Table 1.
Experimental studies in vitro.
| Experimental materials |
Radiation condition |
Major biological consequences | Refs | ||||
|---|---|---|---|---|---|---|---|
| Type of radiation | Energy | LET | Dose | Dose rate | |||
| Golden hamster embryo cells | neutrons | 430 keV | - | 0.001-1.5 Gy | 0.1-0.8 Gy/h | Compared with X-ray, high-energy neutrons and argon ions had higher ability to induce malignant transformation of cells. | [19] |
| argon ions | 429 MeV/u | - | 0.01 or 0.1 Gy | - | |||
| X-rays | 250 kVp | - | 0.75-3 Gy, 0.01-0.1 Gy | 0.13-0.6 Gy/min | |||
| Syrian hamster embryo cells | carbon ions | 290 MeV/u | 13, 50, 100 keV/µm | 0001, 0.025, 0.05, 0.1, 0.2 Gy | 0.04-0.2 Gy/min, 1-2 Gy/min |
The RBE of heavy ions first increased with the increase of LET, and reached the maximum value of about 7 at 100 keV/µm. | [54] |
| silicon ions | 490 MeV/u | 150, 240, 400 keV/µm | 0.025, 0.05, 0.1, 0.2 Gy | 0.04-0.2 Gy/min, 1-2 Gy/min |
|||
| X-rays | 250 kVp | 2.5 keV/µm | 0.05, 0.1, 0.2 Gy | 0.5 Gy/min | |||
| Human bronchial epithelial cells | iron ions | 996.8 MeV/u | 151 keV/µm | 0.5, 1 Gy | - | Some growth-related pathways in cells were significantly up-regulated. | [62] |
| silicon ions | 990 MeV/u | 44 keV/µm | 0.5, 1 Gy | - | |||
| γ-rays | 0.661 MeV | - | 1, 3 Gy | - | |||
| Immortalized human esophageal epithelial cells, Lung epithelial cells of non-transformed mink |
silicon ions | 170 MeV/u | 99 keV/µm | 0-2 Gy | 0.25-1 Gy/min | 0.1 Gy silicon ions or iron ions could induce EMT, and 2 Gy rays could induce EMT more obviously. | [66] |
| iron ions | 600 MeV/u | 180 keV/µm | 0-2 Gy | 0.25-1 Gy/min | |||
| Mouse embryo fibroblasts | iron ions | 1 GeV/u | 151 keV/µm | 0.25 Gy | 0.5 Gy/min | The malignant transformation frequency of bystander progeny cells irradiated by iron ions increased significantly. | [60] |
| protons | 1 GeV/u | 0.2 keV/µm | 1 Gy | 1 Gy/min | |||
| Human salivary gland tumor cells | carbon ions | 290 MeV/u | 13, 100 keV/µm | 1, 2, 3, 4, 5 Gy | - | The abilities of colony formation and proliferation of bystander cells were enhanced. | [68] |
| Human fibroblasts | carbon ions | 290 MeV/u | 50 keV/µm | 0.5-3 Gy | 0.03 Gy/min | Simultaneous exposure to microgravity and space radiation increased the rate of chromosome aberration. | [69] |
| X-rays | 200 kVp | - | 0.5-3 Gy | 0.03 Gy/min | |||
| Immortalized human mammary epithelial cells | iron ions | - | - | - | - | Low-dose-rate heavy ions could induce malignant transformation of cells. | [70] |
| Mouse embryo fibroblasts | X-rays | 225 kVp | - | 0-1.2 Gy | - | The malignant transformation of cells induced by heavy ions was mostly a direct effect, and with the increase of LET, the cell damage became difficult to repair. | [71] |
| γ-rays | 1.25 MeV | - | 0-12 Gy | 0.005, 0.04, 1, 100, 1000 cGy/min | |||
| argon ions | 400, 330 MeV/u | 120, 140 keV/µm | 0-6 Gy | 0.01, 1 Gy/min | |||
| protons | 240 MeV/u | - | 0-12 Gy | - | |||
