ABSTRACT
Intensive cancer treatment with drug combination is widely exploited in the clinic but suffers from inconsistent pharmacokinetics among different therapeutic agents.To overcome it,the emerging nanomedicine offers an unparalleled opportunity for encapsulating multiple drugs in a nano-carrier.Herein,a two-step super-assembled strategy was performed to unify the pharmacokinetics of a pep-tide and a small molecular compound.In this proof-of-concept study,the bioinformatics analysis firstly revealed the potential synergies towards hepatoma therapy for the associative inhibition of exportin 1(XPO1)and ataxia telangiectasia mutated-Rad3-related(ATR),and then a super-assembled nano-pill(gold nano drug carrier loaded AZD6738 and 97-110 amino acids of apoptin(AP)(AA@G))was con-structed through camouflaging AZD6738(ATR small-molecule inhibitor)-binding human serum albumin onto the AP-Au supramolecular nanoparticle.As expected,both in vitro and in vivo experiment results verified that the AA@G possessed extraordinary biocompatibility and enhanced therapeutic effect through inducing cell cycle arrest,promoting DNA damage and inhibiting DNA repair of hepatoma cell.This work not only provides a co-delivery strategy for intensive liver cancer treatment with the clinical translational potential,but develops a common approach to unify the pharmacokinetics of peptide and small-molecular compounds,thereby extending the scope of drugs for developing the advanced com-bination therapy.
ABSTRACT
PURPOSE: The DNA damage response (DDR) is a multi-complex network of signaling pathways involved in DNA damage repair, cell cycle checkpoints, and apoptosis. In the case of biliary tract cancer (BTC), the strategy of DDR targeting has not been evaluated, even though many patients have DNA repair pathway alterations. The purpose of this study was to test the DDR-targeting strategy in BTC using an ataxia-telangiectasia and Rad3-related (ATR) inhibitor. MATERIALS AND METHODS: A total of nine human BTC cell lines were used for evaluating anti-tumor effect of AZD6738 (ATR inhibitor) alone or combination with cytotoxic chemotherapeutic agents through MTT assay, colony-forming assays, cell cycle analyses, and comet assays. We established SNU478-mouse model for in vivo experiments to confirm our findings. RESULTS: Among nine human BTC cell lines, SNU478 and SNU869 were the most sensitive to AZD6738, and showed low expression of both ataxia-telangiectasia mutated (ATM) and p53. AZD6738 blocked p-Chk1 and p-glycoprotein and increased γH2AX, a marker of DNA damage, in sensitive cells. AZD6738 significantly increased apoptosis, G2/M arrest and p21, and decreased CDC2. Combinations of AZD6738 and cytotoxic chemotherapeutic agents exerted synergistic effects in colony-forming assays, cell cycle analyses, and comet assays. In our mouse models, AZD6738 monotherapy decreased tumor growth and the combination with cisplatin showed more potent effects on growth inhibition, decreased Ki-67, and increased terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling than monotherapy with each drug. CONCLUSION: In BTC, DDR targeting strategy using ATR inhibitor demonstrated promising antitumor activity alone or in combination with cytotoxic chemotherapeutic agents. This supports further clinical development of DDR targeting strategy in BTC.