Figure 4.

Effect of lovastatin on cell cycle progression of HUVEC. (a) HUVEC were pretreated overnight with lovastatin (1 μM)(+Lova) or were left untreated (−Lova). Afterwards, fresh medium was added. After a further incubation period of up to 48 h, cells were harvested and cell cycle distribution was analysed by FACS. Data shown are the mean and s.d. from at least two independent experiments. (b) After overnight pretreatment of HUVEC with lovastatin (1 μM) fresh medium containing BrdU was added and cells were further incubated for 3 h in the absence (Lova) or presence (Lova, post-treatment) of lovastatin. BrdU incorporation was quantified by ELISA as described in Methods. Data shown are mean and s.d. from one representative experiment performed in quadruplicate. Con, untreated cells. (c) HUVEC were pretreated overnight with different concentration of lovastatin as indicated. Afterwards, medium was replaced by fresh medium. After a postincubation period of 48 h, cells were pulse-labelled with BrdU for 2 h. BrdU incorporation was quantified by ELISA as described in Methods. Data show are the mean and s.d. from at least two independent experiments each performed in triplicate. (d) HUVEC were left untreated (Con) or were pretreated overnight with lovastatin (Lova). Afterwards, cells were irradiated with different doses of UV-C light. After incubation period of 48 h, cell viability was determined as described in Methods. Data shown are the mean and s.d. from at least two independent experiments each performed in triplicate. Under identical experimental conditions, lovastatin pretreatment rendered human fibroblasts more sensitive to UV-C irradiation (data not shown).