Pathobiologic roles of epstein–barr virus-encoded microRNAs in human lymphomas

Epstein–Barr virus (EBV) is a human γ-herpesvirus implicated in several human malignancies, including a wide range of lymphomas. Several molecules encoded by EBV in its latent state are believed to be related to EBV-induced lymphomagenesis, among which microRNAs—small RNAs with a posttranscriptional regulating role—are of great importance. The genome of EBV encodes 44 mature microRNAs belonging to two different classes, including BamHI-A rightward transcript (BART) and Bam HI fragment H rightward open reading frame 1 (BHRF1), with different expression levels in different EBV latency types. These microRNAs might contribute to the pathogenetic effects exerted by EBV through targeting self mRNAs and host mRNAs and interfering with several important cellular mechanisms such as immunosurveillance, cell proliferation, and apoptosis. In addition, EBV microRNAs can regulate the surrounding microenvironment of the infected cells through exosomal transportation. Moreover, these small molecules could be potentially used as molecular markers. In this review, we try to present an updated and extensive view of the role of EBV-encoded miRNAs in human lymphomas

Gene expression profile predicts response to the combination of tosedostat and low-dose cytarabine in elderly AML

Tosedostat is an orally administered metalloenzyme inhibitor with antiproliferative and antiangiogenic activity against hematological and solid human cancers. Clinical activity has been demonstrated in relapsed acute myeloid leukemia (AML). Thirty-three elderly patients with AML (median age, 75 years) received 120 mg tosedostat orally once daily combined with subcutaneous low-dose cytarabine (20 mg twice per day for 10 days, up to 8 cycles), until disease progression. Induction mortality was 12%. According to an intention-to-treat analysis, the complete remission (CR) rate was 48.5%, and thus the primary end point of the study was reached (expected CR, 25%). The partial remission rate was 6.1%, with an overall response rate of 54.5%. Furthermore, 4 of 33 patients had stable disease (median: 286 days). The median progression-free survival and overall survival (OS) were 203 days and 222 days, respectively. Responding patients had a longer median OS than nonresponding patients (P = .001). A microarray analysis performed in 29 of 33 patients identified 188 genes associated with clinical response (CR vs no CR). Three of them (CD93, GORASP1, CXCL16) were validated by quantitative polymerase chain reaction, which correctly classified 83% of the patients. Specifically, CR achievement was efficiently predicted by the gene expression patterns, with an overall accuracy exceeding 90%. Finally, a negative predictive value of 100% was validated in an independent series, thus representing the first molecular predictor for clinical response to a specific combination drug treatment for AML. This trial has been registered at the European Medicines Agency and on the European Clinical Trials Database (https://www.clinicaltrialsregister.eu) as #2012-000334-19

MicroRNAs sequencing unveils distinct molecular subgroups of plasmablastic lymphoma

Plasmablastic lymphoma (PBL) is an aggressive lymphoma, often arising in the context of immunodeficiency and associated with Epstein-Barr virus (EBV) infection. The most frequently detected genetic alteration is the deregulation of MYC gene through the translocation - t(8;14)(q24;q32). The diagnosis of PBL is often challenging because it has an overlap in morphology, immunophenotype, cytogenetics and virus association with other lymphomas and plasma cell neoplasms; further, its molecular basis remains elusive. In the present study we aimed to better define the possible contribution of EBV infection as well as miRNA deregulation in PBL pathogenesis. We studied 23 cases of PBL, 19 Burkitt lymphomas (BL), and 17 extra-medullary plasmacytoma (EMPC). We used qPCR and immunohistochemistry to assess EBV latency patterns, while micro-RNA (miRNA) profiling was performed by next generation sequencing (Illumina) and validated by qPCR. Our analysis revealed a non-canonical EBV latency program with the partial expression of some proteins characterizing latency II and the activation of an abortive lytic cycle. Moreover, we identified miRNA signatures discriminating PBL from BL and EMPC. Interestingly, based on the miRNA profile, PBL appeared constituted by two discrete subgroups more similar to either BL or EMPC, respectively. This pattern was confirmed in an independent set of cases studied by qPCR and corresponded to different clinico-pathological features in the two groups, including HIV infection, MYC rearrangement and disease localization. In conclusion, we uncovered for the first time 1) an atypical EBV latency program in PBL; 2) a miRNA signature distinguishing PBL from the closest malignant counterparts; 3) the molecular basis of PBL heterogeneity

SNPs Array Karyotyping in Non-Hodgkin Lymphoma

The traditional methods for detection of chromosomal aberrations, which included cytogenetic or gene candidate solutions, suffered from low sensitivity or the need for previous knowledge of the target regions of the genome. With the advent of single nucleotide polymorphism (SNP) arrays, genome screening at global level in order to find chromosomal aberrations like copy number variants, DNA amplifications, deletions, and also loss of heterozygosity became feasible. In this review, we present an update of the knowledge, gained by SNPs arrays, of the genomic complexity of the most important subtypes of non-Hodgkin lymphomas

