Folate deficiency in vitro induces uracil misincorporation and DNA hypomethylation and inhibits DNA excision repair in immortalized normal human colon epithelial cells

Susan Joyce Duthie, S Narayanan, S Blum, Lynn Peters Pirie, G M Brand

    Research output: Contribution to journalArticle

    162 Citations (Scopus)

    Abstract

    Epidemiological studies have indicated that folic acid protects against a variety of cancers, particularly cancer of the colorectum. Folate is essential for efficient DNA synthesis and repair. Moreover folate can affect cellular S-adenosylmethionine levels, which regulate DNA methylation and control gene expression. We have investigated the mechanisms through which folate affects DNA stability in immortalized normal human colonocytes (HCEC). DNA strand breakage, uracil misincorporation, and DNA repair, in response to oxidative and alkylation damage, were determined in folate-sufficient and folate-deficient colonocytes by single cell gel electrophoresis. In addition, methyl incorporation into genomic DNA was measured using the bacterial enzyme Sss1 methylase. Cultured human colonocyte DNA contained endogenous strand breaks and uracil. Folate deficiency significantly increased strand breakage and uracil misincorporation in these cells. This negative effect on DNA stability was concentration dependent at levels usually found in human plasma (1-10 ng/ml). DNA methylation was decreased in HCEC grown in the absence of folate. Conversely, hypomethylation was nor concentration dependent. Folate deficiency impaired the ability of HCEC to repair oxidative and alkylation damage. These results demonstrate that folic acid modulates DNA repair DNA strand breakage, and uracil misincorporation in immortalized human colonocytes and that folate deficiency substantially decreases DNA stability in these cells.

    Original languageEnglish
    Pages (from-to)245-251
    Number of pages7
    JournalNutrition and Cancer
    Volume37
    Issue number2
    DOIs
    Publication statusPublished - 2000

    Keywords

    • HAMSTER OVARY CELLS
    • COLORECTAL-CANCER RISK
    • IN-VITRO
    • ULCERATIVE-COLITIS
    • ALKYLATING-AGENTS
    • DAMAGE
    • LINE
    • EXPRESSION
    • METABOLISM
    • CARCINOMA

    Cite this

    Folate deficiency in vitro induces uracil misincorporation and DNA hypomethylation and inhibits DNA excision repair in immortalized normal human colon epithelial cells. / Duthie, Susan Joyce; Narayanan, S ; Blum, S ; Pirie, Lynn Peters; Brand, G M .

    In: Nutrition and Cancer, Vol. 37, No. 2, 2000, p. 245-251.

    Research output: Contribution to journalArticle

    Duthie, Susan Joyce ; Narayanan, S ; Blum, S ; Pirie, Lynn Peters ; Brand, G M . / Folate deficiency in vitro induces uracil misincorporation and DNA hypomethylation and inhibits DNA excision repair in immortalized normal human colon epithelial cells. In: Nutrition and Cancer. 2000 ; Vol. 37, No. 2. pp. 245-251.
    @article{a262841e7d324f2da52e0fb7ff5ac23f,
    title = "Folate deficiency in vitro induces uracil misincorporation and DNA hypomethylation and inhibits DNA excision repair in immortalized normal human colon epithelial cells",
    abstract = "Epidemiological studies have indicated that folic acid protects against a variety of cancers, particularly cancer of the colorectum. Folate is essential for efficient DNA synthesis and repair. Moreover folate can affect cellular S-adenosylmethionine levels, which regulate DNA methylation and control gene expression. We have investigated the mechanisms through which folate affects DNA stability in immortalized normal human colonocytes (HCEC). DNA strand breakage, uracil misincorporation, and DNA repair, in response to oxidative and alkylation damage, were determined in folate-sufficient and folate-deficient colonocytes by single cell gel electrophoresis. In addition, methyl incorporation into genomic DNA was measured using the bacterial enzyme Sss1 methylase. Cultured human colonocyte DNA contained endogenous strand breaks and uracil. Folate deficiency significantly increased strand breakage and uracil misincorporation in these cells. This negative effect on DNA stability was concentration dependent at levels usually found in human plasma (1-10 ng/ml). DNA methylation was decreased in HCEC grown in the absence of folate. Conversely, hypomethylation was nor concentration dependent. Folate deficiency impaired the ability of HCEC to repair oxidative and alkylation damage. These results demonstrate that folic acid modulates DNA repair DNA strand breakage, and uracil misincorporation in immortalized human colonocytes and that folate deficiency substantially decreases DNA stability in these cells.",
    keywords = "HAMSTER OVARY CELLS, COLORECTAL-CANCER RISK, IN-VITRO, ULCERATIVE-COLITIS, ALKYLATING-AGENTS, DAMAGE, LINE, EXPRESSION, METABOLISM, CARCINOMA",
    author = "Duthie, {Susan Joyce} and S Narayanan and S Blum and Pirie, {Lynn Peters} and Brand, {G M}",
    year = "2000",
    doi = "10.1207/S15327914NC372_18",
    language = "English",
    volume = "37",
    pages = "245--251",
    journal = "Nutrition and Cancer",
    issn = "0163-5581",
    publisher = "Routledge",
    number = "2",

