An engineered Abcb4 expressing model reveals the central role of NF-κB in the regulation of drug resistance in zebrafish

Multidrug resistance (MDR) represents the major cause of unsatisfaction in the application of chemotherapy for cancer treatment. So far, an in vivo robust high-throughput screening system for anti-tumor drug MDR is still lacking and the molecular mechanisms for MDR still remain elusive. Given a myriad of merits of zebrafish relative to other animal models, we aimed to establish MDR system in zebrafish stably expressing ATP-binding cassette (ATP-cassette) superfamily transporters and study the potential regulatory mechanism. We first constructed a Tg(abcb4:EGFP) transgenic zebrafish stably expressing both Abcb4 and EGFP using Tol2-mediated approach. The expression level of Abcb4 and EGFP was significantly induced when Tg(abcb4:EGFP) transgenic zebrafish embryos were exposed to doxorubicin (DOX) or vincristine (VCR), accompany with a marked decrease in rhodamine B (RhB) accumulation in embryos, which indicates a remarkable increase in drug efflux upon the exposure to DOX or VCR. Mechanistically, AKT and ERK signaling were activated when treated with DOX or VCR. With the application of AKT and ERK inhibitors, the drug resistance phenomena could be reversed with differential responsive effects. Of note, downstream NF-κB played a central role in the regulation of Abcb4-mediated drug resistance. Taken together, the engineered Tg(abcb4:EGFP) transgenic zebrafish model provides a new platform for drug resistance screening in vivo, which could facilitate and accelerate the process of drug development.View Full Text