Enhanced transcription of the s-adenosylhomocysteine hydrolase gene precedes Epstein-Barr virus lytic gene activation in ganglioside-stimulated lymphoma cells

Stimulation of Epstein-Barr virus (EBV) genome-positive Burkitt lymphoma ce lls with the ganglioside IV(3)NeuAc-nLcOse(4)Cer leads to the induction of cell differentiation processes and activates the EBV lytic viral cycle. In cells of the Burkitt lymphoma line Raji differential expression of host cel l genes was analysed in the early phase (150 min) post stimulation with the ganglioside to display the cell activities that precede the activation of the EBV lytic cycle using the differential display reverse transcription-po lymerase chain reaction technique. Multiple fragment cDNAs derived from con trol cells and ganglioside-stimulated cells were amplified using random pri mers and displayed via polyacrylamide gel electrophoresis. The expression p attern of 8,400 bands was analysed. Eleven differentially expressed fragmen t cDNAs were reamplified and identified by nucleotide sequencing. Six of th ese could be identified as coding for proteins that may take part in virus reactivation and differentiation. The most striking finding was the inducti on of s-adenosylhomocysteine hydrolase (AHCY) expression. The cellular enzy me AHCY plays an important role in transmethylation reactions controlling t he replication of several viruses. Thus, an involvement in EBV replication can be suggested.