Table 1. IC₅₀ of combination treatment of Tdp1 expression and topotecan.

Schedule@		TDP1-TPT		TPT-TDP1
Cell line	Dox$	IC50#	Fold Change*	IC50#	Fold Change*
Vector	-	11.0		9.5
	+	10.6	1.0	8.8	1.1
hTdp1	-	32.8		13.2
	+	18.7	1.8	9.4	1.4
H493N	-	11.6		10.0
	+	2.5	4.6	3.9	2.6
H263A	-	10.6		7.4
	+	0.3	35.2	1.0	7.4

@ Schedule TDP1-TPT: 4 days with (+Dox) or without (-Dox) TDP1 expression combined with 3 days TPT; TPT-TDP1. Schedule TPT-TDP1: 4 days TPT combined with 3 days with (+Dox) or without (-Dox) TDP1 expression; $ -/+ 0.1 μg/ml to induce Tdp1 allele expression; # IC₅₀ in nM calculated from the average survival curve (Figure 7) using Prism 7

^*Fold change= IC₅₀ -Dox/IC₅₀ +Dox, indicate fold increase in cell toxicity in combination with indicated TDP1 protein expression and topotecan (TPT).