Project description:Nasal T/NK lymphoma is a unique subtype of non-Hodgkin lymphoma (NHL) that is aggressive and incurable closely associated with Epstein-Barr virus (EBV)3. The clonal expansion of EB infected T- or NK cell is also seen in patients with chronic active EBV (CAEBV) infection, suggesting that two diseases might partly share a similar mechanism by which EBV affect host cellular genes. In order to understand the pathogenesis of EBV-associated T/NK lymphoproliferative disorders (LPD) and design new therapies, we employed a novel EBV DNA microarray to compare patterns of EBV expression in SNK/T cells established from EBV-associated T/NK LPD. Keywords: parallel sample
Project description:Nasopharyngeal carcinoma (NPC) is endemic in Southeast Asia and southern China. The primary treatment for NPC is radiotherapy. Despite of the encouraging results of radiotherapy, local recurrence or distant metastases of NPC after the initial therapy is frequently found due to radioresistance. Therefore, there is an urgent need to identify genes that control radiosensitivty, aiming to reduce disease recurrence. Epstein-Barr virus (EBV) infection was closely associated with undifferentiated NPC. EBV-encoded microRNAs (miRNAs) played crucial roles in the pathogenesis of NPC. Ebv-miR-BART7 belongs to the 44 EBV BART miRNAs and was found to be up-regulated in NPC tissues and plasma. Forced expression of ebv-miR-BART7 enhanced the radiosensitivity of NPC cells. However, the mechanisms underlying the sensitizing effect of ebv-miR-BART7 on radiation remain largely unknown. Given that miRNA exerts biological functions by regulating its targets, we used microarray to identify the targets of ebv-miR-BART7 that regulate radiosensitivity of NPC cells.
Project description:EBV-positive cell lines were assayed for expression of EBV miRNAs. The names of the miRNAs are from miRBase from Fall 2007. Microarray probes are tandem complements of the mature miRNA sequence. We assayed Burkitt's lymphoma (BL), Nasopharyngeal carcinoma, post-transplant lymphoproliferative disease (PTLD), primary effusion lymphoma, and lymphoblastoid cell lines. We also assayed primary B cells that were infected with the B95-8 strain of EBV, which was found to express EBV miRNAs as early as 20 hours post infection. We have found PTLD and BLs from HIV-positive donors both express EBV miRNAs. These types of cell lines have not previously been found to express viral miRNAs. We have found that cells that support type I and type II latency express only the BART miRNAs, whereas cells that support type III latency express BART and BHRF1 miRNAs. Furthermore, BL cell lines that spontaneously lose EBV express levels of the viral miRNAs that are at least 5-fold lower than cell lines that do not lose EBV. In total, 48 samples have been assayed and included in this study. EBV-negative control samples are not included in this data set, but raw and processed data may be requested from the contributors. These EBV-negative cell lines include the Burkitt's lymphoma cell lines, BJAB and Akata-negative, the gastric carcinoma cell line, AGS, and uninfected primary B cells. Of the 48 samples, we have assayed 22 different EBV-positive cell lines and 4 different time points after infection of primary B cells with EBV. Replicates of the majority of cell lines is included in this data set. Replicates are from independent RNA isolations that were then hybridized to individual microarrays.
Project description:Latent infection with Epstein-Barr virus (EBV) is recognised as a factor in the pathogenesis of nasopharyngeal carcinoma (NPC). We found that EBV encoded Latent membrane protein 2A (LMP2A) enhances lipid accumulation significantly in NPC cells. We used microarrays to identify differential genes regulated by LMP2A in NPC cell lines.
Project description:EBV-positive cell lines were assayed for expression of EBV miRNAs. The names of the miRNAs are from miRBase from Fall 2007. Microarray probes are tandem complements of the mature miRNA sequence. We assayed Burkitt's lymphoma (BL), Nasopharyngeal carcinoma, post-transplant lymphoproliferative disease (PTLD), primary effusion lymphoma, and lymphoblastoid cell lines. We also assayed primary B cells that were infected with the B95-8 strain of EBV, which was found to express EBV miRNAs as early as 20 hours post infection. We have found PTLD and BLs from HIV-positive donors both express EBV miRNAs. These types of cell lines have not previously been found to express viral miRNAs. We have found that cells that support type I and type II latency express only the BART miRNAs, whereas cells that support type III latency express BART and BHRF1 miRNAs. Furthermore, BL cell lines that spontaneously lose EBV express levels of the viral miRNAs that are at least 5-fold lower than cell lines that do not lose EBV.
