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MYD88 Somatic Mutation Is a Genetic Feature of Primary Cutaneous Diffuse Large B-Cell Lymphoma, Leg Type

2012; Elsevier BV; Volume: 132; Issue: 8 Linguagem: Inglês

10.1038/jid.2012.102

1523-1747

Anne Pham‐Ledard, David Cappellen, Fabián Martínez, B. Vergier, M. Beylot‐Barry, Jean‐Philippe Merlio,

Chronic Lymphocytic Leukemia Research

activated B cell diffuse large B-cell lymphoma germinal center primary cutaneous B-cell lymphoma primary cutaneous follicle center lymphoma primary cutaneous diffuse large B-cell lymphoma, leg type primary cutaneous marginal zone lymphoma TO THE EDITOR Primary cutaneous diffuse large B-cell lymphoma leg type (PCDLBCL-LT) is a unique entity (ICD-O code 9680/3) individualized from other primary cutaneous B-cell lymphomas (PCBCL) and from nodal B-cell lymphomas by three main clinical features: preferential leg localization, occurrence in the elderly, and poor prognosis with a 45% 5-year survival rate (Vermeer et al., 1996Vermeer M.H. Geelen F.A. van Haselen C.W. et al.Primary cutaneous large B-cell lymphomas of the legs. A distinct type of cutaneous B-cell lymphoma with an intermediate prognosis.Arch Dermatol. 1996; 132: 1304-1308Crossref PubMed Google Scholar; Meijer et al., 2008Meijer C.L.J.M. Vergier B. Duncan L.M. Willemze R. Primary cutaneous DLBCL, leg type. 4th ed. International Agency for Research on Cancer, Lyon2008: 242Google Scholar). In nodal DLBCL, gene expression profiling has identified two main signatures, indicative of either germinal center (GC) or post-germinal center–activated B-cell (ABC) stages of B-cell differentiation (Alizadeh et al., 2000Alizadeh A.A. Eisen M.B. Davis R.E. et al.Distinct types of diffuse large B-cell lymphoma identified by gene expression profiling.Nature. 2000; 403: 503-511Crossref PubMed Scopus (7997) Google Scholar). The ABC or post-GC type of DLBCL exhibits a poor overall survival together with a constitutive activation of the NF-κB pathway and a higher proliferation index (Lenz and Staudt, 2010Lenz G. Staudt L.M. Aggressive lymphomas.N Engl J Med. 2010; 362: 1417-1429Crossref PubMed Scopus (470) Google Scholar). Interestingly, the expression profile of PCDLBCL-LT is similar to that of the ABC type with constitutive NF-κB pathway activation and strong expression of the IRF4/MUM1B-cell transcription factor, whereas primary cutaneous follicle center lymphoma (PCFCL), even with large cell morphology, belongs to the GC-like category (Hoefnagel et al., 2005Hoefnagel J.J. Dijkman R. Basso K. et al.Distinct types of primary cutaneous large B-cell lymphoma identified by gene expression profiling.Blood. 2005; 105: 3671-3678Crossref PubMed Scopus (222) Google Scholar; Meijer et al., 2008Meijer C.L.J.M. Vergier B. Duncan L.M. Willemze R. Primary cutaneous DLBCL, leg type. 4th ed. International Agency for Research on Cancer, Lyon2008: 242Google Scholar). An RNA interference screening for genes implicated in proliferation or survival of nodal B-cell lymphoma led to identify oncogenically active MYD88 mutations in 29% of nodal ABC-type DLBCL (Ngo et al., 2011Ngo V.N. Young R.M. Schmitz R. et al.Oncogenically active MYD88 mutations in human lymphoma.Nature. 2011; 470: 115-119Crossref PubMed Scopus (1083) Google Scholar). This prompted us to investigate the MYD88 gene status in PCDLBCL-LT. According to the Declaration of Helsinki Principles, the study was conducted after approval from the regional bioethics committee with informed written consent from the patient. Skin samples from 38 patients were analyzed: 16 with PCDLBCL-LT, 14 with PCFCL, 4 with primary cutaneous marginal-zone lymphoma (PCMZL), and 4 with secondary cutaneous DLBCL. For PCDLBCL-LT and secondary cutaneous DLBCL, the tumor cell content was estimated above 80% on routine sections and after immunostaining. PCFCL and PCMZL cases were similarly selected from surgical skin biopsies containing tumor cell content above 20%. DNA was extracted from frozen material in 35 cases and from formalin-fixed material in 3 cases with the QIAGEN DNA easy kit (QIAGEN, Courtaboeuf, France). Constitutional DNA was extracted from blood samples matched to patients. Sanger sequencing of MYD88 was accomplished with the following primers: 5′-TCCCATGGAGCTCTGACCAC-3′ and 