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Lymphoproliferative disorders are a heterogeneous group of malignant clonal proliferations of lymphocytes whose diagnosis remains challenging, despite diagnostic criteria are now well established, due to their heterogeneity in clinical presentation and immunophenotypic profile. Lymphoid T-cell disorders are more rarely seen than B-cell entities and more difficult to diagnose for the absence of a specific immunophenotypic signature. Flow cytometry is a useful tool in diagnosing T-cell lymphoproliferative disorders since it is not only able to better characterize T-cell neoplasms but also to resolve some very complicated cases, in particular those in which a small size population of neoplastic cells is available for the analysis. Here, we report three patients with mature T-cell neoplasms with atypical clinical and biological features in which analysis of peripheral blood and bone marrow specimens by means of multicolor flow cytometry was very useful to identify and characterize three rare T-cell lymphoproliferative disorders, such as angioimmunoblastic T-cell lymphoma, peripheral T-cell lymphoma not otherwise specified and T-cell prolymphocytic leukemia. The aim of this case series report is not only to describe three rare cases of lymphoproliferative neoplasms but also to raise awareness that a fast, highly sensitive, and reproducible procedure, such as flow cytometry immunophenotyping, can have a determinant diagnostic role in these patients.

Regulation of tumour cell proliferation by molecular chaperones is still a complex issue. Here, the role of the HSP90 molecular chaperone TRAP1 in cell cycle regulation was investigated in a wide range of human breast, colorectal, and lung carcinoma cell lines, and tumour specimens. TRAP1 modulates the expression and/or the ubiquitination of key cell cycle regulators through a dual mechanism: (i) transcriptional regulation of CDK1, CYCLIN B1, and MAD2, as suggested by gene expression profiling of TRAP1-silenced breast carcinoma cells; and (ii) post-transcriptional quality control of CDK1 and MAD2, being the ubiquitination of these two proteins enhanced upon TRAP1 down-regulation. Mechanistically, TRAP1 quality control on CDK1 is crucial for its regulation of mitotic entry, since TRAP1 interacts with CDK1 and prevents CDK1 ubiquitination in cooperation with the proteasome regulatory particle TBP7, this representing the limiting factor in TRAP1 regulation of the G2-M transition. Indeed, TRAP1 silencing results in enhanced CDK1 ubiquitination, lack of nuclear translocation of CDK1/cyclin B1 complex, and increased MAD2 degradation, whereas CDK1 forced up-regulation partially rescues low cyclin B1 and MAD2 levels and G2-M transit in a TRAP1-poor background. Consistently, the CDK1 inhibitor RO-3306 is less active in a TRAP1-high background. Finally, a significant correlation was observed between TRAP1 and Ki67, CDK1 and/or MAD2 expression in breast, colorectal, and lung human tumour specimens. This study represents the first evidence that TRAP1 is relevant in the control of the complex machinery that governs cell cycle progression and mitotic entry and provides a strong rationale to regard TRAP1 as a biomarker to select tumours with deregulated cell cycle progression and thus likely poorly responsive to novel cell cycle inhibitors. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Primary plasma cell leukemia (PPCL) is one of the most aggressive hematological malignancies. The prognosis of PPCL patients remains poor, although some improvements have been made in recent years. Areas covered: In this review recent clinical and biological advances in PPCL are reported. Some recommendations for the practical management of these patients are provided, with a particular focus on the role of novel agents and transplant procedures. A brief description of the currently ongoing clinical trials with new drugs is also enclosed. Expert opinion: PPCL still represents a difficult challenge for all hematologists. Here the authors provide a personal view on how the current, generally unsatisfactory results in this neoplastic disorder could be improved. In particular, dedicated studies exploring alternative therapies are necessary and eagerly awaited. Such studies should possibly be based on new biological information that could be of help in identifying novel genetic biomarkers for risk stratification and new actionable molecular targets.

