Objective To observe the inhibitory effect of silencing survivin through siRNA on the tumor angiogenesis in nude mice bearing human adenoid cystic carcinoma ACC - 2 cells. Methods A total of 15 nude mice were randomized into 3 groups (

n

=5)

intervention plasmid group (inoculated subcutaneously with survivi

n RNAi plasmid transfected ACC - 2 cells)

tumor intervention group (survivin RNAi plasmids were subcutaneously injected into and around the tumor mass which were formed in 15 d after ACC - 2 cells inoculation into the nude mice)

and tumor cell group (inoculated subcutaneously with wide ACC - 2 cells). After all mice were sacrificed in 25 d after tumor cell inoculation

the tumor was stripped

and tumor volume was measured. RT - PCR was used to detect the expression of VEGF mRNA in tumor tissues

and HE staining and immunohistochemical staining were preformed for the morphology and microvessel parameters of the tumor mass. Results  In the intervention plasmid group and tumor intervention group

VEGF mRNA was expressed at an optical density ratio of 0.698 ± 0.023 and 0.612 ± 0.038 in electrophoregram

overall microvessel density was 4.98 ± 1 . 40 and 5.08 ± 1.29

and a cavity microvascular density was 2.98 ± 1.05 and 3.10 ± 1.23 with an average circumference of blood vessel lumen 68.60 ± 15.98 and 70.12 ± 14.19 μ m

and a mean lumen area of 4 119.14 ± 698.12 and 4 339.67 ± 599.76 μ m

2

. These indexes had a significant difference with those of tumor cell group [optical density ratio of VEGF 0.912 ± 0.039

overall microvessel density 8.90 ± 1.36

a cavity microvessel density 5.89 ± 1.68

an average circumference of vascular cavity 129.48 ± 25.68 μ m and lumen area 6 952.74 ± 1 298.54 μ m

2

(

P

0 . 05)

]

while

there was no significant difference in these indexes between the intervention plasmid group and tumor intervention group (

P

0 . 05). Conclusion  Survivin siRNA inhibits the growth of tumor mass in adenoid cystic carcinoma - bearing nude mice by inhibiting VEGF expression to suppress tumor angiogenesis effectively.