TABLE 1.

Sphingolipid composition in PPC1 cells

Sphingolipid	Docetaxel		Radiation
	Adherent [pmol SL/nmol Pi (×100)]	Floating [pmol SL/nmol Pi (×100)]	Adherent [pmol SL/nmol Pi (×100)]	Floating [pmol SL/ nmol Pi (×100)]
C16-ceramide	21.28 ± 2.09	52.92 ± 9.03a	21.82 ± 4.42	51.10 ± 7.82a
C22-ceramide	26.12 ± 10.13	78.98 ± 8.38a	27.72 ± 17.08	71.24 ± 24.90b
C22:1-ceramide	10.88 ± 3.60	30.52 ± 4.96a	12.08 ± 7.18	41.55 ± 19.46b
C24-ceramide	139.32 ± 25.97	352.35 ± 27.71a	147.66 ± 71.10	274.27 ± 114.44b
C24:1-ceramide	137.48 ± 65.35	322.87 ± 47.60c	142.54 ± 96.40	305.30 ± 95.44c
C26-ceramide	23.51 ± 1.85	53.49 ± 9.30a	20.61 ± 7.13	25.47 ± 12.78
C26:1-ceramide	22.65 ± 5.31	49.19 ± 4.70a	17.23 ± 7.82	29.61 ± 15.05
Other ceramides	12.73 ± 3.07	24.24 ± 8.57b	14.37 ± 0.69	27.51 ± 15.22
dhC16-ceramide	1.12 ± 0.44	3.36 ± 1.36	0.85 ± 0.35	2.25 ± 1.67
Sphingosine	11.67 ± 1.84	5.49 ± 1.16a	11.87 ± 1.52	6.52 ± 2.30c
S1P	0.21 ± 0.05	0.21 ± 0.03	0.30 ± 0.06	0.40 ± 0.16
Total ceramide	394.0 ± 106.6	964.6 ± 74.1a	404.0 ± 218.5	834.90 ± 313.60b

Cells were exposed to 5 nM docetaxel or 8 Gy radiation. After 48 h, floating and adherent cells were analyzed for sphingolipids using LC/MS. Data are the average and standard deviation from two independent experiments each performed in triplicate expressed as picomoles of sphingolipid (SL) per nanomole of inorganic phosphate (Pi) (pmol SL/nmol Pi) × 100. Other ceramides represents the sum of C₁₄, C₁₈, C_18:1, C₂₀, C_20:1, and C_20:4.

^aP < 0.0001.

^bP < 0.05.

^cP < 0.001.