Evidence for folate’s protective effects on neural tube defects led the USA and Chile to start mandatory folic acid (FA) fortification programs, decreasing up to 50%. However, \(\sim\)30% of the population consuming fortified foods reach supraphysiologic serum levels. Although controversial, several epidemiological and clinical observations suggest that folate increases cancer risk, giving concern about the risks of FA supplementation. The Cancer stem cells (CSCs) model has been used to explain survival to anticancer therapies. The Notch-1 pathway plays a role in several cancers and is associated with the stemness process. Different studies show that modulation of metabolic pathways regulates stemness capacity in cancer. Supraphysiologic concentrations of FA increase the proliferation of HT-29 cells by Notch-1 activation. However, whether folate can induce a stemness-like phenotype in cancer is not known. We hypothesized that FA protects from glucose deprivation-induced cell death through Notch-1 activation. HT-29 cells were challenged with glucose deprivation at basal (20 nM) and supraphysiological (400 nM) FA and 5–MTHF concentrations. We analyzed changes in stemness-like gene expression, cell death and different energetic metabolic functions. Supraphysiological concentrations of FA increased stemness-like genes, and improved survival and oxygen consumption, inducing AMPK phosphorylation and HSP-70 protein expression. We evaluated the Notch-1 pathway using the DAPT and siRNA as inhibitors, decreasing the stemness-like gene expression and preventing the FA protection against glucose deprivation-induced cell death. Moreover, they decreased oxygen consumption and AMPK phosphorylation. These results suggest that FA protects against glucose deprivation. These effects were associated with AMPK activation, a critical metabolic mediator in nutrient consumption and availability that activates the Notch-1 pathway.

叶酸对神经管缺陷具有保护作用的证据促使美国和智利启动了强制性叶酸 (FA) 强化计划，减少量高达 50%。然而，\(\sim\) 30% 食用强化食品的人群达到了超生理血清水平。尽管存在争议，但一些流行病学和临床观察表明叶酸会增加癌症风险，引起人们对补充 FA 风险的担忧。癌症干细胞（CSC）模型已被用来解释抗癌疗法的存活率。 Notch-1 通路在多种癌症中发挥作用，并与干性过程相关。不同的研究表明，代谢途径的调节可以调节癌症的干细胞能力。 FA 的超生理浓度通过 Notch-1 激活增加 HT-29 细胞的增殖。然而，叶酸是否可以在癌症中诱导干性样表型尚不清楚。我们假设 FA 通过 Notch-1 激活来防止葡萄糖剥夺诱导的细胞死亡。 HT-29 细胞在基础 (20 nM) 和超生理 (400 nM) FA 和 5–MTHF 浓度下受到葡萄糖剥夺的挑战。我们分析了干细胞样基因表达、细胞死亡和不同能量代谢功能的变化。 FA 的超生理浓度增加了干性样基因，并提高了存活率和耗氧量，诱导 AMPK 磷酸化和 HSP-70 蛋白表达。我们使用 DAPT 和 siRNA 作为抑制剂评估了 Notch-1 通路，减少了干细胞样基因的表达，并阻止 FA 对葡萄糖剥夺诱导的细胞死亡的保护。此外，它们还降低了耗氧量和 AMPK 磷酸化。这些结果表明 FA 可以防止葡萄糖剥夺。这些影响与 AMPK 激活有关，AMPK 是营养消耗和利用率中的关键代谢介质，可激活 Notch-1 途径。