| DNA methylation is a kind of important factor in the progress of cancer. Many researchers have demonstrated that gene methylation model is established in fetus; Imprinted gene H19is transcripted highly in fetus, mainly controlled by gene methylation. It has been verified that it is related with many tumors. Thus, to explore the factors affecting the express of epigenetic gene, such as DNA methylation, and clarify the role of environment and nutrition in the establishment of methylation will provide an important clue for the prevention of cancer.Objective:The aim of this study was to explore the relationship among "maternal nutritional intake, environmental factors and H19DNA methylation patterns in offsprings and birth characteristics", and to provide basic data for cancer prevention and nutritional intervention.Materials and methods:1. Selection of subjectsPregnant women who came to houzhai hospital for delivery between April and September2008were recruited into this study. Any one with diabetes, hepatitis B infection or other coeliac diseases was not included. Total99pregnant women were recruited as subjects and willing to participate in the study after being informed the prupose of the study.2. Questionnaire was designed according to the purpose of this study. All investigator were trained strictly and conducted pre-investigation to make sure the success of the investigation. All the information was kept secret. Air pollution data of local region was collected through Environmental Protection Bureau.3. Determination of birth characteristicsThe birth weight of infants was weighed using electronic scale; The head circumference and the birth length of offsprings were measured using horizontal length meter. 4. Determination of one-carbon nutrients in serumSerum folate and vitamin B12was determined by paramagnetic particle chemiluminescent immunoassay method. Serum zinc was determined by Atomic absorption spectrophotometry.5. The determination of H19DNA methylation status Methylation patterns of H19promotor and H19DMR (Different methylation region) were tested by QMS-PCR (quantitative methylation-specific polymerase chain reaction)6. Data management and statistical analysisAll the data was entering using software of Epidata3.1and furtherly analysed by the SPSS software, version12.0. Following methods were used in the study:paired sample T-test, multiple linear regression analysis and so on. A P-value of less than0.05was considered statistically significant.Results:1. The relationship among birth characteristics, nutrient content of maternal serum and maternal environmental exposures during pregnancy.(1)The average birth lengh of infants was49.48cm, the average birth weight of infants was3.19kg, the average birth head circumference of infants was33.83cm; multiliner regressive modle showed that birth lengh, birth weight and birth head circumference were related with BMI (body mass index) of mother (β=-0.198, P=0.046;β=0.336,P=0.003;β=0.34, P=0.012); Birth weight was related with infant genders (β=-0.198, P=0.046); Birth lengh was related with maternal cesarean (β=0.283, P=0.008)。(2)The average serum folate of mother and infants was29ng/ml and7.29ng/ml respectively; The average serum vitamin B12of mother and infants was175.34pg/ml and240.19pg/ml respectively; The average serum zinc of mother and infants was0.67μg/ml and0.93μg/ml respectively。 Serum folate level, vitamin B12and Zinc in cord blood was significantly higher than that in mother’s blood respectively (t=-12.183, P=0.001;t=-4.432, P=0.001; t=-5.551, P=0.001); Serum folate level and vitamin B12in cord blood was correlated with that of mother’s blood repectively (r=0.367,P=0.001; r=0.325, P=0.001); Serum Zinc level in cord blood was not correlated with that of mother’s blood(P>0.05).2.The relationship of serum nutrient content,maternal environmental exposures alld H19DNA methylation pattern.(1)The average percentages of methylation in H19promoter were68.53%for mother’s blood and68.00%for cord blood respectively.There was no significant difference of methylation in H19promoter between cord b1ood and mother’s b1ood (t=0.256,P=0.798),but correlated with each other(β=0.275,P=0.009).There was no significant difference of methylation in H19DMR between cord blood and mother’s blood(t=-0.105,P=0.917),but correlated with each other(β=0.472,p=0.001)(2)H19DNA promoter methylation status ofmaternal was correlated with cord blood serum zinc (β=0.275,P=0.009)；H19DMR methylation status of infants was correlated with vitamin B12of infants,maternal cesarean and passive smoking respectively(β=0.310,P=0.036；β=-0.334,P=0.005；β=-0.284,P=0.018)；H19DMR methylation status of maternal was correlated with maternal serum zinc (β=-0.420,P=0.008)(3)No correlation was observed between methylation in H19promoter of cord blood and maternal serum folate,vitalnin B12,weight gain during pregnanc,mother’s age,air pollution；Neither was methylation in H19promoter of maternal blood.Conclusion:1.Maternal pre-pregnancy body mass index is related with birth characteristics.2.Methylation of cord blood mainly depelldents on maternal Serum Hl9methylation.3.H19methylation is affected by nutrient of blood and environmental exposures... |
PDF Full Text Request