Effects of Genetic Polymorphisms on the Expression of mRNA and Protein of ABCG2 Gene in Human Placenta

Abstract

Objective To evaluate the effects of mononucleotide polymorphisms on the mRNA and protein expression of ABCG2 gene in human placenta. Methods From March to May 2013, a total of 46 healthy Han Chinese pregnant women and their newborns were selected as study subjects from the Department of Obstetrics and Gynecology in West China Second University Hospital, Sichuan University.Their placentas and umbilical cords were consecutively collected.The study protocol was approved by the Ethical Review Board of Investigation in Human Being of West China Second University Hospital, Sichuan University.Informed consents were obtained from all participants.Fetal DNA were extracted from the umbilical cords, RNA and protein of ABCG2 gene were extracted from the placental tissue.Genotypes of the ABCG2 gene 421C>A and 34G>A polymorphism were performed by sequencing.The expression of ABCG2 gene mRNA and protein in the placenta were determined by real time(RT)-PCR and Western-blotting. The comparisons of mRNA and protein expression were performed among different genotypes of 421C>A and 34G>A polymorphism of ABCG2 gene.The general clinical data of pregnant women and neonates among different genotypes had no significant differences (P>0.05). Results The mean ABCG2 gene mRNA and protein expression had no significant differences among CC, CA and AA genotypes of 421C>A polymorphism (F=1.060, 3.051; P>0.05); however, for 34G>A polymorphism, the mean ABCG2 gene mRNA and protein expression of GG genotype were significantly higher than those of AA genotype(q=3.540, 4.720; P 0.05), respectively. Conclusions The 421C>A polymorphism has no impacted on the expression of mRNA and protein of the ABCG2 gene in human placenta, while the 34G>A polymorphism has effected on both of them. Key words: ABCG2 protein, human; Polymorphism, single nucleotide; Placenta