scholarly journals Three decades of progress from surgery to medical therapy for isolated neuroaxis BRAF V600E–positive Langerhans cell histiocytosis management: illustrative case

2021 ◽  
Vol 1 (19) ◽  
Author(s):  
Nallammai Muthiah ◽  
Kamil W. Nowicki ◽  
Jennifer L. Picarsic ◽  
Michael P. D’Angelo ◽  
Daniel F. Marker ◽  
...  
Keyword(s):  
Langerhans Cell Histiocytosis ◽  
Mapk Pathway ◽  
Clinical Manifestations ◽  
Tumor Burden ◽  
Langerhans Cell ◽  
Mitogen Activated Protein Kinase ◽  
Braf V600e ◽  
Illustrative Case ◽  
Surgical Interventions ◽  
Mitogen Activated Protein

BACKGROUND “Langerhans cell histiocytosis” (LCH) is a term that encompasses single-system or multisystem disorders traditionally characterized by a proliferation of clonal CD1a+/CD207+ myeloid-derived histiocytes. In most cases of LCH, mitogen-activated protein kinase (MAPK) pathway somatic mutations lead to near universal upregulation of phosphorylated extracellular signal-regulated kinase expression. The clinical manifestations of LCH are numerous, but bone involvement is common. Intracranial lesions, especially as isolated manifestations, are rare. OBSERVATIONS The authors presented the case of a long-term survivor of exclusive intracranial LCH that manifested with isolated craniofacial bone and intraparenchymal central nervous system recurrences, which were managed with 3 decades of multimodal therapy. The patient was initially diagnosed with LCH at age 2 years, and the authors documented the manifestations of disease and treatment for 36 years. Most of the patient’s treatment course occurred before the discovery of BRAF V600E. Treatments initially consisted of chemotherapy, radiosurgery, and open resections for granulomatous LCH lesions. Into young adulthood, the patient had a minimal disease burden but still required additional radiosurgical procedures and open resections. LESSONS Surgical treatments alleviated the patient’s immediate symptoms and allowed for tumor burden control. However, surgical interventions did not cure the underlying, aggressive disease. In the current era, access to systemic MAPK inhibitor therapy for histiocytic lesions may offer improved outcomes.

scholarly journals Biological and clinical significance of somatic mutations in Langerhans cell histiocytosis and related histiocytic neoplastic disorders

Hematology ◽  
2015 ◽  
Vol 2015 (1) ◽  
pp. 559-564 ◽  
Author(s):  
Carl E. Allen ◽  
D. Williams Parsons
Keyword(s):  
Langerhans Cell Histiocytosis ◽  
Somatic Mutations ◽  
Mapk Pathway ◽  
Clinical Manifestations ◽  
Langerhans Cell ◽  
Braf V600e ◽  
Common Mechanism ◽  
Recurrent Mutations ◽  
Wide Range ◽  
Neoplastic Disorders

AbstractLangerhans cell histiocytosis (LCH), juvenile xanthogranuloma (JXG), and Erdheim–Chester disease (ECD) represent histiocytic disorders with a wide range of clinical manifestations. Until recently, mechanisms of pathogenesis have been speculative and debate has focused on classification of these conditions as reactive versus neoplastic. Genomic studies have been challenged by scarce tissue specimens, as well as heterogeneous nature of the lesions with variable infiltration of pathologic histiocytes. Whole-exome sequencing recently revealed a very low frequency of somatic mutations in LCH, JXG, and ECD compared to other neoplastic disorders. However, at least in the cases of LCH and ECD, there is a very high frequency of activating mutations in MAPK pathway genes, most notably BRAF-V600E, as well as MAP2K1, in LCH and NRAS in ECD. In ECD, recurrent mutations in the PI3K pathway gene PIK3CA have also been described. The heterogeneous clinical manifestations of these disorders may therefore be the cumulative result of activation of MAPK mutations (along with modifying signals from other pathways) at distinct stages of myeloid differentiation. Implications of this model include redefinition of LCH, JXG, and ECD as a group of clinically diverse myeloid neoplastic disorders with a common mechanism of pathogenesis. This model supports refocusing therapeutic strategies for these diseases on a personalized approach based on specific mutations and the cell(s) of origin.

scholarly journals RAF/MEK/extracellular signal–related kinase pathway suppresses dendritic cell migration and traps dendritic cells in Langerhans cell histiocytosis lesions

