Study On DNA Methylation Status Of PCDH8 Gene In Its Promoter Gegion In Acute Leukemia

Objecti: 1.To analyze the correlation of between PCDH8 gene promoter region methylation and acute leukemia(AL),we test the protocadherin 8(PCDH8) gene promoter region methylation. 2.we collected some parts of clinical information,and analyzed the correlation of PCDH8 gene promoter region methylation and AL patients’ Parameters. 3.In the basis of PCDH8 mRNA expression level in acute leukemia,we analyzed the correlation between PCDH8 gene promoter region methylation and PCDH8 mRNA expression level. Method: 1.We test the promoter region methylation of PCDH8 gene in 70 cases of AL patients and 20 cases Iron Deficiency Anemia(IDA)who have been eliminated the malignant blood diseases by the Methylation Specific Polymerase(MSP). 2.We can test the mRNA expression of PCDH8 gene in 70 cases of AL patients and 20 cases Iron Deficiency Anemia(IDA)who have been eliminated the malignant blood diseases by the Reverse Transcription-Polymerase Chain Reaction( RT-PCR). 3.we applicate the software of IBM SPSS statistics 20 and chi-square test statistics to analyze the correlation of PCDH8 gene promoter region methylation and its mRNA expression and AL patients’ Parameters. Result: 1.In the AL group of 70 cases, there are 51 cases occurred methylation in the PCDH8 gene promoter region. The positive rate is 72.86%. There is only one case in the control group of 20 cases occurred methylation in the PCDH8 gene promoter region. The positive rate was 5%.The Al group methylation rate was significantly higher than the adult group(P < 0.05). So it has the statistical significance. 2.According to the age,AL group can be divided into elderly group(a‰§ 60 y) and the adult group(60 y > and < 18y). There are 35 cases In the of 40 cases of elderly group occurred methylation in the PCDH8 gene promoter region, the positive rate was 87.50%, the adult group of 30 cases with 16 cases occurred methylation in the PCDH8 gene promoter region, and the positive rate was 53.33%.Elderly group methylation rate was significantly higher than the adult group,(P < 0.05). So it has the statistical significance.According to the type of acute leukemia,AL group is divided into AML and ALL groups.There are 32 cases in 41 cases of AML group occurred methylation in the PCDH8 gene promoter region.The positive rate was 78.0%.There are 19 cases in 29 cases of ALL group occurred methylation in the PCDH8 gene promoter region. The positive rate was 65.5%,The methylation rate have no significant differences between the two groups(P > 0.05). According to quantity of the white blood cell, AL group can be divided into high white blood cell group(> 10 x 109 / L) and low white blood cell group( ≦10 x 109 / L).There are 47 cases in 53 cases of the high white blood cell group occurred methylation in the PCDH8 gene promoter region, the positive rate was 88.7%, and there are only 4 cases in 17 cases of the low white blood cell group occurred methylation in the PCDH8 gene promoter region, the positive rate was 23.5%.The high white blood cell group methylation rate is significantly higher than low white blood cells(P < 0.05);There are 42 cases of acute leukemia patients have been developed liver or spleen enlargement.There are 36 patients appeared PCDH8 gene promoter region methylation,he positive rate was 85.7%,and there are 38 patients have been appeared swollen lymph nodes, There are 30 patients appeared PCDH8 gene promoter region methylation,the positive rate was 78.9%. The PCDH8 gene promoter region methylation has no significant ralationship with the lymph node enlargement, liveromegaly or splenomegaly and antigens which expressed by Hematopoietic cells(P > 0.05). 3.There are 26 cases were appeared PCDH8 gene mRNA expression in AL group,the positive rate was 37.1%, and all of 20 cases normal appeared PCDH8 gene mRNA expression.The Al group methylation rate was significantly lower than the adult group(P < 0.05). So it has the statistical significance. 4.It is negative correlation between the PCDH8 gene promoter region methylation and its m RNA expression.(r = 0.728, P < 0.01). Conclusion: 1.In acute leukemia, PCDH8 gene promoter region methylation rate was significantly higher than the normal control group, It shows that the PCDH8 gene promoter region methylation may be take part in the occurance of AL. 2.The PCDH8 gene promoter region methylation is related with patients’ age and white blood count.But there’s no significant ralationship with the type of AL,lymph node enlargement, liveromegaly or splenomegaly and antigens expressed by Hematopoieticcells. 3.The PCDH8 gene mRNA expression rate is steadly in normal control group.But in the acute leukemia group,the PCDH8 gene mRNA expression rate has been falling.It shows that the PCDH8 gene mRNA expression may be associated with the occurrence of acute leukemia. 4.It is negative correlation between the PCDH8 gene promoter region methylation and its mRNA expression,This suggests that the high PCDH8 gene promoter methylation may be one of the factors that lead to low PCDH8 gene mRNA expression.