中文摘要：

目的：探讨Na^＋-K^＋-ATP酶d亚单位表达对人结直肠癌细胞增殖及侵袭力的影响，及哇巴因治疗结直肠癌的可能机制。方法：以SW480和SW620细胞为研究对象，予生理浓度的哇巴因（1rim）干预，应用MTT法、Transwell侵袭小室、生化酶学、实时定量PCR及蛋白免疫印迹等方法检测细胞的增殖及侵袭力，Na^＋-K^＋-ATP酶活性及其亚单位（α1、α2及α3）表达水平。结果：与SW480细胞比较，SW620细胞增殖及侵袭力明显增加（尸均〈0．05），Na^＋-K^＋-ATP酶活性下降，Na^＋-K^＋-ATP酶仅。亚单位mRNA表达上调（P均〈0．001）；而SW480细胞Na^＋-K^＋-ATP酶Or．，亚单位mRNA表达上调（P〈O．001）；且均与蛋白表达水平一致：哇巴因在24、48及72h均能显著抑制两种细胞的增殖活力，以48h效应最强，减弱其侵袭力，并下调两种细胞Na^＋-K^＋-ATP酶OL，亚单位蛋白表达，增加SW620细胞Na^＋-K＋-ATP酶活性，而对两种细胞Na^＋-K^＋-ATP酶α2和α3亚单位蛋白表达及SW480细胞Na^＋-K^＋-ATP酶活性无影响。结论：Na^＋-K^＋-ATP酶活性下降部分源于Q，亚单位表达下调及α1亚单位表达上调，可能共同参与结直肠癌的转移；哇巴因抑制结直肠癌细胞的增殖及侵袭力的机制，可能部分与下调Na^＋-K^＋-ATPα1亚单位蛋白表达有关。

英文摘要：

Objective： To explore the effect of Na^＋-K^＋-ATPase subtmit expression on the proliferation and invasion of human colorectal cancer cell lines SW480 and SW620 and to determine the potential molecular mechanisms of ouabain anticancer therapeutics in human eolorectal cancer. Methods： SW620 （ Dukes C phase ） and SW480 （ Dukes B phase ） cells were derived from the same pa- tient and treated with or without a physiological concentration of 1 nM of ouabain. The proliferation of SW620 and SW480 cells was evaluated using an MTT reduction assay （ i.e., 3-[ 4, 5 ] -dimethylthiahiazo [ -z-yl ] -3, 5-di- phenytetrazoliumromide ）. The invasion capacity was detected using a Transwell chamber. The Na^＋-K^＋-ATPase activity was measured using biochemistry and enzymology. The expression of the Na^＋-K^＋-ATPase α1-, α1-, and α3-subunits were determined using real-time quantitative PCR and Western blot analysis. Results： The proliferation and invasion of SW620 cells significantly increased compared with those of SW480 cells （ P 〈 0.05 to P 〈 0.01 ）. The enzymatic activity of Na^＋-K^＋-ATPase remarkably decreased in SW620 cells （ P 〈 0.001 ）. Furthermore, in SW620 cells, the mRNA-level expression of Na^＋-K^＋-ATPase ct3-subunits was significantly downregulated compared with that of the α- and a2-subunits. However, the Na^＋-K^＋-ATPase ct 1-subunit expression was significantly upregulated （ P 〈 0.01 ）. Interestingly, the Na^＋-K^＋-ATPase a3-sub- unit expression in SW480 cells was upregulated （ P 〈 0.001 ）. Nevertheless, the Na^＋- K^＋-ATPase α2-subunit expressions in the SW480 and SW620 cells were not significantly different （ P 〉 0.05 ）. In addition, the protein expression of the Na^＋-K^＋-ATPase α1-, α2-, and α 3-subunits were in line with the accompanying mR_NA expression. A physiological concentration of 1 nM of ouabain, a Na＋, K^＋-ATPase inhibitor, could significantly downregulate the protein-level expression of Na^＋-K^＋-ATPase ct,-subu