ABSTRACT
Objective Studies and researches have indicated that the methylation level of PLAGL1 differentially methylated region (DMR) was associated with some development disorder syndromes.This project is purposed to prove whether methylation levels of PLAGL1 DMR is related to the fetal and early postnatal development.Methods We performed a meta-analysis of the published data on PLAGL1 DMR methylation levels in children with developmental disorders compared with that in normal children.Results PubMed,Medline,EMBASE,WanFang databases were systematically searched to identify relevant studies.We included 7 studies in this meta-analysis,with a total of 195 cases and 438 controls concerning 6 kinds of developmental disorder syndromes.The methylation level of PLAGL1 DMR was lower in children with abnormal growth (excess growth or retarded growth) than that in normal children,with a pooled percentage mean methylation difference (95％ confidence intervals) of-1.05 (-1.93,-0.17).On this basis,we analyzed the odds ratio (95％ confidence intervals) of hypomethylation of PLAGL1 DMR in abnormal growth children in comparison with normal children.The combined odds ratio (95％ confidence intervals) of hypomethylation in abnormal growth children is 2.18 (1.23,3.88) in comparison with normal children.Conclusion Hypomethylation of PLALG1 is actually a risk factor of suffering abnormal growth for children.
ABSTRACT
Background and purpose:PLAGL1 gene is a newly discovered gene, which could induce tumor cells’ apoptosis and cell cycle arrest. This study aimed to investigate the expression and the promoter methylation level ofPLAGL1 gene and its correlation withSDHB gene mutations in pheochromocytoma.Methods:The expressions of PLAGL1 mRNA was detected by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) method in 13 cases of normal adrenal medulla, 32 cases of benign pheochromocytoma group and 54 cases of malignant pheochromocytoma. We examined the promoter methylation status by methylation-speciifc polymerase chain reaction (MSP) andSDHB gene mutation by qRT-PCR ampliifcation and direct sequencing.Results:The relative expression volume ofPLAGL1 gene in malignant tumor tissue was (0.527±0.201), which was signiifcant lower than those in benigntumor tissue and normal adrenal medulla[(1.517±0.662) and (1.734±0.756)]. There was no remarkable difference between benign tumor tissue and normal tissue forPLAGL1 gene expression and promoter methylation.PLAGL1 gene methylation rate in malignant tumor tissue, benign tumor tissue and normal adrenal medulla were 68.5%, 18.8% and 15.4% respectively.SDHB gene mutation was detected in 7 malignant tumor tissues, while no mutation was found in benign and normal group.Conclusion:Lower expression status ofPLAGL1 gene showed signiifcant correlation with promoter methylation which may be associated withSDHB gene mutation.