Radiobiological characterization of human tumor cell multilayers after conventional and particle irradiation

Area of Science:

• Radiobiology
• Cellular Biology
• Oncology

Background:

• Solid tumors are complex 3D structures, but most radiobiological studies use 2D monolayers.
• Understanding multicellular effects is crucial for accurate tumor irradiation modeling.

Purpose of the Study:

• To develop planar multilayers of human tumor cells (WiDr, SiHa) as a model for solid tumor irradiation.
• To assess the suitability of these multilayers for cell survival studies using X-rays and heavy ions.

Main Methods:

• Established planar multilayers and monolayers of WiDr and SiHa human tumor cell lines.
• Irradiated cells using conventional X-rays (250 kV) and heavy-ion irradiation ((12)C(6+)) at the plateau and extended Bragg peak.
• Analyzed cell survival and cell cycle progression (G2/M phase arrest) using flow cytometry.

Main Results:

• Multilayers exhibited decreased cell survival compared to monolayers after both X-ray and heavy-ion irradiation.
• Observed a multicellular sensitization effect, contrasting with reported multicellular resistance.
• Irradiated SiHa multilayers showed prolonged G2/M phase arrest compared to monolayers, with no difference between X-ray and heavy-ion effects.

Conclusions:

• Planar human tumor cell multilayers serve as a viable model for studying solid tumor irradiation.
• Multilayers demonstrate a sensitization effect to irradiation, highlighting the importance of 3D models.
• Prolonged G2/M arrest in multilayers suggests altered cell cycle regulation under irradiation conditions.