The prevalence of TP53 mutations greatly varies between tumor types; in multiple myeloma (MM) they were rarely detected at presentation, while increased frequency was reported with disease progression. Using next-generation sequencing, we analyzed TP53 exons 4-9 in a large representative cohort comprising patients with MM at diagnosis and more aggressive forms of plasma cell (PC) dyscrasia, identifying mutations in 4/129 (3%) MM, 6/24 (25%) primary PC leukemia, and 2/10 (20%) secondary PC leukemia cases. A similar increase in prevalence associated with disease aggressiveness (5%, 29.2% and 44%, respectively) was observed for TP53 deletion. Interestingly, in five patients mutations were not concomitant with TP53 deletion. Furthermore, longitudinal analysis revealed the acquisition of TP53 mutations in three of nineteen cases analyzed at relapse. Identified variants were mostly missense mutations concentrated in the DNA binding domain, only partly reflecting the pattern globally observed in human cancers. Our data confirm that TP53 mutations are rare in MM at presentation and rather represent a marker of progression, similarly to del(17p); however, their occurrence even in absence of deletions supports the importance of their assessment in patients with PC dyscrasia, in terms of both risk stratification and therapeutic implications.

Pellegrino Musto,1 Vittorio Simeon,2 Roberto Guariglia,3 Gabriella Bianchino,4 Vitina Grieco,4 Filomena Nozza,4 Francesco La Rocca,2 Gioacchino Marziano,1 Anna Vittoria Lalinga,5 Emiliano Fabiani,6 Maria Teresa Voso,6 Patrizia Scaravaglio,7 Cristina Mecucci,8 Giovanni D'Arena31Scientific Direction, 2Laboratory of Preclinical and Translational Research, 3Unit of Hematology and Stem Cell Transplantation, 4Laboratory of Clinical Research and Advanced Diagnostics, 5Pathology Unit, IRCCS, Centro di Riferimento Oncologico della Basilicata, Rionero in Vulture, Italy; 6Department of Hematology, Universita Cattolica del Sacro Cuore, Rome, Italy; 7Laboratory of Internal Medicine and Hematology, S Luigi Gonzaga Hospital, Orbassano, Italy; 8Hematology and Bone Marrow Transplantation Unit, University of Perugia, Perugia, ItalyAbstract: The concomitant presence of del(5q) and JAK2V617F mutation is an infrequent event which occurs in rare patients with peculiar cytogenetic, molecular, morphological and clinical features, resembling those of both myelodysplastic syndromes and myeloproliferative neoplasms. Lenalidomide may induce rapid, profound, and long-lasting responses in a subset of these patients. However, the mechanism(s) by which the drug acts in these conditions remain not completely elucidated. A new case report and a review of all cases published so far in this setting are provided. Furthermore, the possibility of categorizing – from a clinical, pathological, and biological point of view – for at least some of these patients as a potential distinct entity is discussed.Keywords: myelodysplastic syndromes, myeloproliferative neoplasms, lenalidomide, del(5q), JAK2, World Health Organization

Regulation of tumour cell proliferation by molecular chaperones is still a complex issue. Here, the role of the HSP90 molecular chaperone TRAP1 in cell cycle regulation was investigated in a wide range of human breast, colorectal, and lung carcinoma cell lines, and tumour specimens. TRAP1 modulates the expression and/or the ubiquitination of key cell cycle regulators through a dual mechanism: (i) transcriptional regulation of CDK1, CYCLIN B1, and MAD2, as suggested by gene expression profiling of TRAP1-silenced breast carcinoma cells; and (ii) post-transcriptional quality control of CDK1 and MAD2, being the ubiquitination of these two proteins enhanced upon TRAP1 down-regulation. Mechanistically, TRAP1 quality control on CDK1 is crucial for its regulation of mitotic entry, since TRAP1 interacts with CDK1 and prevents CDK1 ubiquitination in cooperation with the proteasome regulatory particle TBP7, this representing the limiting factor in TRAP1 regulation of the G2-M transition. Indeed, TRAP1 silencing results in enhanced CDK1 ubiquitination, lack of nuclear translocation of CDK1/cyclin B1 complex, and increased MAD2 degradation, whereas CDK1 forced up-regulation partially rescues low cyclin B1 and MAD2 levels and G2-M transit in a TRAP1-poor background. Consistently, the CDK1 inhibitor RO-3306 is less active in a TRAP1-high background. Finally, a significant correlation was observed between TRAP1 and Ki67, CDK1 and/or MAD2 expression in breast, colorectal, and lung human tumour specimens. This study represents the first evidence that TRAP1 is relevant in the control of the complex machinery that governs cell cycle progression and mitotic entry and provides a strong rationale to regard TRAP1 as a biomarker to select tumours with deregulated cell cycle progression and thus likely poorly responsive to novel cell cycle inhibitors. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John WileySons, Ltd.

