Aberrant ERG expression associates with downregulation of miR‐4638‐5p and selected genomic alterations in a subset of diffuse large B‐cell lymphoma

ERG (avian v‐ets erythroblastosis virus E26 oncogene homolog), an oncoprotein in prostate carcinoma and Ewing's sarcoma is associated with poor prognosis in patients with acute myeloid leukemia and T lymphoblastic leukemia. However little is known about ERG in lymphoma. Here we studied ERG in diffuse large B‐cell lymphoma (DLBCL) by immunohistochemistry, fluorescence in situ hybridization (FISH), genome‐wide microRNA (miRNA) expression profiling, real‐time reverse‐transcriptase polymerase chain reaction (RT‐PCR) and whole exome sequencing (WES). Approximately 30% of de novo DLBCLs (37 of 118) expressed ERG (ERG+). ERG expression showed no significant correlation with DLBCL cell‐of‐origin classification, patient's age, sex, nodal, or extranodal disease status, tumor expression of p53 or p63. There was no ERG rearrangement in 10 randomly selected ERG+ DLBCLs by FISH. Forty‐three miRNAs showed significant differential expression between ERG+ and ERG− DLBCLs. Downregulation of miR‐4638‐5p was confirmed by real‐time RT‐PCR. WES not only confirmed known gene mutations in DLBCLs but also revealed multiple novel gene mutations in POLA1, E2F1, PSMD8, AXIN1, GAB2, and GNB2L1, which occur more frequently in ERG+ DLBCLs. In conclusion, our studies demonstrated aberrant ERG expression in a subset of DLBCL, which is associated with downregulation of miR‐4638‐5p. In comparison with ERG‐negative DLBCL, ERG+ DLBCL more likely harbors mutations in genes important in cell cycle control, B‐cell receptor‐mediated signaling and degradation of β‐catenin. Further clinicopathological correlation and functional studies of ERG‐related miRNAs and pathways may provide new insight into the pathogenesis of DLBCL and reveal novel targets for better management of patients with DLBCL

Primary Effusion Lymphoma: A Clinicopathological Study of 70 Cases

Primary effusion lymphoma (PEL) is a rare type of large B-cell lymphoma associated with human herpesvirus 8 (HHV8) infection. Patients with PEL usually present with an effusion, but occasionally with an extracavitary mass. In this study, we reported a cohort of 70 patients with PEL: 67 men and 3 women with a median age of 46 years (range 26-91). Of these, 56 (80%) patients had human immunodeficiency virus (HIV) infection, eight were HIV-negative, and six had unknown HIV status. Nineteen (27%) patients had Kaposi sarcoma. Thirty-five (50%) patients presented with effusion only, 27 (39%) had an extracavitary mass or masses only, and eight (11%) had both effusion and extracavitary disease. The lymphoma cells showed plasmablastic, immunoblastic, or anaplastic morphology. All 70 (100%) cases were positive for HHV8. Compared with effusion-only PEL, patients with extracavitary-only PEL were younger (median age, 42 vs. 52 years, p = 0.001), more likely to be HIV-positive (88.9% vs. 68.6%, p = 0.06) and EBV-positive (76.9% vs. 51.9%, p = 0.06), and less often positive for CD45 (69.2% vs. 96.2%, p = 0.01), EMA (26.7% vs. 100%, p = 0.0005), and CD30 (60% vs. 81.5%, p = 0.09). Of 52 (50%) patients with clinical follow-up, 26 died after a median follow-up time of 40.0 months (range 0-96), and the median overall survival was 42.5 months. The median OS for patients with effusion-only and with extracavitary-only PEL were 30.0 and 37.9 months, respectively (p = 0.34), and patients with extracavitary-only PEL had a lower mortality rate at the time of last follow-up (35% vs. 61.5%, p = 0.07). The median OS for HIV-positive and HIV-negative patients were 42.5 and 6.8 months, respectively (p = 0.57), and they had a similar mortality rate of 50% at last follow-up. In conclusion, patients presenting with effusion-only versus extracavitary-only disease are associated with different clinicopathologic features. PEL is an aggressive lymphoma with a poor prognosis, regardless of extracavitary presentation or HIV status

PRMT5 is upregulated by B-cell receptor signaling and forms a positive-feedback loop with PI3K/AKT in lymphoma cells

