Foetal bovin serum fbs

EJp21 were maintained in DMEM supplemented with 10% foetal bovin serum
(FBS, Gibco, Paisley, UK), penicillin–streptomycin (50 unit/ml),
hygromycin (100 μg/ml) and genticin
(750 μg/ml). EJp16 cells were maintained in DMEM
supplemented with 10% FBS, penicillin–streptomycin
(50 unit/ml), hygromycin (100 μg/ml) and
puromycin (2 μg/ml). In order to inhibit p21 or p16
expression, tet was added to the medium every 3 days to a final concentration of
1 μg/ml. To induce p21 and p16 expression, cells were
washed three times and seeded directly in culture medium in the absence of
tet.^{37 (link)} IMR90 (human fibroblasts
derived from lungs of a 16-week female foetus) and normal human diploid
fibroblasts (Cellworks, San Jose, CA, USA) were maintained in DMEM supplemented
with 10% FBS, and penicillin–streptomycin (50 unit/ml)
until they reached replicative senescence. HT1080p21 were maintained in in DMEM
supplemented with 10% FBS and penicillin–streptomycin
(50 unit/ml). To induce p21 expression, 100 μM
isopropyl β-D-1-thiogalactopyranoside was added to the medium. To
induce ras expression, cells were infected with a retroviral construct containing
ras (gift of Stuart A Aaronson, Mount Sinai School of Medicine, New York, NY,
USA).