Exploring the absence of LMP1-XhoI deletion in nasopharyngeal carcinoma patients: A genetic perspective.

Background: Nasopharyngeal carcinoma (NPC) is the most common type of head and neck cancer, and its development is closely linked to Epstein-Barr virus (EBV). Notably, changes in the viral Latent Membrane Protein 1 (LMP-1) gene, such as the absence of the Xhol restriction site, contribute to its oncogenic properties. This study was to explore the connection between the XhoI site and NPC progression, with the goal of enhancing early diagnosis and treatment strategies. Methods: Formalin-fixed paraffin-embedded (FFPE) tissues from NPC patients were collected, and using restriction fragment length polymorphism (RFLP-PCR), variants of the EBV LMP-1 XhoI gene were identified, followed by amplification of the BamHI-W gene. Results: EBV DNA was detected in all NPC tissue samples via amplification of the BamHI-W region, confirming widespread EBV association in the Jordanian cohort. Wild-type (WT) XhoI variant was identified in 82.86 % of NPC cases, whereas no samples exhibited the mutant-type (MT) XhoI variant, as substantiated by Sanger Sequencing of representative cases. Statistical analysis revealed no significant correlation between the presence of WT XhoI and variables such as patient sex, age, tissue origin, NPC subtype, or disease stage. Notably, most samples from stage III/IV harbored the WT XhoI variant. Overall, BamHI-W gene detection proved to be a more consistent molecular marker than LMP-1 XhoI in this population, and no relationship was established between LMP-1 XhoI mutation and NPC development. Conclusion: These findings primarily highlight the epidemiological association between EBV and NPC in Jordanian patients, rather than demonstrating immediate clinical applicability for screening or early diagnosis. The absence of the LMP-1 XhoI deletion in this cohort underscores significant geographic and ethnic heterogeneity in the prevalence of this genetic alteration among NPC patients.