In Situ Generated Novel (1)H MRI Reporter for β-Galactosidase Activity Detection and Visualization in Living Tumor Cells.

For wide applications of the lacZ gene in cellular/molecular biology, small animal investigations, and clinical assessments, the improvement of noninvasive imaging approaches to precisely assay gene expression has garnered much attention. In this study, we investigate a novel molecular platform in which alizarin 2-O-β-d-galactopyranoside AZ-1 acts as a lacZ gene/β-gal responsive (1)H-MRI probe to induce significant (1)H-MRI contrast changes in relaxation times T (1) and T (2) in situ as a concerted effect for the discovery of β-gal activity with the exposure of Fe(3+). We also demonstrate the capability of this strategy for detecting β-gal activity with lacZ-transfected human MCF7 breast and PC3 prostate cancer cells by reaction-enhanced (1)H-MRI T (1) and T (2) relaxation mapping.