Leucovorin-induced resistance against FDH growth suppressor effects occurs through DHFR up-regulation

Serum folate concentrations and all-cause, cardiovascular disease and cancer mortality: A cohort study based on 1999–2010 National Health and Nutrition Examination Survey (NHANES)

“…The mechanisms of the harmful effects have been suggested by former literatures. One theory is that excess folate concentrations may result in a dramatic increase in the levels of non-bound folate, which may in turn accelerate folate's degradation rate [25]. Another theory is that high folate concentrations could lead to decreased levels of thymidylate and 5-methylenetetrahydrofolate (5-MTHF), thus impairing DNA integrity and affecting protein production [26].…”

Rho GTPases RhoA and Rac1 Mediate Effects of Dietary Folate on Metastatic Potential of A549 Cancer Cells through the Control of Cofilin Phosphorylation

“…Lysates were chilled on ice and centrifuged for 5 min at 17,000 ϫ g at 4°C. Folate pools were measured in tissue lysates by the ternary complex assay method as we described previously (30,31). Folate levels were calculated per milligram of protein measured by Bradford assay or per milliliter of whole blood.…”

“…Four reduced folate forms represent the majority of the folate pool in mammalian cells (tetrahydrofolate (THF), 5-methyltetrahy- drofolate (5-CH 3 -THF), 5,10-methylenetetrahydrofolate (5,10-CH 2 -THF), and 10-formyltetrahydrofolate (10-CHO-THF)), whereas in plasma, 5-CH 3 -THF comprises more than 90% of the reduced folate (41). We measured reduced folate pools in blood, lung, and liver using a technique allowing the measurement of major folate forms independent of their polyglutamylation status (30,31). We observed that the total folate in blood, represented mostly by 5-CH 3 -THF, was decreased 2.2-fold in mice kept on folate-free chow compared with mice on a typical folate diet (Fig.…”

Ubiquitin-like protein MNSFβ covalently binds to cytosolic 10-formyltetrahydrofolate dehydrogenase and regulates thymocyte function

“…FDH converts 10-formyltetrahydrofolate to THF. FDH-resistant cells strongly up-regulate DHFR that is proposed to be a mechanism for the alteration of folate pools [29]. Thus, it is conceivable that MNSFb and SUMO are closely related to regulation of folate in cytosol.…”