Non-Hodgkin lymphoma is the fourth most common malignancy in children, has an even higher incidence in adolescents, and is primarily represented by only a few histologic subtypes. Dramatic progress has been achieved, with survival rates exceeding 80%, in large part because of a better understanding of the biology of the different subtypes and national and international collaborations. Most patients with Burkitt lymphoma and diffuse large B-cell lymphoma are cured with short intensive pulse chemotherapy containing cyclophosphamide, cytarabine, and high-dose methotrexate. The benefit of the addition of rituximab has not been established except in the case of primary mediastinal B-cell lymphoma. Lymphoblastic lymphoma is treated with intensive, semi-continuous, longer leukemia-derived protocols. Relapses in B-cell and lymphoblastic lymphomas are rare and infrequently curable, even with intensive approaches. Event-free survival rates of approximately 75% have been achieved in anaplastic large-cell lymphomas with various regimens that generally include a short intensive B-like regimen. Immunity seems to play an important role in prognosis and needs further exploration to determine its therapeutic application. ALK inhibitor therapeutic approaches are currently under investigation. For all pediatric lymphomas, the intensity of induction/consolidation therapy correlates with acute toxicities, but because of low cumulative doses of anthracyclines and alkylating agents, minimal or no long-term toxicity is expected. Challenges that remain include defining the value of prognostic factors, such as early response on positron emission tomography/computed tomography and minimal disseminated and residual disease, using new biologic technologies to improve risk stratification, and developing innovative therapies, both in the first-line setting and for relapse

Key Points• A subset of lymphomas with gene expression and pathological characteristics of Burkitt lymphomas but absence of MYC translocation does exist.• These lymphomas carry chr 11q proximal gains and telomeric losses, suggesting co-deregulation of oncogenes and tumor suppressor genes.The genetic hallmark of Burkitt lymphoma (BL) is the t(8;14)(q24;q32) and its variants leading to activation of the MYC oncogene. It is a matter of debate whether true BL without MYC translocation exists. Here, we identified 59 lymphomas concordantly called BL by 2 gene expression classifiers among 753 B-cell lymphomas. Only 2 (3%) of these 59 molecular BL lacked a MYC translocation, which both shared a peculiar pattern of chromosome 11q aberration characterized by interstitial gains including 11q23.2-q23.3 and telomeric losses of 11q24.1-qter. We extended our analysis to 17 MYC-negative high-grade B-cell lymphomas with a similar 11q aberration and showed this aberration to be recurrently associated with morphologic and clinical features of BL. The minimal region of gain was defined by highlevel amplifications in 11q23.3 and associated with overexpression of genes including PAFAH1B2 on a transcriptional and protein level. The recurrent region of loss contained a focal homozygous deletion in 11q24.2-q24.3 including the ETS1 gene, which was shown to be mutated in 4 of 16 investigated cases. These findings indicate the existence of a molecularly distinct subset of B-cell lymphomas reminiscent of BL, which is characterized by deregulation

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We studied the prognostic value of minimal disseminated disease (MDD) and anti-ALK immune response in children with NPM-ALK-positive anaplastic-large cell lymphoma (ALCL) and evaluated their potential for risk stratification. NPM-ALK transcripts were analyzed by RT-PCR in bone marrow/peripheral blood of 128 ALCL patients at diagnosis, whereas ALK antibody titers in plasma were assessed using an immunocytochemical approach. MDD was positive in 59% of patients and 96% showed an anti-ALK response. Using MDD and antibody titer results, patients could be divided into three biological risk groups (bRG) with different prognosis: high risk (bHR): MDD-positive and antibody titer ≤ 1/750, 26/128 (20%); low risk (bLR): MDD negative and antibody titer >1/750, 40/128 (31%); intermediate risk (bIR): all remaining patients, 62/128 (48%). Progression-free survival was 28% (s.e., 9%), 68% (s.e., 6%) and 93% (s.e., 4%) for bHR, bIR and bLR, respectively (P<0.0001). Survival was 71% (s.e., 9%), 83% (s.e., 5%) and 98% (s.e., 2%) for bHR, bIR and bLR (P=0.02). Only bHR and histology other than common type were predictive of higher risk of failure (hazard ratio 4.9 and 2.7, respectively) in multivariate analysis. Stratification of ALCL patients based on MDD and anti-ALK titer should be considered in future ALCL trials to optimize treatment.

Transcription factor AP-1 is constitutively activated and IRF4 drives growth and survival in ALK+ and ALK– anaplastic large cell lymphoma (ALCL). Here we demonstrate high-level BATF and BATF3 expression in ALCL. Both BATFs bind classical AP-1 motifs and interact with in ALCL deregulated AP-1 factors. Together with IRF4, they co-occupy AP-1-IRF composite elements, differentiating ALCL from non-ALCL. Gene-specific inactivation of BATFs, or global AP-1 inhibition results in ALCL growth retardation and/or cell death in vitro and in vivo. Furthermore, the AP-1-BATF module establishes TH17/group 3 innate lymphoid cells (ILC3)-associated gene expression in ALCL cells, including marker genes such as AHR, IL17F, IL22, IL26, IL23R and RORγt. Elevated IL-17A and IL-17F levels were detected in a subset of children and adolescents with ALK+ ALCL. Furthermore, a comprehensive analysis of primary lymphoma data confirms TH17–, and in particular ILC3-skewing in ALCL compared with PTCL. Finally, pharmacological inhibition of RORC as single treatment leads to cell death in ALCL cell lines and, in combination with the ALK inhibitor crizotinib, enforces death induction in ALK+ ALCL. Our data highlight the crucial role of AP-1/BATFs in ALCL and lead to the concept that some ALCL might originate from ILC3.

