Association of E-cadherin single nucleotide polymorphisms with the increased risk of endometriosis in Indian women

Abstract

The objective of the present study was to investigate the association between gene E-cadherin single nucleotide polymorphisms (SNPs) and risk of developing endometriosis in Indian women and to evaluate the role of E-cadherin expression in the pathophysiology of endometriosis. A genetic association study was conducted in 715 endometriosis cases and 500 controls of Indian origin. We genotyped -160 C/A, +54 C/T and -347 G/GA SNPs of gene E-cadherin by PCR-sequencing and PCR-restriction fragment length polymorphism techniques. Haplotype frequencies for multiple loci and the standardized disequilibrium coefficient (D') for pair-wise linkage disequilibrium (LD) were assessed by Haploview Software. In addition, to better understand genetic contributions to the pathophysiology of endometriosis, the expression pattern of E-cadherin in the endometrium of women with and without endometriosis was analyzed by western blot and immunohistochemical analysis. The frequencies of -347GA/GA (P = 0.026) and -160A/A (P = 0.0019) genotypes and -347G/-160A/+54C (P = 0.007) and -347GA/-160A/+54C (P < 0.0001) haplotypes were significantly different between patients and controls. Strong LD was observed between -347G/GA and -160C/A loci (D' = 0.64) when compared with -347G/GA and +54C/T (D' = 0.585) or -160C/A and +54C/T (D' = 0.05) loci in cases. Furthermore, increased membranous E-cadherin expression was observed in cases than in controls. The expression seems to be genotype dependent. In conclusion, the E-cadherin -347GA/GA and -160A/A genotypes and -347GA/-160A/+54C and -347G/-160A/+54C haplotypes may jointly modify the risk of endometriosis in Indian women. In addition, the differential expression of E-cadherin may play an important role in pathogenesis of endometriosis.