2017 ◽  
Vol 215 (1) ◽  
pp. 319-336 ◽  
Author(s):  
Brandon Hogstad ◽  
Marie-Luise Berres ◽  
Rikhia Chakraborty ◽  
Jun Tang ◽  
Camille Bigenwald ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Langerhans Cell Histiocytosis ◽  
Mapk Pathway ◽  
Mek Inhibitor ◽  
Langerhans Cell ◽  
Mitogen Activated Protein Kinase ◽  
Phagocytic Cells ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Myeloid Neoplasia

Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplasia characterized by granulomatous lesions containing pathological CD207+ dendritic cells (DCs) with constitutively activated mitogen-activated protein kinase (MAPK) pathway signaling. Approximately 60% of LCH patients harbor somatic BRAFV600E mutations localizing to CD207+ DCs within lesions. However, the mechanisms driving BRAFV600E+ LCH cell accumulation in lesions remain unknown. Here we show that sustained extracellular signal–related kinase activity induced by BRAFV600E inhibits C-C motif chemokine receptor 7 (CCR7)–mediated DC migration, trapping DCs in tissue lesions. Additionally, BRAFV600E increases expression of BCL2-like protein 1 (BCL2L1) in DCs, resulting in resistance to apoptosis. Pharmacological MAPK inhibition restores migration and apoptosis potential in a mouse LCH model, as well as in primary human LCH cells. We also demonstrate that MEK inhibitor-loaded nanoparticles have the capacity to concentrate drug delivery to phagocytic cells, significantly reducing off-target toxicity. Collectively, our results indicate that MAPK tightly suppresses DC migration and augments DC survival, rendering DCs in LCH lesions trapped and resistant to cell death.

scholarly journals Recurrent BRAF mutations in Langerhans cell histiocytosis

Blood ◽  
2010 ◽  
Vol 116 (11) ◽  
pp. 1919-1923 ◽  
Author(s):  
Gayane Badalian-Very ◽  
Jo-Anne Vergilio ◽  
Barbara A. Degar ◽  
Laura E. MacConaill ◽  
Barbara Brandner ◽  
...  
Keyword(s):  
Langerhans Cells ◽  
Langerhans Cell Histiocytosis ◽  
Langerhans Cell ◽  
Mitogen Activated Protein Kinase ◽  
Braf V600e ◽  
Neoplastic Disease ◽  
Braf Mutations ◽  
Multiple Organs ◽  
Mitogen Activated Protein ◽  
Formalin Fixed Paraffin Embedded

Abstract Langerhans cell histiocytosis (LCH) has a broad spectrum of clinical behaviors; some cases are self-limited, whereas others involve multiple organs and cause significant mortality. Although Langerhans cells in LCH are clonal, their benign morphology and their lack (to date) of reported recurrent genomic abnormalities have suggested that LCH may not be a neoplasm. Here, using 2 orthogonal technologies for detecting cancer-associated mutations in formalin-fixed, paraffin-embedded material, we identified the oncogenic BRAF V600E mutation in 35 of 61 archived specimens (57%). TP53 and MET mutations were also observed in one sample each. BRAF V600E tended to appear in younger patients but was not associated with disease site or stage. Langerhans cells stained for phospho-mitogen–activated protein kinase kinase (phospho-MEK) and phospho-extracellular signal-regulated kinase (phospho-ERK) regardless of mutation status. High prevalence, recurrent BRAF mutations in LCH indicate that it is a neoplastic disease that may respond to RAF pathway inhibitors.

Polymorphous Low-Grade Neuroepithelial Tumor of the Young (PLNTY): Molecular Profiling Confirms Frequent MAPK Pathway Activation

2021 ◽  
Author(s):  
Cristiane M Ida ◽  
Derek R Johnson ◽  
Asha A Nair ◽  
Jaime Davila ◽  
Thomas M Kollmeyer ◽  
...  
Keyword(s):  
Copy Number ◽  
Mapk Pathway ◽  
Braf V600e Mutation ◽  
Mitogen Activated Protein Kinase ◽  
Braf V600e ◽  
Low Grade ◽  
Pathway Activation ◽  
Mitogen Activated Protein ◽  
Copy Number Changes ◽  
Cd34 Expression

