PLAGL1 gene expression and methylation level and correlation with SDHB mutations in benign and malignant pheochromocytoma / 中国癌症杂志

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.