A study of radiation injury in rat C6 glioma cell line by 1H-nuclear magnetic resonance spectroscopy

Objective To study the radiation injury of rat C6 glioma cell line by high resolution, 1H-nuclear magnetic resonance (1H NMR) spectroscopy, and to preliminarily investigate its mechanism. Methods Metabolite concentrations in C6 cells were determined by 1H NMR spectroscopy. Comet assay was used to evaluate DNA damage. Flow cytometry was used to determine the cell cycle and apoptosis rate. Colony-forming assay was used to measure the colony-forming rate and preliminarily investigate the mechanism of radiation injury. The results were analyzed by one-way analysis of variance and Pearson correlation analysis. Results With the increase in radiation dose from 0 Gy to 1, 5, 10, and 15 Gy, DNA damage was enhanced in a dose-dependent manner (P=0.000-0.690); the percentage of cells in G1 phase increased (P=0.026-0.749); the apoptosis rate significantly increased (all P=0.000); the colony-forming rate significantly declined (P=0.000-0.004); the Lac/Cr ratio significantly decreased (P=0.000-0.015), which had a negative linear correlation with DNA damage parameters (tail length, r=-0.971; %DNA in the tail, r=-0.998; tail moment, r=-0.995) and apoptosis rate (r=0.978). Conclusions 1H NMR spectroscopy reveals that the change in the Lac/Cr ratio is associated with injury and apoptosis of C6 cells after radiation. 1H NMR spectroscopy has the potential to predict radiation injury of glioma. Key words: Deoxyribonucleic acid damage; Proton magnetic resonance; Cell line, glioma; Apoptosis; Cell cycle arrest