| Background:Nasopharyngeal carcinoma(NPC)is one of the major causes of death in South China.Docetaxel(DOC)is one of the commonly used drugs for locally advanced NPC in clinical practice,which kills tumor cells as well as has toxic effects on normal human cells,affecting its anti-tumor efficacy to a large extent.JS-K is a novel nitric oxide(NO)prodrug,and recent studies have shown that JS-K has a good inhibitory effect on a variety of tumors.In this study,we investigated the effect of DOC combined with JS-K on the proliferation,migration,and apoptosis of NPC cells(HNE-1)from the perspective of combination therapy;analyzed its possible molecular mechanisms.More importantly,the tumor-bearing mouse model of NPC was established to evaluate the effect and safety of combination treatment.Considering the current clinical status of NPC,we hope to find a relatively effective and safe regimen to enhance NPC treatment.Objective:To investigate the antitumor effect and mechanisms of combination treatment on HNE-1 cells in vitro and in vivo.Methods:Cell proliferation-toxicity assay(CCK-8)was used to detect the inhibitory effect of DOC and JS-K on the proliferation of NPC cells.Cell scratch assay was applied to detect the cell migration ability.The effect of DOC combined with JS-K on the apoptosis rate of HNE-1 cells were detected by flow cytometry.The change of NO level in HNE-1 cells were observed by fluorescence microscopy.Western-blot was used to detect the effect of DOC,JS-K and their combination on the expression of apoptotic protein molecules Bcl-2,Caspase-3,Caspase-9 and Bax.Furthermore,BALB/c nude mouse HNE-1 subcutaneous xenograft model was established and administered by tail vein injection.At the end of experiment,the mice were sacrificed for recording the tumor mass volume,body weight and levels of serum ALT,AST,ALB,CREA,BUN and CK.Results:CCK-8 results showed that DOC and JS-K could inhibit the proliferation of HNE-1 cells,and the inhibitory effect of the combination group was higher than that of the monotherapy group(p<0.05).DOC combined with JS-K could significantly inhibit the migration and apoptosis of NPC cells,and its inhibition rate was superior to that of DOC or JS-K alone(p<0.05).JS-K could stably release NO in HNE-1 cells.Western-blot experiments showed that JS-K may cause different degrees of apoptosis by releasing different levels of NO,however,the pathway of apoptosis caused by DOC and JS-K is more complex than it actually is.In vivo results further showed that the combination of this two drugs could effectively inhibit the growth of NPC xenograft volume in nude mice without obvious toxicity.Conclusions:DOC combined with JS-K can enhance the activity of anti-NPC cells in vitro and in vivo,and the mechanisms may be related to the release of NO by JS-K,which provides a promising idea for the treatment of locally advanced NPC. |
