Therapeutic Effect And Mechanism Of A Novel Phosphodiesterase 4 Inhibitor ZL-n-91 On Glioma

Glioma is the most common primary malignant brain tumor,with the characteristics of strong invasion and poor prognosis.At present,although great efforts have been made in the diagnosis and treatment of glioma,the prognosis of high-grade glioblastoma(GBM)has not been significantly improved.Even with the standard treatment,the median survival time of the patient is still less than 15 months,and the recurrence rate is close to 100%.Phosphodiesterase 4(PDE4),a member of the PDE family,is able to specifically hydrolyze cyclic adenosine monophosphate(c AMP).The expression and activity of PDE4 are negatively correlated with the malignancy grade of tumors.Studies have shown that PDE4-specific inhibitors have significant therapeutic potential in cancer therapy.The novel PDE4 inhibitor ZL-n-91 is a second generation PDE4 inhibitors with improved designs.Its selectivity against PDE4 B and PDE4 D is more than 5000 times that of other PDE family members.It has strong targeting,high selectivity,small side effects,and being able to effectively penetrate the blood-brain barrier.However,the effectiveness of ZL-n-91 in the treatment of glioma has not yet been known.Therefore,we will systematically explore the therapeutic effects and potential mechanisms of ZL-n-91 on glioma,in order to provide new ideas for clinical treatment of glioma.Objective: This subject aims to investigate the therapeutic effect of a novel PDE4 inhibitor ZL-n-91 on glioma.Methods:1.The inhibitory effects of ZL-n-91 at different concentrations on the proliferation of glioma cells U87,snb19 and U251 were evaluated by the CCK8 method.We also compared the effect of ZL-n-91 and a control PDE4 inhibitors,Rolipram,on cell proliferation by plate cloning experiment;2.Use flow cytometry to detect the effects of different concentrations of ZL-n-91 on the cell cycle of glioma cells.Use Western blot assay to detect the expression of cell-cycle regulatory proteins.3.The effects of different concentrations of ZL-n-91 on apoptosis of glioma cells were examined by flow cytometry and Western blot assay.4.Use U87 cells to construct a nude mouse xenograft tumor model,and evaluate the therapeutic effect of ZL-n-91 on glioma by HE and immunohistochemical staining.Results:1.ZL-n-91 significantly inhibited the proliferation of glioma cells.Compared with Rolipram,ZL-n-91 significantly inhibited the cloning ability of glioma cells on the plate;2.ZL-n-91 significantly induced cell cycle arrest of glioma cells by down-regulating the expressions of cycle-related proteins CDK2,CKD4 and Cyclin D1;3.ZL-n-91 significantly induced glioma cell apoptosis,which may be mediated by regulating Bcl-2/Bax apoptosis pathway;4.The treatment of ZL-n-91 significantly inhibited the growth of tumors in mice without inducing obvious toxic or side effects on nude mice.Concluntion:In vitro experiments,the novel PDE4 inhibitor ZL-n-91 significantly inhibited the proliferation of glioma cells,stalled cell cycle progression,and promoted apoptosis.In vivo experiments,ZL-n-91 slowed the growth of tumors,changed the morphology of tumor cells without inducing obvious toxic or side effects on nude mice,which may help provide new ideas for the treatment of glioma.