Relationship between the amounts of EBV-DNA and EBNA per cell, clonability and tumorigenicity in two ebv-negative lymphoma lines and their EBV-converted sublines.

The effect of EBV-conversion of two EBV-negative lymphoma lines (Ramos and BJAB) on agarose clonability and tumorigenicity in nude mice was explored. The cloning frequency was increased in all 9 sublines investigated, between 1.1 and 4.9 times compared to the original "parental" lines. Tumorigenicity was increased in one out of 2 BJAB-derived, EBV-positive lines and in 3 of 6 Ramos-derived lines, while it was decreased in 3 others. A strong positive correlation between the number of genomes/cell and the amount of EBNA/cell was detected, and in 7 of 9 converted lines the cloning frequency also correlated to the number of EBV genomes. On the other hand, no relation was established between the number of EBV-genomes/cell, the amount of EBNA/cell and tumorigenicity.