Cell cycle-specific effects of lovastatin Journal Article


Authors: Jakóbisiak, M.; Bruno, S.; Skierski, J. S.; Darzynkiewicz, Z.
Article Title: Cell cycle-specific effects of lovastatin
Abstract: Lovastatin (LOV), the drug recently introduced to treat hypercholesteremia, inhibits the synthesis of mevalonic acid. The effects of LOV on the cell cycle progression of the human bladder carcinoma T24 cell line expressing activated p21ras were investigated. At a concentration of 2-10 μM, LOV arrested cells in G1 and also prolonged - or arrested a minor fraction of cells in - the G2 phase of the cell cycle; at a concentration of SO μM, LOV was cytotoxic. The cytostatic effects were reversed by addition of exogenous mevalonate. Cells arrested in the cycle by LOV were viable for up to 72 hr and did not show any changes in RNA or protein content or chromatin condensation, which would be typical of either unbalanced growth or deep quiescence. The expression of the proliferation-associated nuclear proteins Ki-67 and p105 in these cells was reduced by up to 72% and 74%, respectively, compared with exponentially growing control cells. After removal of LOV, the cells resumed progression through the cycle; they entered S phase asynchronously after a lag of ≈6 hr. Because mevalonate is essential for the posttranslational modification (isoprenylation) of p21ras, which in turn allows this protein to become attached to the cell membrane, the data suggest that the LOV-induced G1 arrest may be a consequence of the loss of the signal transduction capacity of p21ras. Indeed, while exposure of cells to LOV had no effect on the cellular content of p21ras (detected immunocytochemically), it altered the intracellular location of this protein, causing its dissociation from the cell membrane and translocation toward the cytoplasm and nucleus. However, it is also possible that inhibition of isoprenylation of proteins other than p21ras (e.g., nuclear lamins) by LOV may be responsible for the observed suppression of growth of T24 cells.
Keywords: human cell; ki-67 antigen; cell survival; cell cycle; tumor cells, cultured; nuclear proteins; immunocytochemistry; bladder carcinoma; carcinoma cell; in vitro; protein modification; proliferating cell nuclear antigen; mevinolin; G1 arrest; lovastatin; mevalonic acid; human; priority journal; article; support, non-u.s. gov't; support, u.s. gov't, p.h.s.; proto-oncogene protein p21(ras); ki-67 antibody; p21ras farnesylation; protiferation-associated proteins
Journal Title: Proceedings of the National Academy of Sciences of the United States of America
Volume: 88
Issue: 9
ISSN: 0027-8424
Publisher: National Academy of Sciences  
Date Published: 1991-05-01
Start Page: 3628
End Page: 3632
Language: English
DOI: 10.1073/pnas.88.9.3628
PUBMED: 1673788
PROVIDER: scopus
PMCID: PMC51505
DOI/URL:
Notes: Source: Scopus
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