. Anti-H3 T11ph chromatin immunoprecipitation followed by deep sequencing demonstrated that H3 T11ph was highly enriched at presumed sites of attachment of chromatin to chromosome axes, gave a more modest signal along chromatin loops, and was present at still lower levels immediately adjacent to DSB hotspots. These localization patterns closely tracked the distribution of Red1 and Hop1, axis proteins required for Mek1 activation. These findings provide insight into the spatial disposition of Mek1 kinase activity and the higher order organization of recombining meiotic chromosomes.
2017-10-17 | GSE103823 | GEO
Project description:Histiocytic neoplasms are clonal, hematopoietic disorders characterized by an accumulation of abnormal, monocyte-derived dendritic cells or macrophages in Langerhans cell histiocytosis (LCH) and non-Langerhans cell histiocytosis (non-LCH), respectively. The discovery of BRAF(V600E) mutations in approximately 50% of these patients provided the first molecular therapeutic target in histiocytosis. However, recurrent driving mutations in the majority of patients with BRAF(V600E)-wild-type non-LCH are unknown, and recurrent cooperating mutations in non-MAP kinase pathways are undefined for the histiocytic neoplasms. Through combined whole-exome and transcriptome sequencing, we identified recurrent kinase fusions involving BRAF, ALK, and NTRK1, as well as recurrent, activating MAP2K1 and ARAF mutations in patients with BRAF(V600E)-wild-type non-LCH. In addition to MAP kinase pathway lesions, recurrently altered genes involving diverse cellular pathways were identified. Treatment of patients with MAP2K1- and ARAF-mutated non-LCH using MEK and RAF inhibitors, respectively, resulted in clinical efficacy, demonstrating the importance of detecting and targeting diverse kinase alterations in these disorders.We provide the first description of kinase fusions in systemic histiocytic neoplasms and activating ARAF and MAP2K1 mutations in non-Langerhans histiocytic neoplasms. Refractory patients with MAP2K1- and ARAF-mutant histiocytoses had clinical responses to MEK inhibition and sorafenib, respectively, highlighting the importance of comprehensive genomic analysis of these disorders.
| S-EPMC4744547 | biostudies-literature