The spectrum of peripheral T-cell lymphomas:

Identification of Hub Genes and Key Pathways Associated with Peripheral T-cell Lymphoma

Peripheral T-cell lymphoma (PTCL) is a very aggressive and heterogeneous hematological malignancy and has no effective targeted therapy. The molecular pathogenesis of PTCL remains unknown. In this study, we chose the gene expression profile of GSE6338 from the Gene Expression Omnibus (GEO) database to identify hub genes and key pathways and explore possible molecular pathogenesis of PTCL by bioinformatic analysis. Differentially expressed genes (DEGs) between PTCL and normal T cells were selected using GEO2R tool. Gene ontology (GO) analysis and Kyoto Encyclopedia of Gene and Genome (KEGG) pathway analysis were performed using Database for Annotation, Visualization and Integrated Discovery (DAVID). Moreover, the Search Tool for the Retrieval of Interacting Genes (STRING) and Molecular Complex Detection (MCODE) were utilized to construct protein-protein interaction (PPI) network and perform module analysis of these DEGs. A total of 518 DEGs were identified, including 413 down-regulated and 105 up-regulated genes. The down-regulated genes were enriched in osteoclast differentiation, Chagas disease and mitogen-activated protein kinase (MAPK) signaling pathway. The up-regulated genes were mainly associated with extracellular matrix (ECM)-receptor interaction, focal adhesion and pertussis. Four important modules were detected from the PPI network by using MCODE software. Fifteen hub genes with a high degree of connectivity were selected. Our study identified DEGs, hub genes and pathways associated with PTCL by bioinformatic analysis. Results provide a basis for further study on the pathogenesis of PTCL.

The Role of Activator Protein-1 (AP-1) Family Members in CD30-Positive Lymphomas

The Activator Protein-1 (AP-1) transcription factor (TF) family, composed of a variety of members including c-JUN, c-FOS and ATF, is involved in mediating many biological processes such as proliferation, differentiation and cell death. Since their discovery, the role of AP-1 TFs in cancer development has been extensively analysed. Multiple in vitro and in vivo studies have highlighted the complexity of these TFs, mainly due to their cell-type specific homo- or hetero-dimerization resulting in diverse transcriptional response profiles. However, as a result of the increasing knowledge of the role of AP-1 TFs in disease, these TFs are being recognized as promising therapeutic targets for various malignancies. In this review, we focus on the impact of deregulated expression of AP-1 TFs in CD30-positive lymphomas including Classical Hodgkin Lymphoma and Anaplastic Large Cell Lymphoma.

Anaplastic lymphoma kinase negative anaplastic large cell lymphoma of hard palate as first clinical manifestation of acquired immune deficiency syndrome

Anaplastic large cell lymphoma (ALCL) is an uncommon disease, accounting for <5% of all cases of non-Hodgkin's lymphoma. We report a case of 48-year-old male who presented a clinically benign swelling in the right anterior palatal region since last 2 months. Radiographic evaluation showed no bone loss in palatal area. Histological and radiological examination was in favor of a peripheral reactive lesion like pyogenic granuloma or a benign salivary gland tumor. Immunohistochemistry confirmed the diagnosis of anaplastic lymphoma kinase-negative (ALK(-)) ALCL. Further laboratory tests ELISA for human immunodeficiency virus (HIV) and CD4 cell count was done which showed positivity for HIV. To the best of our knowledge, it is the first case of ALK(-) ALCL in the hard palate presenting as the first clinical manifestation of acquired immune deficiency syndrome.

Comorbidity as an independent prognostic factor in elderly patients with peripheral T-cell lymphoma

The aim of the present study was to investigate the role of comorbidities in the outcomes of patients with peripheral T-cell lymphoma (PTCL) in a Chinese population. Fifty-six newly diagnosed PTCL patients aged >60 years were enrolled in our institution between April 2008 and August 2014. Medical record details including clinical parameters, pathological status, and treatment were reviewed. Prognostic factors were assessed using univariate and multivariate analyses. Forty-one (73.2%) patients with PTCL, not otherwise specified (PTCL-NOS), nine (16.1%) with angioimmunoblastic T-cell lymphoma, and six (10.7%) with anaplastic large cell lymphoma were recruited in this study. Twenty-eight (50%) had at least one comorbidity. Univariate analysis showed that an Eastern Cooperative Oncology Group score of 2-4, the presence of B symptoms, an International Prognostic Index (IPI) score of 3-5, and a Charlson Comorbidity Index (CCI) score ≥2 were significantly associated with shortened overall survival (OS), whereas the presence of B symptoms, an IPI of 3-5, and a CCI ≥2 were associated with worsened progression-free survival (PFS). Multivariate analysis indicated that a high CCI (≥2) and a high IPI (3-5) were poor independent prognostic factors for OS and PFS in the elderly patients with PTCL. Comorbidity was identified as a new independent poor prognostic factor for elderly patients with PTCL.