5′-TAGSAGGAGATGCCCAGTAT-3′ (PCR amplification and sequencing exon 3); 5′-ATGCTGAACTAAGTTGCCACA-3′ and 5′-GAGGCCCCACCTACACATTC-3′ (PCR amplification and sequencing exon 4); 5′-CTGGGGTTGAAGACTGGGCT-3′ and 5′-ATGGACAGGCAGACAGATAC-3′ (PCR amplification and sequencing exon 5. The sequence of each amplified fragment was determined on both strands with the Big Dye Terminator v1.1 ready reaction cycle sequencing kit (Applied Biosystems, Villebon-sur-Yvette, France). Among 16 cases of PCDLBCL-LT tested, a thymine to cytosine base transition at position 794 of the complementary DNA coding sequence (c. 794 T>C), causing a L265P—leucine to proline—amino-acid mutation, was detected in 11 cases (69%) (Table 1). All cases harboring the L265P mutation appeared heterozygous, as both normal and mutated alleles were detected at similar levels (Figure 1). None of our samples harbored any of the other mutations of MYD88 identified in nodal B-cell lymphoma cases (V217F, W218R, S219C, I220T, S222R, M232T, S243N, T294P) (Ngo et al., 2011Ngo V.N. Young R.M. Schmitz R. et al.Oncogenically active MYD88 mutations in human lymphoma.Nature. 2011; 470: 115-119Crossref PubMed Scopus (1083) Google Scholar). In six PCDLBCL-LT cases for which matched germline DNA was available, the L265P MYD88 gene mutation was shown to be somatically acquired (Figure 1, Table 1). Clinical features of PCDLBCL-LT with L265P mutation (11/16, 69%) did not differ from those without MYD88 mutation (5/16, 31%). No correlation was found with prognosis (overall survival, progression free survival, time to relapse or specific death) or response to therapy (Table 1).Table 1MYD88 status in primary cutaneous diffuse large B-cell lymphoma, leg typeCase no.Gender/ageSiteFinal status (months)MYD88 (tumor)MYD88 (blood)1M/59LegDD (13)L265PNA2M/72ArmDD (26)L265PNo mutation3F/88ArmDD (5)L265PNA4F/88LegAD (41)L265PNA5F/83TrunkCR (13)L265PNo mutation6M/62LegCR (31)No mutationND7M/75ArmDD (18)No mutationND8F/83LegDA (41)No mutationND9F/83LegDD (11)No mutationND10F/88LegDD (39)L265PNA11F/81LegAD (17)L265PNo mutation12F/63LegCR (12)L265PNo mutation13F/75LegDD (66)L265PNo mutation14F/73LegNAL265PNA15M/78LegDD (3)L265PNo mutation16M/90LegNANo mutationNDAbbreviations: AD, alive with disease; CR, complete remission; DA, dead of another cause; DD, dead of disease; NA, not available; ND, not done. Open table in a new tab Abbreviations: AD, alive with disease; CR, complete remission; DA, dead of another cause; DD, dead of disease; NA, not available; ND, not done. The MYD88 mutation was found to be specific for PCDLBCL-LT among other PCBCLs. None of the 14 PCFCL cases (three of them with large cell morphology) and none of the 4 PCMZL cases displayed any MYD88 mutation. A more extensive study of the PCMZL category would be relevant. A peculiar case of PCFCL with small-cell morphology followed by secondary extra-cutaneous nodal involvement with large-cell transformation did not carry MYD88 mutation at both sites. The MYD88 L265P mutation was found in one of the four secondary cutaneous DLBCL cases and cannot be used in differential diagnosis between primary and secondary cutaneous DLBCL. Moreover, L265P mutation and other nonsynonymous mutations of the MYD88 gene have been identified by massive parallel sequencing at lower frequencies in chronic lymphocytic leukemia (10%) and in gastric mucosa–associated lymphoid tissue (MALT) lymphoma (9%) (Ngo et al., 2011Ngo V.N. Young R.M. Schmitz R. et al.Oncogenically active MYD88 mutations in human lymphoma.Nature. 2011; 470: 115-119Crossref PubMed Scopus (1083) Google Scholar; Wang et al., 2011Wang L. Lawrence M.S. Wan Y. et al.SF3B1 and other novel cancer genes in chronic lymphocytic leukemia.N Engl J Med. 2011; 365: 2497-2506Crossref PubMed Scopus (891) Google Scholar). Nodal ABC DLBCL may also harbor several genetic alterations involving PRDM1/BLIMP1 (Pasqualucci et al., 2006Pasqualucci L. Compagno M. Houldsworth J. et al.Inactivation of the PRDM1/BLIMP1 gene in diffuse large B cell lymphoma.J Exp Med. 2006; 203: 311-317Crossref PubMed Scopus (306) Google Scholar; Mandelbaum et al., 2010Mandelbaum J. Bhagat G. Tang H. et al.BLIMP1 is a tumor suppressor gene frequently disrupted in activated B cell-like diffuse large B cell lymphoma.Cancer Cell. 2010; 18: 568-579Abstract Full Text Full Text PDF PubMed Scopus (226) Google Scholar), CARD11 CD79A/B, and/or TNFAIP3 (also known as A20) genes (Lenz et al., 2008aLenz G. Davis R.E. Ngo V.N. et al.Oncogenic CARD11 mutations in human diffuse large B cell lymphoma.Science. 