Ferritin Enhances SPIO Tracking of C6 Rat Glioma Cells by MRI

Purpose To investigate the effect of ferritin protein overexpression on superparamagnetic iron oxide (SPIO) particle labeling of C6 rat glioma cells, and track the labeled cells in vivo using magnetic resonance imaging (MRI). Materials and Methods A plasmid of H-chain of murine ferritin gene was constructed and transfected into C6 cells. The parental and the transfected C6 cells labeled with SPIO were bilaterally inoculated subcutaneously into nude mice. The mice were imaged by multiple T2-weighted MR scans after C6 cell inoculation. The mice were killed 2 weeks later, and the concentration of iron in the tumor tissue was measured by inductively coupled plasma. Results The iron concentration in xenografts derived from SPIO-labeled C6 cells that were transfected with ferritin plasmid was significantly higher than that in xenografts from parental C6 cells that were labeled with SPIO but not transfected ( p = 0.034, N = 5). Ferritin-transfected C6 cells showed an improved T 2 contrast in vivo compared with parental cells labeled with SPIO but not transfected. Conclusion Coordinating ferritin with SPIO can lead to a longer MRI cellular tracking period.