Inhibition of Growth on Human Glioma Cells by Estramustiene, Anti-microtubule Agent ; In Vitro Study

由于微管是细胞运动和细胞内运输的重要组成部分，因此有理由提出，抗微管剂雌莫司汀对胶质瘤微管的解聚作用将调节细胞侵袭力。为了确定是否基质金属蛋白酶，在细胞侵袭的关键因素，暴露于雌莫司汀，细胞增殖试验，酶谱，胶原溶解试验，和haptoinvasion试验的影响，在这项研究中。酶谱显示基质金属蛋白酶-2的活化形式（62 kD）随着雌莫司汀浓度的增加而减少。胶原溶解试验表明，与对照组相比，雌莫司汀浓度为1、5和10 μM时，雌莫司汀以剂量依赖性方式抑制酶活性的速率约低2.5至21倍。在接触侵袭试验中，0.5 μM雌莫司汀组无统计学显著性差异，而1 - 10 μM雌莫司汀组显示6 - 24小时的侵袭以剂量依赖性方式受到显著抑制。结果表明雌莫司汀通过减少微管解聚引起的基质金属蛋白酶-2抑制U87 MG细胞的体外侵袭。抑制恶性胶质瘤细胞的浸润能力可能对该疾病的治疗具有重要价值。

Because microtubules are important components of cell motility and intracellular transport, it is reasonable to propose that an antimicrotubule agent, estramustine's depolymerizing effect on glioma microtubules would modulate cell invasiveness. To determine whether matrix metalloproteinases, key factors in cell invasion, are affected by exposure to estramustine, a cell proliferation assay, a zymogram, a collagenolysis assay, and a haptoinvasion assay were employed in this study. The zymogram revealed that an activated (62kD) form of Matrix Metalloproteinase-2 diminished with increasing estramustine concentrations. The collagenolysis assay demonstrated approximately 2.5 to 21 fold lower rates of enzymatic activity suppressed by estramustine in a dose-dependent manner at estramustine concentrations of 1, 5, and 10 μM, compared with the control group. On the haptoinvasion assay, no statistically significant difference was seen in the 0.5 μM estramustine group, while 1 to 10 μM estramustine groups revealed significant suppression of invasion from 6 to 24 hours in a dose-dependent manner. The results suggest that estramustine suppresses the invasion of U87MG cells in vitro by the decreasing available matrix metalloproteinase-2, an affect caused by the disassembly of microtubules. Suppression of the infiltrative capacity of malignant glioma cells could be of significant value in the treatment of this disease.