Apoptosis of Lewis Lung Carcinoma Cells Induced by Microwave via p53 and Proapoptotic Proteins In vivo

Abstract

Background:Microwave therapy is a minimal invasive procedure and has been employed in clinical practice for the treatment of various types of cancers. However, its therapeutic application in non-small-cell lung cancer and the underlying mechanism remains to be investigated. This study aimed to investigate its effect on Lewis lung carcinoma (LLC) tumor in vivo.Methods:Fifty LLC tumor-bearing C57BL/6 mice were adopted to assess the effect of microwave radiation on the growth and apoptosis of LLC tumor in vivo. These mice were randomly assigned to 10 groups with 5 mice in each group. Five groups were treated by single pulse microwave at different doses for different time, and the other five groups were radiated by multiple-pulse treatment of a single dose. Apoptosis of cancer cells was determined by terminal deoxynucleotidyl transferase dUTP nick-end labeling assay. Western blotting was applied to detect the expression of proteins.Results:Single pulse of microwave radiation for 5 min had little effect on the mice. Only 15-min microwave radiation at 30 mW/cm2 significantly increased the mice body temperature (2.20 ± 0.82)°C as compared with the other groups (0.78 ± 0.29 °C, 1.24 ± 0.52 °C, 0.78 ± 0.42 °C, respectively), but it did not affect the apoptosis of LLC tumor cells significantly. Continous microwave radiation exposure, single dose microwave radiation once per day for up to seven days, inhibited cell division and induced apoptosis of LLC tumor cells in a dose- and duration-dependent manner. It upregulated the protein levels of p53, Caspase 3, Bax and downregulated Bcl-2 protein.Conclusions:Multiple exposures of LLC-bearing mice to microwave radiation effectively induced tumor cell apoptosis at least partly by upregulating proapoptotic proteins and downregulating antiapoptotic proteins. Continuous radiation at low microwave intensity for a short time per day is promising in treating non-small-cell lung cancer.

Theabrownin Inhibits Cell Cycle Progression and Tumor Growth of Lung Carcinoma through c-myc-Related Mechanism

“…As previously described, the tumor tissue in each mouse was dissected, fixed in 10% formaldehyde for 24 h, and embedded in paraffin wax. Sections (2∼3 μm) were stained by terminal deoxynucleotidyl TUNEL using the in situ cell death detection kit (Roche) according to the manufacturer’s instructions to detect the apoptotic cells ( Zhang et al, 2017 ). Apoptotic cells were manifested by green staining in the nuclei under microscopy and five microscopic fields (×400) of each section were randomly examined, and the positive cells were counted by a single-blinded observer in a coded randomized order.…”

The non-thermal biological effects and mechanisms of microwave exposure

“…Recently, Zhao et al (12) also showed that microwave dose-dependently induced cellular apoptosis, cell cycle arrest and decreased cytotoxic activity in Natural killer cells 92 (NK-92), possibly through extracellular regulated protein kinases (ERK)-mediated regulation of apoptosis and perforin expression. Additionally, Zhang et al (13) demonstrated that continuous microwave radiation once a day for up to 7 days efficiently induced Lewis lung carcinoma (LLC) tumor cell apoptosis in mice even at the low intensity of 10 mW/cm 2 for 5 min each time, and revealed that non-thermal effect played a critical role in the induction of tumor cell apoptosis in-vivo.…”

“…Changed possibly through ERK-mediated regulation of apoptosis and perforin expression 2017 Zhang et al (13) 10 mW/cm 2 LLC cells cell apoptosis changed 2006 Zhadobov et al (15) 60 GHz Artificial Biological Membranes lateral pressure increased 1995 Geletyuk et al (16) 42.25 GHz kidney cells K+ channel changed 2014 Rougier et al (17) 2.45 GHz Escherichia coli cellular permeability increased 2014 Zeng et al (18) 2.45 GHz Yeast cellular permeability increased…”

Construction a CO2 incubator for cell culture with capability of transmitting microwave radiation

“…[ 10 ] Some studies have also claimed that these fields can reduce cell growth and survival and induce apoptosis in cells. [ 11 12 13 14 15 16 ] In contrast, there are other studies that do not confirm the above and their results have shown that electromagnetic waves and fields have no effect on cell growth and survival. [ 6 7 8 ]…”