ALBERT

Beschreibung: Anaplastic Large Cell Lymphoma (ALCL) is an aggressive subtype of T-cell lymphoma. ALCLs are stratified based on the presence of anaplastic lymphoma kinase (ALK) translocations. ALK negative (ALK-ALCLs) are heterogeneous subtypes characterized by higher aggressiveness and poorer outcome than ALK+ALCL. The molecular and genetic asset of ALK-ALCLs has recently begun to emerge (i.e. JAK/STAT3 activating mutations, DUSP22, TP63, TP53 and IRF4 rearrangements), but an exhaustive picture of the molecular drivers leading to ALK-ALCLs transformation, progression, and immune evasion is still lacking. Long non coding RNAs (LncRNAs) are transcripts longer than 200 nucleotides with different regulatory functions ranging from transcriptional regulation to structural functions, which are emerging as relevant players in many cellular processes including cancer. Using deep RNA-sequencing profiling combined with de novo transcriptome assembly, we explored and validated the potential contribution of non-coding RNAs in a large series of ALCLs. 24 lncRNAs were found specifically enriched in ALCL samples. Among these, a 70Kb chromatin associated lncRNA (BlackMamba) was identified as preferentially associated with the ALK-ALCLs subtypes and was shown to be a target of the JAK/STAT3 signaling. BlackMamba was overexpressed in ALK-ALCL patient samples as well as in patient-derived tumor xenograft (PDTX) models. Its shRNA mediated knockdown (KD) in ALK-ALCL cells reduces cell proliferation and clonogenicity. BlackMamba KD cells also showed a remarkable increase in the number of multinucleated cells (without ploidy alteration) providing evidence that this lncRNA may be required for correct cytokinesis. To better characterize the role of BlackMamba we performed RNA-sequencing profiling in BlackMamba KD ALK-ALCL cells showing that this lncRNA affects primarily the expression of genes involved in cytoskeleton organization and remodeling. Noticeably, the DNA-helicase HELLS emerged among the most relevant BlackMamba target gene in ALK-ALCL cells and patients. Loss of BlackMamba causes profound reduction of HELLS concomitant with a reorganization of chromatin markers (reduction of K4me3 and increase of K27me3) in the HELLS locus. To test whether HELLS enforces BlackMamba-mediated transcription, we silenced HELLS by shRNA approach in ALK-ALCLs. Noticeably, loss of HELLS led to a reduction in cell growth, a delay in the duplication rate and a dramatic drop of clonogenicity potential of ALK-ALCL cells. This phenotype was also associated with an increased number of multinucleated cells, phenocopying the BlackMamba KD cells. We also showed that, HELLS KD causes expression changes in a subset of cytoskeleton-related genes previously identified as BlackMamba targets confirming that HELLS is a crucial mediator of BlackMamba function. Indeed, ectopic over-expression of HELLS in BlackMamba KD cells rescued the cell growth defects induced by the loss of lncRNA mitigated the polynucleation phenotype and restored the baseline expression of BlackMamba target genes. Being established that lncRNAs affect gene expression by recruiting chromatin remodeling complexes to target promoters or enhancers we also investigated whether BlackMamba may associates with HELLS and dictates its chromatin positioning in ALK-ALCL cells. By RNA-immunoprecipitation (RIP) we showed that HELLS binds to BlackMamba at in two distinct regions the 3'-end of the lncRNA. Next, by Chromatin Immunoprecipitation (ChIP) we demonstrated that HELLS is associated to BlackMamba target gene promoters exclusively in ALK-ALCLs in which BlackMamba is expressed. Collectively, these data demonstrate the existence of a new lncRNA-dependent mechanism controlling the recruitment of HELLS on chromatin sites and its expression in lymphomas. The axis BlackMamba-HELLS sustains the neoplastic phenotype of ALK-ALCL representing a potential vulnerability of ALCL cells. Disclosures Merli: Mundipharma: Honoraria; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses, Research Funding; Sandoz: Membership on an entity's Board of Directors or advisory committees; Teva: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Other: Travel Expenses; Janssen: Honoraria; Takeda: Honoraria, Other: Travel Expenses; Gilead: Honoraria.