| iron ions | 600 MeV/u | 200 keV/µm | 0-8 Gy | - | |||
| neon ions | 425 MeV/u | 32 keV/µm | 0-10 Gy | 0.02, 2 Gy/min | |||
| Immortalized human bronchial epithelial cells | iron ions | 1 GeV/u | - | 0-4 Gy, 0.06 Gy | - | Iron ions or α-particles could induce genomic instability and malignant transformation of human bronchial epithelial cells. | [72] |
| α-particles | - | 150 | 0-2 Gy, 0.06 Gy | - | |||
| γ-rays | - | - | 0-10 Gy | - | |||
| Immortalized human bronchial and mammary cells | iron ions | 1 GeV/u | - | 0.06 Gy | - | The malignant transformation was related to the repair of DNA damage and the expression of cell cycle regulatory genes. | [73] |
| α-particles | - | 150 keV/µm | 0.06 Gy | - | |||
| V79-4 Chinese hamster cells | α-particles | 3.26 MeV | 121 keV/µm | 0.36, 0.56, 0.69, 1.39, 2.23 Gy | 0.008, 0.154, 0.28 Gy/h | The induction of chromosomal aberrations exhibited a linear relationship with dose and showed evidence of significant conventional dose-rate dependence. | [74] |
| Human neonatal primary fibroblasts | iron ions | 1 GeV/u | - | - | ≤ 1 Gy/min | Silicon ions were more likely to induce malignant transformation than protons. | [75] |
| silicon ions | 600 MeV/u | - | - | ≤ 1 Gy/min | |||
| protons | 235, 188 MeV/u | - | 0.05 Gy | - | |||
| X-rays | 250 kVp | - | - | ≤ 1 Gy/min | |||
| Human neonatal primary fibroblasts | iron ions | 1.005 GeV/u | 151.3 keV/µm | 0.02 Gy | < 1 Gy/min | The frequency of malignant transformation induced by sequential irradiation was related to the time interval between the two kinds of particle irradiation. | [76] |
| titanium ions | 1.007 GeV/u | 108.1 keV/µm | 0.02 Gy | < 1 Gy/min | |||
| protons | 1 GeV/u | 0.22 keV/µm | 0.02 Gy | < 1 Gy/min | |||
| Human fibroblasts | protons | 0.05, 1 GeV/u | 1.25, 0.2 keV/µm | 0.2 Gy | 0.1 Gy/min | Low-dose proton irradiation could protect human fibroblasts which are subsequently irradiated by iron ions. | [77] |
| iron ions | 1 GeV/u | 151 keV/µm | 0.5 Gy | 0.5 Gy/min | |||
| Human lymphoblastic cells | X-rays | 200 kVp | - | 0.5, 1, 1.1, 1.5 Gy | 0.03 Gy/min | The combination of microgravity and GCR can increase chromosome aberrations. | [78] |
| carbon ions | 290 MeV/u | 50 keV/µm | 0.25, 0.5, 0.75, 1 Gy | 0.03 Gy/min | |||
| Immortalized human bronchial epithelial cells | titanium ions | 230, 1000 MeV/u | 200, 108 keV/µm | 1 Gy | - | 1 Gy of HZE ions have the ability to stimulate the exosome release by about 4-fold from human bronchial epithelial cells relative to 10 Gy reference γ-rays. | [63] |
| silicon ions | 65, 148 MeV/u | 200, 100 keV/µm | 1 Gy | - | |||
| oxygen ions | 35 MeV/u | 100 keV/µm | 1 Gy | - | |||
| γ-rays | 0.661 MeV | - | 3, 10 Gy | 1.5 Gy/min | |||
| Human lymphocytes | X-rays | 250 kVp | - | 1-6 Gy | 1-2 Gy/min | Complex chromosome exchanges are responsible for the increased effectiveness of carbon ions compared to X-rays at the first post-irradiation mitosis. | [61] |
| carbon ions | 9.5 MeV/u | 175 keV/µm | 1, 2 Gy | 1-2 Gy/min | |||