Figure 6.

Reversal of the survival-promoting activity of TS by the PI-3 kinase inhibitors. PC12 cells were switched to serum-free RPMI without and with TS-F (100 ng/ml), NGF (100 ng/ml), CNTF (50 ng/ml), and TS-F (2.5 ng/ml) plus CNTF (50 ng/ml). After 24 h, wortmannin (A) or LY294002 (B) was added to the cultures at the indicated concentrations. Neuronal viability was measured by DAPI staining 24 h after addition of wortmannin or LY294002. Viability of PC12 cells in RPMI alone (33%) was similar to the viability of the cells in RPMI 1640 plus CNTF. Values are from a representative experiment (each point in triplicate) repeated three times, with similar results.