Tetrahydrofolate increases suspension growth of dihydrofolate reductase‐deficient chinese hamster ovary DG44 cells in chemically defined media

Abstract

Adaptation of dihydrofolate reductase (DHFR)-deficient Chinese hamster ovary (CHO) DG44 cells to chemically defined suspension culture conditions is a time-consuming and labor-intensive process because nonadapted DHFR-deficient CHO DG44 cells normally show poor growth in chemically defined medium (CDM). We examined the effects of folate derivatives, ribonucleotides, and nucleobases on the growth of suspension-adapted DHFR-deficient CHO DG44 cells in CDM. Among the tested additives, tetrahydrofolate (THF) was identified as an effective component for increasing cell growth. THF supplementation in the range of 0.2-359 μM enhanced cell growth in in-house CDM. Addition of 3.6 μM THF to in-house CDM resulted in a more than 2.5-fold increase in maximum viable cell density. Moreover, supplementation of six different commercial CDMs with 3.6 μM THF yielded up to 2.9-fold enhancement of maximum viable cell density. An anchorage- and serum-dependent DHFR-deficient CHO DG44 cell line was adapted within two consecutive passages to suspension growth in in-house CDM supplemented with 3.6 μM THF. These data indicate that supplementation of chemically defined cell culture media with greater than 0.2 μM THF can help achieve a high density of suspension-adapted DHFR-deficient CHO DG44 cells and may facilitate rapid adaptation of nonadapted DHFR-deficient CHO DG44 cells to suspension culture. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1539-1546, 2016.

Tetrahydrofolate Alleviates the Inhibitory Effect of Oxidative Stress on Neural Stem Cell Proliferation through PTEN/Akt/mTOR Pathway

“…Tetrahydrofolate (THF), the active form of folate (vitamin B9), is an essential cofactor of one-carbon (1C) cycle and involved in the biosynthesis of thymidylate, purines, and glycine [23,24]. Previous researches have delineated that THF is susceptible to oxidative stress and exhibits a high antioxidant activity when excessive level of ROS cumulation is available [25,26], implying that THF might be a candidate for ameliorating surplus ROS to enhance rehabilitative capacity of NSC.…”

“…Meanwhile, previous study has demonstrated that the THF transporter of SLC25A32 is highly expressed in varying tumors, and obviously facilitated tumor cell growth to reduce patients' survival, whereas downregulation of SLC25A32 inhibits tumor cell propagation [27]. Moreover, THF administration is an effective intervention in promoting proliferation of dihydrofolate reductase-(DHFR-) deficient Chinese hamster ovary (CHO) DG44 cells [24], while the effect of THF on NSC proliferation and the underlying mechanism remains largely unknown.…”