MRI measurement of alanine uptake in a mouse xenograft model of U-87 MG glioblastoma

The potential use of alanine as an MRI contrast agent was investigated. The relaxation properties of alanine solutions were measured at 9.4 T. The T-2 relaxivity caused by the chemical exchange (R-2ex) between amine protons and water protons was 0.10 mM(-1) s(2) at 37 ?. As a demonstration, alanine uptake in a mouse xenograft model of U-87 MG glioblastoma was measured using MRI, and was compared with immunohistochemistry staining of ASCT2, a transporter that imports amino acids into cancer cells. Statistically significant (p = 0.0079) differences in ASCT2 distribution were found between regions that show strong and weak alanine uptake in MRI. To better understand the influence of perfusion, the effect of ASCT2 inhibition on the alanine uptake in MRI was investigated, and dynamic contrast enhanced MRI was compared with alanine MRI.

Automated summary

This study investigated the potential use of alanine as an MRI contrast agent and measured its relaxation properties in solution. The uptake of alanine in a mouse xenograft model of glioblastoma was measured using MRI and compared with immunohistochemistry staining. Statistically significant differences in ASCT2 distribution were found between regions with strong and weak alanine uptake in MRI.