摘要
目的 :金属蛋白酶是降解细胞外基质的重要酶 ,最近有研究表明四环素族化合物有抑制金属蛋白酶活性和某些肿瘤细胞增殖的作用。但其对层粘连蛋白和 型胶原蛋白的降解以及对人 EJ细胞增殖作用影响尚不清楚。方法 :用 EJ细胞体外培养加入不同浓度的四环素和米诺环素 ,用 MTT法测定其对 EJ细胞的增殖作用的影响。EJ细胞体外培养后 ,加入不同浓度的四环素和米诺环素培养 2 4h后再加入外源性的 型胶原和层粘连蛋白 ,继续培养 2 4h,用放射免疫法测定培养液中的 型胶原和层粘连蛋白含量。结果 :四环素和米诺环素对层粘连蛋白的降解无明显影响 ,但两者均能阻止 型胶原的降解 ,且相互间无显著性差异。四环素和米诺环对 EJ细胞的增殖均无影响。结论 :四环素和米诺环素均能抑制 型胶原的降解 ,保护细胞外基质 ,这可能是由于两者络合 Ca2 +或 Zn2 +影响了 型胶原酶的结构和活性。本实验发现四环素和米诺环素对层粘连蛋白的降解无明显影响 ,可能由于层粘连蛋白的降解有多种酶参与 ,如血浆纤维蛋白溶解酶等。米诺环素和四环素对 EJ细胞增殖无明显影响 ,其原因可能是两者透过 EJ细胞膜困难 ,不能影响细胞内线粒体内蛋白质合成。
PURPOSE: Matrix metalloproteinases (MMPs) are major enzymes of the degradation of extracellular matrix (ECM). Recent studies have revealed that tetracyclines suppress activity of MMPs and proliferation of some tumor cells by inhibition of mitochondria protein synthesis. But whether the tetracyclines have also possessed activities to affect the proliferation of human EJ cell line and the degradation of laminin and Ⅳ type collagen are still to be determined. Method: EJ cell line was cultured, and proliferation was tested by the MTT method in the presence of different concentrations of tetracycline and minocycline in vitro . After EJ cells were incubated, treated with various concentrations of tetracycline and minocycline respectively for 24h, exogenous collagen and laminin were added into medium for another 24h in which laminin and Ⅳ type collagen were assayed by radioimmunoassay. RESULT: EJ cells of human bladder carcinoma were treated by tetracycline and minocycline, proliferation arrest was not occur, but both of them can inhibit type Ⅳ collagenolysis in 2×10 -8 mol/L concentrations, however both drugs can not affect the degradation of laminin. CONCLUSION: Minocycline and tetracycline can inhibit Ⅳtype collagenase, and protect ECM, which is probably contributed to chelation of Ca 2+ or Zn 2+ , and affecting the structure and activity of Ⅳ type collagenase. However both drugs can not affect the degradation of laminin, maybe other enzymes take part in the process of degradation besides MMPs, in particular plasmin. Minocycline and tetracycline do not affect on growing of bladder tumor cells, probably due to EJ cell membranes had comparatively stronger barriers against both drugs to permeate, and without affecting mitochondria protein synthesis of EJ cells.
出处
《中国抗生素杂志》
CAS
CSCD
北大核心
2001年第2期127-130,共4页
Chinese Journal of Antibiotics
