A Preliminary Study On The Implication Of Apaf-1 Promoter Methylation And The Expression Of Apoptosis Inhibitor Protein Apollon In Adult Acute Leukemia

Objective Study on the Apaf-1 gene promoter methylation in adult acute leukemia,in order to understand the significance of tumor suppressor gene silencing in acute leukemiaMethods:Select 38 newly diagnosed patients,15 of relapsed patients with AL of receiving hospitalization and 10 of healthy or nonmalignant person from march to October in 2009 in department of Hematology,Qianfoshan Hospital,Shandong University.Methylation specific PCR(MSP) was used to detect the methylation status of Apaf-1 gene promoter in 53 acute leukemia patients (28 AML 10 ALL and 15 relapsed). The Diagnosis and Curative Standard based on the editor of zhang zhi-nan. RT-PCR was used to detect the expression levels of Apaf-1 mRNA. The methylation of Apaf-1 gene mRNA expression influence was analysed.All data were used to demonstrate data. To compare measurement data use T-test or Analysis of varinace. To compare enumeration data use X2 test(Chi square test) or Fisher's exact probabilityα=0.05 is significant level. The standard of test in statistical significant difference is p<0.05.(double sides)Results The abnormal methylation of Apaf-1 gene promoter in AL were 18/53(33.9%), including 9 of AML,3 of ALL and 6 of relapsed. No Apaf-1 mRNA was detected in methylation positive patients. Only one case in healthy and nonmalignant group was found deletion of Apaf-1 mRNA expression. The positive methylation rate in AL bone marrow mononuclear cells was significant higher than that in control(P<0.05). The positive methylation ratio in white blood cells counts group(>10×109/L) was higher than that of≤10×109/L (p<0.05). In the 53 cases, 39.6% is undetected,21.5% is decrease in Apaf-1 mRNA expression.Conclusions With the data, we find the Apaf-1 gene promoter methylation cause Apaf-1 mRNA expression level decrease or deletion. It maybe involved in leukemogenesis. Objective To investigate the interaction between Apaf-1 gene promoter methylation and Apollon protein expression. In order to understand their roles in leukemogenesis.Methods:Select 38 newly diagnosed patients,15 of relapsed patients with AL of receiving hospitalization and 10 healthy or nonmalignant person from march to october in 2009 in department of Hematology,Qianfoshan Hospital,Shandong University. Using lymphocyte separation medium to separate marrow mononuclear cells. Immunocytochemistry(ICC) was used to detect inhibitor of apoptosis protein Apollon expression, meanwhile, Correlation analysis were used to analyze the realtionship between Apaf-1 gene promoter methylation and type or white blood cell counts of disease.Result Apollon protein expression level was overexpressed in AL bone marrow mononuclear cells. (p<0.05).The Apollon protein expression level was higher in methylation patients than that of the nonmethylation patients. Apaf-1 promoter methylation ratio had a positive correlation with Apollon expressin level. Apaf-1 gene promoter methylation ratio and Apollon expressin level were higher in the patients which white blood cell counts> 10×109/L than that of≤10×109/L (p>0.05)Conclusion Abnormal methylation of Apaf-1 gene promoter methylation and overexpression of inhibitor of apoptosis ptotein Apollon maybe involved in leukemogenesis.