Extranodal Natural Killer/T-Cell Lymphoma in Children and Adolescents: A Report of 17 Cases in China

OBJECTIVES

To investigate the clinicopathologic features of extranodal natural killer/T-cell lymphoma (ENKTL) not preceded by another Epstein-Barr virus (EBV)-related disorder in children and adolescents.

METHODS

A series of 17 cases of ENKTL not preceded by another EBV-related disorder in children and adolescents in one institution from China was retrospectively analyzed.

RESULTS

The patients had a median age of 13 years (range, 2-17 years), and the male to female ratio was 3.25:1. All the patients were of Chinese origin and without a history of another EBV-related disorder. The upper aerodigestive tract was involved in 14 (82.4%) cases, of which the sinonasal region was involved in 10 (58.8%) cases. Twelve (70.6%) patients had stage I/II disease. Morphologically, coagulative necrosis and angiocentric/angiodestructive growth pattern were observed in 94.1% (16/17) and 88.2% (15/17) of all cases, respectively. Thirteen (76.5%) cases were mainly composed of medium-sized cells. All cases expressed cytoplasmic CD3 and at least one marker for cytotoxic granules. CD56 expression was seen in 16 (94.1%) of 17 cases. Each case harbored EBV.

CONCLUSIONS

ENKTL not preceded by another EBV-related disorder in children and adolescents is occasionally observed in China. It tends to have a male predominance. The upper aerodigestive tract, especially the sinonasal region, is the most commonly involved site. The morphologic features and immunophenotype in children and adolescents are similar to that occurring in adults.

PIM kinases as potential therapeutic targets in a subset of peripheral T cell lymphoma cases

Currently, there is no efficient therapy for patients with peripheral T cell lymphoma (PTCL). The Proviral Integration site of Moloney murine leukemia virus (PIM) kinases are important mediators of cell survival. We aimed to determine the therapeutic value of PIM kinases because they are overexpressed in PTCL patients, T cell lines and primary tumoral T cells. PIM kinases were inhibited genetically (using small interfering and short hairpin RNAs) and pharmacologically (mainly with the pan-PIM inhibitor (PIMi) ETP-39010) in a panel of 8 PTCL cell lines. Effects on cell viability, apoptosis, cell cycle, key proteins and gene expression were evaluated. Individual inhibition of each of the PIM genes did not affect PTCL cell survival, partially because of a compensatory mechanism among the three PIM genes. In contrast, pharmacological inhibition of all PIM kinases strongly induced apoptosis in all PTCL cell lines, without cell cycle arrest, in part through the induction of DNA damage. Therefore, pan-PIMi synergized with Cisplatin. Importantly, pharmacological inhibition of PIM reduced primary tumoral T cell viability without affecting normal T cells ex vivo. Since anaplastic large cell lymphoma (ALK+ ALCL) cell lines were the most sensitive to the pan-PIMi, we tested the simultaneous inhibition of ALK and PIM kinases and found a strong synergistic effect in ALK+ ALCL cell lines. Our findings suggest that PIM kinase inhibition could be of therapeutic value in a subset of PTCL, especially when combined with ALK inhibitors, and might be clinically beneficial in ALK+ ALCL.

Factors predicting survival in peripheral T-cell lymphoma in the USA: a population-based analysis of 8802 patients in the modern era

Current prognostic models for peripheral T-cell lymphoma (PTCL) have multiple limitations, and questions exist regarding applicability to current patients. We utilized the Surveillance Epidemiology and End Results (SEER)-18 database to evaluate factors affecting overall survival (OS) of PTCL in the modern era and identified 8802 patients between 2000-2010. Most subtypes of PTCL increased in incidence during the study period. In univariate analyses, age >55 years, black race, advanced stage, absence of extra-nodal disease, omission of radiation therapy (RT) and high-risk histology each predicted inferior OS (P < 0·0001). Multivariate analysis (MVA) demonstrated that hepatosplenic, enteropathy-associated and extra-nodal Natural Killer/T cell histologies, each had hazard ratios >1·5 (P ≤ 0·0001) for death. Further, age ≥55 years, black race and advanced stage maintained their significance in the MVA (P < 0·0001 each). Based on the significant factors, a prognostic model was constructed and subsequently validated in an independent cohort. The new model incorporated age, stage, histology and race, with an OS ranging from 9 months (highest risk group) to 120 months (lowest risk group). In summary, this is the largest study of PTCL patients in the modern era that provides risk stratification utilizing a new prognostic model that can be incorporated into future prospective clinical trials.