Abstract Polymorphous low-grade neuroepithelial tumor of the young (PLNTY) is a recently described epileptogenic tumor characterized by oligodendroglioma-like components, aberrant CD34 expression, and frequent mitogen-activated protein kinase (MAPK) pathway activation. We molecularly profiled 13 cases with diagnostic histopathological features of PLNTY (10 female; median age, 16 years; range, 5–52). Patients frequently presented with seizures (9 of 12 with available history) and temporal lobe tumors (9 of 13). MAPK pathway activating alterations were identified in all 13 cases. Fusions were present in the 7 youngest patients: FGFR2-CTNNA3 (n = 2), FGFR2-KIAA1598 (FGFR2-SHTN1) (n = 1), FGFR2-INA (n = 1), FGFR2-MPRIP (n = 1), QKI-NTRK2 (n = 1), and KIAA1549-BRAF (n = 1). BRAF V600E mutation was present in 6 patients (17 years or older). Two fusion-positive cases additionally harbored TP53/RB1 abnormalities suggesting biallelic inactivation. Copy number changes predominantly involving whole chromosomes were observed in all 10 evaluated cases, with losses of chromosome 10q occurring with FGFR2-KIAA1598 (SHTN1)/CTNNA3 fusions. The KIAA1549-BRAF and QKI-NTRK2 fusions were associated respectively with a 7q34 deletion and 9q21 duplication. This study shows that despite its name, PLNTY also occurs in older adults, who frequently show BRAF V600E mutation. It also expands the spectrum of the MAPK pathway activating alterations associated with PLNTY and demonstrates recurrent chromosomal copy number changes consistent with chromosomal instability.

Pulmonary Langerhans Cell Histiocytosis

2020 ◽  
Vol 41 (02) ◽  
pp. 269-279
Author(s):  
Brian Shaw ◽  
Michael Borchers ◽  
Dani Zander ◽  
Nishant Gupta
Keyword(s):  
Langerhans Cell Histiocytosis ◽  
Treatment Options ◽  
Skin Lesions ◽  
Langerhans Cell ◽  
Mitogen Activated Protein Kinase ◽  
Myeloid Neoplasm ◽  
Cystic Lung ◽  
Pulmonary Langerhans Cell Histiocytosis ◽  
Mitogen Activated Protein ◽  
The Central Nervous System

AbstractPulmonary Langerhans cell histiocytosis (PLCH) is a diffuse cystic lung disease that is strongly associated with exposure to cigarette smoke. Recently, activating pathogenic mutations in the mitogen-activated protein kinase pathway have been described in the dendritic cells in patients with PLCH and have firmly established PLCH to be an inflammatory myeloid neoplasm. Disease course and prognosis in PLCH are highly variable among individual patients, ranging from spontaneous resolution to development of pulmonary hypertension and progression to terminal respiratory failure. A subset of patients with PLCH may have extrapulmonary involvement, typically involving the skeletal system in the form of lytic lesions, skin lesions, or the central nervous system most commonly manifesting in the form of diabetes insipidus. Smoking cessation is the cornerstone of treatment in patients with PLCH and can lead to disease regression or stabilization in a substantial proportion of patients. Further insight into the underlying molecular pathogenesis of PLCH has paved the way for the future development of disease-specific biomarkers and targeted treatment options directed against the central disease-driving mutations.

scholarly journals RecurrentNRASmutations in pulmonary Langerhans cell histiocytosis

2016 ◽  
Vol 47 (6) ◽  
pp. 1785-1796 ◽  
Author(s):  
Samia Mourah ◽  
Alexandre How-Kit ◽  
Véronique Meignin ◽  
Dominique Gossot ◽  
Gwenaël Lorillon ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Lung Tissue ◽  
Langerhans Cell Histiocytosis ◽  
Kinase Inhibitor ◽  
Mapk Pathway ◽  
Univariate Analysis ◽  
Langerhans Cell ◽  
Mitogen Activated Protein Kinase ◽  
Normal Lung ◽  
Pulmonary Langerhans Cell Histiocytosis

