-174G/C polymorphism in the interleukin-6 promoter is differently associated with prostate cancer incidence depending on race.
Interleukin-6 (IL-6), a pro-inflammatory cytokine, is involved in prostate cancer progression, including androgen independence. Serum IL-6 levels also correlate with prostate tumor burden, prostate-specific antigen levels and metastasis. Since circulating cytokine levels vary considerably inter-individually, such variation could be linked to genetic factors, including genetic polymorphism. The -174G>C/rs1800795 polymorphism in the IL-6 promoter is functionally relevant in terms of transcriptional regulation and disease association. We investigated a possible association of the -174G/C polymorphism with prostate cancer. Since significant racial disparities exist in prostate cancer incidence, we also investigated this association between the -174G/C polymorphism and prostate cancer in Caucasians and African-Americans, separately. Direct sequencing of the PCR amplicon from genomic DNA was used for genotyping rs1800795 in all subjects [age-matched controls (N = 140) and prostate cancer patients (N = 164)]. Sample size and power was calculated using the PGA software. We found the GG genotype to be associated with increased risk of prostate cancer in Caucasian subjects, whereas the CC genotype was associated with increased risk in the African-American sample set. Such a dimorphic genotypic association with cancer and race is unique and suggests a complex gene-gene and gene-environment interaction.
Center for Cancer Research and Therapeutics Development, Clark Atlanta University, Atlanta, GA, USA.
S
S
Mandal
Department of Mathematics, Clark Atlanta University, Atlanta, GA, USA.
F
F
Abebe
Center for Cancer Research and Therapeutics Development, Clark Atlanta University, Atlanta, GA, USA jchaudhary@cau.edu.
J
J
Chaudhary
D000293:Adolescent; D000328:Adult; D001741:Black or African American; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic; D011471:Prostatic Neoplasms / Q000208:ethnology / Q000235:genetics*; D044465:White People
C508600:IL6 protein, human; D015850:Interleukin-6