ARREST OF CULTURED-CELLS IN THE G1-PHASE OF THE CELL-CYCLE BY INDOMETHACIN

  • 1 January 1979
    • journal article
    • research article
    • Vol. 210  (1) , 106-111
Abstract
Indomethacin [an antiinflammatory drug] reversibly inhibited growth of rat hepatoma cells (HTC) and human diploid fibroblasts in the G1 phase of the cell cycle. Cytophotometric measurements showed that greater than 90% of cells incubated for 48 h with indomethacin had a DNA content that corresponded to the G1 state. Synchronous growth of the HTC and fibroblast cultures occurred after removal of the drug as indicated by the sequence of changes in [3H]thymidine incorporation into DNA, cellular DNA content, mitotic index and cell number. Autoradiographs of HTC cell cultures incubated with [3H]thymidine indicated that all (98%) of the cells engaged in DNA synthesis following the removal of indomethacin. Since viability of the cells was not impaired, even by prolonged exposure to indomethacin, this drug provides a means of synchronizing growth. Suppression of cell proliferation could contribute to the therapeutic and/or toxic effects of indomethacin in vivo.