2008; 319: 1676-1679Crossref PubMed Scopus (673) Google Scholar; Kato et al., 2009Kato M. Sanada M. Kato I. et al.Frequent inactivation of A20 in B-cell lymphomas.Nature. 2009; 459: 712-716Crossref PubMed Scopus (460) Google Scholar; Davis et al., 2010Davis R.E. Ngo V.N. Lenz G. et al.Chronic active B-cell-receptor signalling in diffuse large B-cell lymphoma.Nature. 2010; 463: 88-92Crossref PubMed Scopus (1199) Google Scholar). These alterations may overlap with MYD88 mutations, and the coding genome of DLBCL was shown to contain >30 clonally represented gene alterations per case (Ngo et al., 2011Ngo V.N. Young R.M. Schmitz R. et al.Oncogenically active MYD88 mutations in human lymphoma.Nature. 2011; 470: 115-119Crossref PubMed Scopus (1083) Google Scholar; Pasqualucci et al., 2011Pasqualucci L. Trifonov V. Fabbri G. et al.Analysis of the coding genome of diffuse large B-cell lymphoma.Nat Genet. 2011; 41: 830-837Crossref Scopus (781) Google Scholar). Somatic hypermutation caused by sustained activation-induced cytidine deaminase (AID) activity has been found to contribute to several genetic mutations in cutaneous PCDLBCL-LT, as reported in nodal DLBCL (Dijkman et al., 2006Dijkman R. Tensen C.P. Buettner M. et al.Primary cutaneous follicle center lymphoma and primary cutaneous large B-cell lymphoma, leg type, are both targeted by aberrant somatic hypermutation but demonstrate differential expression of AID.Blood. 2006; 107: 4926-4929Crossref PubMed Scopus (41) Google Scholar; Pasqualucci et al., 2011Pasqualucci L. Trifonov V. Fabbri G. et al.Analysis of the coding genome of diffuse large B-cell lymphoma.Nat Genet. 2011; 41: 830-837Crossref Scopus (781) Google Scholar). The T>C transition accounting for the L265P MYD88 mutation cannot result from deamination of 5-methylcytosine residues but from other mechanisms driving the rapid development of PCDLBCL-LT at such site in elderly patients. MYD88 is a universal adaptor protein through which most Toll-like receptors and receptors for IL-1 and IL-18 activate signaling pathways such as NF-κB during normal immune innate response (Kawai and Akira, 2010Kawai T. Akira S. The role of pattern-recognition receptors in innate immunity: update on Toll-like receptors.Nat Immunol. 2010; 11: 373-384Crossref PubMed Scopus (6188) Google Scholar). MYD88 coordinates the assembly of a multi-subunit signaling complex including the IRAK1 and IRAK4 kinase. In ABC DLBCL cell lines, the MYD88 L265P protein was shown to form a stable complex containing phosphorylated IRAK1 and to promote NF-κB and JAK-STAT3 signaling, conferring a selective advantage in cell survival (Ngo et al., 2011Ngo V.N. Young R.M. Schmitz R. et al.Oncogenically active MYD88 mutations in human lymphoma.Nature. 2011; 470: 115-119Crossref PubMed Scopus (1083) Google Scholar). Inhibitors of IRAK4 kinase of the MYD88 signaling complex were shown to inhibit cell survival in nodal ABC cell lines with MYD88 L265P mutation (Ngo et al., 2011Ngo V.N. Young R.M. Schmitz R. et al.Oncogenically active MYD88 mutations in human lymphoma.Nature. 2011; 470: 115-119Crossref PubMed Scopus (1083) Google Scholar). The non-receptor tyrosine kinase BTK could also represent a good target for small molecules (Hendriks, 2011Hendriks R.W. Drug discovery: new BTK inhibitor holds promise.Nat Chem Biol. 2011; 7: 4-5Crossref PubMed Scopus (45) Google Scholar). The original high recurrence of MYD88 L265P mutation in PCDLBCL-LT (69%) may lead to evaluate the potential use of such targeted therapies. This work was supported by grants from the Programme Hospitalier de Recherche Clinique REV-LEG and from the Institut National Contre le Cancer (INCA) for supporting the Aquitaine database of cutaneous lymphoma register and the tumor bank of CHU de Bordeaux and Cancéropôle Grand Sud-Ouest. We also thank Dr Patrick Guillot and Dr Marie Parrens from CHU Bordeaux, Dr Houchingue Eghbali (Institut Bergonié, Bordeaux, France), and Dr Olivier Fitoussi (Clinique Bordeaux Nord Aquitaine, Bordeaux, France) for providing clinicopathological data.