Millimeter-wave pulsed heating in vitro: cell mortality and heat shock response

Abstract

Millimeter wave (MMW)-induced heating represents a promising alternative for non-invasive hyperthermia of superficial skin cancer, such as melanoma. Pulsed MMW-induced heating of tumors allows for reaching high peak temperatures without overheating surrounding tissues. Herein, for the first time, we evaluate apoptotic and heat shock responses of melanoma cells exposed in vitro to continuous (CW) or pulsed-wave (PW) amplitude-modulated MMW at 58.4 GHz with the same average temperature rise. Using an ad hoc exposure system, we generated 90 min pulse train with 1.5 s pulse duration, period of 20 s, amplitude of 10 °C, and steady-state temperature at the level of cells of 49.2 °C. The activation of Caspase-3 and phosphorylation of HSP27 were investigated using fluorescence microscopy to monitor the spatial variation of cellular response. Our results demonstrate that, under the considered exposure conditions, Caspase-3 activation was almost 5 times greater following PW exposure compared to CW. The relationship between the PW-induced cellular response and SAR-dependent temperature rise was non-linear. Phosphorylation of HSP27 was 58% stronger for PW compared to CW. It exhibits a plateau for the peak temperature ranging from 47.7 to 49.2 °C. Our results provide an insight into understanding of the cellular response to MMW-induced pulsed heating.

Morphological Changes in H1299 Human Lung Cancer Cells Following W-Band Millimeter-Wave Irradiation

“…However, radiotherapy results in immun-ocompromise [4] and chemotherapeutics drive drug resistance [23], thereby complicating full recoveries and leading to drug dependence. Although developments of microwave bronchoscopy [47] and cytotoxic effects of MMW exposure have been demonstrated [48], clinical adaptation is restricted due to the presence of thermal ablation used in these methods, which complicates the targeted application at lung tumor sites. This study provides the first threshold energy limits for using MMW irradiation within a non-thermal power density to elicit H1299 cancer cell annihilation, thereby making a clinical adaptation possible.…”

Exposure Assessment in Millimeter‐Wave Reverberation Chamber Using Murine Phantoms

“…The exposure system and methodology reported in this paper can be applied to study potential modifications induced in mice models after mmW exposure. This type of studies are of importance due to near future integration of mmW technologies in 5 G as well as due to increasing interest in biomedical applications of mmW [Zhadobov et al, ; Orlacchio et al, ].…”

Morphological Changes in H1299 Human Lung Cancer Cells Following Millimeter-Wave Irradiation

“…But, radiotherapy results in immunocompromise [4] and chemotherapeutics drive drug resistance [23], thereby complicating full recoveries and leading to drug dependence. Although developments of microwave bronchoscopy [47] and cytotoxic effect of MMW exposure been demonstrated [48], clinical adaptation is restricted due to the presence of thermal ablation used in these methods which complicates the targeted application at lung tumor sites. This study provides the first threshold energy limits for using MMW irradiation within a non-thermal power density to elicit H1299 cancer cell annihilation, thereby making a clinical adaptation possible.…”