【摘要】 目的探讨内质网滞留型胞内抗体对Ⅳ型胶原酶分泌及其对人巨细胞肺癌PG细胞侵袭的抑制作用。方法构建了编码胞浆和内质网滞留型抗Ⅳ型胶原酶抗体的表达载体pcDNA3.1-CP.scFv和pcDNA3.1-ER.scFv。对人巨细胞肺癌PG细胞系进行基因转染。以Western blot检测pcDNA3.1-CP.scFv和pcDNA3.1-ER.scFv的表达,明胶酶谱检测PG细胞Ⅳ型胶原酶分泌情况,Matrigel实验检测细胞侵袭。结果CP.scFv和ER.scFv胞内抗体在PG细胞内表达,ER.scFv对Ⅳ型胶原酶分泌具有显著的抑制作用,对基质金属蛋白酶-9和基质金属蛋白酶-2的抑制率分别为85.7%和51.2%;而CP.scFv对Ⅳ型胶原酶分泌无抑制作用。ER.scFv编码基因转染的PG细胞与野生型和空白质粒组比较,对体外侵袭有明显的抑制,抑制率为76.3%;而CP.scFv编码基因转染的PG细胞未显示出有抑制作用。结论内质网滞留型胞内抗体技术可以在蛋白加工、分泌通路中抑制Ⅳ型胶原酶的活性,进而抑制肿瘤侵袭,可能在肿瘤基因治疗中具有重要的应用前景。更多还原

【Abstract】 Objective To explore the inhibitory effects of endoplasmic reticulum-retained intrabody on the secretion of type Ⅳ collagenase and the invasion of human pulmonary giant cell carcinoma PG cells in vitro. Methods Two expression plasmids were constructed, pcDNA3.1-CP.scFv and pcDNA3.1-ER.scFv encoding cytoplasm-retained and endoplasmic reticulum-retained single chain antibodies against the type Ⅳ collagenase, respectively. The intracellular antibody genes were transfected into the human pulmonary giant cell carcinoma PG cells. Western blot was performed to detect the expression of pcDNA3.1-CP.scFv and pcDNA3.1-ER.scFv. Gelatin zymography was performed to detect seretion of type Ⅳ collagenase in PG cells and Matrigel assay was employed for determination of the cell invasiveness. Results Both of cytoplasm-retained and endoplasmic reticulum-retained introbodies, CP.scFv and ER.scFv, were expressed in PG cells. ER.scFv, significantly inhibited the secretion of type Ⅳ collegenase. As shown, matrix metalloproteinase 9 and matrix metalloproteinase 2 were inhibited by 85.7% and by 51.2%, respectively. However, CP.scFv did not show such inhibitory effect. The ER.scFv encoding gene-transfected PG cells were much less invasive than parental or vector control cells, the inhibition rate was 76.3% (P<0.05), whereas CP.scFv encoding gene-transfected PG cells showed no reduction in invasiveness. Conclusion Those findings demonstrate that endoplasmic reticulum (ER)-retained intracellular antibody technology may selectively abrogate the activity of type Ⅳ collagenase in the protein trafficking and secretory pathway and effectively inhibit tumor cell invasion in vitro. Anti-type Ⅳ collagenase intrabody may be further used in cancer gene therapy.更多还原