. 2021 Feb 15;12:620874. doi: 10.3389/fphar.2021.620874

TABLE 1.

The effect of OTS964 on the anticancer efficacy of chemotherapeutic drugs in drug-selected and gene-transfected ABCG2-overexpressing cell lines.

Treatment	IC₅₀ ^a ± SD (μM) (RF ^b )
Treatment	S1	S1-M1-80	HEK293/pcDNA3.1	HEK293/ABCG2-482-R2	HEK293/ABCG2-482-G2	HEK293/ABCG2-482-T7
Mitoxantrone	0.19 ± 0.13 (1.00)	3.75 ± 0.78 (19.57)^*	0.02 ± 0.01 (1.00)	0.08 ± 0.02 (5.03)^*	0.37 ± 0.03 (24.49)^*	0.59 ± 0.14 (38.90)^*
+OTS964 5 nM	-	11.79 ± 0.08 (61.47)^*	-	0.09 ± 0.03 (6.10)^*	0.51 ± 0.15 (34.11)^*	0.77 ± 0.21 (50.81)^*
+OTS964 10 nM	-	11.05 ± 0.41 (57.63)^*	-	0.14 ± 0.01 (9.07)^*	0.66 ± 0.09 (43.77)^*	0.80 ± 0.13 (53.29)^*
+Ko143 3 μM	0.20 ± 0.07 (1.05)	0.17 ± 0.10 (0.91)	0.02 ± 0.01 (1.20)	0.04 ± 0.01 (2.68)	0.06 ± 0.03 (3.72)	0.07 ± 0.01 (4.48)
Topotecan	0.04 ± 0.01 (1.00)	0.87 ± 0.29 (19.72)^*	0.03 ± 0.02 (1.00)	0.19 ± 0.06 (6.05)^*	1.21 ± 0.05 (38.44)^*	1.85 ± 0.69 (58.74)^*
+OTS964 5 nM	-	0.94 ± 0.28 (21.51)^*	-	0.17 ± 0.04 (5.25)^*	1.35 ± 0.07 (42.69)^*	1.85 ± 0.49 (58.67)^*
+OTS964 10 nM	-	0.97 ± 0.44 (22.18)^*	-	0.19 ± 0.08 (6.01)^*	1.23 ± 0.39 (38.85)^*	1.95 ± 0.88 (61.87)^*
+Ko143 3 μM	0.05 ± 0.01 (1.06)	0.09 ± 0.05 (2.08)	0.03 ± 0.01 (1.01)	0.04 ± 0.07 (1.32)	0.04 ± 0.04 (1.32)	0.05 ± 0.18 (1.72)
SN-38	0.09 ± 0.01 (1.00)	0.61 ± 0.04 (6.72)^*	0.02 ± 0.01 (1.00)	0.43 ± 0.21 (20.08)^*	0.12 ± 0.05 (5.74)^*	0.71 ± 0.86 (32.80)^*
+OTS964 5 nM	-	0.67 ± 0.15 (7.36)^*	-	0.49 ± 0.26 (22.94)^*	0.11 ± 0.01 (5.14)^*	0.81 ± 0.42 (37.73)^*
+OTS964 10 nM	-	0.69 ± 0.18 (7.59)^*	-	0.53 ± 0.09 (24.38)^*	0.25 ± 0.12 (11.76)^*	1.19 ± 0.74 (55.25)^*
+Ko143 3 μM	0.09 ± 0.01 (0.96)	0.14 ± 0.05 (1.53)	0.03 ± 0.01 (1.24)	0.05 ± 0.47 (2.36)	0.03 ± 0.48 (1.21)	0.05 ± 0.03 (2.47)
Cisplatin	1.08 ± 0.23 (1.00)	1.22 ± 0.29 (1.12)	0.61 ± 0.12 (1.00)	0.81 ± 0.21 (1.34)	0.47 ± 0.40 (0.77)	0.93 ± 0.03 (1.53)
+OTS964 5 nM	-	1.22 ± 0.15 (1.13)	-	0.73 ± 0.04 (1.21)	0.40 ± 0.20 (0.65)	1.00 ± 0.13 (1.64)
+OTS964 10 nM	-	1.39 ± 0.13 (1.28)	-	0.82 ± 0.21 (1.34)	0.43 ± 0.04 (0.70)	0.80 ± 0.07 (1.31)
+Ko143 3 μM	1.11 ± 0.02 (1.02)	1.48 ± 0.06 (1.37)	0.71 ± 0.18 (1.17)	0.79 ± 0.36 (1.30)	0.48 ± 0.14 (0.79)	0.72 ± 0.26 (1.18)

Indicated that the IC₅₀ values of chemotherapeutic drugs in drug-resistant cell line had significant statistical difference from the counterparts in corresponding sensitive cell line without inhibitor (p < 0.05).

^{^a}

IC₅₀ values were determined by modified MTT colorimetric assay, and are shown as mean ± SD.

^{^b}

Resistance fold (RF) were calculated by the IC₅₀ values for chemotherapeutic drugs of drug-sensitive cells without inhibitor, divided by the IC₅₀ values for chemotherapeutic drugs of drug-sensitive cells with inhibitor or drug-resistant cells in the absence or presence of inhibitor.