Beschreibung: Burkitt lymphoma (BL) is the most common non-Hodgkin lymphoma (NHL) in children. Although it accounts for only 1-5% of NHL in adults, approximately 60% of the BL cases diagnosed each year in western countries occur in patients 〉40 years of age. Although adult and pediatric BL cases are indistinguishable by molecular classification, pediatric patients have a significantly better outcome than adults. While translocation of MYC to the immunoglobulin heavy or light chain genes is characteristic of pediatric and adult BL, genetic differences may contribute to the superior clinical outcome of childhood cases. Therefore, we aimed to identify the spectrum of additional genetic abnormalities that occur in adult and pediatric BL. Copy number analysis, gene expression profiling (GEP), and targeted sequencing of ~400 genes known to be mutated in NHLs were performed on a cohort of molecularly defined BL samples. Copy number abnormalities (CNAs) were identified by the Affymetrix 250k NspI SNP array in 73 BL tumors (28 adult, 45 pediatric), and sequencing was performed on 52 BLs (21 adult, 31 pediatric). Pediatric cases had fewer CNAs than adults. The most common focal abnormality identified was a gain on 13q31.3 encompassing MIR17HG. It was more frequent in adult compared to pediatric cases (35% vs 16%, p=0.085) and was associated with increased expression of miR-17~92 cluster members; and among adults, patients with this gain trended towards worse overall survival, though the number of cases with available information was small. Gain of 8q was found in ~20% of adult cases, but in no pediatric cases. Surprisingly, cases with 8q gain had significantly lower MYC mRNA expression (p〈 0.001) and lower protein expression. In cases with MYC gain 0/4 cases were positive for MYC protein expression by immunohistochemistry; in contrast,6/10 cases with no MYC gain were positive for MYC expression. This suggests that gain of 8q is driven by another gene in the region. Additional genetic alterations included gains of genomic loci encompassing MCL1 and MDM4 (1q21-24) and losses encompassing RB1, p53 and CDKN2A/CDKN2B. Pathway analysis of genes differentially expressed by CN status showed an enrichment of genes involved in cell cycle regulation, the p53 signaling pathway, and the ubiquitin proteasome pathway. The frequencies of mutations in commonly mutated genes including MYC, ID3, TP53, CCND3, DDX3X, ARID1A, and TCF3 were not significantly different in adult and pediatric BL. However, BCL2, (43%, p

Beschreibung: Diffuse large B-cell lymphoma (DLBCL) displays significant heterogeneity with regard to clinical, pathological, and genetic features. Using gene expression profiling, we have delineated 3 molecular subgroups within DLBCL: germinal center B cells (GCB-DLBCL), activated B cells (ABC-DLBCL), and primary mediastinal B-cell lymphoma (PMBL),while these defined subgroups show characteristic mutation profiles and oncogenic pathways, a small set of cases of DLBCL still remain "unclassifiable" (UC). Burkitt lymphoma (BL) is characterized by the t(8;14)(q24;q32) with distinct morphological and immunophenotypic features. The diagnostic distinction between BL and DLBCL is challenging in a subset of cases that have overlapping morphological, immunohistochemical, and even molecular features, but is crucial for effective therapy. The identification of long non-coding RNA (lncRNA) has added another critical component to cancer biology. LncRNAs are defined as a distinct set of non-protein coding transcripts longer than 200 nucleotides. The functions of a few lncRNAs have been recently elucidated of which some are thought to regulate gene-specific transcription. The goal of the current study was to identify reliable lncRNA signatures for the BL and DLBCL subgroups and evaluate their usefulness as prognostic biomarkers. We examined