Mechanism Of Curcumin Potentiating The Antitumor Activity Of ACNU Against Glioblastoma

Obstruction:Glioblastoma(GBM)is a highly invasive and challenging primary tumor of the central nervous system(CNS),and currently available treatments provide limited benefit to patients with this disease.Hence the development of novel therapeutic targets and effective treatment strategies is essential.Nimustine hydrochloride(ACNU)is widely used as standard chemotherapeutic agent,and is frequently administered alongside other chemotherapy agents in clinical studies.Curcumin,a natural polyphenolic compound,could potentially be combined with chemotherapeutics for cancer treatment;however,there are no reports of studies where ACNU and curcumin were combined for GBM treatment,and the mechanisms underlying their activity remain poorly understood.Method:In this study,CCK8 method was used to measure the cell viability of human U118 GM,U87GM and U251 GM cells treated with Curcumin and Nimustine,and the activity of curcumin and Nimustine on human normal glial SVGp12 cell.The effects of Curcumin and Nimustine on the invasion and migration of human glioblastoma cells were studied by wound healing assay,invasion experiment and cell colony formation.The effects of curcumin and Nimustine on the cell autophagy and cell cycle inhibition of human glioblastoma cells were investigated by cell cycle assays and cell apoptosis detection with flow cytometry technique.In mechanism investigation,it were studied bylaser confocal immunofluorescence technique the localization of cytochrome c,p50 and p65 of U87 GM dealt with the combination of curcumin and Nimustine.Western blot technique was used to analyze the expressions of apoptosis-related proteins,including Caspase-3,Bcl and Bax,cell cycle proteins,including Cyclin B1,CDK1 and CDK2,cell invasion and migration associated proteins,including N-cadhetin,MMP2 and MMP9,PI3 K / AKT pathway protein and NF-?B / COX-2 pathway-associated protein.Real-time quantitative PCR(q PCR)was used to detect the effect of Curcumin and Nimustine on the neuroblastoma Tumor cell lines U118 and U87 on COX-2 m RNA levels.Results Compared with curcumin or ACNU alone,the combination of drugs can inhibit N-cadherin and MMP2/9 protein expression and migration and invasion activity of human glioblastoma cell.At the same time,combined drugs can also strengthen inhibiting the proliferation of cells.The main mechanism is through three ways to complete: at first,the inhibition of p65 / p50 dimer activation and nuclear transfer inhibition of NF-?b can induce COX-2 down-regulated expression;the second,p-PI3 K and AKT signal pathway inactivation can suppress cancer cell proliferation;the last,by promoting cytochrome c migrating from mitochondria to the cytoplasm,the apoptosis-related protein expression are up-regulated.Through the above mechanism,the purpose of inhibition of tumor growth have been achieved.Conclusions Our results indicate that Curcumin can enhance the anti-proliferation,anti-migration,and pro-apoptotic activities of ACNU against GBM,and provide strong evidence that combined treatment with curcumin and ACNU has the potential to be an effective therapeutic option for GBM.