Discrete alterations in the BZLF1 promoter in tumor and non-tumor-associated Epstein-Barr virus.
BACKGROUND
Although the Epstein-Barr virus (EBV) is associated with malignant and nonmalignant diseases, its lytic replication is predominantly associated with nonmalignant diseases such as acute infectious mononucleosis (IM) or chronic active EBV infection. Lytic replication is also associated with type B EBV more than with type A EBV. Sustained lytic replication, however, is not compatible with tumor growth. We investigated whether control of an EBV lytic regulatory gene, BZLF1, differed in these diseases.


METHODS
Polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and direct DNA sequence analyses were used to characterize the promoter sequence of BZLF1 (Zp) in 52 tumors (34 non-Hodgkin's lymphomas, 13 post-transplant lymphoproliferative disease samples, and five nasopharyngeal carcinomas), and in peripheral blood lymphocytes from seven patients with chronic active EBV, six with IM, and 40 healthy, EBV-seropositive individuals. All sequences were compared with the prototype EBV strain B95.8 sequence. All statistical tests were two-sided.


RESULTS
Three polymorphic Zp sequences were detected. Among the malignant samples, sequence Zp-P, associated with 84% of type A EBV, was identical to that of EBV strain B95.8, whereas a second sequence (Zp-V3), associated exclusively with type B EBV (P<.001), contained three base substitutions. Among the nonmalignant samples, a distinct polymorphism, Zp-V4, containing the substitutions detected in Zp-V3 and an additional base change, was identified in all samples from chronic active EBV, IM, and healthy individuals, but in none of the malignant samples (P<.001). Zp-V4 was independent of the EBV type.


CONCLUSIONS
Polymorphisms in the regulatory sequences of BZLF1 are differentially distributed among malignant and nonmalignant cells and may identify EBV subtypes with various lytic activities, including those not associated with malignancies.
Gutiérrez
Marina I
MI
King Fahad National Centre for Children's Cancer and Research (KFNCCC&R), King Faisal Specialist Hospital and Research Centre, Riyadh, 11211 Saudi Arabia.
Ibrahim
Muna M
MM
Dale
Janet K
JK
Greiner
Timothy C
TC
Straus
Stephen E
SE
Bhatia
Kishor
K
D002051:Burkitt Lymphoma / Q000821:virology; D002277:Carcinoma / Q000821:virology; D004279:DNA, Viral / Q000032:analysis; D004268:DNA-Binding Proteins / Q000235:genetics*; D020031:Epstein-Barr Virus Infections / Q000235:genetics*; D004854:Herpesvirus 4, Human / Q000235:genetics*; D006801:Humans; D007244:Infectious Mononucleosis / Q000235:genetics; D008228:Lymphoma, Non-Hodgkin / Q000821:virology; D008232:Lymphoproliferative Disorders / Q000821:virology; D009303:Nasopharyngeal Neoplasms / Q000821:virology; D009369:Neoplasms / Q000235:genetics / Q000821:virology*; D016133:Polymerase Chain Reaction; D018807:Polymorphism, Single-Stranded Conformational; D011401:Promoter Regions, Genetic; D017422:Sequence Analysis, DNA; D015534:Trans-Activators / Q000235:genetics*; D014412:Tumor Virus Infections / Q000235:genetics*; D014764:Viral Proteins / Q000235:genetics
C063676:BZLF1 protein, Herpesvirus 4, Human; D004279:DNA, Viral; D004268:DNA-Binding Proteins; D015534:Trans-Activators; D014764:Viral Proteins