the expression of lncRNAs from our earlier studies using Affymetrix-HG-U133 plus 2 arrays to distinguish unique gene expression profiles between BL and DLBCL (PMID: 27292966). In the initial analysis, we compared BL (n=77) with DLBCL (n=474) and identified 275 differentially expressed lncRNAs (p=0.005, fold change〉1.5). There was high expression of TCL6 and DDX-AS11 in BL. We confirmed the microarray results for TCL6 and DDX-AS11 by qRT-PCR in a subset of cases. We further tested whether expression of TCL6 and DDX-AS11 was regulated by the MYC oncogene and observed significant downregulation of these transcripts upon CRISPR/cas9 mediated deletion of the MYC promoter in the Raji cell line. We also sought to identify GCB-DLBCL and ABC-DLBCL associated lncRNAs. We observed 36 lncRNAs highly expressed in ABC-DLBCL and 40 lncRNAs highly expressed in GCB-DLBCL (P=0.005, fold change〉1.5). Of the differentially expressed lncRNAs, lnc00487 and DUBR were upregulated in GCB-DLBCL, whereas lnc00944 and FUT8 were upregulated ABC-DLBCL. The observed expression differences were validated in ABC-DLBCL and GCB-DLBCL cell lines. The differentially expressed LncRNAs were also validated in other DLBCL cohorts. LncRNA00487 expression was associated with superior clinical outcome in DLBCL series treated with Rituximab (R)-CHOP (p=0.01), and gene expression and overall survival (OS) were validated in another DLBCL series treated with R-CHOP (PMID:22437443). In the present study, we found that lncRNAs are differentially expressed in aggressive B cell lymphoma and could be useful as diagnostic or prognostic markers. They may play an important role in lymphoma biology and further studies of their functions are warranted. Disclosures No relevant conflicts of interest to declare.

Beschreibung: Peripheral T-cell lymphoma (PTCL) is a group of complex clinicopathological entities, often associated with an aggressive clinical course. Angioimmunoblastic T-cell lymphoma (AITL) and PTCL-not otherwise specified (PTCL-NOS) are the 2 most frequent categories, accounting for 〉50% of PTCLs. Gene expression profiling (GEP) defined molecular signatures for AITL and delineated biological and prognostic subgroups within PTCL-NOS (PTCL-GATA3 and PTCL-TBX21). Genomic copy number (CN) analysis and targeted sequencing of these molecular subgroups revealed unique CN abnormalities (CNAs) and oncogenic pathways, indicating distinct oncogenic evolution. PTCL-GATA3 exhibited greater genomic complexity that was characterized by frequent loss or mutation of tumor suppressor genes targeting the CDKN2A/B-TP53 axis and PTEN-PI3K pathways. Co-occurring gains/amplifications of STAT3 and MYC occurred in PTCL-GATA3. Several CNAs, in particular loss of CDKN2A, exhibited prognostic significance in PTCL-NOS as a single entity and in the PTCL-GATA3 subgroup. The PTCL-TBX21 subgroup had fewer CNAs, primarily targeting cytotoxic effector genes, and was enriched in mutations of genes regulating DNA methylation. CNAs affecting metabolic processes regulating RNA/protein degradation and T-cell receptor signaling were common in both subgroups. AITL showed lower genomic complexity compared with other PTCL entities, with frequent co-occurring gains of chromosome 5 (chr5) and chr21 that were significantly associated with IDH2R172 mutation. CN losses were enriched in genes regulating PI3K–AKT–mTOR signaling in cases without IDH2 mutation. Overall, we demonstrated that novel GEP-defined PTCL subgroups likely evolve by distinct genetic pathways and provided biological rationale for therapies that may be investigated in future clinical trials.

Beschreibung: Key Points Adult-mBLs have distinct and more frequent DNA copy number abnormalities compared with pediatric-mBL. Comprehensive genomic analysis revealed that the BCR signaling pathway is a potential therapeutic target in adult-mBL.

