MiR-375 And Doxorubicin Co-delivered By Liposomes For Combination Therapy Of Hepatocellular Carcinoma And Inhibiting Of Drug Resistance

Background and aims Doxorubicin(DOX)is one of the most frequently used anti-cancer drugs and the front line options for hepatocellular carcinoma(HCC)treatment.However,the clinical applications of DOX are restricted largely due to its toxicity and chemo-resistance.Previously,we and others have found that miR-375 significantly downregulated in HCC tissues and inhibits the core hallmarks of cancer of HCC by targeting several important oncogenes like AEG-1,YAP1 and ATG7.In addition,it has been reported that the miR-375 could decrease the expression of MDR1 by targeting gene AEG-1.In recent years small molecule gene segments combine with chemotherapeutic drugs for the treatment of cancer has been a prevalent trend.Here,we report that miR-375 and DOX co-delivered by liposome(named L-miR-375/DOX-NPs)for combination therapy of HCC and reversing the drug resistance of DOX.Methods Firstly,after transfected with L-miR-375/DOX-NPs in HCC cells,we observed under the fluorescence microscopy and performed flow cytometry assay to examine the uptake ratio of miR-375 and DOX.Also we used Bulge-LoopTM miRNA qRT-PCR to verify the upregulation of mature miR-375.Secondly,we conducted flow cytometry,CCK-8 assay,cell migration and invasion assay to test the anti-tumor efficiency of L-miR-375/DOX-NPs in vitro.Thirdly,the specific molecular mechanism of L-miR-375/DOX-NPs was confirmed by Western Blot.Finally,animal experiment was performed to detect the synergistic therapeutic effects in vivo.Results In vitro,L-miR-375/DOX-NPs could deliver both DOX and miR-375 efficiently and simultaneously into HCC cells and ensure the successfully release of mature miR-375 and DOX.Then,the released miR-375 suppressed the malignant hallmarks of HCC by significantly decreasing the expression of AEG-1,YAP1,and ATG7.While the released DOX evidently accelerated cell apoptosis and blocked cycle at a G2/M stage by activating the P53/ Bax/Bcl-2,caspase-3 and p-JNK,P-P38 pathway.Furthermore,miR-375 dramatically inhibited drug resistance of DOX by reducing the expression of multidrug resistance gene 1(MDR1).In vivo,L-miR-375/DOX-NPs exhibit enhanced antitumor efficiency in xenograft HCC mouse models with mild adverse effects compared with doxorubicin or miR-375 alone.Conclusions Our research demonstrated that L-miR-375/DOX-NPs have significant synergetic anti-tumor effects and added values in overcoming drug resistance,which may represent a promising therapy for HCC in the future.