内皮抑素30肽对SGC-7901细胞增殖及转移能力的影响

目的研究经RGD修饰的人内皮抑素（endostatin）N-端的30肽对胃癌SGC-7901细胞增殖及转移能力的影响。方法人工合成人内皮抑素1～30位氨基酸(30肽,序列25～31由RGIRGAD改为RGDRGD)所对应的核苷酸序列,连接到质粒pTYB2中,再转化至大肠埃希菌BL21(DE3)中表达。用WST-1试剂检测30肽对SGC-7901细胞增殖的影响；细胞划痕实验和迁移实验观察30肽对细胞运动迁移的影响;明胶酶谱实验观察其对肿瘤转移相关基因MMP-2、MMP-9表达和分泌的影响。结果30肽能够有效抑制SGC-7901细胞的增殖、侵袭和迁移，同时还抑制了MMP-2和MMP-9的活性。结论30肽可能是通过下调MMP-2和MMP-9的活性而抑制SGC-7901细胞的转移，其在胃癌的临床治疗上具有潜在的应用前景。

Effects of Peptide 30 Derived from Endostatin on Proliferation,Invasion and Metastasis of Human Gastric Adenocarcinoma SGC-7901 Cells

Objective
To study the effects of a 30-amino-acid N-terminal peptide of endostatin modified by RGD on the proliferation and
metastasis of human gastric adenocarcinoma cell(SGC-7901).MethodsThe nucleotide sequence encoding amino acids 1-30
of endostatin(peptide 30,with amino acids 25-31 mutated from RGIRGAD to RGDRGD)was artificially synthesized and
cloned into the plasmid pTYB2 and expressed in E.coli(DE3).WST-1 kit was used to evaluate the effects of peptide 30
on the growth of SGC-7901.Wound healing assay and Transwell assay were adopted to evaluate the effects of the
peptide 30 on the migration of cancer cells.The expression and secretion of tumor metastasis-related protein MMP-2
(metalloproteinase-2)and MMP-9(metalloproteinase-9) were determined by gelatin zymography.ResultsPeptide 30
effectively suppressed the proliferation of SGC-7901 cells.Peptide 30 was found to effectively suppress the
invasion and migration of SGC-7901 cells.Moreover,peptide 30 inactivated MMP-2 and MMP-9 activity.ConclusionThe
mechanism of peptide 30 suppressed cancer metastasis may involve the down-regulation of MMP-2 and MMP-9
activity.The peptide 30 can potentially be used to treat gastric carcinoma in clinic.