Beschreibung: Peripheral T-cell lymphoma (PTCL) is a heterogeneous group of non-Hodgkin lymphomas and approximately 30% of PTCLs are designated as not-otherwise specified (PTCL-NOS). Gene expression profiling (GEP) identified molecular classifiers for PTCL entities and identified 2 novel biological subgroups within PTCL-NOS (PTCL-GATA3 and PTCL-TBX21), associated with T-cell differentiation subsets. To further investigate molecular oncogenesis, we performed microRNA expression profiling (miR-EP) in several molecular subtypes of PTCL including angioimmunoblastic T-cell lymphoma (AITL), PTCL-GATA3 and PTCL-TBX21 using formalin fixed paraffin embedded tissues. We also performed miR-EP of normal T-cell subsets polarized to represent different differentiation stages (TFH, TH1 and TH2). We performed miR-EP on 102 PTCL cases using either quantitative real time PCR (ABI, Biosystem) or ultra-sensitive direct miRNA counting (nCounter, NanoString). Corresponding GEP (mRNA) were available for 67 PTCL cases. Normal T-cells were polarized in-vitro with different cytokine milieu and examined by flow cytometry. We observed distinct miRNA profiles, with miRNA being uniquely expressed in TFH polarized cells (miR-26a-5p, miR-17-5p, miR-30d-5p, miR-22-3p, miR-222-3p, miR-142-3p, let-7i-5p and miR-29b-3p). In contrast, the TH1 lineage was enriched for expression of miR-155-5p, miR-146a-5p, miR-1246, miR-93-5p, miR-16-5p, miR-21-5p, miR-363-3p, miR-1260a, miR-186-5p, miR-148a-3p and miR-579-3p, whereas TH2 polarized cells expressed miR-181a-5p, let-7a-5p, miR-191-5p, miR-15b-5p, let-7d-5p, let-7b-5p, miR-140-5p, miR-98-5p, miR-423-5p and miR-630. Several of these miRNA expressed in the T-cells subsets showed corresponding expression in their respective PTCL entity such as miR-142-3p, let7i-5p, miR-21-5p and miR-29b-3p with AITL, miR-146-5p, miR-155-5p and miR-16-5p in PTCL-TBX21 and miR-181a-5p, miR-630 and let7a-5p in PTCL-GATA3. We also performed the MiRNA Enrichment Analysis and Annotation (miEAA) for miRNA signatures and observed an enrichment of miRNA regulating epigenetic modifications in TFH cells (p=0.028), whereas TH1 showed an enrichment of miRNA regulating IFN-g signaling (p=0.0024), and miRNA signatures in TH2 showed negative regulation of TGF-b signaling (p=0.023). Supervised analysis (p=0.05) of the miRNA profiles identified significant association of miR-126, miR-145, and let-7c-5p with AITL, when compared to other PTCLs. Similarly, miR-92a, miR-25, miR-636, miR-210, miR-222 and miR-491-5p significantly associated with PTCL-GATA3 and miRNA 126-3p, 145-5p, miR-26a-5p and miR-34a-5p associated with PTCL-TBX21. The miEAA for tumor miRNA signatures revealed enrichment of miRNAs regulating histone methylation (h3 k4 methylation) and chemokine receptor signaling in AITL, whereas miRNA regulating T-cell receptor were enriched in PTCL-TBX21 and TP53 signaling pathway in PTCL-GATA3. We validated the expression of miR-126 in AITL by qRT-PCR and also observed its increased expression in IL21 stimulated CD4+ T-cells. Ectopic expression of miR-126 resulted in a ~3 fold increased expression in T-cell lines and led to reduced proliferation and increased apoptosis with expression of T-cell exhaustion makers PD1 and TIM3. Computational algorithmic programs identified relevant biological targets of miR-126, including p85/PIK3R2, S1PR2 and DNMT3A that were further validated in-vitro. We observed an inverse correlation of miR-126 expression with S1PR2 expression (r=-0.64). S1PR2 is a crucial G protein-coupled receptor regulating B and T-cell migration in the germinal center (GC) reaction. Migration assays demonstrated significant decreases in T to B-cell migration, when B-cells (Raji) were co-cultured with Jurkat cells with ectopic expression of miR-126. With the GC reaction holding an important role in AITL, we investigated the biological significance of miRNA-126 in the context of the AITL microenvironment. High expression of miRNA-126 significantly associated with inferior survival in AITL (p=0.008) and significant differences in tumor microenvironment signatures. We identified distinct miRNA signatures for AITL and molecular subgroups of PTCL-NOS. Furthermore, elevated expression of miR-126 may contribute to the dysregulation and the homing of TFH cells in GC reaction through S1PR2 and warrants further mechanistic investigation. Disclosures No relevant conflicts of interest to declare.