The mitogen-activated protein kinase (MAPK) pathway is constantly activated in Langerhans cell histiocytosis (LCH). Mutations of the downstream kinasesBRAFandMAP2K1mediate this activation in a subset of LCH lesions. In this study, we attempted to identify other mutations which may explain the MAPK activation in nonmutatedBRAFandMAP2K1LCH lesions.We analysed 26 pulmonary and 37 nonpulmonary LCH lesions for the presence ofBRAF,MAP2K1,NRASandKRASmutations. Grossly normal lung tissue from 10 smoker patients was used as control. Patient spontaneous outcomes were concurrently assessed.BRAFV600Emutations were observed in 50% and 38% of the pulmonary and nonpulmonary LCH lesions, respectively. 40% of pulmonary LCH lesions harbouredNRASQ61K/Rmutations, whereas noNRASmutations were identified in nonpulmonary LCH biopsies or in lung tissue control. In seven out of 11NRASQ61K/R-mutated pulmonary LCH lesions,BRAFV600Emutations were also present. Separately genotyping each CD1a-positive area from the same pulmonary LCH lesion demonstrated that these concurrentBRAFandNRASmutations were carried by different cell clones.NRASQ61K/Rmutations activated both the MAPK and AKT (protein kinase B) pathways. In the univariate analysis, the presence of concurrentBRAFV600EandNRASQ61K/Rmutations was significantly associated with patient outcome.These findings highlight the importance ofNRASgenotyping of pulmonary LCH lesions because the use of BRAF inhibitors in this context may lead to paradoxical disease progression. These patients might benefit from MAPK kinase inhibitor-based treatments.

scholarly journals Identification of pathways modulating vemurafenib resistance in melanoma cells via a genome-wide CRISPR/Cas9 screen

2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Corinna Jie Hui Goh ◽  
Jin Huei Wong ◽  
Chadi El Farran ◽  
Ban Xiong Tan ◽  
Cynthia R Coffill ◽  
...  
Keyword(s):  
Kinase Inhibitor ◽  
Mapk Pathway ◽  
Enrichment Analysis ◽  
Melanoma Cells ◽  
Mitogen Activated Protein Kinase ◽  
Braf V600e ◽  
Genome Wide ◽  
A Genome ◽  
Mitogen Activated Protein ◽  
Genome Scale

Abstract Vemurafenib is a BRAF kinase inhibitor (BRAFi) that is used to treat melanoma patients harboring the constitutively active BRAF-V600E mutation. However, after a few months of treatment patients often develop resistance to vemurafenib leading to disease progression. Sequence analysis of drug-resistant tumor cells and functional genomic screens has identified several genes that regulate vemurafenib resistance. Reactivation of mitogen-activated protein kinase (MAPK) pathway is a recurrent feature of cells that develop resistance to vemurafenib. We performed a genome-scale CRISPR-based knockout screen to identify modulators of vemurafenib resistance in melanoma cells with a highly improved CRISPR sgRNA library called Brunello. We identified 33 genes that regulate resistance to vemurafenib out of which 14 genes have not been reported before. Gene ontology enrichment analysis showed that the hit genes regulate histone modification, transcription and cell cycle. We discuss how inactivation of hit genes might confer resistance to vemurafenib and provide a framework for follow-up investigations.

Transcriptomic Landscape of Circulating Mononuclear Phagocytes in Langerhans Cell Histiocytosis at Single-cell Level

Blood ◽  
2021 ◽  
Author(s):  
Hui Shi ◽  
Han He ◽  
Lei Cui ◽  
Egle Kvedaraite ◽  
Zhilei Bian ◽  
...  
Keyword(s):  
Single Cell ◽  
Langerhans Cell Histiocytosis ◽  
Mapk Pathway ◽  
Braf Inhibitor ◽  
Clinical Diagnostics ◽  
Langerhans Cell ◽  
Mononuclear Phagocytes ◽  
Mitogen Activated Protein Kinase ◽  
Erk Signaling

Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplasm caused by aberrant activation of the mitogen-activated protein kinase (MAPK) pathway. Circulating myeloid cells from patients often carry disease-associated mutations and can be differentiated into langerinhigh LCH-like cells in vitro, but their detailed immune-phenotypic and molecular profiles are lacking and could shed key insights into disease biology. Here we recruited 217 pediatric LCH patients and took blood and tissue samples for BRAFV600E analysis. Immune-phenotyping of the circulating Lin-HLA-DR+ immune population in 49 of these patients revealed that decreased frequency of pDC was significantly linked to disease severity. By single-cell RNA sequencing of samples from 14 patients, we identified key changes in expression of RAS-MAPK-ERK signaling-related genes and transcription factors in distinct members of the mononuclear phagocyte system in the presence of BRAFV600E. Moreover, treatment of patients with the BRAF inhibitor Dabrafenib resulted in MAPK cascade inhibition, inflammation prevention, and regulation of cellular metabolism within mononuclear phagocytes. Finally, we also observed elevated expression of RAS-MAPK-ERK signaling-related genes in a CD207+CD1a+ cell subcluster in skin. Taken together, our data extends the molecular understanding of LCH biology at single-cell resolution, which might contribute to improvement of clinical diagnostics and therapeutics, and aid in the development of personalized medicine approaches.

