Association of polymorphism of Interleukins Il6 (-174 G/C) and Il8 (-251 T/A) in Senegalese patients with colorectal cancers

Cytokines are proteins involved in cellular communication, particularly in the immune system. They are ambivalent and can promote or inhibit tumor progression. Their stimulation represents a promising strategy against cancer, particularly in the context of immunotherapy. To highlight the link between cytokines and tumorigenesis, polymorphisms of IL8 (-251T/A) and IL6 (-174G/C) were studied in Senegalese patients. The analysis of the polymorphism of interleukins IL6 (-174 G/C) and IL8 (-251 T/A) in 24 patients with colorectal cancer and 20 control individuals was performed by the PCR-RFLP method. Polymorphism and allelic diversity as well as genetic differentiation parameters and factorial correspondence analysis were generated by Genetix software version 4.05.2. Linkage equilibrium was sought using GenePop software version 4.3. Analysis of interleukin polymorphism showed a higher frequency of mutant genotypes CC (60%) and AA (54%) of interleukins IL6 and IL8 respectively. The frequency of these mutant genotypes was higher in controls with (85%) for IL6 and (80%) for IL8. The distribution of allelic and genotypic frequencies of the two loci are not in Hardy-Weinberg equilibrium. Poor discrimination between cancer cases and controls was observed. The low frequency of mutant alleles in the cancer population suggests a reduction in the transcriptional activity of the promoter of these genes and may compromise the antitumor immune response. The low distribution of these mutant alleles between the two populations shows that polymorphisms of IL6 (-174 G/C) and IL8 (-251 T/A) exert reduced penetrance of these genes in the occurrence of colorectal cancer.