Table 1.
Human tumor cells of diverse origin recovering from photon or proton radiation harbor similar patterns of immunogenic modulation on the cell surface.
| Surface Expression: % Positive cells (MFI) | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Gy | Viability | HLA | CEA | MUC-1 | ICAM-1 | Fraction per cell line |
|||
| Radiation Modality | LNCaP | Photon | 0 | 95 | 92(104) | 2 (27) | 8 (27) | 3 (30) | |
| 8 | 84 | 92 (425) | 15 (181) | 8 (70) | 6 (53) | 4/4 | |||
| Proton | 0 | 96 | 99 (123) | 2 (21) | 9 (32) | 3 (38) | |||
| 8 | 86 | 95 (304) | 9 (102) | 12 (58) | 6 (750) | 4/4 | |||
| MDA-MB-231 | Photon | 0 | 78 | 99 (415) | 4 (38) | 17 (138) | 90 (250) | ||
| 8 | 65 | 99 (886) | 4 (220) | 31 (210) | 95 (1110) | 4/4 | |||
| Proton | 0 | 91 | 99 (390) | 3 (63) | 4 (13) | 69 (129) | |||
| 8 | 76 | 99 (682) | 4 (109) | 14 (81) | 86 (751) | 4/4 | |||
| H1703 | Photon | 0 | 92 | 99 (633) | 2 (39) | 47 (25) | 7 (40) | ||
| 8 | 77 | 99 (930) | 2 (190) | 25 (119) | 25 (119) | 3/4 | |||
| Proton | 0 | 96 | 99 (409) | 2 (31) | 21 (32) | 4 (34) | |||
| 8 | 81 | 99 (501) | 2 (52) | 27 (47) | 16 (45) | 3/4 | |||
| JHC7 | Photon | 0 | 83 | 98 (536) | 5 (239) | 11 (120) | 57 (235) | ||
| 8 | 76 | 98 (580) | 10 (180) | 12 (113) | 63 (243) | 2/4 | |||
| Proton | 0 | 88 | 99 (579) | 13 (133) | 10 (99) | 87 (254) | |||
| 8 | 81 | 99 (667) | 15 (179) | 12 (102) | 90 (395) | 3/4 | |||
| 28/32 (87.5%) | |||||||||
Human prostate (LNCaP), breast (MDA-MB-231), lung (H1703), and chordoma (JHC7) carcinoma cells were mock-irradiated (0 Gy) or exposed to a single dose of 8 Gy photon or proton radiation. After 96 h, cells were analyzed by flow cytometry. Viability was determined for the entire cell populations by live/dead staining as described in materials and methods. For surface expression of HLA-ABC (MHC-I), CEA, MUC-1, and ICAM-1, analysis was conduced on gated viable cells. Numbers indicate percentage of positive cells. Numbers in parentheses denote mean fluorescence intensity (MFI). Bold type indicates marked upregulation (≥ 10% increase in percent of cells or 50% increase in MFI not observed in isotype control vs. untreated cells). Data shown is representative of experiment repeated 3 times with similar results.