The Methylation And Expression Of Angiopoietin Tie2Receptor In Infantile Hemangioma

Objective: To investigate the expression of angiopoietinTie2receptor and methylation of Tie2receptor gene in infantilehemangioma. To discuss the role of Tie2and methylation of Tie2gene inthe development of infant hemangioma. Methods:60specimens ofinfantile hemangioma(30specimens of proliferating hemangioma and30specimens of involuting hemangioma) and30specimens of normalforeskins which acquired from30boys(undergoing circumcision) wereused in this experiment. Methylation of Tie2gene was examined by usingmethylation specific PCR(MSP) analysis. The expression of Tie2receptors mRNA and protein were examined by using Real-time PCR,Western blot staining analysis. The expression of MMP-9was examinedby using Real-time PCR and gelatin zymography analysis. Results: MSPshowed that no aberrant methylation of Tie2gene was detected in normalforeskins; aberrant methylation of Tie2gene was detected in specimens ofinfantile hemangioma. In proliferative hemangiomas,21cases werepositive for aberrant methylation of Tie2gene. Among of them,14specimens were completely methylated,7specimens was hemimethy-lation. In involuting hemangiomas,24cases were positive for aberrantmethylation of Tie2gene. Among of them,21specimens werecompletely methylated,3specimens was hemimethylation. Real-time PCR and Western blot showed that the level of Tie2was higher inproliferative and involuting hemangioma than in normal foreskins(P<0.05). Real-time PCR and gelatin zymography analysis showed thatthe level of MMP-9mRNA and the activity of MMP-9protein inproliferating and involuting hemangioma were higher than in normalforeskins (P<0.05). Conclusion: High expression of Tie2and abnormalmethylation of Tie2gene are found in infantile hemangiomas, whichindicated that Tie2participated in the development of hemangioma.