AMINO-ACID CHANGE IN THE EPSTEIN-BARR-VIRUS ZEBRA PROTEIN IN UNDIFFERENTIATED NASOPHARYNGEAL CARCINOMAS FROM EUROPE AND NORTH-AFRICA

Different Epstein-Barr-virus(EBV) variants were found to be associated with nasopharyngeal carcinoma (NPC). The type-C variant lacks the Bam HI site between the BamHI WI and I* regions and the type-f variant ha s an extra BamHI site in the BamHI F fragment. The BNLF1 gene (which e ncodes the LMPI protein) from a nude-mouse-passaged CAO strain and fro m NPC biopsies from Taiwanese patients also exhibits variations result ing in structural and functional differences in the protein. The BZLF1 gene encodes the ZEBRA protein which triggers the EBV lytic cycle. A difference has been observed in 8 amino acids in the ZEBRA sequence in B95-8 (295) and P3HRI (ZP3) cell lines. EBV found in NPC biopsies and peripheral-blood cells from Asians was predominantly of the ZP3 type (72%), while 81% of samples from different EBV-associated diseases and peripheral-blood cells from North Africa or Europe were of the 295 ty pe. We found that an alanine 206 had been replaced by a serine in the 295 sequence in 72% of the NPC biopsies from European and North Africa n patients. The Zser206 variant is found in a significantly lower perc entage (p < 0.001) of other EBV-positive tissues from individuals in t he same region (10-33%). In contrast, a 30-bp deletion is observed nea r the 3' end of the LMPI gene in the majority of EBV (86%) from NPC an d peripheral-blood cells from Asians, whereas a significantly lower pe rcentage (p < 0.001) of NPC biopsies from European and North African p atients (56%) have this deletion, as do lymphocytes from control indiv iduals from the same region (36 and 55% respectively). (C) 1998 Wiley- Liss, Inc.