Mir-30-5p Regulates CSAD,which Affects The Proliferation,Invasion And Metabolism Of Glioma

Glioma is the most common malignant tumor of nervous system,accounting for 40%-50%of the tumors of nervous system.Due to abundant blood vessels in brain tissue,glioma has the characteristics of invasive growth and no obvious boundary with normal brain tissue,so there is no effective treatment and the prognosis of patients is poor.Today,tumors are considered metabolic diseases,where metabolic reprogramming can disrupt the metabolites of tumor cells.In previous studies,we found that taurine content in high-grade glioma was significantly lower than that in low-grade glioma.Taurine has been reported to have anti-tumor effects.It was speculated that the decrease of taurine content in high-grade glioma was related to the enhancement of antioxidant and anti-apoptotic ability.Therefore,we hope to study the metabolic pathway of taurine and find out the effect of its key enzymes and upstream regulators on the proliferation,invasion and migration of glioma cells.In vivo,cysteine decarboxylase(CSAD)is a rate-limiting enzyme synthesized from taurine.The target effect of mir-30-5p on cysteine decarboxylase was predicted by the database.Based on this,this study will explore the effect of taurine on the biological behavior of glioma cells,and verify the targeting relationship between mir-30-5p and CSAD,as well as the influence of both on changes in taurine content downstream.In this study,the expression level of CSAD in glioma cells was detected by qPCR and Western Blot,and the results showed that CSAD was significantly lower in glioma cells(LN229,U251)than in normal glioma cells(HEB).Moreover,the content of taurine in LN229 and U251 was lower than that in HEB.After taurine was used on glioma cells,the proliferation,invasion and migration of LN229 and U251 decreased,while the apoptosis rate increased.Bioxin analysis and dual luciferase assay indicated that mir-30-5p directly bound to the 3 ’-utr region of CSAD.QPCR showed that the expression of mir-30-5p in LN229 and U251 was higher than that in HEB,and was negatively correlated with the expression of CSAD.After the knockdown of mir-30-5p,the expression levels of CSAD mRNA and protein and the content of taurine also increased,the proliferation,invasion and migration capacity of LN229 and U251 decreased,and the apoptosis rate also increased.These results indicate that taurine has an anti-tumor effect in glioma and can increase the expression of taurine synthase(CSAD)by knocking down mir-30-5p,thereby increasing taurine content.The metabolic pathway of taurine may be a new target for the treatment of glioma and may prompt us to further investigate the mechanism of taurine metabolism in glioma.