SF3B1 Gene Abnormalities are Not Common in Peripheral T-Cell Lymphomas-Not Otherwise Specified

The molecular basis of Peripheral T cell lymphoma not otherwise specified (PTCL/ NOS) has remained essentially elusive, due to heterogeneous nature of this malignancy. Recently recurrent genetic lesions affecting normal RNA splicing have been described in different hematological malignancies. Therefore, this study aimed to investigate the possible role of SF3B1 gene, the core component of splicing machinery, in PTCL/NOS pathogenesis

Increased angiogenesis seems to correlate with inferior overall survival in myeloid sarcoma patients

Myeloid sarcomas (MS) are tumors composed by myeloid elements and developing outside bone marrow. The prognosis is overall poor, only stem cell transplantation being consistently reposted as a potentially curative approach. In this study we explored whether microvessel density, a biomarker of angiogenesis, might be relevant in MS. We studied 60 MS, 24 acute myeloid leukemia, 5 normal bone marrow samples and 2 cases of extramedullary hemopoiesis in patients without evidence of hematological malignancy. We used immunohistochemistry (anti-CD34) to identify and quantify micro-vessel density (MVD) and micro-vessel grading (MVG). We found that MS had significantly higher MVD and MVG than normal bone marrow (p = 0.0002 and p < 0.001, respectively). We then found that cases with monocytic morphology had significantly higher MVD than myelo-monocytic and blastic ones (p = 0.005), while no differences were recorded based on extramedullary site. Finally, we found that higher MVD and higher MVG were associated with inferior outcome in terms of overall survival in multivariate analysis (p = 0.05 and p = 0.02, respectively), when censoring for stem cell transplantation was undertaken. In conclusion, we documented for the first time that increased angiogenesis is characteristic of MS and correlates with survival, suggesting that anti-angiogenic approaches might deserve a clinical evaluation in this setting

Single-Step IGHV Next-Generation Sequencing Detects Clonality and Somatic Hypermutation in Lymphoid Malignancies: A Phase III Diagnostic Accuracy Study

Background: Multiplex PCR based on consensus primers followed by capillary electrophoresis and Sanger sequencing are considered as the gold standard method for the evaluation of clonality and somatic hypermutation in lymphoid malignancies. As an alternative, the next-generation sequencing (NGS) of immune receptor genes has recently been proposed as a solution, due to being highly effective and sensitive. Here, we designed a phase III diagnostic accuracy study intended to compare the current gold standard methods versus the first commercially available NGS approaches for testing immunoglobulin heavy chain gene rearrangements. Methods: We assessed IGH rearrangements in 68 samples by means of both the NGS approach (LymphoTrack® IGH assay, and LymphoTrack® IGH somatic hypermutation assay, run on Illumina MiSeq) and capillary electrophoresis/Sanger sequencing to assess clonality and somatic hypermutations (SHM). Results: In comparison to the routine capillary-based analysis, the NGS clonality assay had an overall diagnostic accuracy of 96% (63/66 cases). Other studied criteria included sensitivity (95%), specificity (100%), positive predictive value (100%) and negative predictive value (75%). In discrepant cases, the NGS results were confirmed by a different set of primers that provided coverage of the IGH leader sequence. Furthermore, there was excellent agreement of the SHM determination with both the LymphoTrack® FR1 and leader assays when compared to the Sanger sequencing analysis (84%), with NGS able to assess the SHM rate even in cases where the conventional approach failed. Conclusion: Overall, conventional Sanger sequencing and next-generation-sequencing-based clonality and somatic hypermutation analyses gave comparable results. For future use in a routine diagnostic workflow, NGS-based approaches should be evaluated prospectively and an analysis of cost-effectiveness should be performed

Cancer immunotherapy by a recombinant phage vaccine displaying EGFR mimotope: an in vivo study

To date, several small molecule inhibitors and monoclonal-antibodies (like ICR-62) have been used to treat tumors over-expressing epidermal growth factor receptor (EGFR). However, the limitations associated with these conventional applications accentuate the necessity of alternative approaches. Mimotopes as compelling molecular tools could rationally be employed to circumvent these drawbacks. In the present study, an M13 phage displaying ICR-62 binding peptide mimotope is exploited as a vaccine candidate. It exhibited high affinity towards ICR62 and polyclonal anti-P-BSA antibodies. Following the mice immunization, phage-based mimotope vaccine induced humoral immunity. Elicited anti-EGFR mimotope antibodies were detected using ELISA method. Moreover, the phage vaccine was tested on the Lewis lung carcinoma mice model to investigate the prophylactic and therapeutic effects. The tumor volume was measured and recorded in different animal groups to evaluate the anti-tumor effects of the vaccine. Our data indicate that the reported phage-based mimotope could potentially elicit specific antibodies resulting in low titers of EGFR-specific antibodies and reduced tumor growth. However, in vivo experiments of prophylactic or therapeutic vaccination showed no specific advantage. Furthermore, phage-mimotope vaccine might be a promising approach in the field of cancer immunotherapy