【摘要】 目的探究细胞生长抑制因子和组织应力对处于初期生长阶段肿瘤的影响。方法将处于初期生长阶段的实体肿瘤分为肿瘤细胞相和间质相,采用二相模型描述其生长、演变过程。组织间营养的供给促进肿瘤细胞的生长;新陈代谢及细胞自身分泌的抑制因子加速细胞的凋亡。建立肿瘤细胞相的连续性方程与营养、抑制因子的扩散方程。考虑到两相的互相作用对肿瘤生长的影响,建立两相的力平衡方程,并利用各相的本构关系确定最终耦合的质量守恒方程、动量守恒方程和扩散方程,进行数值求解。结果数值计算结果显示,营养物质浓度随时间增加而减小,其分布由肿瘤中心向周边递增;抑制因子的含量随时间推进而减少,在肿瘤中心区域变化明显,周边变化不大;在抑制因子与组织应力的共同影响下,生长初期阶段肿瘤的中心区域活性小,周边区域活性大;忽略抑制因子的作用,肿瘤内部活性很高且肿瘤细胞分布均匀。结论抑制因子的存在,使生长初期阶段的肿瘤内部出现坏死区;间质挤压肿瘤细胞,细胞产生释放应力的趋势,从而向外生长。更多还原

【Abstract】 Objective To explore the impact of stress and inhibitor on avascular tumor growth. Methods A two-phase model, including the tumor cell and the extra-cellular interstitium is presented to describe avascular tumor growth. The diffusion of nutrients gives rise to the cellular growth while metabolism and inhibitor released by tumor cell itself accelerate the death rate. The continuum equation for tumor cell and the diffusion equation for nutrients and inhibitor are established. Given the interaction between the two phases, equations of momentum conservation are gained. With the constitutive relationship of each phase, the final coupled equations are linked together and numerical results are obtained. Results The tension of nutrients declines as time goes by, with lower value in the central area compared with its surrounding. Much more inhibitors are absorbed by the central area than its edge. Given the inhibitor and stress of each phase, the out-ring area of tumor shows more potential to grow and the central area tends to be dormant. The whole tumor tends to grow actively if inhibitors are neglected. Conclusion The existence of inhibitor is essential for the formation of necrosis. The stress of tumor cell phase drives the tumor to grow outside so that the high stress could be relieved.更多还原