Deletion within LMP-1 Oncogene in Hodgkin's Disease in Korea

ABSTRACT

LMP (latent membrane protein)-1 protein is one of the Epstein-Barr viral proteins and it is the most crucial one for the transforming activity. It is known to show considerable variation in its nucleic acid sequence and some biologic difference is reported to be associated with the variation. Twenty four cases of the EBV-associated Hodgkin's disease cases were searched for the 30-bp deletion within the C terminal intracytoplasmic domain of LMP-1 oncogene, one of the well-known genetic variation, by PCR and Southern blot using selected sets of primers and probes. The strain of the virus was also determined with PCR. Each case was positive both on LMP-1 immunostaining and in situ hybridization for EBER (Epstein-Barr encoded RNA). Deletion within LMP-1 oncogene was identified in 22 cases (92%), of which 5 cases showed wild form as well as a deleted form of LMP-1 at the same specimens. In seven cases showing the non-deleted form, pure or mixed with a deleted form, the distribution of sex and age was similar to that of the deleted form-only-group, but there was a slight tendency for a higher stage at presentation (4 of the 7 cases presented with stage IV). Those seven cases comprised of 4 cases of nodular sclerosis (NS), 2 cases of mixed cellularity (MC) and a case of lymphocyte depletion subtype while there were 9 and 12 cases of NS and MC among all the examined cases, respectively. Two cases with both a deleted form and the non-deleted form of LMP-1 showed type I and II strain of the virus while all the others contained only type of the. In conclusion, the rate of deletion in LMP-1 oncogene in our series was higher than that reported in western countries and there was a slight tendency for higher stages in cases detecting mixed deleted and non-deleted forms of LMP-1 than in cases a of deleted from of LMP-1.