A new culture medium for the synthesis of exopolysaccharide by streptococcus salivarius subsp.thermophilus was formulated,based on MRS,M17,ATP,SL,Elliker,SDM usually used in lactic acid bacterium.The suitability of a ...A new culture medium for the synthesis of exopolysaccharide by streptococcus salivarius subsp.thermophilus was formulated,based on MRS,M17,ATP,SL,Elliker,SDM usually used in lactic acid bacterium.The suitability of a semi defined culture media (named LCX) was obtained.The formula of culture medium was optimized as:peptone,1.50%,typtone,1.00%;K 2HPO 4,0.20%;MgSO 4.7H 2O,0.02%;MnSO 4.4H 2O,50 mg·L -1 ;Tween 80,1ml·L -1 ;Sodium acetate,0.50%;Sodium glycerate,1.90%.展开更多
目的:探讨乳酸对三阴性乳腺癌(triple-negative breast cancer,TNBC)细胞恶性行为的影响,并揭示胰岛素样生长因子2 mRNA结合蛋白3(insulin-like growth factor 2 m RNA binding protein 3,IGF2BP3)通过m6A依赖性方式调控EP300,进而介导...目的:探讨乳酸对三阴性乳腺癌(triple-negative breast cancer,TNBC)细胞恶性行为的影响,并揭示胰岛素样生长因子2 mRNA结合蛋白3(insulin-like growth factor 2 m RNA binding protein 3,IGF2BP3)通过m6A依赖性方式调控EP300,进而介导代谢重编程的表观遗传学机制。方法:通过外源性添加乳酸钠处理TNBC细胞,采用CCK-8、集落形成、划痕愈合和Transwell实验检测细胞增殖与迁移能力;利用shRNA慢病毒载体构建IGF2BP3稳定敲低细胞模型,结合Western blot分析组蛋白乳酸化修饰水平;进一步通过RIP-seq、MeRIP-seq筛选IGF2BP3的m6A靶基因,并利用qRT-PCR和Western blot验证关键分子表达。结果:乳酸钠处理显著增强了TNBC细胞的增殖和迁移能力,且泛乳酸化水平随乳酸浓度梯度升高而增加。IGF2BP3敲低可降低组蛋白乳酸化修饰水平。通过整合RIP-seq和MeRIP-seq数据,鉴定出699个其转录本同时被IGF2BP3特异性结合且携带m6A修饰的候选基因,这些基因显著富集于表观遗传调控和代谢相关通路。EP300转录本上IGF2BP3的结合区域与m6A修饰位点高度重合,且EP300的表达水平在IGF2BP3敲低后明显下调。结论:外源性乳酸通过泛乳酸化修饰促进TNBC的恶性进展。IGF2BP3通过m6A依赖性机制调控EP300的表达,进而介导组蛋白乳酸化修饰与代谢重编程的协同作用,最终驱动TNBC的肿瘤进展。上述发现为靶向代谢-表观遗传交互调控的新型治疗策略提供了理论依据。展开更多
文摘A new culture medium for the synthesis of exopolysaccharide by streptococcus salivarius subsp.thermophilus was formulated,based on MRS,M17,ATP,SL,Elliker,SDM usually used in lactic acid bacterium.The suitability of a semi defined culture media (named LCX) was obtained.The formula of culture medium was optimized as:peptone,1.50%,typtone,1.00%;K 2HPO 4,0.20%;MgSO 4.7H 2O,0.02%;MnSO 4.4H 2O,50 mg·L -1 ;Tween 80,1ml·L -1 ;Sodium acetate,0.50%;Sodium glycerate,1.90%.
文摘目的:探讨乳酸对三阴性乳腺癌(triple-negative breast cancer,TNBC)细胞恶性行为的影响,并揭示胰岛素样生长因子2 mRNA结合蛋白3(insulin-like growth factor 2 m RNA binding protein 3,IGF2BP3)通过m6A依赖性方式调控EP300,进而介导代谢重编程的表观遗传学机制。方法:通过外源性添加乳酸钠处理TNBC细胞,采用CCK-8、集落形成、划痕愈合和Transwell实验检测细胞增殖与迁移能力;利用shRNA慢病毒载体构建IGF2BP3稳定敲低细胞模型,结合Western blot分析组蛋白乳酸化修饰水平;进一步通过RIP-seq、MeRIP-seq筛选IGF2BP3的m6A靶基因,并利用qRT-PCR和Western blot验证关键分子表达。结果:乳酸钠处理显著增强了TNBC细胞的增殖和迁移能力,且泛乳酸化水平随乳酸浓度梯度升高而增加。IGF2BP3敲低可降低组蛋白乳酸化修饰水平。通过整合RIP-seq和MeRIP-seq数据,鉴定出699个其转录本同时被IGF2BP3特异性结合且携带m6A修饰的候选基因,这些基因显著富集于表观遗传调控和代谢相关通路。EP300转录本上IGF2BP3的结合区域与m6A修饰位点高度重合,且EP300的表达水平在IGF2BP3敲低后明显下调。结论:外源性乳酸通过泛乳酸化修饰促进TNBC的恶性进展。IGF2BP3通过m6A依赖性机制调控EP300的表达,进而介导组蛋白乳酸化修饰与代谢重编程的协同作用,最终驱动TNBC的肿瘤进展。上述发现为靶向代谢-表观遗传交互调控的新型治疗策略提供了理论依据。
