Biologic effects of SMF and paclitaxel on K562 human leukemia cells

Abstract

Abstract. In this study, we evaluated the ability of 8.8 mT static magnetic fields (SMF) to enhance the in vitro action of a chemotherapeutic agent, paclitaxel, against K562 human leukemia cells. We analyzed the cell proliferation, cell cycle distribution, DNA damage and alteration of cell surface and cell organelle ultrastructure after K562 cells were exposed to paclitaxel in the presence or absence of 8.8 mT SMF. The results showed that in the presence of SMF, the efficient concentration of paclitaxel on K562 cells was decreased from 50 to 10 ng/ml. Cell cycle analysis indicated that K562 cells treated with SMF plus paclitaxel were arrested at the G2 phase, which was mainly induced by paclitaxel. Through comet assay, we found that the cell cycle arrest effect of paclitaxel with or without SMF on K562 cells was correlated with DNA damage. The results of atomic force microscopy and transmission electron microscopy observation showed that the cell ultrastructure was altered in the group treated with the combination of SMF and paclitaxel, holes and protuberances were observed, and vacuoles in cytoplasm were augmented. Our data indicated that the potency of the combination of SMF and paclitaxel was greater than that of SMF or paclitaxel alone on K562 cells, and these effects were correlated with DNA damage induced by SMF and paclitaxel. Therefore, the alteration of cell membrane permeability may be one important mechanism underlying the effects of SMF and paclitaxel on K562 cells.

Decreased P‐glycoprotein is associated with the inhibitory effects of static magnetic fields and cisplatin on K562 cells

“…The inhibitory effect of the combination of SMFs and antineoplastic drugs on cancer cells has been described in several studies [Raylman et al, ; Gray et al, ; Sabo et al, ; Chen et al, ; Qi et al, ; Sun et al, ]. The present study showed that a combination of SMFs and DDP in 8 and 12 h treatment groups could significantly inhibit the metabolic activity of K562 cells ( P < 0.05), whereas neither DDP (10 µg/ml) nor SMFs (8.8 mT) alone influenced metabolic activity.…”

“…Evidence suggests that static magnetic fields (SMFs) not only influence the growth, proliferation, and structure of cancer cells [Chionna et al, 2003[Chionna et al, , 2005Dini and Abbro, 2005;Tenuzzo et al, 2006;Brix et al, 2008;Hsu and Chang, 2010;Yang et al, 2010] but also have the potential to enhance the cytotoxicity of chemical factors, especially chemotherapeutic drugs [Raylman et al, 1996;Gray et al, 2000;Sabo et al, 2002;Chen et al, 2010;Qi et al, 2011;Sun et al, 2012;Gellrich et al, 2014]. In the past two decades, accumulating evidence suggests that SMFs can enhance the killing effect of antineoplastic drugs on cancer cells, indicating that SMFs may act synergistically with pharmacological treatment [Gray et al, 2000;Sabo et al, 2002;Tofani et al, 2003].…”

Impact of Inhomogeneous Static Magnetic Field (31.7–232.0 mT) Exposure on Human Neuroblastoma SH-SY5Y Cells during Cisplatin Administration

“…The protective effect of the SMF against the action of the cis Pt that was revealed in this study is in agreement with other studies that report protection against drug-induced apoptosis in different cell lines and primary cultures [5] . On the other hand, taking similar approaches in one [5] , and different types of cells [10] – [12] , [45] – [46] , it was shown that drug activity was enhanced by SMF exposure. The synergistic effects of SMF with certain drugs, including cis Pt, taxol, doxorubicin and cyclophosphamide have been already reported [11] .…”

“…Accordingly, the cytotoxic effect of antineoplastic drugs on cancer cells was enhanced by a combined treatment of moderate magnetic induction of SMFs and chemotherapeutic drugs. Such studies highlight the synergistic action of SMF combined with pharmacological treatment [7] – [12] . However, due to various characteristics of the field such as, induction level, duration and direction as well as the dosage of administered drug, further studies are required to reveal the mechanism(s) involved in the combined approaches.…”

Bioeffects of Static Magnetic Fields: Oxidative Stress, Genotoxic Effects, and Cancer Studies

“…Sun et al [97] evaluated the ability of 8.8 mT SMFs to enhance the in vitro action of a chemotherapeutic agent, paclitaxel, against K562 human leukemia cells. The authors analyzed the cell proliferation, cell cycle distribution, DNA damage, and alteration of cell surface and cell organelle ultrastructure after K562 cells were exposed to paclitaxel in the presence or absence of SMF.…”