It has been suggested that CD1a and CD1d molecules induce tumor-specific immune responses by presentation of tumor cell glycolipids to specific T cells and NKT cells. A decrease in the CD1a expressing dendritic cells in lung cancer as a mechanism of tumor escape from immune system has been reported. Therefore, this study was conducted to compare the genotypic frequencies of CD1a and CD1d genes in lung cancer patients and healthy controls.
Polymorphisms in exon 2 of CD1A (C622T) and CD1D (A354T) genes, were studied in 64 Iranian lung cancer patients compared to 95 age/sex/ethnicity matched and 311 non-matched healthy blood donors by a Polymerase Chain Reaction Sequence Specific Primer method.
The frequencies of CC, CT and TT genotypes of CD1A gene among patients were 75%, 18.8% and 6.2% compared to 78.9%, 28.1% and 0% in the matched control group and 79.7%, 18.7%, and 1.6% in the non-matched control group, respectively. There was a significant difference in the genotype frequencies of CD1A between lung cancer patients and matched controls (P = 0.047). However, the difference became less significant by comparing CD1A genotypes between patients and 311 non-matched blood donors (P = 0.085). No deviations from Hardy-Weinberg equilibrium in control groups were observed. The only observed genotype of CD1D among patients and controls was AA hompzygote genotype.
Our results suggest that there is a correlation between CD1A genotypes and lung cancer. Although the exact effect of this polymorphism on the protein expression or function is not understood, the resulted substitution of Threonine with Isoleucine in the antigen binding groove of the CD1a protein might affect antigen presentation potential of the molecule.
This study will help us in better understanding of genetic susceptibility to lung cancer and might provide opportunities for developing screening methods and/or lipid vaccines for cancer therapy in future.
Mehrnoosh Doroudchi, None.