Project description:The cellular microRNA, miR-155 has been shown to be involved in lymphocyte activation and is expressed in EBV infected cells displaying type III latency gene expression but not type I latency gene expression. We show here that the elevated levels of miR-155 in type III latency cells is due to EBV gene expression and not epigenetic differences in cell lines tested and we show that expression in EBV infected cells requires a conserved AP-1 element in the miR-155 promoter. Gene expression analysis was carried out in a type I latency cell line transduced with a miR-155 expressing retrovirus. This analysis identified both miR-155 suppressed and induced cellular mRNAs and suggested that in addition to direct targeting of 3’ UTRs, miR-155 alters gene expression in part through the alteration of signal transduction pathways. 3’ UTR reporter analysis of predicted miR-155 target genes identified the transcriptional regulatory genes, BACH1, ZIC3, HIVEP2, CEBPB, ZNF652, ARID2, and SMAD5 as miR-155 targets. Western blot analysis of the most highly suppressed of these, BACH1, showed lower expression in cells transduced with a miR-155 retrovirus. Inspection of the promoters from genes regulated in EBV infected cells and in cells infected with a miR-155 retrovirus identified potential binding sequences for BACH1 and ZIC3. Together, these experiments suggest that the induction of miR-155 by EBV contributes to EBV mediated signaling in part through the modulation of transcriptional regulatory factors. Keywords: Gene expression analysis in EBV positive vs EBV negative cells
Project description:Purpose: Evaluation of the m6A modification of EBV and BJAB transcripts during EBV infection Methods: Human B lymphoma cell line BJAB was uninfected or infected with EBV for 24 hours. Total RNA from each sample were extracted. Intact mRNA was isolated from total RNA samples and then chemically fragmented to 100-nucleoside-long fragments. m6A methylated mRNAs were immunoprecipitated with anti-N6-methyadenosine (m6A) antibody (a part of the fragmented mRNAs was kept as input). Both m6A enriched mRNAs and input mRNAs were concentrated for RNA-seq library construction. Sequencing was performed using an Illumina HiSeq 4000. Results: EBV EBNA2 and BHRF1 transcripts were m6A modified and m6A modification of BJAB transcripts changed during EBV infection. Conclusions: Our study found that some EBV transcripts were m6A modified during EBV infection and EBV infection changed m6A modification profiles of BJAB transcripts.
Project description:DNA from Epstein-Barr virus (EBV)-transformed lymphocyte cell lines (LCLs) has proven very useful for studies of genetic sequence polymorphisms. Whether EBV-LCL DNA is suitable for methylation studies is less clear. We conduct a genome-wide methylation investigation using an array set with 45 million probes to investigate the methylome of EBV-LCL DNA and technical duplicates of whole blood (WB) DNA from the same 10 individuals. Methylation sites that show variation between individuals are potentially useful as biomarkers in disease studies. Our comparison is, therefore, focused specifically on these methylation variable sites. The sample correlations (i.e., a measure of whether the rank of the signals remains consistent between two samples from the same individual) for the methylation variable probes ranged from 0.69-0.78 for the WB duplicates and from 0.27-0.72 for WB versus EBV-LCL. To compare the pattern of the methylation signals, we grouped adjacent probes based on their inter-correlations. These analyses showed ~29,000 blocks in WB and ~14,000 blocks in EBV-LCL. Furthermore, merely 31% of the methylated regions detected in WB were detectable in EBV-LCLs. Our study shows that there are substantial differences in the DNA methylation patterns between EBV-LCL and WB. Thus, EBV-LCL DNA cannot be used as a proxy for WB DNA in methylation studies.