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. 2017 Jul 6;16(1):115.
doi: 10.1186/s12943-017-0690-z.

New somatic BRAF splicing mutation in Langerhans cell histiocytosis

Sébastien Héritier  1   2   3 , Zofia Hélias-Rodzewicz  4   5 , Rikhia Chakraborty  6   7 , Amel G Sengal  6   7 , Christine Bellanné-Chantelot  8 , Caroline Thomas  9 , Anne Moreau  10 , Sylvie Fraitag  11 , Carl E Allen  6   7 , Jean Donadieu  12   4   13 , Jean-François Emile  4   5
Affiliations

New somatic BRAF splicing mutation in Langerhans cell histiocytosis

Sébastien Héritier et al. Mol Cancer. .

Abstract

Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplasia with constitutive activation of the MAPKinase RAS-RAF-MEK-ERK cell signaling pathway. We analyzed 9 LCH cases without BRAF V600 and MAP2K1 mutations by whole exome sequencing. We identified a new somatic BRAF splicing mutation in 2 cases. Both cases were childhood single system (SS) LCH cases, with self-healing outcome of the bone lesions. This mutant consisted in a 9 base pair duplication (c.1511_1517 + 2 duplication), encoding for a predicted mutant protein with insertion of 3 amino acids (p.Arg506_Lys507insLeuLeuArg) in the N-terminal lobe of the kinase domain of BRAF. Transient expression of the c.1511_1517 + 2dup BRAF mutant in HEK293 cells enhanced MAPKinase pathway activation, and was not inhibited by vemurafenib but was inhibited by PLX8394, a second-generation BRAF inhibitor able to inhibit signaling of BRAF monomers and dimers. Future LCH molecular screening panel should include this new mutation to better define its prevalence in LCH and its restriction to autoregressive bone SS LCH.

Keywords: BRAF; Langerhans cell histiocytosis; Splicing mutation; Targeted therapy.

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Conflict of interest statement

Ethics approval and consent to participate

This study was approved by the ethics committee Ile de France III (#2011-A00447-34) and conducted in accordance with the Declaration of Helsinki.

Consent for publication

Not applicable.

Competing interests

JFE received honoraria from Roche, GlaxoSmithKline (GSK) and Pierre Fabre. The remaining authors declare no competing financial interests.

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Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Figures

Fig. 1
Fig. 1
Analysis of LCH samples. a Sanger sequencing of P5 and P6 LCH samples shows duplication of the c.1511_1517 + 2 sequence. b In silico analysis (Alamut® Visual, hg19) predicts a 5′ splice site change, causing the insertion of 9 nucleotides in the cDNA sequence [GTTACTCAG] at the end of exon 12. (C) P5 cDNA analyse confirms insertion of 9 nucleotides by rt.-PCR product length analysis. d Immunohistochemistry performed on FFPE samples from P5 showed a strong cytoplasmic and nuclear positivity of histiocytes with phosphoERK1/2 (D13.14.4E, Rabbit mAb, Cell Signaling) in areas containing numerous CD1a + LCH cells. e Results of the western blot (p- and total-ERK1/2) for P5 and P6 LCH. Protein extracts from two BRAF wild type, a BRAF V600E-mutated LCH and a BRAF V600D-mutated LCH were used as positive control for p-ERK. Functional analysis of the BRAF c.1511_1517 + 2 duplication. HEK293 cells were transiently transfected with expression plasmids encoding BRAF wild-type, BRAF V600E and BRAF c.1511_1517 + 2dup mutant cDNAs, and corresponding lysates from cells maintained in serum were subjected to immunoblotting with the indicated antibodies. f Where indicated, cells were treated with inhibitor of BRAFV600E (vemurafenib) or MEK (trametinib) for 4 h before harvest. g Where indicated, cells were treated with combination of vemurafenib and trametinib, or with inhibitors of BRAF (PLX8394) or ERK (TCS ERK 11e) for 4 h before harvest. h To test dose response to vemurafenib and trametinib on BRAF V600E and BRAF c.1511_1517 + 2dup transfected cells, the cells were treated for 4 h with the specified agents (vemurafenib or trametinib) at the specified doses before harvest
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References

    1. Emile J-F, Abla O, Fraitag S, Horne A, Haroche J, Donadieu J, et al. Revised classification of histiocytoses and neoplasms of the macrophage-dendritic cell lineages. Blood. 2016;127:2672–2681. doi: 10.1182/blood-2016-01-690636. - DOI - PMC - PubMed
    1. Héritier S, Emile J-F, Barkaoui M-A, Thomas C, Fraitag S, Boudjemaa S, et al. BRAF Mutation Correlates With High-Risk Langerhans Cell Histiocytosis and Increased Resistance to First-Line Therapy. J Clin Oncol. 2016;34:3023–3030. doi: 10.1200/JCO.2015.65.9508. - DOI - PMC - PubMed
    1. Héritier S, Jehanne M, Leverger G, Emile J-F, Alvarez J-C, Haroche J, et al. Vemurafenib Use in an Infant for High-Risk Langerhans Cell Histiocytosis. JAMA Oncol. 2015;1:836–838. doi: 10.1001/jamaoncol.2015.0736. - DOI - PubMed
    1. Badalian-Very G, Vergilio J-A, Degar BA, MacConaill LE, Brandner B, Calicchio ML, et al. Recurrent BRAF mutations in Langerhans cell histiocytosis. Blood. 2010;116:1919–1923. doi: 10.1182/blood-2010-04-279083. - DOI - PMC - PubMed
    1. Brown NA, Furtado LV, Betz BL, Kiel MJ, Weigelin HC, Lim MS, et al. High prevalence of somatic MAP2K1 mutations in BRAF V600E-negative Langerhans cell histiocytosis. Blood. 2014;124:1655–1658. doi: 10.1182/blood-2014-05-577361. - DOI - PubMed

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