Beschreibung: Peripheral T-cell lymphoma (PTCL) is a group of clinically and pathologically heterogeneous non-Hodgkin lymphomas (NHL). Using gene expression profiling (GEP), we have defined molecular classifiers for PTCL subtypes reflecting their pathobiology and oncogenic pathways (Iqbal et al. 2014). We have also shown associations of specific mutations with the molecular subgroups (Wang et al. 2015). Although genomic information is increasing, the pathogenetic mechanisms of PTCLs remain largely unknown. Therefore, we analyzed copy number variation (CNV) and GEP to identify unique genetic abnormalities in the defined PTCL molecular subgroups. CNV data were generated on fresh frozen or formalin-fixed paraffin-embedded genomic DNA (n=114) on 3 Affymetrix platforms (SNP 6.0, 250K SNP, and OncoScan). Two published cohorts (PTCL-NOS, Hartmann et al. 2010; ALCL, Boi et al. 2013) were included for validation. The gene expression analysis, morphological review and clinical characteristics of these cases have been included in previous studies (Iqbal et al. 2010, 2014). Angioimmunoblastic T-cell lymphoma (AITL) represents 20% of all PTCL cases. The most recurrent CNV in AITL was chromosome (chr) 5 gain (39%), followed by chr 21 gain (21%). Interestingly, chr 21 gain co-occurred with chr 5 gain (p=0.003). No recurrent losses (≥20%) were identified among these cases. Molecularly re-classified AITL cases from morphologically classified PTCL-NOS cases showed concordant results with bonafide AITL cases. Of the commonly mutated genes, DNMT3A, IDH2, RHOA and TET2, only IDH2R172Kshowed a significant association (p=0.012) with chr 5 gain. GEP showed enrichment of gene signatures associated with oxidative phosphorylation (PGC-1α target genes) in cases with chr 5 gain. PTCL, not otherwise specified (PTCL-NOS) is the most common PTCL subtype and cannot be further sub-classified using conventional approaches; however, we have identified 2 molecular subgroups within PTCL-NOS, the GATA3 and TBX21 subgroups which are related to 2 distinct T-helper subsets (Iqbal et al. 2014), by employing GEP. Consistent with earlier observations (Hartmann et al. 2010), PTCL-NOS showed remarkably varied CNVs with nearly 50% of cases showing high CNV frequencies. When correlated with molecular subgroups, distinctive CNVs were observed in the molecular GATA3 and TBX21 subgroups. The GATA3 subgroup displayed a large assortment of CNVs. Complete or partial gain of chr 7 (57%) was the most recurrent gain in these cases. Losses affecting 17p, 10q and 9p21, encompassing tumor suppressors such as TP53 (57%), PTEN (43%) and CDKN2A (43%), were frequent in the GATA3 subgroup. The TBX21 subgroup had significantly fewer CNVs, as none were recurring (≥20%); but gains of 5p or 11p were observed in 14%. Additionally, PTCL-NOS cases with ≥10% abnormal genome had significantly poorer overall survival (p=0.012) compared to those with fewer abnormalities. This finding validates the GEP molecularly defined subgroups, as the GATA3 subgroup displayed more CNVs and has been associated with a worse prognosis compared to the TBX21 subgroup (Iqbal et al. 2014). We were able to distinguish CNVs characteristic of the different entities, including the co-occurrence of chr 5 and 21 gains specific in AITL. Gain of 1q (complete or partial) was identified in the GATA3 subgroup of PTCL-NOS and anaplastic lymphoma kinase (ALK) (-) ALCL with equal frequencies (~ 36%), but only 16% in ALK(+) ALCL. Complete or partial gain of chr 7 was also observed in ALCL, but at a considerably lower frequency than in the GATA3 subgroup. Additionally, gain of chr 18 or regions of 17q, and loss of 5q or regions on both arms of chr 9, were more frequent in the GATA3 subgroup compared to other entities. The TBX21 subgroup was primarily differentiated from the GATA3 subgroup by presence of fewer CNVs. Our analysis provides a framework for future investigations into the molecular pathogenesis of PTCL, and highlights potential candidate oncogenes and tumor suppressors deregulated by copy number aberrations. Comparative analysis revealed that certain chromosomal abnormalities are entity-specific. AITL cases with IDH2R172K also had trisomy 5 suggesting that these oncogenic events cooperate in malignant transformation. Thus, the complexity of PTCL is finally becoming clearer with the integration of high resolution molecular techniques for global genomic analysis. Disclosures No relevant conflicts of interest to declare.

