Study type: Medical/biological study (experimental study)

Determination of death thresholds and identification of Terahertz (THz)-specific gene expression signatures. med./bio.

Published in: No authors listed, Optical interactions with tissues and cells XXI: 25 - 27 January 2010, San Francisco, California, United States SPIE, 2010: 7562 OK-1-7562 OK-8

Aim of study (acc. to author)

To study if high-power THz radiation causes cellular and/or molecular effects in human Jurkat cells and dermal fibroblast cell lines.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 2.52 THz
Exposure duration: continuous for up to 15 s
cell viability experiments with fibroblasts
Exposure 2: 2.52 THz
Exposure duration: continuous for 1 min or 2 min
gene expression experiments
Exposure 3: 2.52 THz
Exposure duration: continuous for 5, 10, 20, 30, 40 min
cell viability experiments with Jurkat cells

Exposure 1

Main characteristics
Frequency 2.52 THz
Type
Exposure duration continuous for up to 15 s
Additional info cell viability experiments with fibroblasts
Exposure setup
Exposure source
Chamber 25.4 mm 90° off-axis gold parabolic mirror used to focus the THz beam on the cell cultures in 35 mm petri dishes
Setup exposure system consists of a 50 W tunable CO2 pump laser, a pump frequency laser lock, and two non-folded THz laser cells; CO2 laser (tuned to 9P36) used to excite the rotational bands of methanol (at 380 mTorr), difluoromethane and methyl chloride
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power density 227 mW/cm² - - - -

Exposure 2

Main characteristics
Frequency 2.52 THz
Type
Exposure duration continuous for 1 min or 2 min
Additional info gene expression experiments
Exposure setup
Exposure source
Setup cells exposed in plates with 24 wells
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power density 227 mW/cm² - - - -

Exposure 3

Main characteristics
Frequency 2.52 THz
Type
Exposure duration continuous for 5, 10, 20, 30, 40 min
Additional info cell viability experiments with Jurkat cells
Exposure setup
Exposure source
Setup cells seeded in plates with 96 wells
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power density 227 mW/cm² - - - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

The MTT assay showed that 60% of the Jurkat cells survived the 30-minutes THz exposure, whereas only 20% survived the 40-minutes exposure. The flow cytometry data showed similar results and provided additional evidence suggesting that THz-induced cell death was mediated by both necrotic and apoptotic processes.
The preliminary confocal microscopy data suggested that cells exposed to THz radiation for 12 seconds or longer show appreciable signs of cell death.
The preliminary microarray data showed that dermal fibroblasts upregulated several genes when exposed to THz irradiation (primarily inflammatory cytokines).
Overall, these findings provide evidence for the cellular and molecular effects of THz irradiation.

Study character:

Study funded by

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