Objective        To investigate the effect of propranolol on the expression of matrix metalloproteinase 2 (MMP-2)

matrix metalloproteinase 9 (MMP-9)

tissue inhibitor of metalloproteinase 1 (TIMP-1) and tissue inhibitor of metalloproteinase 2 (TIMP-2) in infantile hemangioma.       Methods        Thirty-nine patients (age≤3 months) with proliferative phase of hemangioma in our hospital from May

2010 to December

2010 were enrolled. The patients were treated with propranolol for 8 weeks after hemangioma biopsy

and then underwent surgery for hemangioma resection. The mRNA and protein expression levels of MMP-2

MMP-9

TIMP-1 and TIMP-2 in hemangioma tissues were examined by quantitative real-time RT-PCR and immunohistochemical method

respectively

and the microvessel density (MVD) was calculated before and after propranolol treatment.       Results        The MVD in the hemangioma tissues decreased significantly after propranolol treatment (P0.01). The protein and mRNA expressions of MMP-2 and MMP-9 decreased significantly (P0.01)

but the protein and mRNA expressions of TIMP-1 and TIMP-2 increased significantly after propranolol treatment (P0.01). The changes of MVD were closely correlated with the protein and mRNA expression levels of MMP-2

MMP-9

TIMP-1 and TIMP-2.       Conclusion        Propranolol can reduce proliferative hemangioma through down-regulating MMP-2 and MMP-9 expression and up-regulating TIMP-1 and TIMP-2 expression.