scholarly journals Results of TETimaX Trial of Langerhans Cell Histiocytosis Treatment and Perspectives on the Role of Imatinib Mesylate in the Era of MAPK Signaling

Biomedicines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1759
Author(s):  
Liliana Montella ◽  
Margaret Ottaviano ◽  
Vittorio Riccio ◽  
Fernanda Picozzi ◽  
Gaetano Facchini ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Kinase Inhibitor ◽  
Langerhans Cell Histiocytosis ◽  
Kinase Inhibitor ◽  
Growth Factor Receptor ◽  
Mapk Signaling ◽  
Langerhans Cell ◽  
Mitogen Activated Protein Kinase ◽  
Mitogen Activated Protein

Langerhans cell histiocytosis (LCH) is a rare disease that has a variable clinical presentation and unpredictable behavior. Until recently, therapeutic options were limited. Insights into the role of mitogen-activated protein kinase (MAPK) signaling have allowed the increased use of targeted treatments. Before the advent of drugs that interfere with this pathway, investigations concerning the tyrosine kinase inhibitor imatinib opened the way to a rationale-based therapeutic approach to the disease. Imatinib block the binding site of ATP in the BCR/ABL protein and is also a platelet-derived growth factor receptor (PDGFR) and a KIT (CD117) kinase inhibitor. A case of refractory LCH with brain involvement was reported to be successfully treated with imatinib. Thereafter, we further explored the role of this tyrosine kinase inhibitor. The present study is composed of an immunohistochemical evaluation of PDGFRβ expression and a clinical evaluation of imatinib in a series of LCH patients. In the first part, a series of 10 samples obtained from LCH patients was examined and a strong immunohistochemistry expression of PDGFRβ was found in 40% of the cases. In the clinical part of the study, five patients were enrolled. Long-lasting disease control was obtained. These results may suggest a potential role for this drug in the current age.

scholarly journals NFB-05. AN UNUSUAL PRESENTATION OF RECURRENT LANGERHANS CELL HISTIOCYTOSIS OF THE CRANIOFACIAL BONES IN A PATIENT WITH NEUROFIBROMATOSIS TYPE I

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii418-iii418
Author(s):  
Blake Chaffee ◽  
Alexis Judd ◽  
Sarah Rush ◽  
Erin Wright
Keyword(s):  
Langerhans Cell Histiocytosis ◽  
Malignant Tumors ◽  
Neurofibromatosis Type ◽  
Mapk Signaling ◽  
Langerhans Cell ◽  
Mitogen Activated Protein Kinase ◽  
Type I ◽  
Braf Mutations ◽  
Surveillance Imaging ◽  
Mitogen Activated Protein

Abstract Neurofibromatosis type 1 (NF1), predisposes patients to benign and malignant tumors due to lack of suppression of the mitogen activated protein kinase (MAPK) signaling pathway. Langerhans cell histiocytosis (LCH) manifests in numerous ways, from localized lesions to multisystem organ involvement secondary to a constitutively active MAPK signaling cascade often driven by BRAF mutations. While both LCH and NF1 are characterized by overactive MAPK signaling, there are few reports of the two diseases occurring simultaneously. We report a novel case of a patient with underlying NF1 and recurrent LCH without a BRAFV600E mutation. She initially presented at 2 years of age with an aggressive appearing mass of the left temporal bone found on surveillance imaging. Pathology was consistent with Langerhans histiocytosis and she was treated with the LCH-III protocol for patients with high-risk LCH due to the location of her lesion. Five years after completion of therapy, MRI demonstrated development of a calvarial mass consistent with relapsed LCH in a new risk site. Lesional curettage was performed and pathology confirmed recurrence of LCH with juvenile xanthogranulomatous features. BRAF testing of blood and the lesion were negative for any BRAF alterations. Further genomic evaluation of the tumor is in progress at this time to evaluate for other known mutations associated with LCH. The patient is currently receiving monthly cytarabine treatment which she has tolerated to date. Our patient represents a unique presentation of recurrent LCH in a patient with NF1 and further molecular evaluation may help identify other drivers of LCH activation.

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