Department of Diagnostic and Interventional Radiology, 39058University Hospital RWTH Aachen, Aachen, Germany.
60994Philips Research, Eindhoven, the Netherlands.
Technol Cancer Res Treat. 2023 Jan-Dec;22:15330338221136694. doi: 10.1177/15330338221136694.
Hepatocellular carcinoma is a leading cause of cancer-related death in many parts of the world. Traditional treatment options are not always effective. During the promising minimally invasive electroporation-based therapies, biological cell membranes are exposed to an external, sufficiently high, pulsed electric field which creates so-called nanopores into the lipid bilayer of the cell membrane. These pores can either be permanent (irreversible electroporation (IRE)), leading to apoptosis, or repairable (reversible electroporation (RE)), with continued cell function. In tumor therapy, RE is used to increase the diffusion of a chemotherapeutic drug during electrochemotherapy. For both IRE and RE, the success of the treatment is dependent on application of the appropriate electric field. Therefore, this study aims to define the pulse parameters and thresholds for IRE and RE on hepatocellular carcinoma (HepG2) cells .In a custom-made setup, HepG2 cell viability (0, 5, 10, and 15 min), and the peak temperature were measured after electroporation with the different IRE and RE pulsing protocols, to determine the most successful settings for IRE and RE. A CAM/PI flow cytometric assay was performed to confirm cell permeabilization for the RE pulsing protocols with the highest cell viability.The results indicated that an IRE pulsing protocol (70 pulses, 100 s pulse length, and 100 ms interval) with an electric field strength of 4000 V/cm was needed as threshold for almost complete cell death of HepG2 cells. A RE pulsing protocol (8 pulses, 100 s pulse length, and 1000 ms interval) with an electric field strength of 1000 V/cm was needed as threshold for viable and permeabilized HepG2 cells. The low peak temperatures (max 30.1°C for IRE, max 23.1°C for RE) within this study indicated that the reduction in HepG2 cell viability was caused by the applied electric field and was not a result of Joule heating.
肝细胞癌是世界上许多地区癌症相关死亡的主要原因。传统的治疗选择并不总是有效。在有前途的微创基于电穿孔的治疗中，生物细胞膜暴露于足够高的外部脉冲电场中，该电场在细胞膜的脂质双层中产生所谓的纳米孔。这些孔可以是永久性的（不可逆电穿孔（IRE）），导致细胞凋亡，也可以是可修复的（可逆电穿孔（RE）），细胞功能持续。在肿瘤治疗中，RE 用于增加电化学治疗过程中化疗药物的扩散。对于 IRE 和 RE，治疗的成功都取决于适当电场的应用。因此，本研究旨在定义肝细胞癌（HepG2）细胞的 IRE 和 RE 的脉冲参数和阈值。在定制的设置中，在不同的 IRE 和 RE 脉冲方案下测量 HepG2 细胞活力（0、5、10 和 15 分钟）和峰值温度，以确定 IRE 和 RE 最成功的设置。进行 CAM/PI 流式细胞术测定以确认具有最高细胞活力的 RE 脉冲方案的细胞通透性。结果表明，IRE 脉冲方案（70 个脉冲，100 s 脉冲长度和 100 ms 间隔），电场强度为 4000 V/cm，是 HepG2 细胞几乎完全死亡的阈值。RE 脉冲方案（8 个脉冲，100 s 脉冲长度和 1000 ms 间隔），电场强度为 1000 V/cm，是存活和通透的 HepG2 细胞的阈值。本研究中的低峰值温度（IRE 最大 30.1°C，RE 最大 23.1°C）表明 HepG2 细胞活力的降低是由施加的电场引起的，而不是焦耳加热的结果。
