Tumors Established with Glioma Cells Transfected with the Gene mms6 Produce a Strong Increase in Transverse Relaxivity in Vivo

Brenda Robledo¹, Xiaoyong Zhang¹, Xiaoping P. Hu¹

In magnetotactic bacteria, the gene mms6 expresses a protein thought to initiate magnetite crystal formation. We previously found that transfecting glioma cells with mms6 increased the cells’ ability to uptake iron and increased their spin-spin relaxation rate (R2) in vitro. We hypothesized that tumors established with glioma cells transfected with mms6 would uptake endogenous iron and produce MR contrast. Our results show that mms6-positive tumors exhibit a larger R2 in vivo, likely due to the increased intracellular iron accumulation observed by Prussian staining the tumor. Our results suggest that mms6 may function as an MR reporter gene in cancer studies.