Beschreibung: INTRODUCTION: The diagnosis of Peripheral T-cell lymphomas not otherwise specified (PTCL-NOS) is currentlybased on an "exclusion criteria" model, since PTCL-NOS lack pathognomonic features. Nevertheless, based on gene expression data, Iqbal et al(Blood 2014) have recently identified two different PTCL-NOS subgroups with different biological and prognostic features that accounts for approximately 80% of the cases and have different biological and prognostic features: one characterized by TBX21 overexpression and T-CD8+ molecular profile; the other by GATA3 overexpression and T-CD4+ profile. Herein, we used a wide comprehensive gene expression profiling (GEP) data set in order to further investigate the molecular features of different PTCL-NOS molecular entities. MATHERIAL AND METHODS: A data set were created including samples from 8 main published series (GSE6338, GSE14879, GSE19067, GSE19069, GSE58445 and GSE65823 at http://www.ncbi.nlm.nih.gov/geo/; E-TABM-702 and E-TABM-783 at https://www.ebi.ac.uk/arrayexpress) for a total of 541 patients. R/Bioconductor was used to generate and analyze the gene expression data. We applied the CIBERSORT algorithm (Gentles et al, Nat Gen 2015), which connects specific global expression profiles to the relative prevalence of tissue components (tumour and microenvironment cells). RESULTS: We first re-classified each sample included in the investigated data set based on previously published signatures (Iqbal et al. Blood 2014, Agnelli et al. Blood 2012). This approach led to a final data set of 144 PTCL-NOS (28%), 127 AITL (23%), 69 ALCL Alk neg (12%), 56 ALCL Alk pos (10%), 59 NK (11%) %), together with 86 healthy T-cell tissues. To our knowledge, this is the largest GEP data set ever described in PTCL so far. In the 144 PTCL-NOS cases, two main molecular clusters were extracted based on published signature, replicating previous findings: the first was characterized by both GATA3 expression (GATA3+) and T-CD4+ cell origin; the second by TBX21 expression (TBX21+) and T-CD8+ cell origin. Approximately 30% of all PTCL-NOS were characterized by neither GATA3 (GATA-) nor TBX21 expression (TBX21-), and for this reason they were classified as "double negative" PTCL-NOS. Based on data obtained by the CIBERSORT algorithm we found that the contribution of cellular microenvironment components was extremely heterogeneous and variable through the entire PTCL-NOS series. A significant T-CD4+ and T-CD8+ cell enrichment was reported among GATA3+ and TBX21+ groups, respectively. Interestingly, a fraction of GATA3+ PTCL-NOS (n=11, 7.6%) was characterized by a significant γδ T-cell component. Conversely, PTCL-NOS GATA3+ patients without γδ T-cell component signature were characterized by a low non-T-cell microenvironment component. This may reflect the major tumour infiltration due to higher proliferation rate as suggested by the strong GATA3 correlation with MIB1 and MYC expression (p

