Abstract:

Objective   To evaluate biodistribution and tumor targeting of 131I-labeled recombinant macrophage migration inhibition factor(rMIF) in tumor-bearing mice, and to provide an imaging marker for early diagnosis of hepatocellular carcinoma. Methods   MIF was labeled with 131I using Iodogen method and the labeled rate and stability were identified with paper chromatography. The specific binding with hepatocellular carcinoma H22cells in vitro was analyzed by cells uptake assay. Biodistribution and tumor targeting were analyzed after injection of 131I-rMIF through the tail vein in tumorbearing mice. Results   131I-rMIF, with a good bioactivity, was successfully prepared. The labeled rate of 131I-rMIF was 87.34%, radiochemical purity was 94.95%, and the stability was good. The uptake of 131I-rMIF by tumor cells was much higher than that of the controls (free Na131I) in 0.5, 1, 2 and 4h (P<0.05). 131I-rMIF was mainly metabolized through the liver and kidney. And higher radioactivity was detected within tumors (target). T/NT (target-to-non-target) ratios were 2.701±0.230, 3.931±0.281, 4.242±0.111 and 3.587±0.241 at 1, 3, 6 and 24h after injection, separately(P<0.05). The result of autoradiography showed that 131I-rMIF could be specifically localized in tumors after 6h. Conclusion   131I-rMIF, with good stability, good labeled ratios and rapid targeted distribution in tumor cells, may be used for detection of hepatocellular carcinoma.

Key words: Macrophage migration inhibition factor; Radioisotope; Biodistribution; Hepatocellular carcinoma; Mice