TY - JOUR
T1 - Growth inhibition of hepatoma cells induced by vitamin K and its analogs
AU - Nishikawa, Y.
AU - Carr, B. I.
AU - Wang, M.
AU - Kar, S.
AU - Finn, F.
AU - Dowd, P.
AU - Zheng, Z. B.
AU - Kerns, J.
AU - Naganathan, S.
PY - 1995
Y1 - 1995
N2 - Congeners of vitamin K are known to inhibit cell growth, although the precise mechanisms of growth inhibition are not well understood. To investigate the mechanisms involved, we synthesized several vitamin K analogs and examined their growth inhibitory activities for a human hepatoma cell line (Hep3B). The analogs included 2-methyl-1,4-naphthoquinone and trimethyl- benxoquinone, with and without aliphatic side chains at position 3. The side chains were all-carbon, thioethers, or O-ethers. Growth inhibition was potent in the compounds with short chains. The presence of a sulfur (thioether) or oxygen atom (O-ether) at the site of attachment of the side chain to the ring potentiated the activity. Apoptotic cell death was induced by the potent growth inhibitory compounds at low concentrations (20-60 μM), whereas necrotic cell death followed treatment with the same compounds at high concentrations. Expression of c-myc, which is thought to be associated with apoptosis, was increased by most of the compounds tested. Both reduced glutathione and cysteine almost completely abrogated the growth inhibitory effects of the thioether analogs as well as of vitamin K3. The effect of glutathione was less prominent for the all-carbon and O-ether analogs, and cysteine had no effect on these analogs. Catalase and deferoxamine mesylate had no significant effect on the thioether analogs, although they showed partial antagonistic effects on the growth inhibition of vitamin K3 and the all-carbon and O-ether analogs. Other non-thiol antioxidants tested had no effect on any of the analogs. Our results indicated that vitamin K-related quinoid compounds cause growth inhibition and both apoptotic and necrotic cell death and that the effects may be mediated by interaction at position 3 of their quinoid nuclei with cellular thiols.
AB - Congeners of vitamin K are known to inhibit cell growth, although the precise mechanisms of growth inhibition are not well understood. To investigate the mechanisms involved, we synthesized several vitamin K analogs and examined their growth inhibitory activities for a human hepatoma cell line (Hep3B). The analogs included 2-methyl-1,4-naphthoquinone and trimethyl- benxoquinone, with and without aliphatic side chains at position 3. The side chains were all-carbon, thioethers, or O-ethers. Growth inhibition was potent in the compounds with short chains. The presence of a sulfur (thioether) or oxygen atom (O-ether) at the site of attachment of the side chain to the ring potentiated the activity. Apoptotic cell death was induced by the potent growth inhibitory compounds at low concentrations (20-60 μM), whereas necrotic cell death followed treatment with the same compounds at high concentrations. Expression of c-myc, which is thought to be associated with apoptosis, was increased by most of the compounds tested. Both reduced glutathione and cysteine almost completely abrogated the growth inhibitory effects of the thioether analogs as well as of vitamin K3. The effect of glutathione was less prominent for the all-carbon and O-ether analogs, and cysteine had no effect on these analogs. Catalase and deferoxamine mesylate had no significant effect on the thioether analogs, although they showed partial antagonistic effects on the growth inhibition of vitamin K3 and the all-carbon and O-ether analogs. Other non-thiol antioxidants tested had no effect on any of the analogs. Our results indicated that vitamin K-related quinoid compounds cause growth inhibition and both apoptotic and necrotic cell death and that the effects may be mediated by interaction at position 3 of their quinoid nuclei with cellular thiols.
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U2 - 10.1074/jbc.270.47.28304
DO - 10.1074/jbc.270.47.28304
M3 - Article
C2 - 7499329
AN - SCOPUS:0028868944
VL - 270
SP - 28304
EP - 28310
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 47
ER -