Genetic polymorphism study of the BCL-6 gene, in diffuse large B-cell lymphoma

Abstract

Background: Diffuse large B-cell lymphoma (DLBCL) is characterized by a marked degree of morphologic and clinical heterogeneity. BCL-6 gene rearrangements are the most common frequent chromosomal abnormalities in DLBCL. Genetic modifications of the BCL-6 gene in lymphoma include translocations, deletions, and somatic mutations (SM) of the 5′-non-coding region. Mutations in the 5′-regulatory region of BCL-6 were suggested to play a role in non-Hodgkin's lymphoma (NHL) progression. Materials and Methods: We studied single nucleotide polymorphism (SNP) at position 397(G->C) of the 5'-non-coding regulatory region of BCL-6. We examined 30 patients with DLBCL treated at the National Cancer Institute (NCI), Cairo University, and 21 normal lymph nodes from patients with breast cancer were selected as controls. We used (Polymerase chain reaction- Restriction fragment length polymorphism) PCR-RFLP coupled analysis to detect the polymorphism. Results: From 30 patients with DLBCL, 17 were males (56.7%) and 13 were females (43.3%), the polymorphism G397C in the 5′ region of BCL-6 was detected in seven cases (23.3%). There was no significant association of clinical characteristics of DLBCL patients with this polymorphism, but there a trend for this polymorphism to occur more frequent in patients with aggressive disease. Conclusion: In our study, we found the incidence of the G397C SNP mutations in the 5′-regulatory region of BCL-6 to be 23.3%. No statistically significant association between the G397C SNP in BCL-6 gene with the standard clinico-pathological factors in patients with DLBCL was observed; however, there a trend for this polymorphism to occur more frequent in patients with aggressive disease.