论文标题
环境应力水平以建模肿瘤细胞生长和存活率
Environmental stress level to model tumor cell growth and survival
论文作者
论文摘要
活肿瘤细胞的存活构成了许多影响,例如营养饱和度,氧气水平,药物浓度或机械力。数据支持的数学建模可以成为更好地了解不同设置中细胞行为的强大工具。但是,在考虑众多环境因素的数学建模可能会变得具有挑战性。我们提出了一种通过引入“环境应力水平”,以集体方式对每个环境数量对细胞的单独影响进行建模的方法。它是一个不可估量的辅助变量,如果暴露于某些条件,可以量化可存活的细胞在应力状态的程度。高应激水平可以抑制细胞生长,促进细胞死亡并影响细胞运动。作为概念的证明,我们比较了两个普通微分方程的系统,它们分别在各种营养饱和度下对肿瘤细胞动力学进行了对环境应力水平的影响。基于粒子的贝叶斯反演方法用于量化不确定性,并通过对肝癌细胞体外种群的时间分解测量进行校准未知模型参数。比较了两个模型的校准结果,并量化了拟合质量。尽管两个模型的预测都与数据符合良好的一致性,但有迹象表明,考虑应力水平的模型会产生更好的拟合。提出的建模方法为考虑具有影响细胞动态的其他环境因素的系统提供了灵活且可扩展的框架。
Survival of living tumor cells underlies many influences such as nutrient saturation, oxygen level, drug concentrations or mechanical forces. Data-supported mathematical modeling can be a powerful tool to get a better understanding of cell behavior in different settings. However, under consideration of numerous environmental factors mathematical modeling can get challenging. We present an approach to model the separate influences of each environmental quantity on the cells in a collective manner by introducing the "environmental stress level". It is an immeasurable auxiliary variable, which quantifies to what extent viable cells would get in a stressed state, if exposed to certain conditions. A high stress level can inhibit cell growth, promote cell death and influence cell movement. As a proof of concept, we compare two systems of ordinary differential equations, which model tumor cell dynamics under various nutrient saturations respectively with and without considering an environmental stress level. Particle-based Bayesian inversion methods are used to quantify uncertainties and calibrate unknown model parameters with time resolved measurements of in vitro populations of liver cancer cells. The calibration results of both models are compared and the quality of fit is quantified. While predictions of both models show good agreement with the data, there is indication that the model considering the stress level yields a better fitting. The proposed modeling approach offers a flexible and extendable framework for considering systems with additional environmental factors affecting the cell dynamics.