Beschreibung: Systemic Anaplastic Large Cell Lymphomas (ALCLs) is among the common subtypes of T-cell lymphomas. The prognosis of ALCLs patients has been proven to be associated with translocations of the anaplastic lymphoma kinase (ALK) gene, having ALK negative patients (ALK-ALCL) a poorer 5-years survival rate (30-40%). We now recognize that ALK- ALCL includes multiple subsets some of which are bear unique genetic defects and unique clinical outcomes. Long non coding RNAs (lncRNAs) are regulators of gene expression controlling critical processes (epigenetic regulation, imprinting, cell cycle, apoptosis) frequently deregulated in cancer. In T-cells, more than 500 lncRNAs are associated with lymphocyte signatures, control cell differentiation and cell identity. While lncRNAs are found to be differentially expressed in solid cancer and directly linked to the different stages of carcinogenesis, their role in lymphoid neoplasms is largely unknown. To identify novel lncRNAs maintaining the neoplastic phenotype of ALCL, we prepared cDNA libraries representative of coding and non-coding RNA. High coverage and directional RNA-sequencing was performed in 30 purified human T lymphocytes from multiple healthy donors, corresponding to different stages of differentiation, 22ALK+ ALCL and 20 ALK-ALCL patients' samples. Seven bona fide ALCL cell lines were included. By de novo transcriptome reconstruction and using a new bioinformatic pipeline, we identified 83lncRNAs exclusively expressed in ALCL patient's samples. Among them, 82 lncRNAs were coshared between ALK+ and ALK- ALCL and only one was exclusively expressed in ALK-ALCL samples. We named this new lncRNA BlackMamba. We selected the 10 top-scoring ALCL-associated lncRNAs and BlackMamba and determined their expression by RT-PCR, in a validation set of ALCL (ALK+: n=3, ALK-: n=3), T-ALL (n=8), PTCL (n=9), and AITL (n=9) samples. Resting and activated PBMCs from two additional donors were included. Our data confirmed that the 10 top-scoring ALCL-associated lncRNAs were expressed exclusively in ALCLs without differences in the expression among ALCL subtypes. Moreover, BlackMamba was detected only in ALCL samples with a preferential expression in ALK-ALCL samples. All lncRNAs were not expressed in normal T-lymphocytes. We next determine the BlackMamba expression in ALCL (n=6), T-ALL (n=3), cutaneous T-lymphomas (n=3) cell lines by RT-PCR. FedP, MAC1 and MAC2a (ALK-ALCL) cell lines showed the highest expression. Because the cellular localization of lncRNAs affects their function, we assessed the sub-cellular localization of BlackMamba by nucleo/cytoplasm cell fractionation and RT-PCR in FedP and MAC2A cell lines. BlackMamba displayed a preferential nuclear/chromatin-associated localization. Having proven that JAK/STAT signaling pathway plays a key role in both ALK+ and ALK-ALCL, we test whether the expression of BlackMamba could be modulated after treatment with JAK1/2 (ruxolitinib) TKi. Our data showed that, in FedP and MAC2A cell lines, BlackMamba expression was 50% down-regulated relative to control. Next, to identify whether BlackMamba may have a unique associated to specific chromatin remodel proteins, we verified its association with several candidates and found the physical interaction with the histone-lysine N-methyltransferase enzyme EZH2 by RIP in the FedP cells. Notably, after BlackMamba knock down, the proliferation of FedP cells was reproducibly reduced (25% at 84hrs using multiple RNAi oligonucleotides). Collective, our data indicate that ALCL aberrantly express novel and uncharacterized lncRNAs and that BlackMamba is a novel lncRNA associated with ALK-ALCL. Moreover, BlackMamba may contributes to the maintenance of ALK-ALCL neoplastic phenotype. Disclosures Merli: Roche: Membership on an entity's Board of Directors or advisory committees, Research Funding; Teva Pharmaceuticals Industries: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees.