Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
Cardiovascular Engineering Lab, Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran.
J Mech Behav Biomed Mater. 2018 Sep;85:188-193. doi: 10.1016/j.jmbbm.2018.06.009. Epub 2018 Jun 6.
Radiation therapy has been widely utilized as an effective method to eliminate malignant tumors and cancerous cells. However, subjection of healthy tissues and the related networks of blood vessels adjacent to the tumor area to irradiation is inevitable. The aim of this study was to investigate the consequent effects of fractionation radiotherapy on the mechanical characteristics of human umbilical vein endothelial cells (HUVECs) through alterations in cytoskeleton organization and cell and nucleus morphology. In order to simulate the clinical condition of radiotherapy, the HUVECs were exposed to the specific dose of 2 Gy for 1-4 times among four groups with incremental total dose from 2 Gy up to 8 Gy. Fluorescence staining was performed to label F-actin filaments and nuclei. Micropipette aspiration and standard linear solid model were employed to evaluate the elastic and viscoelastic characteristics of the HUVECs. Radiotherapy significantly increased cell elastic moduli. Due to irradiation, instantaneous and equilibrium Young's modulus were also increased. Radiotherapy diminished HUVECs viscoelastic behavior and shifted their creep compliance curves downward. Furthermore, gamma irradiation elevated the nuclei sizes and to a lesser extent the cells sizes resulting in the accumulation of F-actin filaments within the rest of cell body. Endothelial stiffening correlates with endothelial dysfunction, hence the results may be helpful when the consequent effects of radiotherapy are the focus of concern.
放射治疗已被广泛应用于消除恶性肿瘤和癌细胞的有效方法。然而，不可避免的是，健康组织和肿瘤区域附近的相关血管网络会受到照射。本研究旨在通过改变细胞骨架组织和细胞及细胞核形态，研究分割放射治疗对人脐静脉内皮细胞（HUVEC）力学特性的后续影响。为了模拟放射治疗的临床情况，将 HUVEC 暴露于特定剂量的 2Gy 下，4 组 HUVEC 分别接受 1-4 次照射，总剂量从 2Gy 逐渐增加到 8Gy。通过荧光染色标记 F-肌动蛋白丝和细胞核。采用微管吸吮技术和标准线性固体模型评估 HUVEC 的弹性和粘弹性特性。放射治疗显著增加了细胞的弹性模量。由于照射，瞬时和平衡杨氏模量也增加了。放射治疗降低了 HUVEC 的粘弹性，并使其蠕变曲线向下移动。此外，γ射线照射会增加细胞核的大小，并在一定程度上增加细胞的大小，导致细胞剩余部分内 F-肌动蛋白丝的积累。内皮变硬与内皮功能障碍有关，因此当放射治疗的后续影响成为关注焦点时，这些结果可能会有所帮助。
