Imaging of radioiodine-labeled KH901, a tumor-specific oncolytic recombinant adenovirus, in nude mice with human hepatocellular carcinoma.

Objective: To study the biodistribution and imaging of I/I-labeled KH901, a tumor-specific oncolytic recombinant adenovirus, in nude mice bearing human hepatocarcinoma.

Methods: KH901 was labeled with I/I according to the N-bromosuccinimide labeling method. The activity of granulocyte-macrophage colony-stimulating factor was determined by enzyme-linked immunosorbent assay. After I-KH901 was injected into the tumor, the label was followed in different organs and tumor tissues in nude mice with hepatocellular carcinoma. I-KH901 was injected directly into the tumor of nude mice bearing hepatocellular carcinoma, and their concentrations were detected at different times on radionuclide images.

Results: The radiochemical purity of I/I-KH901 was over 95%. I-KH901 stimulated massive expression of granulocyte-macrophage colony-stimulating factor in tumor cells. Twenty-four hours after the addition of I-KH901, the concentrations of granulocyte-macrophage colony-stimulating factor were 183.27+/-6.90 and 20.44+/-0.77 pg/ml in tumor and normal cells, respectively. I-KH901 was mainly distributed in the tumor and had a longer retention time, which was 14.93%ID/g at 24 h. Radionuclide imaging showed that the radioactive retention of I-KH901 in the tumor was significant. The tumor was shown clearly in the whole-body scan at 2 h after injection.

Conclusion: I or I-KH901 concentrates specifically at the tumor site, which makes it a novel drug (combination of oncolytic adenovirus and radionuclide therapies) for the treatment of cancer.