PRMT5, which regulates gene expression by symmetric dimethylation of histones and non-histone target proteins, is overexpressed and plays a pathogenic role in many cancers. In diffuse large B cell lymphoma (DLBCL), the mechanisms of PRMT5 dysregulation and its role in lymphomagenesis remain largely unknown. Here we demonstrate that B cell receptor (BCR) signaling regulates PRMT5 expression in DLBCL cells. Immunohistochemical analysis reveals elevated levels of PRMT5 expression in DLBCL cases and in germinal center (GC) B cells when compared to naive B cells. PRMT5 can be induced in naive B cells by BCR stimulation. We discovered that BTK-NF-κB signaling induces PRMT5 transcription in activated B cell-like (ABC) DLBCL cells while BCR downstream PI3K-AKT-MYC signaling upregulates PRMT5 expression in both ABC and GCB DLBCL cells. PRMT5 inhibition inhibits the growth of DLBCL cells in vitro and patient derived xenografts. Genomic and biochemical analysis demonstrate that PRMT5 promotes cell cycle progression and activates PI3K-AKT signaling, suggesting a feedback regulatory mechanism to enhance cell survival and proliferation. Co-targeting PRMT5 and AKT by their specific inhibitors is lethal to DLBCL cell lines and primary cancer cells. Therefore, this study provides a mechanistic rationale for clinical trials to evaluate PRMT5 and AKT inhibitors for DLBCL

GJB2 mutation spectrum in 2063 Chinese patients with nonsyndromic hearing impairment

Background: Mutations in GJB2 are the most common molecular defects responsible for autosomal recessive nonsyndromic hearing impairment (NSHI). The mutation spectra of this gene vary among different ethnic groups. Methods: In order to understand the spectrum and frequency of GJB2 mutations in the Chinese population, the coding region of the GJB2 gene from 2063 unrelated patients with NSHI was PCR amplified and sequenced. Results: A total of 23 pathogenic mutations were identified. Among them, five (p.W3X, c.99delT, c.155_c.158delTCTG, c.512_c.513insAACG, and p.Y152X) are novel. Three hundred and seven patients carry two confirmed pathogenic mutations, including 178 homozygotes and 129 compound heterozygotes. One hundred twenty five patients carry only one mutant allele. Thus, GJB2 mutations account for 17.9% of the mutant alleles in 2063 NSHI patients. Overall, 92.6% (684/739) of the pathogenic mutations are frame-shift truncation or nonsense mutations. The four prevalent mutations; c.235delC, c.299_c.300delAT, c.176_c.191del16, and c.35delG, account for 88.0% of all mutantalleles identified. The frequency of GJB2 mutations (alleles) varies from 4% to 30.4% among different regions of China. It also varies among different sub-ethnic groups. Conclusion: In some regions of China, testing of the three most common mutations can identify at least one GJB2 mutant allele in all patients. In other regions such as Tibet, the three most common mutations account for only 16% the GJB2 mutant alleles. Thus, in this region, sequencing of GJB2 would be recommended. In addition, the etiology of more than 80% of the mutant alleles for NSHI in China remains to be identified. Analysis of other NSHI related genes will be necessary

p63 expression confers significantly better survival outcomes in high-risk diffuse large B-cell lymphoma and demonstrates p53-like and p53-independent tumor suppressor function

The role of p53 family member, p63 in oncogenesis is the subject of controversy. Limited research has been done on the clinical implications of p63 expression in diffuse large B-cell lymphoma (DLBCL). In this study, we assessed p63 expression in de novo DLBCL samples (n=795) by immunohistochemistry with a pan-p63-monoclonal antibody and correlated it with other clinicopathologic factors and clinical outcomes. p63 expression was observed in 42.5% of DLBCL, did not correlate with p53 levels, but correlated with p21, MDM2, p16INK4A, Ki-67, Bcl-6, IRF4/MUM-1 and CD30 expression, REL gains, and BCL6 translocation. p63 was an independent favorable prognostic factor in DLBCL, which was most significant in patients with International Prognostic Index (IPI) >2, and in activated-B-cell–like DLBCL patients with wide-type TP53. The prognostic impact in germinal-center-B-cell–like DLBCL was not apparent, which was likely due to the association of p63 expression with high-risk IPI, and potential presence of ∆Np63 isoform in TP63 rearranged patients (a mere speculation). Gene expression profiling suggested that p63 has both overlapping and distinct functions compared with p53, and that p63 and mutated p53 antagonize each other. In summary, p63 has p53-like and p53-independent functions and favorable prognostic impact, however this protective effect can be abolished by TP53 mutations

