Hervagault J F, Ortoleva P J, Ross J
Unité de Recherche Associée 1442, Centre National de la Recherche Scientifique, Université de Compiègne, France.
Proc Natl Acad Sci U S A. 1991 Dec 1;88(23):10797-800. doi: 10.1073/pnas.88.23.10797.
We offer a plausible interpretation of some experiments on the reversal of neoplastic transformations in plants. We suggest that normal cells and tumorous cells represent multiple stable-steady states corresponding to a reaction feedback mechanism. The (autocatalytic) feedback loop is constructed from observations on the role played by myo-inositol: it increases the permeability of ions through the membrane and the biosynthetic pathway to myo-inositol is activated by ions. Provided that the permeabilities of nutrients (sugars and salts) are a product-enhanced function of myo-inositol, then we have a (oversimplified) model that can exhibit multiple stationary stable states, one or two depending on the exogenous nutrients and myo-inositol concentrations, and reversible and irreversible transitions from one of these states to the other are possible. From this model, straightforward simple experiments are suggested. We also propose that recent models dealing with the intracellular calcium regulation by hormones, where one key step requires the hydrolysis of inositol phospholipids, take into account free myo-inositol and endogenous hormone concentrations (e.g., auxins).
我们对一些关于植物肿瘤转化逆转的实验给出了一种合理的解释。我们认为正常细胞和肿瘤细胞代表了对应于反应反馈机制的多个稳定稳态。（自催化）反馈回路是基于对肌醇所起作用的观察构建的：它增加了离子通过膜的通透性，并且离子激活了通往肌醇的生物合成途径。假设营养物质（糖和盐）的通透性是肌醇的产物增强函数，那么我们就有了一个（过于简化的）模型，该模型可以呈现多个静止稳定状态，其数量取决于外源营养物质和肌醇浓度，可能为一个或两个，并且从这些状态中的一个到另一个的可逆和不可逆转变都是可能的。基于这个模型，我们提出了一些直接简单的实验。我们还提出，最近处理激素对细胞内钙调节的模型，其中一个关键步骤需要肌醇磷脂的水解，要考虑游离肌醇和内源性激素浓度（例如生长素）。
