Analysis Of DNA Methylation Of RASSF1A、DAPK Gene In Osteosarcoma From Formalin-fixed And Paraffin-embedded

Objective To study the DNA methylation of RASSF1A、 DAPK gene inosteosarcoma from Formalin-fixed and Paraffin-embedded Tissues.Methods Methylation-specific PCR was adopted to investigate the promotermethylation of FFPE Tissue specimens from30osteosarcoma patients diagnosed at theInstitute of Pathology, The First Affiliated Hospital of Anhui Medical University. Therelationship between the frequency of methylation of the gene and clinical data wasanalyzed.Results In30osteosarcom tumor and non-tumor tissue，the frequency of RASSF1Amethylation was46.7%、13.3%,respectively.RASSF1A methylation was morefrequent in osteosarcom than in non-tumor tissue(X2=7.937；P=0.005)．The frequency ofRASSF1A methylation in osteosarcoma before20year is significantly higher than thatafter20years. The value of Alkaline phosphatase ALP is high in the group ofmethylation compaired with unmethylation(Z=-2.723；P=0.006); In30osteosarcomatumor and non-tumor tissues，the frequency of DAPK methylation was50%,6.7%,respectively. DAPK methylation was more frequent in osteosarcoma tumor tissues thanin non-tumor tissues(X2=13.87，P <0.05)．The value of Alkaline phosphatase ALP ishigh in the group of methylation compaired with unmethylation（Z=-1.991，P<0.05）. Astatistically significant trend was observed between DAPK methylation and age(X2=5.000, P <0.05).Conclusions Methylation of multiple genes is a common event in osteosarcoma.