X-ray-induced bio-acoustic emissions from cultured cells

Area of Science:

• Biophysics
• Cell Biology
• Radiation Oncology

Background:

• The study of cellular responses to ionizing radiation is crucial for understanding cancer treatment and biological effects.
• Intercellular communication, including bystander effects, plays a significant role in radiation response.
• Acoustic phenomena in biological systems are an emerging area of research.

Purpose of the Study:

• To characterize for the first time the emission of acoustic waves from cultured cells irradiated with X-ray photon radiation.
• To investigate the influence of radiation dose rate and cell viability on acoustic signal generation.
• To explore the potential role of radiation-induced acoustic emission (RIAE) in intercellular signaling.

Main Methods:

• Human cancer cell lines (MCF-7, HL-60) and cell-free media were exposed to 1 Gy X-ray photons.
• A custom large-bandwidth ultrasound transducer was used to record acoustic signals before, during, and after irradiation.
• Effects of dose rate and cell viability on acoustic emissions were analyzed.

Main Results:

• The first recorded acoustic signals from a collective pressure wave response to ionizing irradiation in cell culture were obtained.
• The acoustic signal magnitude correlated with the radiation dose rate.
• Live and dead cells exhibited distinct acoustic signal characteristics, with HL-60 cells showing wider peaks and higher acoustic power than MCF-7 cells.

Conclusions:

• X-ray irradiation induces a characteristic acoustic signal in cultured cancer cells during the radiation pulse.
• The rapid decay of acoustic signals suggests they are unlikely to be the primary cause of inter-organism bystander signals.
• Radiation-induced acoustic emission (RIAE) warrants further investigation for its potential role in intercellular bystander effects within tissues and cell cultures.