Qualitative analysis of the expression of Epstein--Barr virus lytic genes in nasopharyngeal carcinoma biopsies

Abstract

We recently showed that BZLF1, the gene encoding the Epstein-Barr virus (EBV) ZEBRA protein, was expressed in all eight nasopharyngeal carcinoma (NPC) specimens studied. We present here studies on the expression of EBV lyric cycle genes in the same eight NPC biopsies to determine if production of the ZEBRA transactivator could lead to a complete productive cycle. The tumour lesions exhibit a number of different patterns of limited lytic gene expression. In three out of eight tumours neither BRLF1 nor BMLF1 expression could be detected. Otherwise BMLF1 mRNA was expressed in all the other specimens. Three specimens also expressed BRLF1. Two specimens not only exhibited BZLF1, BMLF1 and BRLF1 transcripts, but also expressed the late gene BLLF1 which encodes the membrane protein gp220. The early gene product BBLF2 could not be detected in any of the eight NPC. However, expression of the late gene encoding the lyric truncated form of LMP1 (D1LMP) was found in seven of the eight NPC biopsies. Thus, it could be suggested that the EBV abortive lytic cycle occurred in most of the NPC studied.

Quantification of gp350/220 Epstein–Barr Virus (EBV) mRNA by Real-Time Reverse Transcription-PCR in EBV-Associated Diseases

“…Our study also demonstrated the presence of gp350/ 220 mRNAs in three of five nasopharyngeal carcinoma biopsies, as demonstrated previously by Martel-Renoir et al (27 ) who found gp220 mRNA in two of eight biopsies, although all of them were positive for immediate-early transcripts. Another study using qualitative RT-PCR detected late major-capsid transcripts in five of seven nasopharyngeal carcinomas but also in three of five normal nasopharyngeal biopsies (5 ).…”

IFN-α–Stimulated Genes and Epstein-Barr Virus Gene Expression Distinguish WHO Type II and III Nasopharyngeal Carcinomas

“…Weak signals were detected for Z mRNA in approximately one third of the NPC samples (average estimated signal V1 Akata cell; data not shown), consistent with previous failures to detect the protein immunohistochemically (40). Only one sample expressed detectable VCA transcripts (data not shown), suggesting that the lytic cycle in the NPC tumor cells may be nonproductive (41). By comparison, we readily detected Ead expression in virtually all (z90%) of the samples (Table 3), making Ead the best lytic gene for comparative purpose.…”

Heterogeneous Epstein–Barr virus latent gene expression in AIDS-associated lymphomas and in type I Burkitt's lymphoma cell lines

“…PCR products were analysed by electrophoresis on agarose gels and transferred onto Hybond filters (Amersham) by Southern blotting. Filters were hybridized with specific 32 P-labelled probes to confirm the specificity of the PCR product generated, as described (Martel-Renoir et al, 1995). Comparison of the efficiency of the different PCR amplifications was performed using a semi-quantitative RT-PCR method.…”

“…The quality of the cDNA products was checked by amplification of hypoxanthine phosphoribosyl transferase (HPRT) (vi). PCR products were hybridized as described by Martel-Renoir et al (1995) with specific 32 P-labelled probes to confirm the specificity of the generated PCR products (data not shown). Tunours #3, #4 and #11 were used in the assay.…”