Placental expression of CDKN1C imprinted gene and birth weight of appropriate and small for gestational age neonates / 中华围产医学杂志

ABSTRACT

Objective To investigate the relationship between the expression of imprinted gene CDKN1C in placenta and the birth weight of neonates.Methods Twenty-nine term small for gestational age (SGA) neonates admitted to Peking University Third Hospital from January 1,2014 to December 31,2014 were recruited,and 29 appropriate for gestational age (AGA) neonates with a difference of not more than one week in gestational age served as controls.Fresh placental tissue was collected and the expression of imprinted gene CDKN1C mRNA in the placenta were detected by real-time fluorescence quantitative-polymerase chain reaction,and its protein expression was estimated by Western-blot.Chi-square test,independent-sample t test,Pearson's correlation analysis were used for statistical analysis.Results The CDKN1C mRNA expression level in SGA was significantly higher than that in AGA (0.133± 0.059 vs 0.100±0.046,t=2.401,P=0.020),so was the CDKN1C protein expression (0.280±0.043 vs 0.190±0.041,t=8.410,P=0.000).The CDKN1C mRNA expression levels were negatively correlated with birth weight in both groups (SGA group,r=-0.587,P=0.001;AGA group,r=-0.569,P=0.001),and the correlation was slightly stronger in SGA (r2=0.344) than in AGA (r2=0.324).The CDKN1C protein expression levels of the two groups were negatively correlated with birth weight (SGA group,r=-0.579,P=0.001;AGA group,r=-0.497,P=0.006),the correlation being stronger in SGA group (r2=0.335) than in AGA group (r2=0.247).The CDKN1C mRNA and protein expression levels of the two groups were negatively correlated with birth weight for gender,especially in males [mRNAr2=0.293(male)vs r2=0.185(female);proteinr2=0.730 (male) vs r2=0.601(female)].Neither CDKN1C mRNA nor protein expression level was correlated to the placenta weight (mRNASGA group,r=0.119,P=0.540;AGA group,r=-0.069,P=0.722;proteinSGA group,r=0.126,P=0.515;AGA group,r=-0.247,P=0.196).Conclusions The expressions of CDKN1C mRNA and protein may be related to birth weight of term SGA neonates,especially in male infants.