Application of non-invasive low-intensity pulsed electric field with thermal cycling-hyperthermia for synergistically enhanced anticancer effect of chlorogenic acid on PANC-1 cells

Abstract

Most existing cancer treatments involve high-cost chemotherapy and radiotherapy, with major side effects, prompting effort to develop alternative treatment modalities. It was reported that the combination of thermal-cycling hyperthermia (TC-HT) and phenolic compound exhibited a moderate cytotoxic effect against human pancreatic cancer PANC-1 cells. In this study, we investigate the efficacy of triple combination in PANC-1 cancer cells by adopting low-intensity pulsed electric field (LIPEF) to couple with TC-HT and CGA (chlorogenic acid). The study finds that this triple combination can significantly impede the proliferation of PANC-1 cells, with only about 20% viable cells left after 24h, whereas being nontoxic to normal cells. The synergistic activity against the PANC-1 cells was achieved by inducing G2/M phase arrest and apoptosis, which were associated with up-regulation of p53 and coupled with increased expression of downstream proteins p21 and Bax. Further mechanism investigations revealed that the cytotoxic activity could be related to mitochondrial apoptosis, characterized by the reduced level of Bcl-2, mitochondrial dysfunction, and sequential activation of caspase-9 and PARP. Also, we found that the triple treatment led to the increase of intracellular reactive oxygen species (ROS) production. Notably, the triple treatment-induced cytotoxic effects and the elevated expression of p53 and p21 proteins as well as the increased Bax/Bcl-2 ratio, all could be alleviated by the ROS scavenger, N-acetyl-cysteine (NAC). These findings indicate that the combination of CGA, TC-HT, and LIPEF may be a promising modality for cancer treatment, as it can induce p53-dependent cell cycle arrest and apoptosis through accumulation of ROS in PANC-1 cells.

3EZ, 20Ac-ingenol-induced Apoptosis in Chemoresistant Cancers With Cyclin D1 Accumulation

“…Recently, mutant p53 has become an attractive target for cancer therapy (45). Reportedly, it also induces apoptosis through activation of mutant p53 (46)(47)(48). 3EZ, 20Ac-ingenol also significantly increased the expression of mutant p53 protein and the p53-downstream target gene p21 and the activation of caspase 3 in Panc-1 cells.…”

Protection of high-frequency low-intensity pulsed electric fields and BDNF for SH-SY5Y cells against hydrogen peroxide-induced cell damage

“…Therefore, it is believed that the development of non-contact, non-invasive electric field therapy will be inevitable, which can also be further applied in conjunction with drugs for various therapeutic purposes. Previously, our team has achieved synergistic inhibitory effects on cancer cells by combining such electric fields with herbal extracts such as EGCG, CGA, and curcumin, and has also accomplished satisfactory results in repairing mouse motor neuron cell NSC-34, demonstrating the versatility of non-contact, non-invasive electric field stimulations [Hsieh et al, 2017; Hsieh et al, 2018; Lu et al, 2018; Hsieh et al, 2019 Lu et al, 2020]. In application, the electric field’s strength and frequency would vary among different cellular tissues, depending on accompanying drugs, tissue structure, and protein response, which needs further research.…”

“…Third, ultrasound can be added to the combination treatment, further boosting the anticancer effect [Hsieh et al, 2018]. Moreover, our team has found another effective anticancer triple therapy, combining LIPEF, chlorogenic acid (CGA), and thermal cycling-hyperthermia technique [Lu et al, 2020]. Besides, LIPEF can join hands with fucoidan to modulate rho-associated protein kinase (ROCK) and the downstream Akt protein, thereby protecting motor neurons NSC-34 against damage by oxidative stress [Hsieh et al, 2019].…”

Transcriptional Regulation of the Colorectal Cancer Stem Cell Markers, Nanog and Oct4, Induced by a Thermodynamic-Based Therapy Approach

“…Previous studies have also reported a decrease in cell viability and increased DNA fragmentation and ROS production [37,38]. The combination therapy induced the mitochondrial activation and increased the Caspases-9, -3 and poly ADP-ribose polymerase (PARP) expression leading to apoptosis [39]. In one study, authors showed that hyperthermia increased e cacy of PDT on gastric cancer cells through elevated ROS production leading to enhanced PDT-induced cytotoxicity [37].…”