Figure 3.

Etoposide induces a biphasic increase in Cer formation. (a) LNCaP and PC-3 cells were treated with 10 μM etoposide for various periods, and Cer levels were determined. (b) LNCaP cells were treated with 10 μM etoposide for various periods, and SM levels are determined by TLC. The nSMase and aSMase were measured as described in Methods. PE, phosphatidylethanolamine; PS, phosphatidylserine. (c) LNCaP cells were treated with the complex (10 μM etoposide, 10 μM Rottlerin, 50 μM FB-1, 100 μM MeSM) for the indicated periods, and Cer levels were determined. Etop, etoposide; Rot, Rottlerin. In each treatment, the time at which etoposide was added was set to 0 hours. (d) LNCaP cells were treated with the complex indicated (10 μM etoposide, 10 μM Rottlerin, 50 μM FB-1) for 9 hours, and nSMase activity was determined. In each treatment, the time at which etoposide was added was set to 0 hours. For all, bars represent SD. Experiments were repeated three times with similar results.