Elevated LDH and paranasal sinus involvement are risk factors for central nervous system involvement in patients with peripheral T-cell lymphoma

Background: The incidence and risk factors of central nervous system (CNS) involvement in peripheral T-cell lymphomas (PTCLs) are still unclear.

Patients and methods: We analyzed 228 patients with PTCLs, excluding cases of extranodal natural killer/T-cell lymphoma and primary cutaneous T-cell lymphoma, by retrospectively collecting the clinical features and outcomes of the patients.

Results: Twenty events (8.77%, 20/228) of CNS involvement were observed during a median follow-up period of 13.9 months (range 0.03–159.43). Based on univariate analysis, elevated serum lactate dehydrogenase (LDH) level [P = 0.019, relative risk (RR) 5.904, 95% confidence interval (CI) 1.334–26.123] and involvement of the paranasal sinus (P = 0.032, RR 3.137, 95% CI 1.105–8.908) adversely affect CNS involvement. In multivariate analysis, both were independently poor prognostic factors for CNS relapse [elevated LDH level: P = 0.011, hazard ratio (HR) 6.716, 95% CI 1.548–29.131; involvement of the paranasal sinus: P = 0.008, HR 3.784, 95% CI 1.420–10.083]. The survival duration of patients with CNS involvement was significantly shorter than that of the patients without CNS involvement (P = 0.009), with median overall survival of 7.60 months (95% CI of 4.92–10.28) versus 27.43 months (95% CI of 0.00–57.38), respectively.

Conclusions: Elevated LDH level and involvement of the paranasal sinus are two risk factors for CNS involvement in patients with PTCLs. Considering the poor prognoses after CNS relapse, prophylaxis should be considered with the presence of any risk factor.

Constitutively overexpressed 21 kDa protein in Hodgkin lymphoma and aggressive non-Hodgkin lymphomas identified as cytochrome B5b (CYB5B)

BACKGROUND

We have previously reported a novel constitutively overexpressed 21 kDa protein in Hodgkin Lymphoma (HL) and aggressive Non-Hodgkin Lymphomas (NHL). The objective of the current study was to 1) identify this protein using two independent methods, 2) study the expression of the protein and its encoding mRNA in reactive lymph nodes, normal lymphocytes and CD34+ bone marrow precursor cells, 3) analyse patterns of expression of the protein in tissue microarrays assembled from a large number of diagnostic clinical biopsies from patients with HL, and 4) determine the copy number variation and mutation status of the encoding gene in HL cell lines.

RESULTS

Peptide sequencing by LC-MS/MS and protein identification by protein array screening identified a single protein, CYB5B. No mutations were detected in the CYB5B gene in HL cell lines. Quantitative PCR showed CYB5B gene expression was increased in HL and NHL cell lines. Array CGH using a submegabase resolution tiling array revealed gains in the CYB5B locus in HL cell lines KMH2 and L428. Membrane expression was seen in Reed-Sternberg cells in clinical biopsies from patients with HL but not in reactive lymph nodes. Bone marrow CD34+ precursor cells were CYB5B negative on the cell surface. RT-PCR assays of RNA extracted from T and B cell enriched fractions obtained from normal peripheral blood mononuclear cells, reactive lymph nodes, tonsils and normal bone marrow samples showed no evidence of increased mRNA levels of CYB5B in comparison to housekeeping gene GAPDH.

CONCLUSIONS

The 21 kDa protein overexpressed in HL and aggressive NHL is identical to CYB5B. CYB5B gene expression is increased in a subset of HL and NHL cell lines tested. This is associated with CYB5B gene amplification in HL cell lines KMH2 and L428. CYB5B may be a potential target for antibody-based therapy of HL and aggressive NHL as although cytoplasmic expression is present in reactive lymphocytes, it is not expressed on the cell surface of non-neoplastic lymphocytes or bone marrow precursor cells.