“…After incubated for 48 h, cells were treated with LY294002 (0, 10, 20, 30, 40, 50 μmol/l), rapamycin (1, 10, 30, 50, 90 nmol/l) and NVP-BEZ235 (0.1, 1, 10, 500, 1000, 2000 nmol/l). The viability was examined at incubation for 6, 12, 24, 36 h according to the process by Natali (Natali et al, 2007). Cell monolayers were incubated for 4 h with 1 mg/ml MTT (Beyotime, Jiangsu, China), which is converted from the yellow tetrazolium compound to the purple formazan derivative by mitochondria of living cells.…”