Immunoglobulin heavy variable (IgHV) gene mutation and micro-RNA
expression in Burkitt\u2019s lymphoma at Moi Teaching and Referral
Hospital in Western Kenya
Introduction: Burkitt\u2019s lymphoma (BL) is a virus associated
childhood B-cell cancer common in Eastern Africa. Continued survival of
B-cells in germinal centres depend on expression of high affinity
immunoglobulins (Ig) to complementary antigens by somatic hypermutation
of Ig genes. Cellular microRNAs, non-coding RNAs have been reported to
play role in cell cycle regulation. Both viral antigen dependent
mutation and micro-RNA expression maybe involved in BL pathogenesis.
Objective: To describe immunoglobulin heavy variable (IgHV)
rearrangement and micro-RNA expressions in BL tumours. Methods: Genomic
DNA were extracted and purified from BL tissue blocks at Moi Teaching
and Referral Hospital, before amplification using IgHV consensus
primers and sequencing. The sequences were then aligned with germline
alleles in IMGT/ V-QUEST\uae database. Total RNA extracted from
tissue blocks and cell lines were used to determine relative expression
of hsamiR-34a and hsa-miR-127. Results: In all tumours, allele
alignment scores and number of mutations range were 89.2-93.2%, 15-24
respectively. The range of IgHV amino acid changes were higher in
EBER-1+ (15-25) than EBER-1- (9-15). In MYC+ tumours, the relative
expression were: hsa-miR-127(2.09);hsa-miR-34a (2.8) and MYC-
hsa-miR-127 (1.2), hsa-miR-34a (1.0). Conclusion: B-cell in BL
contained somatic mutated IgHV gene and upregulated cellular microRNAs
with possible pathogenetic role(s)