中文摘要：

通过基因转染技术培育caveolin—1过表达乳癌HS578T耐药细胞株Hs578T／Dox＋cav-1和空载体细胞株Hs578T／Dox＋vector，探讨caveolin-1蛋白对耐药肿瘤细胞体内和体外侵袭转移能力的影响．由于caveolin．1表达的增加，Hs578T／Dox＋cav-1细胞形态变为长梭形，伪足更长而伸展，其粘附能力高于空载体Hs578T／Dox＋vector细胞株（（0．897±0．163）vs（0．633±0．053），P〈O．01）．侵袭小室试验发现，Hs578T／Dox＋cav-1侵袭转移能力增强，培养6h迁徙进入微孔膜的细胞数比Hs578T／Dox＋vector细胞株明显增多（（107．8±10．9）vs（80．8±8．07），P〈0.01），侵袭破坏matrigel基质蛋白胶进入膜内的细胞数也明显增多（（68．8±9．88）Fs（25．6±5．41），P〈O．01）．悬浮培养的Hs578T／Dox＋cav．1细胞比Hs578T／Dox＋vector细胞更容易聚集，形成相对较致密的细胞团块，24h检测流式细胞凋亡指数下降（（8．79±1．54）％Fs（16．42±1．42）％，P〈0.01）．这表明其具有更强的抗失巢凋亡和继续生存的能力，为循环转移的肿瘤细胞定植前取了更多时间．Hs578T／Dox＋vector细胞在裸鼠皮下种植成瘤试验中不能成瘤，而Hs578T／Dox＋cav-1细胞接种15只裸鼠，全部形成肿瘤，平均直径（0．8±0．45）cm．发现一只成瘤裸鼠双肺可见瘤样肿块转移．HE病理组织染色见肿瘤细胞弥漫性分布，细胞核异型性明显．上述结果表明，caveolin-1对Hs578T耐药肿瘤细胞侵袭、转移和成瘤性具有明显的促进作用．

英文摘要：

To investigate the effect of caveolin-1 on invasion and metastasis of human breast carcinoma Hs578T doxorubicin-resistanted cells, Hs578T/Dox＋cav-1 was as experiment group which up-regulated caveolin-1 by introducing the pCI-neo caveolin-1 gene, and Hs578T/Dox ＋vector introduced the pCI-neo vector was as controlled group. It was revealed that caveolin-1 in Hs578T/Dox cells is an important factor for mediating filopodia formation, which may enhance the invasive of cells. Hs578T/Dox＋cav-1 cell formed long and abundant pseudopodia and only few filopodia were detectable in Hs578T/Dox ＋vector cells. It was shown that adhesive capability of Hs578T/Dox cells enhanced with up-regulated expression of caveolin-1 protein（P〈0.01）. Introducing the caveolin-1 gene into Hs578T/Dox cells enhanced their migration and invasive capability, as revealed by an in vitro chamber invasion assay（P〈0.01）. Apoptosis index of Hs578T/Dox＋cav-1 group resulting from loss of cell-matrix interactions decreased comparing Hs578T/Dox＋vector group（P〈0.01）. Caveolin-1 inhibited anoikis of Hs578T/Dox cells and that allowed survival of cancer cells during systemic circulation, thereby facilitating secondary tumor formation in distant organs. The efficacy in vivo of caveolin-1 was tested using cells xenografted into nude mice. Each mouse in both fifteen-mice groups were hypodermically injected with equivalent doses of 5 ×10^5 cells from Hs578T/Dox ＋cav-1 or Hs578T/Dox ＋vector. Tumors in Hs578T/Dox ＋cav-1 group were all formed after injection followed for 4 weeks, while no one in Hs578T/Dox＋vector group. Lung metastasis was found in one mouse injected Hs578T/Dox＋cav-1 cells. In conclusion, up-regulated caveolin-1 level in Hs578T doxorubicin-resistanted cells markedly elevates their capacity to tumor invasion and metastasis.