线粒体溶质载体蛋白SLC25A26诱导肝癌细胞衰老作用及分子机制

目的探究线粒体溶质载体蛋白SLC25A26通过蛋氨酸循环代谢诱导肝癌细胞衰老的调控作用。方法体外培养HepG2细胞系,用阳性药Etoposide(2μmol·L-1)诱导HepG2细胞衰老后,蛋氨酸循环代谢物SAM (0.1 mmol·L-1)处理,Western blot、Real-time PCR检测细胞衰老指标(p16、p21、HMGA1),流式细胞仪检测细胞周期;转染SLC25A26过表达质粒,Western blot、免疫荧光检测过表达SLC25A26对HepG2细胞衰老指标的影响;HPLC法检测过表达SLC25A26对蛋氨酸循环代谢指标SAM、SAH的影响,Real-time PCR检测过表达SLC25A26对SAM处理后HepG 2细胞衰老指标的影响。结果 Western blot和Real-time PCR检测表明,蛋氨酸循环代谢可以削弱Etoposide诱导的HepG 2细胞衰老水平,流式检测表明细胞周期阻滞在G1期;过表达SLC25A26降低了胞质中蛋氨酸循环代谢物SAM、SAH水平,补充外源性SAM部分抵消了过表达SLC25A26诱导的HepG 2细胞衰老作用。结论促进蛋氨酸循环代谢可以抑制肝癌细胞衰老,过表达SLC25A26可以诱导肝癌细胞衰老,SLC25A26通过调控蛋氨酸循环代谢诱导肝癌细胞衰老。

Effect and molecular mechanism of mitochondrial solute carrier protein SLC25A26 inducing hepatoma cell senescence

Aim To explore the regulatory effect of mitochondrial solute carrier protein SLC25A26 on senescence of hepatoma cells induced by methionine cycle metabolism.Methods HepG2 cell line was cultured in vitro.After hepatoma cell senescence was induced by toposide(2μmol·L^-1),a positive drug for inducing cell senescence,methionine circulating metabolite SAM(0.1 mmol·L^-1)was treated.Western blot and Real-time PCR were used to detect the senescence indexes including p16,p21,and HMGA1,and flow cytometry was used to detect cell cycle.Transfecting SLC25A26 overexpression plasmid,the effect of overexpressing SLC25A26 on the senescence indexes of hepatoma cells was detected by Western blot and immunofluorescence detection,and the level of SAM after overexpressing SLC25A26 was detected by the kit.The effect of overexpressing SLC25A26 on the senescence of hepatoma cells after SAM treatment was detected by Real-time PCR.Results Western blot and Real-time PCR showed that methionine cycle metabolism could weaken the senescence level of HepG2 cells induced by Etoposide,and flow cytometry showed that cell cycle was arrested in G1 phase;overexpression of SLC25A26 decreased the levels of SAM and SAH in cytoplasm of HepG2 cells,and exogenous SAM partially offset the aging effect of HepG2 cells induced by SLC25A26.Conclusions Promoting methionine cycle metabolism can inhibit hepatoma cells senescence;overexpression of SLC25A26 can induce hepatoma cells senescence;SLC25A26 can induce hepatoma cells senescence by regulating methionine cycle metabolism.