[Experimental study of transferrin receptor molecular imaging in human hepatocellular carcinoma transplanted in nude mice].

OBJECTIVE

To investigate the feasibility of (99m)Tc-transferrin ((99m)Tc-Tf) as an transferrin receptor imaging agent in nude mice bearing human hepatoma SMMC-7721 tumor.

METHODS

Biodistribution of (99m)Tc-Tf in Balb/c mice was assayed, and transferrin receptor imaging in Balb/c nu/nu nude mice bearing human hepatocellular carcinoma SMMC-7721 xenografts was carried out, with or without inhibition of transferrin receptor with unlabeled transferrin. The receptor radioligand binding assay with (125)I-transferrin as ligand was established, and the number of receptors per cell and the K(d) were worked out.

RESULTS

(99m)Tc-Tf was mainly distributed in the liver, blood and kidneys. At 18 h post injection, the ratios of tumor/blood, tumor/liver and tumor/muscle were 24.2, 1.7 and 35.5, respectively. The ratio of tumor uptake at 18 h without unlabeled transferrin pretreatment to that with pretreatment was 16.3. The number of receptors per cell was 2.4 x 10(5) and the K(d) was found to be 4.46 nmol/L.

CONCLUSION

All those results indicate that (99m)Tc-Tf is specifically localized in tumor lesions of nude mice. (99m)Tc-Tf may be useful in detection of hepatocellular carcinoma.