Heacock C S, Sutherland R M
Int J Radiat Oncol Biol Phys. 1986 Aug;12(8):1287-90. doi: 10.1016/0360-3016(86)90155-0.
Extreme hypoxia induces many changes in the biology of cells, including the enhanced synthesis of oxygen regulated proteins (ORPs). We investigated the conditions required for the induction of ORPs and by modifying culture conditions, eliminated variables other than oxygen concentration. Several exponentially growing rodent and human cell lines were examined before, during, and after various periods of extreme hypoxia. The following responses were analyzed: cell growth, clonogenic survival, glucose consumption, lactate production, media pH, total protein synthesis, and specific protein synthesis. EMT6/Ro cells did not increase in cell number or progress through the cell cycle after initiation of extreme hypoxia. Cell morphology and cell survival were nearly normal for up to 12 hr of hypoxia. During this period, media pH remained constant, with the concentrations of glucose and lactate being virtually indistinguishable from aerobic cultures or initial values. Associated with these conditions, a marked inhibition of total protein synthesis was observed for EMT6/Ro cells, such that the hypoxic protein synthesis rate was about 60% of the aerobic rate. However, enhanced synthesis of a set of proteins, designated as ORPs, was preferentially induced in less than 6 hr. The molecular weights of the five major ORPs are 260, 150, 100, 80 and 33 kD. Under these conditions, the primary inducing agent was a low concentration of oxygen. This set of ORPs was distinctly different from the set of heat induced (heat-shock) proteins, but included the major 100 kD and 80 kD glucose regulated proteins. Although the functions of ORPs are unknown, their induction under conditions that are known to modify the sensitivity of cancer cells to therapeutic agents suggests that the presence of ORPs should be further investigated to determine their possible value in diagnosis and predicting treatment response.
极端缺氧会引发细胞生物学特性的诸多变化，包括氧调节蛋白（ORP）合成的增强。我们研究了诱导ORP所需的条件，并通过改变培养条件，排除了氧浓度以外的其他变量。在极端缺氧的不同时间段之前、期间和之后，对几种呈指数生长的啮齿动物和人类细胞系进行了检测。分析了以下反应：细胞生长、克隆形成存活率、葡萄糖消耗、乳酸生成、培养基pH值、总蛋白合成和特定蛋白合成。在开始极端缺氧后，EMT6/Ro细胞的数量没有增加，也未完成细胞周期进程。在长达12小时的缺氧过程中，细胞形态和细胞存活率几乎正常。在此期间，培养基pH值保持恒定，葡萄糖和乳酸的浓度与需氧培养或初始值几乎没有区别。与这些条件相关的是，观察到EMT6/Ro细胞的总蛋白合成受到显著抑制，以至于缺氧时的蛋白合成速率约为需氧时的60%。然而，一组被指定为ORP的蛋白质在不到6小时内被优先诱导增强合成。五种主要ORP的分子量分别为260、150、100、80和33kD。在这些条件下，主要诱导剂是低浓度的氧。这组ORP与热诱导（热休克）蛋白明显不同，但包括主要的100kD和80kD葡萄糖调节蛋白。尽管ORP的功能尚不清楚，但它们在已知会改变癌细胞对治疗剂敏感性的条件下被诱导，这表明应进一步研究ORP的存在情况，以确定它们在诊断和预测治疗反应方面的潜在价值。
