Multiple myeloma (MM) is a plasma cell neoplasm associated with a broad variety of genetic lesions. In spite of this genetic heterogeneity, MMs share a characteristic malignant phenotype whose underlying molecular basis remains poorly characterized. In the present study, we examined plasma cells from MM using a multi-epigenomics approach and demonstrated that, when compared to normal B cells, malignant plasma cells showed an extensive activation of regulatory elements, in part affecting coregulated adjacent genes. Among target genes up-regulated by this process, we found members of the NOTCH, NF-kB, MTOR signaling, and TP53 signaling pathways. Other activated genes included sets involved in osteoblast differentiation and response to oxidative stress, all of which have been shown to be associated with the MM phenotype and clinical behavior. We functionally characterized MM-specific active distant enhancers controlling the expression of thioredoxin (TXN), a major regulator of cellular redox status and, in addition, identified PRDM5 as a novel essential gene for MM. Collectively, our data indicate that aberrant chromatin activation is a unifying feature underlying the malignant plasma cell phenotype.

Multiple myeloma (MM) is an incurable disease, whose clinical heterogeneity makes its management challenging, highlighting the need for biological features to guide improved therapies. Deregulation of specific long non-coding RNAs (lncRNAs) has been shown in MM, nevertheless, the complete lncRNA transcriptome has not yet been elucidated. In this work, we identified 40,511 novel lncRNAs in MM samples. lncRNAs accounted for 82% of the MM transcriptome and were more heterogeneously expressed than coding genes. A total of 10,351 overexpressed and 9,535 downregulated lncRNAs were identified in MM patients when compared with normal bone-marrow plasma cells. Transcriptional dynamics study of lncRNAs in the context of normal B-cell maturation revealed 989 lncRNAs with exclusive expression in MM, among which 89 showed de novo epigenomic activation. Knockdown studies on one of these lncRNAs, SMILO (specific myeloma intergenic long non-coding RNA), resulted in reduced proliferation and induction of apoptosis of MM cells, and activation of the interferon pathway. We also showed that the expression of lncRNAs, together with clinical and genetic risk alterations, stratified MM patients into several progression-free survival and overall survival groups. In summary, our global analysis of the lncRNAs transcriptome reveals the presence of specific lncRNAs associated with the biological and clinical behavior of the disease.

Multiple myeloma (MM) is a plasma cell neoplasm associated with a broad variety of genetic lesions. In spite of this genetic heterogeneity, MMs share a characteristic malignant phenotype whose underlying molecular basis remains poorly characterized. In the present study, we examined plasma cells from MM using a multi-epigenomics approach and demonstrated that when compared to normal B cells, malignant plasma cells showed an extensive activation of regulatory elements, in part affecting co-regulated adjacent genes. Among target genes upregulated by this process, we found members of the NOTCH, NFkB, mTOR1 signaling and p53 signaling pathways. Other activated genes included sets involved in osteoblast differentiation and response to oxidative stress, all of which have been shown to be associated with the MM phenotype and clinical behavior. We functionally characterized MM specific active distant enhancers controlling the expression of thioredoxin (TXN), a major regulator of cellular redox status, and in addition identified PRDM5 as a novel essential gene for MM. Collectively our data indicates that aberrant chromatin activation is a unifying feature underlying the malignant plasma cell phenotype.

Patient: Male, 62Final Diagnosis: Chronic myeloid leukemiaSymptoms: Gastric polypsMedication: NilotinibClinical Procedure: —Specialty: HematologyObjective:Unusual or unexpected effect of treatmentBackground:Tyrosine kinase inhibitors (TKIs) are currently an important targeted drug class in the treatment of chronic myeloid leukemia (CML). Imatinib was the first approved TKI for CML in 2001. Nilotinib is a second-generation TKI, approved in 2007; it inhibits BCR-ABL, PDGFR, and c-KIT, and is 30 times more potent than imatinib. Tyrosine kinase enzymes are expressed in multiple tissues and are involved in several signaling pathways; they have been shown to have several off-target side effects.Case Report:We report a case of an elderly male with CML and no history of gastrointestinal diseases, treated with nilotinib, and developed recurrent gastric polyps after three years of treatment. We excluded common causes of gastric polyps and therefore considered nilotinib as a probable cause of recurrent gastric polyps.Conclusions:Recurrent gastric polyps could be a potential side effect of nilotinib treatment. Careful long-term monitoring of patients on TKI therapy is necessary and further long-term studies of TKI side effects are needed.

IntroductionLymphoid enhancer‐binding factor 1 (LEF‐1) overexpression has been recently remarkably reported in chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) and has shown utility in distinguishing CLL/SLL from other B‐cell lymphomas. CLL has a well‐defined immunophenotype, yet, some cases of CLL demonstrate atypical morphology/ phenotype reflected by low Matutes score (atypical CLL). Till date, LEF1 expression has not been systematically studied in cases of CLL with atypical features.MethodsIn this study, LEF‐1 expression was assessed by two different techniques, (immunohistochemistry and flow cytometry), to investigate the expression profile of LEF‐1 in cases of CLL/SLL, in comparison with other low‐grade B‐lymphomas and CLL with atypical features, including atypical immunophenotype and CLL with increased prolymphocytes or morphologically atypical cells.ResultsWe found that LEF‐1 expression is downregulated in CLL with atypical immunophenotype/features compared to classic CLL; Chi‐Square P < .0001. The ratio for LEF‐1 expression in malignant B‐cells/NK (by flow cytometry) in CLL/SLL with classic immunophenotype was higher than atypical CLL and is significantly higher in other small B‐cell lymphomas (P < .01). Absence of LEF‐1 expression in CLL/SLL is correlated (P < .05) with downregulation of CD5, CD23, CD200, expression of FMC7, brighter expression of CD79b, brighter expression of surface light chain, increased prolymphocytes and lower Matutes score.ConclusionAs downregulation of LEF‐1 expression is well correlated with atypical CLL, we suggest adding LEF‐1 to Matutes score as a beneficial marker to differentiate classic from atypical CLL LEF‐1 could also serve as a potential prognostic indicator for CLL clinical course.

No abstract

We determined the frequency of post-transfusion alloimmunisation against platelet and granulocyte antigens in 51 Tunisian polytransfused patients with haematological diseases. Serum samples were analysed by a standard and an antiglobulin-augmented lymphocytotoxicity technique, a granulocyte agglutination test, a granulocyte immunofluorescence test, a platelet immunofluorescence test and the monoclonal antibody-specific immobilisation of platelet antigens assay. No granulocyte-specific antibodies were detected. HLA antibodies were found in 58.8% of patients. Platelet-specific antibodies were detected in four patients and were directed against human platelet antigen (HPA)-5b, HPA-1b and HPA-3a. The three patients with Glanzmann's thrombasthenia developed anti-GPIIb/IIIa antibodies. This study provides immunogenetic information that could improve the management of transfusion therapy in Tunisia.

No abstract