IntroductionThere is increasing evidence of the importance of the immune system in cancer development and control. 1,2 Anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL) in children and adolescents represents an ideal tumor model to study the existence and impact of a tumor-specific immune response. First, all tumor cells express high levels of ALK in the form of ALK fusion proteins resulting from oncogenic chromosomal translocations. In contrast to many other tumor-associated antigens (TAAs), ALK fusion proteins exert an essential role in lymphomagenesis and the survival of the tumor cells, therefore representing real oncoantigens. 3 The most common ALK fusion protein is nucleophosmin (NPM)-ALK resulting from the t(2;5)(p23;q35) translocation occurring in 90% of ALK-positive ALCLs. 4 Second, the normal tissue distribution of ALK is restricted to a few scattered neurons in the central nervous system, 5 thus permitting specific targeting of ALK while minimizing problems with autoimmunity. Third, immunity to ALK may be implicated in the control of ALK-positive ALCLs. Antibodies against ALK and cytotoxic T-cell and CD4 T-helper responses to ALK have been detected in patients with ALK-positive ALCLs both at the time of diagnosis and during remission. 6-10 Furthermore, murine studies have identified ALK as an ideal tumor antigen for vaccination-based therapies. 11The current study was therefore performed in a large cohort of uniformly treated children and adolescents with ALK-positive ALCLs to investigate (1) the prevalence of a preexisting antibody response to ALK and (2) whether the strength of the antibody response correlates with parameters of tumor dissemination and the risk of relapse. Methods PatientsA total of 236 patients from the Berlin-Frankfurt-Muenster group study NHL-BFM95 study with a diagnosis of ALCL and German patients enrolled in the European inter-group trial ALCL99 between April 1996 and November 2007 were eligible for this study. Both studies were approved by the institutional Ethics committee of the primary investigator of the BFM group (A.R.) at Justus-Liebig-University. NPM-ALK positivity of the ALCL was confirmed by at least one of the following: presence of NPM-ALK mRNA, positive 2-color fluorescence in situ hybridization for the t(2;5)(p23;q35) NPM-ALK translocation, and/or immunolabeling studies to show the presence of nuclear and cytoplasmic ALK in the tumor cells.The treatment strategy was based on protocol NHL-BFM90, as described previously. For personal use only. on May 11, 2018. by guest www.bloodjournal.org From system) and the involvement of at-risk organs. 14 Staging procedures included bone marrow (BM) aspiration cytology and a spinal tap. Detection and quantification of submicroscopic amounts of circulating tumor cells in BM or blood at diagnosis were carried out by quantitative real-time polymerase chain reaction (PCR) for NPM-ALK transcripts as previously described. 15 Serum and/or plasma samples were obtained at the time of diagnosis from 95 patie...

Deletions on chromosome 6q are frequently reported in hematological malignancies. However, their biological or prognostic impact has not yet been clarified. This study analyzed loss of heterozygosity (LOH) at chromosome 6q and compared the LOH findings in pediatric precursor T lymphoblastic lymphoma (T-LBL) with the LOH findings in precursor-T lymphoblastic leukemia (T-ALL). For LOH analyses, a set of 25 microsatellite-markers on 6q14-q24 were examined. All patients were treated uniformly according to ALL-BFM-type treatment-strategy. A total of 1671 markers were successfully analyzed from 108 T-LBL patients. LOH was detected in 21 T-LBL patients. There was clear association between LOH at 6q and an increased risk of relapse. In comparison, 3109 markers were successfully analyzed from 127 T-ALL-patients. LOH was detected in 16 patients, but was not associated with increased relapse-rate. The localization of the common LOH regions identified for T-LBL and T-ALL samples did not overlap. Therefore patterns of LOH at 6q and the prognostic impact of LOH differ between T-ALL and T-LBL. These results hint at biologic differences between the two diseases.

We have cloned a fusion partner of the MLL gene at 11q23 and identified it as the gene encoding the human formin-binding protein 17, FBP17. It maps to chromosome 9q34 centromeric to ABL. The gene fusion results from a complex chromosome rearrangement that was resolved by fluorescence in situ hybridization with various probes on chromosomes 9 and 11 as an ins(11;9)(q23;q34)inv(11)(q13q23). The rearrangement resulted in a 5-MLL͞FBP17-3 fusion mRNA. We retrovirally transduced murine-myeloid progenitor cells with MLL͞FBP17 to test its transforming ability. In contrast to MLL͞ENL, MLL͞ELL and other MLLfusion genes, MLL͞FBP17 did not give a positive readout in a serial replating assay. Therefore, we assume that additional cooperating genetic abnormalities might be needed to establish a full malignant phenotype. FBP17 consists of a C-terminal Src homology 3 domain and an N-terminal region that is homologous to the cell division cycle protein, cdc15, a regulator of the actin cytoskeleton in Schizosaccharomyces pombe. Both domains are separated by a consensus Rho-binding motif that has been identified in different Rho-interaction partners such as Rhotekin and Rhophilin. We evaluated whether FBP17 and members of the Rho family interact in vivo with a yeast two-hybrid assay. None of the various Rho proteins tested, however, interacted with FBP17. We screened a human kidney library and identified a sorting nexin, SNX2, as a protein interaction partner of FBP17. These data provide a link between the epidermal growth factor receptor pathway and an MLL fusion protein.