Lin28A is a highly conserved RNA-binding protein that concurs to control the balance between stemness and differentiation in several tissue lineages. Here, we report the role of miR-128a/Lin28A axis in blocking cell differentiation in acute myeloid leukemia (AML), a genetically heterogeneous disease characterized by abnormally controlled proliferation of myeloid progenitor cells accompanied by partial or total inability to undergo terminal differentiation. First, we found Lin28A underexpressed in blast cells from AML patients and AML cell lines as compared with CD34+ normal precursors. In vitro transfection of Lin28A in NPM1-mutated OCI-AML3 cell line significantly triggered cell-cycle arrest and myeloid differentiation, with increased expression of macrophage associate genes (EGR2, ZFP36 and ANXA1). Furthermore, miR-128a, a negative regulator of Lin28A, was found overexpressed in AML cells compared with normal precursors, especially in acute promyelocytic leukemia (APL) and in ‘AML with maturation’ (according to 2016 WHO classification of myeloid neoplasms and acute leukemia). Its forced overexpression by lentiviral infection in OCI-AML3 downregulated Lin28A with ensuing repression of macrophage-oriented differentiation. Finally, knockdown of miR-128a in OCI-AML3 and in APL/AML leukemic cells (by transfection and lentiviral infection, respectively) induced myeloid cell differentiation and increased expression of Lin28A, EGR2, ZFP36 and ANXA1, reverting myeloid differentiation blockage. In conclusion, our findings revealed a new mechanism for AML differentiation blockage, suggesting new strategies for AML therapy based upon miR-128a inhibition.

We set up a diagnostic double-color double-fusion fluorescence in situ hybridization (DCDF-FISH) assay to investigate a case of a de novo acute myeloid leukemia (AML)-M4 bearing an inv(11)(p15q22). DCDF-FISH detected the NUP98-DDX10 rearrangement as two fusion signals, at the short and the long arms of the inv(11). Reverse transcription-polymerase chain reaction (RT-PCR) and cloning experiments confirmed the NUP98-DDX10 fusion and identified two splicing fusion isoforms: the known "type II fusion," originating from the fusion of NUP98 exon 14 to DDX10 exon 7 and a new in-frame fusion transcript between NUP98 exon 15 and DDX10 exon 7, which we termed "type III fusion."

Introduction: Primary plasma cell leukemia (PPCL) is a rare and aggressive variant of multiple myeloma. The introduction of novel agents and modern technologies has recently partially changed the clinical and biological scenario of this malignancy, allowing limited, but not negligible, progresses.Areas covered: We will discuss: the complex landscape of genetic alterations in PPCL, derived from conventional and high-throughput technologies; the best available treatments for PPCL; the possible future therapeutic perspectives.Expert commentary: PPCL requires an immediate and intensive multi-phase treatment with short therapy-free intervals, which should include novel agents and autologous stem cell transplantation in eligible patients. Allogeneic transplantation should be considered in selected cases. In older and/or frailer individuals, personalized approaches should be applied. Integrated treatments with next generation proteasome inhibitors/IMIDs and monoclonal antibodies are currently planned or under investigation. The identification of novel genomic biomarkers may be potentially helpful for risk stratification and future personalized therapies.

The MLLT10 gene, located at 10p13, is a known partner of MLL and PICALM in specific leukemic fusions generated from recurrent 11q23 and 11q14 chromosome translocations. Deep sequencing recently identified NAP1L1/12q21 as another MLLT10 partner in T-cell acute lymphoblastic leukemia (T-ALL). In pediatric T-ALL, we have identified 2 RNA processing genes, that is, HNRNPH1/5q35 and DDX3X/Xp11.3 as new MLLT10 fusion partners. Gene expression profile signatures of the HNRNPH1- and DDX3X-MLLT10 fusions placed them in the HOXA subgroup. Remarkably, they were highly similar only to PICALM-MLLT10-positive cases. The present study showed MLLT10 promiscuity in pediatric T-ALL and identified a specific MLLT10 signature within the HOXA subgroup.

