Analysis of polymorphism at site -174 G/C of interleukin-6 promoter region in multiple myeloma

ABSTRACT

It is well established that interleukin-6 (IL-6) is an essential growth factor for multiple myeloma (MM) and patients with increased IL-6 levels have a poor prognosis. In healthy subjects, the presence of the C allele at a polymorphic site (-174 G/C) of the IL-6 gene is related to low IL-6 levels. In view of the potential association of this particular polymorphism with IL-6 concentration, and the relevance of IL-6 in MM pathogenesis, the objective of the present study was to investigate the prevalence of IL-6 (-174 G/C) promoter polymorphism and its association with development of MM in Brazilian individuals. We investigated the prevalence of these alleles in 52 patients and 60 healthy subjects (matched by age, sex, and race) of a Brazilian population. Thirty patients were male (42.4 percent), 24 (46.2 percent) were white and the median age at diagnosis was 58.5 years (range 28 to 84 years). To determine the IL-6 (-174 G/C) polymorphism, molecular analysis was performed by polymerase chain reaction followed by endonuclease restriction digestion. The genotype distributions observed in the group of patients were 4 percent CC, 42 percent GC and 54 percent GG. The C allele frequency was 0.25. These results were similar to the control group, suggesting no impact of this polymorphism on the susceptibility to MM.