Abstract
To identify functions of the fragile tumour suppressor gene, FHIT, matched pairs of Fhit-negative and -positive human cancer cell clones, and normal cell lines established from Fhit -/- and +/+ mice, were stressed and examined for differences in cell cycle kinetics and survival. A larger fraction of Fhit-negative human cancer cells and murine kidney cells survived treatment with mitomycin C or UVC light compared to matched Fhit-positive cells; approximately 10-fold more colonies of Fhit-deficient cells survived high UVC doses in clonigenic assays. The human cancer cells were synchronised in G1, released into S and treated with UVC or mitomycin C. At 18 h post mitomycin C treatment approximately 6-fold more Fhit-positive than -negative cells had died, and 18 h post UVC treatment 3.5-fold more Fhit-positive cells were dead. Similar results were obtained for the murine -/- cells. After low UVC doses, the rate of DNA synthesis in -/- cells decreased more rapidly and steeply than in +/+ cells, although the Atr-Chk1 pathway appeared intact in both cell types. UVC surviving Fhit -/- cells appear transformed and exhibit >5-fold increased mutation frequency. This increased mutation burden could explain the susceptibility of Fhit-deficient cells in vivo to malignant transformation.
Publication types
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Comparative Study
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Acid Anhydride Hydrolases / genetics
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Acid Anhydride Hydrolases / physiology*
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Animals
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Apoptosis* / drug effects
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Apoptosis* / radiation effects
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Ataxia Telangiectasia Mutated Proteins
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Cell Cycle Proteins / metabolism
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Cell Cycle* / drug effects
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Cell Cycle* / radiation effects
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Cell Transformation, Neoplastic / drug effects
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Cell Transformation, Neoplastic / radiation effects
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Checkpoint Kinase 1
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Colony-Forming Units Assay
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DNA / drug effects
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DNA / radiation effects
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Drug Resistance, Neoplasm*
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Gene Expression Regulation, Neoplastic
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Genes, Tumor Suppressor
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Humans
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Kidney / drug effects
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Kidney / radiation effects
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Kinetics
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Mice
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Mitomycin / adverse effects*
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Mutation / genetics
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Neoplasm Proteins / genetics
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Neoplasm Proteins / physiology*
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Protein Kinases / metabolism
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Protein Serine-Threonine Kinases / metabolism
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Radiation Tolerance*
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Signal Transduction
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Stomach Neoplasms / metabolism
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Stomach Neoplasms / pathology*
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Tumor Cells, Cultured
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Ultraviolet Rays
Substances
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Cell Cycle Proteins
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Neoplasm Proteins
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fragile histidine triad protein
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Mitomycin
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DNA
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Protein Kinases
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ATR protein, human
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Ataxia Telangiectasia Mutated Proteins
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CHEK1 protein, human
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Checkpoint Kinase 1
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Chek1 protein, mouse
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Protein Serine-Threonine Kinases
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Acid Anhydride Hydrolases