Fig. S1 C6 Ceramide dramatically sensitizes Doxorubicin/ Etoposide induced cancer cell death in CaOV3 and WM-115 cells

CaOV3 ovarian cancer cell line (a, b and c) and WM-115 melanoma cell line (d, e and f) were treated with combination of Doxorubicin or Etoposide (at a different concentration) and C6 Ceramide (at a different concentration) for 48 hours, cell viability were detected by MTT assay as described. L3.6 cells (g) and MCF-7 cells (h) were treated with Toxol (1 μg/ml) in the presence or absence of C6 Ceramide (10 μg/ml) for 48 hours, cell viability were detected by MTT assay The values in the figures are expressed as the means ±standard deviation (SD).*P<0.05 vs. same dose of Doxorubicin treatment without C6 Ceramide; #p<0.05 vs. Taxol only treatment. All experiments were repeated at least three times and similar results were obtained.

Fig. S2 C6 Ceramide dramatically sensitizes Doxorubicin/ Etoposide induced cancer cell apoptosis in L3.6 cells.

Cell apoptosis of L3.6 cells with indicated treatment (Control, 0.3μg/ml of Doxorubicin, 10 μg/ml of C6 Ceramide and Doxorubicin plus C6 Ceramide) for 36 hours was detected by different methods including Hoechst 33342/Calcein assay (a), Histone DNA apoptosis ELISA assay (b) and TUNEL Staining Confocal assay (c).

For each Hoechst/Calcein experiment at least 200 cells in 5 random scope fields were counted for apoptotic rate (a). The values in the figures are expressed as the means ±standard deviation (SD).* P<0.05 vs. same dose of Doxorubicin treatment without C6 Ceramide. All experiments were repeated at least three times and similar results were obtained. Bar=10 μm.

Fig. S3 Effects of specific siRNAs on AMPKα1/2 expression in MCF-7 and L3.6 cells.

MCF-7 and L3.6 cells were treated with indicated treatments for 48 hours,AMPKα1, AMPKα2 and AKT1/2 were detected by Western blot.

Treatments include 1.un-transfected control, 2.transfection reagents (Plus reagents+Lipofectamine) alone, 3.tranfected with control (scramble) siRNA (sc- 44231, 100 nM), 4.tranfected with 50 nM of AMPKα1/2 siRNA (sc-45312) and 5.tranfected with 100 nM of AMPKα1/2 siRNA (sc-45312). All experiments were repeated at least three times and similar results were obtained.

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