目的:探讨精氨酸-甘氨酸-天冬氨酸(RGD)修饰对肿瘤抑素19肽(T-19)抗肝癌活性的影响,比较分析T-19及RGD修饰的T-19(RGD-T-19)对肝癌SK-Hep-1细胞增殖、侵袭和迁移能力的影响。方法:用Fmoc固相法合成T-19及RGD-T-19,用高效液相色谱仪和质谱进行分离、鉴定。常规培养SK-Hep-1细胞,用0、50、100、150、200、250μg/mL的T-19及RGD-T-19分别处理细胞,分为0μg/mL(对照)组、50μg/mL组、100μg/mL组、150μg/mL组、200μg/mL组、250μg/mL组。CCK-8法、克隆形成实验、划痕愈合实验和Tanswell小室实验、WB法和q PCR法分别检测SK-Hep-1细胞的增殖、迁移、侵袭能力,以及环氧合酶-2(COX-2)、基质金属蛋白酶-2(MMP-2)、MMP-9、组织基质金属蛋白酶抑制剂-1(TIMP-1)、TIMP-2蛋白和MMP-1、MMP-2 mRNA的表达。结果:经质谱鉴定,用Fmoc固相法合成的T-19及RGD-T-19纯度高。T-19和RGD-T-19均能显著抑制SK-Hep-1细胞的增殖、迁移、侵袭能力,抑制COX-2蛋白、MMP-2和MMP-9蛋白及mRNA的表达、促进TIMP-1、TIMP-2蛋白的表达(P <0.05, P <0.01, P <0.001),RGD-T-19的抑制或促进效应均明显强于T-19(均P <0.05)。结论:利用Fmoc固相法合成了纯度高、活性好的T-19及RGD-T-19,两种肽均能抑制SK-Hep-1细胞增殖、侵袭和迁移能力,RGD-T-19作用明显强于T-19。
Tumor growth is an angiogenesis-dependent process and accompanied by the formation of hypoxic areas.Tumstatin is a tumor-specific angiogenesis inhibitor that suppresses the proliferation and induces the apoptosis of tumorous vascular endothelial cells.VNP20009,an attenuated Salmonella typhimurium strain,preferentially accumulates in the hypoxic areas of solid tumors.In this study,a novel Salmonella-mediated targeted expression system of tumstatin(VNP-Tum5)was developed under the control of the hypoxia-induced J23100 promoter to obtain anti-tumor efficacy in mice.Treatment with VNP-Tum5 effectively suppressed tumor growth and prolonged survival in the mouse model of B16F10 melanoma.VNP-Tum5 exhibited a higher efficacy in inhibiting the proliferation and inducing the necrosis and apoptosis of B16F10 cells in vitro and in vivo compared with VNP(control).VNP-Tum5 significantly inhibited the proliferation and migration of mouse umbilical vascular endothelial cells to impede angiogenesis.VNP-Tum5 downregulated the expression of anti-vascular endothelial growth factor A,platelet endothelial cell adhesion molecule-1,phosphorylated phosphoinositide 3 kinase,and phosphorylated protein kinase B and upregulated the expression of cleaved-caspase 3 in tumor tissues.This study is the first to use tumstatin-transformed VNP20009 as a tumor-targeted system for treatment of melanoma by combining anti-tumor and anti-angiogenic effects.