Intravenous administration of dehydroxymethylepoxyquinomicin with polymer enhances the inhibition of pancreatic carcinoma growth in mice

Background/Aim: Pancreatic cancer, which exhibits resistance to cytotoxic and molecular targeted drugs, has an extremely poor prognosis. Nuclear factor-ĸB (NF-ĸB) is constitutively activated in many pancreatic cancer cases. Although the NF-ĸB inhibitor dehydroxymethylepoxyquinomicin (DHMEQ) has exhibited anti-cancer effects in pancreatic cancer models, its poor solubility limits its use to intraperitoneal administration. Materials and Methods: Poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) (PMB) forms stable polymer aggregates with DHMEQ. The stability of DHMEQ aggregated with PMB in the human blood was measured by high-performance liquid chromatography–mass spectrometry (HPLC-MS) ex vivo. Anti-pancreatic cancer effects in AsPC-1 and MIA PaCa-2 pancreatic cancer cells were evaluated by cell growth inhibition assay in vitro and tumor growth inhibition assay in vivo. Results: DHMEQ aggregated with PMB (PMBDHMEQ) remained detectable after 60 min of incubation in the human blood, whereas DHMEQ aggregated with carboxymethyl cellulose (CMC-DHMEQ) was barely detectable. PMB-DHMEQ significantly inhibited AsPC-1 and MIA PaCa-2 cell growth in vitro compared to CMC-DHMEQ. Intravenous administration of PMB-DHMEQ reduced the tumor volume and liver metastasis compared to untreated or CMC-DHMEQ-treated mice. Conclusion: Aggregation with PMB improved the solubility of DHMEQ, and effectively inhibited pancreatic cancer cell growth both in vitro and in vivo.