BACKGROUND: Evidence exists that inhibition of matrix metanoproteinase-2(MMP-2) secretion in the proliferating hernangioma tissue by transfection of adenovirus-active MMP-2(Ad-aMMP-2) cDNA would become an important means for treatment of proliferating hemangioma.OBJECTIVE: To investigate the influences of Ad-aMMP-2 cDNA transfection on human proliferating hemangioma growth in nude mice.DESIGN, TIME AND SETTING: A randomized, grouping, and controlled observation was performed in West China Hospital of Sichuan University between August 2003 and September 2004.MATERIALS: Eighteen BALB/c-nu/nu nude mice, weighing approximately 20 g, were included. Cavernous hemangioma specimen pathologically confirmed as proliferating hemangioma was resected from one 52-day-old female child patient.METHODS: The freshly reseoted human proliferating hemangioma specimen was sliced into small pieces with a size of 5 mm×4 mm×3 mm and subcutaneously implanted into the back of 18 nude mice within 1 hour to develop mouse models of hemangioma.Forty-five days after hemangioma implantation, 15 successful hemangioma nude mice were treated by intratumoral administration of adenovirus green fluorescent protein (Ad-GFP1 n = 51 Ad-GFP group), adenovirus-active MMP-2 (n = 5, Ad-aMMP-2 group), or the same amount of phosphate buffered saline (PBS1 n = 51 control group). Intratumoral administration was performed once every other day, for a total of 4 times.MAIN OUTCOME MEASURES: Observation of tumor volume and compadson of tumor necrosis area among 3 groups; detection of GFP expression in nude mouse; gross, hematoxylin-eosin staining, and transmission etectron microscope observation of tumor tissue morphology; determination of MMP-2 cDNA expression and microvascular density by immunohistochemistry; and detection of growth cycle and apoptosis of tumor cells by flow cytometry.RESULTS:①Ad-aMMP-2 could inhibit hemangioma growth in vivo, without marked adverse reactions. Tumor necrosis of different degrees was found in each group, and tumor necrosis area was significantly greater in the Ad-aMMP-2 group than in the control and Ad-GFP groups (P < 0.01). ②Histological sections displayed GFP gene expression in the Ad-GFP group. ③Gross observation results revealed relatively large tumor tissue in the control and Ad-GFP groups and relatively small tumor tissue in the Ad-aMMP-2 group. Hernatoxylin-eosin staining results showed that in the control and Ad-GFP groups, endothelial cells aggregated together in strip-shaped or lump-shaped appearance, and in the Ad-aMMP-2 group, there were many necrotic loci arranging in lamellar-shape appearance. Transmission electron microscope results revealed vascular endothelial cells with normal morphology in the control group and tumor cells with apparent nucleoli in the Ad-GFP group, while in the Ad-aMMP-2 group, some vascular endothelial cells exhibited chromatin pycnosis in the nucleus, forming apoptotic bodies.④ MMP-2 expression and microvascular density were significantly reduced in the Ad-aMMP-2 group than in the Ad-GFP and control groups (P < 0.05). ⑤The percentage of tumor cells in G0/G1 phase was significantly higher (P < 0.05), while the proliferating index was significantly decreased, in the Ad-aMMP-2 group than in the Ad-GFP and control groups. The Ad-aMMP-2 group exhibited higher apoptosis rate of tumor cells (P < 0.05), as well as more markedly increasing apoptosis index, than the control and Ad-GFP groups.CONCLUSION: It is feasible to block human proliferating hemangioma growth by transfeotion of Ad-aMMP-2 cDNA. The included mechanisms are to inhibit vascular endothelial cells to secrete MMP-21 thereby leading to local ischemia.