Age cutoff for Epstein-Barr virus-positive diffuse large B-cell lymphoma–is it necessary

Epstein-Barr virus-positive diffuse large B-cell lymphoma of the elderly (EBV+ DLBCL-e) is a molecularly distinct variant of DLBCL, characterized by a monoclonal B-cell proliferation that occurs in patients >50 years of age without a history or clinicopathologic evidence of immunodeficiency. However, patients with EBV+ DLBCL younger than 50-years-old also exist in Western countries. We evaluated the clinicopathologic, immunophenotypic and genetic features in Cacausian patients with EBV+ DLBCL who are ≤50 years of age and compared this patient group to patients who are >50 years. In patients who are ≤50 years, less frequent expression of BCL6 and a trend of more frequent expression of CD30 and pSTAT3 were found in patients with EBV+ DLBCL. In patients who are >50 years, common expression of CD30, p50, pSTAT3 and less frequent expression of BCL6 were observed. Older patients also more commonly had a poor performance status (ECOG≥2). Comparing EBV+ DLBCL patients in ≤50 years versus >50 years, both groups had similar clinicopathologic, immunophenotypic and genetic features. Gene expression profiling, microRNA profiling and treatment outcome of the younger patients with EBV+ DLBCL was not distinctive from tumors in older patients. Based on our data, we suggest that the arbitrary age cutoff for EBV+ DLBCL is unnecessary and should be eliminated in the WHO lymphoma classification scheme

Fractal Geometry and Convolutional Neural Networks for the Characterization of Thermal Shock Resistances of Ultra-High Temperature Ceramics

The accurate characterization of the surface microstructure of ultra-high temperature ceramics after thermal shocks is of great practical significance for evaluating their thermal resistance properties. In this paper, a fractal reconstruction method for the surface image of Ultra-high temperature ceramics after repeated thermal shocks is proposed. The nonlinearity and spatial distribution characteristics of the oxidized surfaces of ceramics were extracted. A fractal convolutional neural network model based on deep learning was established to realize automatic recognition of the classification of thermal shock cycles of ultra-high temperature ceramics, obtaining a recognition accuracy of 93.74%. It provides a novel quantitative method for evaluating the surface character of ultra-high temperature ceramics, which contributes to understanding the influence of oxidation after thermal shocks

Aberrant ERG expression associates with downregulation of miR‐4638‐5p and selected genomic alterations in a subset of diffuse large B‐cell lymphoma

ERG (avian v‐ets erythroblastosis virus E26 oncogene homolog), an oncoprotein in prostate carcinoma and Ewing's sarcoma is associated with poor prognosis in patients with acute myeloid leukemia and T lymphoblastic leukemia. However little is known about ERG in lymphoma. Here we studied ERG in diffuse large B‐cell lymphoma (DLBCL) by immunohistochemistry, fluorescence in situ hybridization (FISH), genome‐wide microRNA (miRNA) expression profiling, real‐time reverse‐transcriptase polymerase chain reaction (RT‐PCR) and whole exome sequencing (WES). Approximately 30% of de novo DLBCLs (37 of 118) expressed ERG (ERG+). ERG expression showed no significant correlation with DLBCL cell‐of‐origin classification, patient's age, sex, nodal, or extranodal disease status, tumor expression of p53 or p63. There was no ERG rearrangement in 10 randomly selected ERG+ DLBCLs by FISH. Forty‐three miRNAs showed significant differential expression between ERG+ and ERG− DLBCLs. Downregulation of miR‐4638‐5p was confirmed by real‐time RT‐PCR. WES not only confirmed known gene mutations in DLBCLs but also revealed multiple novel gene mutations in POLA1, E2F1, PSMD8, AXIN1, GAB2, and GNB2L1, which occur more frequently in ERG+ DLBCLs. In conclusion, our studies demonstrated aberrant ERG expression in a subset of DLBCL, which is associated with downregulation of miR‐4638‐5p. In comparison with ERG‐negative DLBCL, ERG+ DLBCL more likely harbors mutations in genes important in cell cycle control, B‐cell receptor‐mediated signaling and degradation of β‐catenin. Further clinicopathological correlation and functional studies of ERG‐related miRNAs and pathways may provide new insight into the pathogenesis of DLBCL and reveal novel targets for better management of patients with DLBCL