Evaluation of ¹¹C-Acetate and ¹⁸ F-FDG PET/CT in mouse multidrug resistance gene-2 deficient mouse model of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) remains a global health problem with unique diagnostic and therapeutic challenges, including difficulties in identifying the highest risk patients. Previous work from our lab has established the murine multidrug resistance-2 mouse (MDR2) model of HCC as a reasonable preclinical model that parallels the changes seen in human inflammatory associated HCC. The purpose of this study is to evaluate modalities of PET/CT in MDR2^−/− mice in order to facilitate therapeutic translational studies from bench to bedside. ¹⁸F-FDG and ¹¹C-acetate PET/CT was performed on 12 m MDR2^−/− mice (n = 3/tracer) with HCC and 12 m MDR2^−/+ control mice (n = 3/tracer) without HCC. To compare PET/CT to biological markers of HCC and cellular function, serum alpha-fetoprotein (AFP), lysophosphatidic acid (LPA), cAMP and hepatic tumor necrosis factor α (TNFα) were quantified in 3-12 m MDR2^−/− (n = 10) mice using commercially available ELISA analysis. To translate results in mice to patients ¹¹C-acetate PET/CT was also performed in 8 patents suspected of HCC recurrence following treatment and currently on the liver transplant wait list. Hepatic¹⁸F-FDG metabolism was not significantly increased in MDR2^−/− mice. In contrast, hepatic ¹¹C-acetate metabolism was significantly elevated in MDR2^−/− mice when compared to MDR2^−/+ controls. Serum AFP and LPA levels increased in MDR2^−/− mice contemporaneous with the emergence of HCC. This was accompanied by a significant decrease in serum cAMP levels and an increase in hepatic TNFα. In patients suspected of HCC recurrence there were 5 true positives, 2 true negatives and 1 suspected false ¹¹C-acetate negative. Hepatic ¹¹C-acetate PET/CT tracks well with HCC in MDR2^−/− mice and patients with underlying liver disease. Consequently ¹¹C-acetate PET/CT is well suited to study 1) HCC emergence/progression in patients and 2) reduce animal numbers required to study new chemotherapeutics in murine models of HCC