MICROPHARMACOLOGY OF BIOLOGICAL LIGANDS

在一定程度上，在培养物中杀死癌细胞比在实体瘤中更容易 因为在后一种情况下，治疗剂的显微可及性很差。为 多年来，我们一直在探索如何在宏观上 和微观方面的生物有趣的药理学 配基，主要是为了解决难以获得的问题。这项工作已经 以单抗为中心，但着眼于 其他生物配体和低分子药物的药理作用。 理论：我们开发了一个程序包(PERC；在Cray上运行 超级计算机)，解宏观和宏观的微分方程 微观药理学。然后，我们制定了“结合部位屏障”。 假设-即成功绑定到目标的事实本身 抗原或受体可以限制对肿瘤实质的渗透。 计算表明：(1)屏障效应可以防止 甚至从血管穿透100-200微米；(2)矛盾的是， 高亲和力和高靶标密度预计会产生较低的 从容器中浓缩出几百微米的配体。 实验：我们验证了结合部位屏障假说 豚鼠L10实体瘤微转移的实验研究 猪。双标记放射自显影与双生色团的结合 免疫组织化学方法同时检测大鼠脑内皮细胞的分布 抗体，控制免疫球蛋白、抗原和血管。我们现在已经延长了 这些计算和实验要分两步进行，在其中缓慢地 分布配体被快速分布的配体效应器追逐 奇美拉。 我们认为，“结合部位障碍”一直是导致 自分泌-旁分泌分子和其他生物配体的进化。 因此，在设计时必须考虑微药理学 外源性给药或体内分泌的配体 转基因细胞。目前的工作主要集中在访问问题上 我们开发的一种新的实体肿瘤中空纤维模型(与 Hollingshead，Mayo等人，见Z01CM07349-02)。

It is easier to kill cancer cells in culture than in solid tumors, in part because therapeutic agents have poor microscopic access in the latter. For a number of years, we have been exploring ways to integrate macroscopic and microscopic aspects of the pharmacology of biologically interesting ligands, principally to get at the problem of poor access. That work has centered on monoclonal antibodies but with an eye to correlates in the pharmacology of other biological ligands and low molecular weight agents. Theoretical: We developed a program package (PERC; operating on the CRAY supercomputer) that solves differential equations for macroscopic and microscopic pharmacology. We then formulated the "binding site barrier" hypothesis - i.e., that the very fact of successful binding to target antigen or receptor can limit penetration into the substance of a tumor. Calculations suggested that (1) the barrier effect could prevent penetration even 100-200 microns from a blood vessel; (2) paradoxically, high affinity and high target density are expected to produce lower concentrations of ligand a few hundred microns from a vessel. Experimental: We validated the binding site barrier hypothesis experimentally in bulk tumor an micrometastases of L10 carcinoma in guinea pigs. A combination of double-label autoradiography and double-chromophore immunohistochemistry was used to detect simultaneously the distribution of antibody, control IgG, antigen, and blood vessels. We have now extended these calculations and experiments to two-step therapy, in which a slowly distributing ligand is chased by a fast-distributing ligand-effector chimera. We believe that the "binding site barrier" has been a factor in the evolution of autocrine-paracrine molecules and other biological ligands. As a corollary, the micropharmacology must be considered when designing ligands for exogenous administration or for secretion in vivo by genetically modified cells. Current work focuses on the access problem in a new hollow fiber model for solid tumors that we have developed (with Hollingshead, Mayo, et al., see Z01CM07349-02).