Study On Felodipine Killing Glioma Stem Cells

Objectives:Gliomas are the most common central nervous system(CNS)malignancies,accounting for more than 50%of intracranial malignancies.In China,5-year mortality rate of glioma ranks third among all tumors after malignant pancreatic cancer and primary lung cancer.Among gliomas,Glioblastom(GBM)is ranked as the most malignant--level ? in the WHO classification because of high invasion,proliferation,anti-apoptosis,pro-angiogenesis,and rapid resistance to chemotherapy and radiotherapy.At present,the treatment of glioblastoma in China is mainly a classic treatment scheme of surgical resection combined with chemotherapy and radiotherapy.However,even the actively treated glioma patients,the survival time is difficult to exceed 12 months.The 5-year survival rate has almost stagnated in recent decades,which suggests that the treatment of GBM urgently requires new treatment options and drugs.Through relevant literature search and inquiry,we found that the current domestic chemotherapy treatment programs are based on temozolomide(TMZ)which has been used as based drug chemotherapy.The selection of drugs is very simple and single.Once temozolomide becomes resistant,patients will be directly at risk of death.Further literature exploration and discovery found that the alkylating agent temozolomide is an alkylation of oxygen and nitrogen atoms in tumor DNA molecules,and during DNA repair,DNA mismatch repair was performed by methylation,and then through cytotoxicity interfere the replication and division of glioma cells.In other words,temozolomide is mainly targeted at rapidly proliferating DNA molecules,that means ordinary glioma cells that continuously replicate and proliferate will be inhibited by TMZ,but it lack effective activity on glioma stem cells.Glioma stem cells are one of the earliest tumor stem cells to be discovered and extracted.Modern research has proven that in specific serum-free media,the genetic background and molecular expression of glioma stem cells can be characterized in cytokines such as EGF and bFGF.Under the effect of maintaining long-term stability without differentiation.This relatively stable genome makes glioma stem cells an important model for screening anti-tumor stem cell chemotherapy drugs.Although the problem of the screening model has been solved so far,if the newly developed chemical synthesis or natural component extraction drug is used for testing,it is bound to face difficult drug development,high medical costs,and clinical phase ?,?,and ? testing and other difficult issues.As research said the market for a new drug often takes 10-20 years or more.Therefore,in order to save test time and improve clinical medical translation and practical efficiency,we directly screen anti-glioma stem cells for drugs that already on the market.Through previous experiments,we found that the primary hypertension drug felodipine has a certain killing effect on glioma stem cells.This topic is to explore the ability of felodipine to selectively kill glioma stem cells and its related mechanismMethods:First.fully grind felodipine sustained-release tablets,and dilute them with dimethyl sulfoxide(DMSO)to a concentration of 10 mg/ml as soon as possible,5000 r/min,5 minutes to centrifuge auxiliary materials such as starch,etc.Take the supernatant solution.Using the drug screening platform of the Kunming Institute of Zoology,Chinese Academy of Sciences and Zhao Xudong's research group to detect half maximal inhibitory concentration IC50 of felodipine killing glioma stem cells(GSC-12#,GSC-18#),and compared IC50 with normal cerebellar glial cells HAC and normal human renal epithelial cells 293t.After confirming killing differences that between glioma stem cells and normal cells,through immunofluorescence.flow cytometry,MTS method,clone formation and other ways to explore and quantify the effect felodipine inhibit glioma stem cell proliferation,apoptosis and "stem" effect,and further exploration was conducted to verify the inhibitory effect of felodipine on glioma stem cells and its related mechanism.Results:Through experiments,we found that the marketed drug felodipine can effectively inhibit the proliferation of glioma stem cells GSC-12#and GSC-18#,and induce the death of GSCs through the apoptotic pathway.In addition,felodipine inhibits human normal cells at a concentration of 1/3 that of tumor stem cells,which means less side effects,and has a certain selectivity.Conclusions:Glioma stem cells are the main reason for the high recurrence rate of gliomas,strong invasiveness,and resistance to chemoradiotherapy of glioma,especially high-grade glioma.However,the existing treatment methods,especially drug chemotherapy,have a poor killing effect on glioma stem cells.The weakness,which makes the therapeutic target of glioma stem cells difficult to apply in clinical practice.This experiment proved that the antihypertensive drug felodipine can inhibit the proliferation of glioma stem cells(GSC-12#,GSC-18#),and induce glioma stem cells(GSC-12#,GSC-18#)to obviously undergo apoptosis through the Caspase pathway.And felodipine can effectively destroy the clonal spheres of tumor stem cells and effectively inhibit their characteristics of stem cells.And as a marketed drug,compared with the economic and practical costs of new drug approval and other clinical trials,felodipine's availability,economics,and practicality have been greatly improved,which indicates that felodipine has become a new type of potential anti-glioma drugs.