    }

    TY - JOUR

    T1 - Folate deficiency in vitro induces uracil misincorporation and DNA hypomethylation and inhibits DNA excision repair in immortalized normal human colon epithelial cells

    AU - Duthie, Susan Joyce

    AU - Narayanan, S

    AU - Blum, S

    AU - Pirie, Lynn Peters

    AU - Brand, G M

    PY - 2000

    Y1 - 2000

    N2 - Epidemiological studies have indicated that folic acid protects against a variety of cancers, particularly cancer of the colorectum. Folate is essential for efficient DNA synthesis and repair. Moreover folate can affect cellular S-adenosylmethionine levels, which regulate DNA methylation and control gene expression. We have investigated the mechanisms through which folate affects DNA stability in immortalized normal human colonocytes (HCEC). DNA strand breakage, uracil misincorporation, and DNA repair, in response to oxidative and alkylation damage, were determined in folate-sufficient and folate-deficient colonocytes by single cell gel electrophoresis. In addition, methyl incorporation into genomic DNA was measured using the bacterial enzyme Sss1 methylase. Cultured human colonocyte DNA contained endogenous strand breaks and uracil. Folate deficiency significantly increased strand breakage and uracil misincorporation in these cells. This negative effect on DNA stability was concentration dependent at levels usually found in human plasma (1-10 ng/ml). DNA methylation was decreased in HCEC grown in the absence of folate. Conversely, hypomethylation was nor concentration dependent. Folate deficiency impaired the ability of HCEC to repair oxidative and alkylation damage. These results demonstrate that folic acid modulates DNA repair DNA strand breakage, and uracil misincorporation in immortalized human colonocytes and that folate deficiency substantially decreases DNA stability in these cells.

    AB - Epidemiological studies have indicated that folic acid protects against a variety of cancers, particularly cancer of the colorectum. Folate is essential for efficient DNA synthesis and repair. Moreover folate can affect cellular S-adenosylmethionine levels, which regulate DNA methylation and control gene expression. We have investigated the mechanisms through which folate affects DNA stability in immortalized normal human colonocytes (HCEC). DNA strand breakage, uracil misincorporation, and DNA repair, in response to oxidative and alkylation damage, were determined in folate-sufficient and folate-deficient colonocytes by single cell gel electrophoresis. In addition, methyl incorporation into genomic DNA was measured using the bacterial enzyme Sss1 methylase. Cultured human colonocyte DNA contained endogenous strand breaks and uracil. Folate deficiency significantly increased strand breakage and uracil misincorporation in these cells. This negative effect on DNA stability was concentration dependent at levels usually found in human plasma (1-10 ng/ml). DNA methylation was decreased in HCEC grown in the absence of folate. Conversely, hypomethylation was nor concentration dependent. Folate deficiency impaired the ability of HCEC to repair oxidative and alkylation damage. These results demonstrate that folic acid modulates DNA repair DNA strand breakage, and uracil misincorporation in immortalized human colonocytes and that folate deficiency substantially decreases DNA stability in these cells.

    KW - HAMSTER OVARY CELLS

    KW - COLORECTAL-CANCER RISK

    KW - IN-VITRO

    KW - ULCERATIVE-COLITIS

    KW - ALKYLATING-AGENTS

    KW - DAMAGE

    KW - LINE

    KW - EXPRESSION

    KW - METABOLISM

    KW - CARCINOMA

    U2 - 10.1207/S15327914NC372_18

    DO - 10.1207/S15327914NC372_18

    M3 - Article

    VL - 37

    SP - 245

    EP - 251

    JO - Nutrition and Cancer

    JF - Nutrition and Cancer

    SN - 0163-5581

    IS - 2

    ER -