VINCA ALKALOIDS AND CELL PROLIFERATION

长春花碱(VLB)和长春新碱(VCR)是重要的抗肿瘤药物。 虽然这些生物碱与纺锤体蛋白(微管蛋白)结合， 导致有丝分裂停滞，已被认为是其 抗有丝分裂作用，其细胞毒作用的机制尚不清楚。 我们已经证明，在低VLB孵育的药物敏感淋巴母细胞中 浓度时，会发生广泛的细胞溶解，表明细胞表面 相关药物效应。这些细胞中细胞表面微管蛋白的存在 可能是他们对药物敏感的原因。同样，在抵抗的细胞中 体外培养至VLB期，细胞表面出现新的糖蛋白。直接式 这些细胞表面蛋白与药物转运机制的关系 肿瘤细胞群体中的耐药性还没有被阐明。也不是 任何有关这些标记与 长春新碱/长春新碱细胞周期时相相关的细胞毒作用。我们现在建议 提取、纯化和浓缩微管蛋白和表面标记蛋白(100 和160K M.W)来自药物敏感和耐药细胞。单克隆 这些标志物的抗体将被标记并用于关联 在标记物、药物转运和耐药之间的关系 人口。我们将分析内容和外观之间的关系 单个细胞上的标志物与细胞周期时相相关 长春新碱/长春新碱细胞毒作用的研究离心式洗脱，密度梯度 分离和荧光激活细胞分选将用于 定量结合抗体的量并选择性地收集浓缩的抗体 人口。放射性标记的药物将被用于研究药物的运输。 将使用多参数流动分析来关联细胞周期阶段和 细胞表面标记。与细胞增殖效应的相关性 将在软琼脂试验和裸鼠移植中进行研究。

Vinblastine (VLB) and VIncristine (VCR) are important antitumor agents. Although binding of these alkaloids to spindle proteins (tubulin), resulting in mitotic arrest, has been suggested as the basis for their antimitotic action, the mechanism for their cytotoxic action is not known. We have shown that in drug sensitive lymphoblasts incubated with low VLB concentrations, extensive cytolysis occurs suggesting a cell surface related drug effect. The presence of cel surface tubulin in these cells may account for their drug sensitivity. Similarly, in cells made resistant in vitro to VLB, new glycoproteins appear on the cell surface. The direct relation of these cell surface proteins to the mechanism of drug transport and resistance in a tumor cel population has not been elucidated. Nor is any information available on the relation between these markers and the cell cycle phase related cytotoxicity of VLB/VCR. We now propose to extract, purify and concentrate tubulin and surface marker proteins (100 and 160 K M.W) from drug sensitive and resistant cells. Monoclonal antibodies to these markers will be labeled and used for correlation between markers, drug transport and resistance in individual cells from a population. We will analyze relation between the appearance and content of the markers on individual cells and the cell cycle phase related cytotoxicity of VLB/VCR. Centrifugal elutriation, density gradient separation and fluorescence activated cell sorting will be used to quantitate amount of bound antibodies and to collect selectively enriched populations. Radiolabelled drugs will be used to study drug transport. Multiparameter flow analysis will be used to correlate cell cycle stage and cell surface labelling. Correlation with effects on cell proliferation will be studied in soft agar assays and nude mice xenografts.