Expression of the Epstein-Barr virus BamHI A fragment in nasopharyngeal carcinoma: evidence for a viral protein expressed in vivo

Abstract

A family of mRNAs that are transcribed rightward through the BamHI A fragment have been detected in C15, a nasopharyngeal carcinoma (NPC) which has been passaged in nude mice. Northern (RNA) blot hybridizations indicate that these RNAs are also expressed in three other NPCs which have been established in nude mice and in an NPC obtained at biopsy. Moreover, hybridization in situ detected transcription from BamHI A in 12 NPCs and 1 Epstein-Barr virus (EBV)-containing carcinoma of the parotid gland. In each case, transcription was detected in all of the malignant epithelial cells. Transcription was not detected in two cases of EBV-positive lymphoma biopsies by in situ hybridization nor in latently infected EBV-positive lymphoblastoid cell lines by Northern blot hybridization. The consistent transcription of these sequences in latently infected epithelial malignancy but not in lymphoid cells suggests that this viral function is associated with latent EBV infection of epithelial cells. Sequence analysis of a cDNA synthesized from the C15 tumor, representing the 3' end of BamHI A messenger RNA, revealed an open reading frame (ORF). Translation of this ORF in vitro produced several peptides that were immunoprecipitated with antisera from patients with NPC. The detection of antibodies to the protein encoded by the ORF present in the BamHI A cDNA indicates that BamHI A encodes a protein which is expressed in vivo and is antigenic.

Epstein-Barr virus and Hodgkin's disease: transcriptional analysis of virus latency in the malignant cells.

“…The identification of novel latent transcripts running through the BamHI A region of the EBV genome in the opposite orientation to conventional BamHI A transcripts of the virus lytic cycle came from work on a nude mousepassaged NPC cell line C15 (18,19). Such "rightwardrunning" transcripts appear, from limited analyses published to date, to be a consistent feature of NPC (53). Using PCR primers spanning introns in the largest BamHI A-specific cDNA isolated from the C15 NPC line, we have recently detected transcripts with this splice structure in 10 fresh NPC biopsies (Brooks et al, manuscript in preparation).…”

“…Given the similarities between NPC and HD with regard to EBV gene expression, we analyzed EBV-positive HD cases for such mRNAs and found easily detectable expression of the appropriately spliced transcript in all but one case. While a putative BamHI A-encoded protein product has been identified (53), the lack of a suitable antibody reagent precludes analysis of the expression of this protein in biopsies of NPC and HD. Whatever the function of the protein encoded by the BamHI A transcript, the expression of this mRNA in EBVpositive HD dearly indicates that it is not preferentially expressed in epithelial cells as has previously been suggested (53).…”

“…While a putative BamHI A-encoded protein product has been identified (53), the lack of a suitable antibody reagent precludes analysis of the expression of this protein in biopsies of NPC and HD. Whatever the function of the protein encoded by the BamHI A transcript, the expression of this mRNA in EBVpositive HD dearly indicates that it is not preferentially expressed in epithelial cells as has previously been suggested (53). Indeed our recent findings show that latently infected B cell lines also contain the same transcript (Brooks et al, manuscript in preparation).…”

Transcriptional expression of Epstein‐Barr virus genes and proto‐oncogenes in North African nasopharyngeal carcinoma

“…A study of viral polymorphism showed no significant difference between young and adult North African NPC patients [Bouzid et al, 19941, but only some 50% of young patients possessed IgA antibodies to viral capsid antigens (VCA) antigens despite a vigorous I g G response [Bouguermouh, 19851. EBV infection of NPC biopsy specimens may be of either the productive (lytic) or latent type [Raab-Traub et al, 19831, and genes. Transcription of BARF0 has been studied extensively by Northern hybridization [Gilligan et al, 1991;Chen et al, 1992;Karran et al, 19921, but that of other genes such as LMP1, LMP2, EBNA1, EBERs and BLZFl has only been demonstrated in NPC biopsies by reverse transcriptase-polymerase chain reaction (RT-PCR) [Brooks et al, 1992;Busson et al, 19921 or in situ hybridization ICochet et al, 1993;Wu et al, 19911. Viral peptides involved in latent infection, such as EBNAl and LMP1, are expressed by a variable number of cells in NPC biopsies [Fahraeus et al, 1988;Young et al, 19881, and early proteins such as ribonucleotide reductase, EA-D (BMRFl), EA-R (BHRFI) and BZLFl have been detected using monoclonal antibodies [Luka et al, 1988;Lung et al, 1989;Cochet et al, 19931.…”

First Record of Identification of RPMS1 Gene Variations in Vietnamese Nasopharyngeal Carcinoma Patients

“…Vietnam has one of the highest incidence rates of NPC in worldwide 1,2 . According to statistics of Globocan (2012), the high prevalence of NPC cases was observed the member of the BamHI-A Rightward Transcripts (BARTs) family, RPMS1 expression has been confirmed in all EBV-associated tumors [9][10][11][12][13] . A number of studies have reported attempts to identify the NPC associated EBV genes' variations, including EBV Nuclear Antigens (EBNAs), Latent Membrane Proteins (LMPs) and EBVencoded small nuclear RNAs (EBERs), have been shown to be associated with NPC pathogenesis [14][15][16][17] .…”