AIM:To investigate the anti-angiogenic effect ofsomatostatin receptor subtype 2 (SSTR2) gene transfer intopancreatic cancer cell line PC-3,and the mechanisms involvedin this effect.METHODS:The full length human SSTR2 cDNA wasintroduced into pancreatic cancer cell line PC-3 bylipofectamine-mediated transfection.Positive clones werescreened by G418 and stable expression of SSTR2 wasdetected by immunohistochemistry SABC methods and RT-PCR.Enzyme-linked immunosorbent assay (ELISA) was usedto detect vascular endothelial growth factor (VEGF) levels inthe cell culture supematants of SSTR2-expressing cells,vectorcontrol and mock control cells.Furthermore,the expressionsof VEGF and matrix metalloproteinase-2 (MMP-2) weredetected by immunohistochemistry SABC methods and RT-PCR in these cells.RESULTS:VEGF levels in the cell culture supernatants weresignificantly reduced in the SSTR2-expressing cells (first week,172.63±21.2 ng/L and after two months,198.85±26.44 ng/L)compared with the vector control (first week,790.39±86.52ng/L and after two months,795.69±72.35 ng/L) and mockcontrol (first week,786.42±90.62 ng/L and after two months,805.32±84.36 ng/L) (P<0.05).The immunohistochemicalassay showed a significant reduction of the integral opticaldensity of VEGF and MMP-2 in the SSTR2-expressing cells(42.25±8.6 and 70.5±6.25,respectively) compared with thevector control (85.75±12.9 and 110.52±13.5,respectively)and mock control (82.6±9.28 and 113.56±9.62,respectively)(P<0.05).Conversely,the average gray value of VEGF andMMP-2 was significantly increased in the SSTR2-expressingcells (121.56±8.43 and 134.46±19.95,respectively) comparedwith the vector control(55.72±5.6 and 62.26±12.68,respectively)and mock control cells (58.48±6.2 and 65.49±9.16,respectively)(P<0.05).Moreover,the expressions of VEGF mRNA and MMP-2 mRNA were significantly reduced in the SSTR2-expressingcells (0.1384±0.017 and 0.2343±0.070,respectively) compared with the vector control (1.024±0.117 and 0.806±0.119,respectively) and mock control (1.085±0.105 and 0.714±0.079,respectively) (P<0.05).CONCLUSION:The expression of reintroduced humanSSTR2 gene exerts its antiangiogenic effects by down-regulating the expressions of the factors involved in tumorangiogenesis and metastasis,suggesting SSTR2 genetransfer as a new strategy of gene therapy for pancreaticcancer. AIM: To investigate the anti-angiogenic effect of somatostatin receptor subtype 2 (SSTR2) gene transfer intopancreatic cancer cell line PC-3, and the mechanisms involved in this effect. METHODS: The full length human SSTR2 cDNA was introduced into pancreatic cancer cell line PC-3 bylipofectamine-mediated transfection. Positive clones werescreened by G418 and stable expression of SSTR2 wasdetected by immunohistochemistry SABC methods and RT-PCR. Enzyme-linked immunosorbent assay (ELISA) was used to detect vascular endothelial growth factor (VEGF) levels inthe cell culture supematants of SSTR2 -expressing cells, vectorcontrol and mock control cells. Frthermore, the expressions of VEGF and matrix metalloproteinase-2 (MMP-2) weredetected by immunohistochemistry SABC methods and RT-PCR in these cells .RESULTS: VEGF levels in the cell culture supernatants weresignificantly reduced in the SSTR2-expressing cells (first week, 172.63 ± 21.2 ng / L and after two months, 198.85 ± 26.44 ng / L) compared with the vector con (first week, 790.39 ± 86.52 ng / L and after two months, 795.69 ± 72.35 ng / L) and mockcontrol (first week, 786.42 ± 90.62 ng / L and after two months, 805.32 ± 84.36 ng / L) 0.05). Immunohistochemlasslassay showed a significant reduction of the integral optical density of VEGF and MMP-2 in the SSTR2-expressing cells (42.25 ± 8.6 and 70.5 ± 6.25, respectively) compared with the vector control (85.75 ± 12.9 and 110.52 ± 13.5, respectively) (82.6 ± 9.28 and 113.56 ± 9.62, respectively) (P <0.05) .Conversely, the average gray value of VEGF and MMP-2 was significantly increased in the SSTR2-expressing cells (121.56 ± 8.43 and 134.46 ± 19.95, respectively) ) comparedwith the vector control (55.72 ± 5.6 and 62.26 ± 12.68, respectively) and mock control cells (58.48 ± 6.2 and 65.49 ± 9.16, respectively) (P <0.05) .Moreover, the expressions of VEGF mRNA and MMP- significantly reduced in the SSTR2-expressing cells (0.1384 ± 0.017 and 0.2343 ± 0.070, respectively) compared with the vector control (1.024 ± 0.117 an d 0.806 ± 0.119, respec(1.085 ± 0.105 and 0.714 ± 0.079, respectively) (P <0.05). CONCLUSION: The expression of reintroduced human SSTR2 gene exerts its antiangiogenic effects by down-regulating the expressions of the factors involved in tumorangiogenesis and metastasis, suggesting SSTR2 genetransfer as a new strategy of gene therapy for pancreatic cancer.