TABLE 2

Summary of IC50 values of endogenous nucleosides on [3H]uridine uptake in HeLa cells

An extra-sum of squares F test (P < 0.05) was done on the best fit lines generated from the nonlinear regression IC50 (eq. 3) to compare generated IC50 values on GraphPad Prism 7. A statistically significant difference between the IC50 values for inosine and cytidine was found (P = 0.0137 and P < 0.0001). No statistical difference was observed for adenosine (P = 0.8384), guanosine (P = 0.7952), and thymidine (P = 0.0574). All values are reported as mean ± S.E.M. of triplicate values (n = 3).

NucleosideIC50 (ENT1) (μM)IC50 (ENT2) (μM)
Adenosine59.17 ± 20.9267.65 ± 34.77
Guanosine297.60 ± 179.60398.40 ± 311.80
Thymidine621.50 ± 272.60159.10 ± 85.37
Inosine312.80 ± 179.10*32.03 ± 17.69*
Cytidine9.44 ± 1.50*144.0 ± 80.91*