| Background and Purposes: Multiple myeloma(MM)is a malignancy of plasma cells,this disease leads to serious damage to multiple systems and organs,it is listed as the second highest incidence among hematological malignancies.One of the key clinical features in MM is bone pain and bone destructure,including spine,rib and pelvic fracture,therefore,the treatmetn of this kind of fracture will target MM,the original disease,in addition to orthopediac operation.Although there are several novel agents are marketed,including proteasome inhibitors and immunomodulators,which have has significantly improved response rates and overall survival,MM remains incurable.Our previous studies found that clioquinol(CLQ)induces marked apoptosis of both leukemia and multiple myeloma cells,which led to the identification of 5-amino-8-hydroxyquinoline(5AHQ),an agent overcoming bortezomib-resistance in the treatment of MM.To identify more potent anti-MM candidates,this study screened a panel of off-patent quinoline drugs and singled out nitroxoline(NXQ)with great potential for MM treatment,at the same time to explore its action mechanism,in order to further provide theoretical and experimental basis for clinical treatment.Methods:(1)Screening of 8 kinds of quinoline drugs and analysis the effect of nitroxoline on 4 kinds of myeloma cell viability and proliferation by MTT assay.(2)Flow cytometry was used to detect the effect of nitroxoline on cell apoptosis and cell cycle in myeloma cells.(3)Immunoblotting was performed to examine apoptosis related proteins expression and detection related cancer gene expression before and after dosing.(4)To explore TRIM25 expression profile at a large scale of MM patients,DNA microarray datasets from the Oncomine database,and from the Gene Expression Omnibus(GEO)database.(5)Animal experiment: a Myeloma xenograft was used to detect the effect o f nitroxoline on tumor growth and body weight in vivo,and observed whether there is a obvious side effects.Results:(1)Nitroxoline is the most potent quinoline-based off-patent drug in suppressing MM cell viability.Using drugs derived from eight different quinoline join myeloma cells in RPMI – 8226,on the analysis of cell proliferation and survivalconditions show that NXQ effect in the eight kinds of compounds is the strongest.(2)Nitroxoline induces MM cell apoptosis.We analysed cell apoptosis by annexin V-FITC and PI staining and found that the percent of apoptosis cell raised in a concentration manner after the NXQ treatment.(3)Nitroxoline activates apoptotic signals and downregulates pro-survival proteins.Immunoblotting test results show that the MM cells after dosing caspase-3 expression is suppressed,PARP cleaved and inactivated at the same time,the pro-survival proteins of Bcl-x L and Mcl-1 were downgraded by NXQ.(4)Nitroxoline slows down MM xenograft growth in a nude mouse model.We established a human myeloma xenograft model.The mice were then administrated NXQ p.o.for continued 29 days.Tumor sizes were monitored every other day during the course.,we found that NXQ markedly decreased tumor growth and there were no significant lose weight between drug and vehicle-treated groups.(5)Nitroxoline downregulates TRIM25 and upregulates p53 but not PTEN.To explore TRIM25 expression profile at a large scale of MM patients,DNA microarray datasets from the Oncomine database and from the Gene Expression Omnibus(GEO)database were concluded that the stem cells or non-stem cells of the MM,TRIM25 is important.Using Immunoblotting test,according to the related oncogenes and tumor suppressor genes NXQ can decreased TRIM25 and upregulated p53,but had no obvious effect on PTEN.Conclusion: We first discovered the nitroxoline at home and abroad is the activity of multiple myeloma,through the decreased TRIM25 and upregulated p53 instead of PTEN and induction of apoptosis,reveals the nitroxoline targets may be TRIM25 / p53 axis.This study demonstrated that the long-term used anti-infective NXQ is a potential for MM treatment. |
