Fig 1: Radiosensitivity of cervical adenocarcinoma cells in 2D and 3D spheroid cultures. A Representative images of HeLa and HCA-1 spheroid. HeLa cells formed cell aggregates and HCA-1 cells formed compact spheroids 24 h after seeding. Scale bars: 500 µm. B Immunoblot of E-cad and ITGB1. Cancer cells and spheroids were cultured for 48 h after seeding, and total proteins were subjected to SDS-PAGE. GAPDH was used as controls. C The illustration to describe 2D or 3D spheroid culture with/without collagen-I. D, E In 2D cultures, HeLa (D) and HCA-1 (E) cells were irradiated with X-rays in microtubes, plated onto 96-well plates, and cultured for 4 days. In 3D spheroid culture, HeLa and HCA-1 cells were seeded onto ULA 96-well U-bottom plates and formed spheroids after 24 h. These spheroids were transferred to microtubes, irradiated with X-rays, then returned to 96-well plates and cultured for 4 days. For 2D or 3D spheroid culture in collagen gel, HeLa cells or spheroids were mixed with collagen type-I gel, plate on 35 mm dishes or 6-well plates and cultured at 37? for 1 h to solidify the collagen gel. Cells and spheroids were cultured for 4 days after X-ray or C-ion irradiation. Cell viability was measured using Cell Titer-Glo 3D. The results are shown as the mean ± SD of three independent experiments. *p < 0.05, **p < 0.01