Mutations at the protein-coding region of TERT gene (chromosome 5p15.33) have been well characterized in patients affected by a constitutional telomere syndrome, including diskeratosis, aplastic anemia and pulmonary fibrosis (Calado RT, Hematology, ASH 2009:338). In rare cases somatic mutations may occur in de novo MDS/AML (Calado RT, Young NS. Blood 2008;111:4446). Mutations involving the regulatory region of TERT gene have been recently identified in a consistent proportion of familial and sporadic melanoma and in a subset of tumors originating from tissues with low rate of self-renewal (glioblastoma, liposarcoma, oligodendroglioma bladder cancer, upper urinary tract cancer). These mutations create new binding motifs for Ets/TCF transcription factors, thus increasing TERT gene transcription (Killela PJ et al, PNAS 2013;110:6021; Horn S et al, Science 2013;339:959). As far as we know TERT promoter mutations were never described in MDS. Material and Methods Index Case. A 52 years old woman was selected because of a complex phenotype including abnormal skin pigmentation, familial pulmonary fibrosis, osteoarthritis, and a refractory cytopenia with multilineage dysplasia (RCMD, WHO 2008) with a 47,XX,+8 karyotype. Screening Cases. Mutational analysis was extended to a cohort of 115 patients (72 males; 44 females, median age 69) referred to the Laboratory of Cytogenetics, Hematology Department,University of Perugia, Italy. Cytogenetics was normal in 49 cases (43%). Abnormalities included: isolated del(5q) (seven cases, 6%); del(5q) plus one additional change (three cases, 3%); isolated del(20q) (fourteen cases, 12%); trisomy 8 (five cases, 4%); monosomy 7 (two cases, 2%); -Y (three cases, 3%); del(11q) (two cases, 2%); complex karyotype (twenty-four cases, 21%); other aberrations (six cases, 5%). Genomic DNA was extracted from bone marrow (BM) of all cases and from peripheral blood T lymphocytes of index case using Salting out method. In all cases TERT promoter was screened using PCR based DHPLC assay (Wave system; MD Transgenomic Inc. Omaha, NE). The 274bp amplicon was amplified with forward primer 5'GTCCTGCCCCTTCACCTTC3' and reverse primer 5'AGCACCTCGCGGTAGTGG3' using Robust Start Taq KAPA2G (Biosystems, Woburn, MA). DNA from abnormal elution profiles were re-amplified and sequenced by Sanger method (ABI 3500 Genetic Analyzer, Applied Biosystems). Variations were detected using Finch TV v. 1.4.0. In the index case 23 amplicons encompassing all 16 exons of TERT gene were also screened (NC_000005.9). Mutations cloning was carried out after RNA extraction (Trizol, Invitrogen, Life Technologies, Paisley, UK), reverse transcription (ThermoscriptTM RT-PCR System, Invitrogen) and amplification (TERT_2CF (5'-CAGCGCTACTGGCAAATGCG-3' Ta-61,4°C; and TERT_2543R (5'-GGCACTGGACGTAGGACTTG-3' Ta-61,4°C). PCR products were sub-cloned into pGEM-T easy vector (Promega, Madison, WI, USA) and sequenced. Results Index Case. Patient was a compound heterozygous for two germline variations: a nonsense mutation c.1209C>A p.C403* (exon 2) and a missense mutation c.2455C>T p.R819C (exon 8). A putative somatic A>C transition 57 bp before the ATG start codon was detected only in BM cells (Table). Screening Cases. DHPLC analysis showed three patients (2.6%) with a two-peak elution profile. Sequencing revealed a 10 bp duplication (c.1-110_1-101) in case 2; a c.1-124 C>T point mutation in case 3; a point mutation c.1-78 C>T in case 4 (Table). Comment We showed that TERT gene promoter variations are recurrent events in 2.6% of MDS patients. Only low/int1 risk MDS (IPSS) were affected in this series. The c.1-57A>C, previously reported as a germline activating variation in familial melanoma (Horn S et al, Science 2013;339:959), was likely a somatic mutation in our index case, thus supporting its role in clonal MDS proliferation. We first found the melanoma activating c.1-124 C>T point mutation (Huang FW et al, Science 2013;339:957; Killela PJ et al, PNAS 2013;110:6021) in a MDS with isolated del(5q). The new variation of our case n.4 does not appear to introduce a new transcription factor binding site (http://www.cbrc.jp/research/db/TFSEARCH.html), whereas the 10bp duplication of case 2 indicates an hypothetical binding site for Ikaros. Further results from ongoing functional studies in these cases will be presented. Disclosures: No relevant conflicts of interest to declare.