Table 1.

Cabozantinib reverses ABCG2-mediated drug resistance in drug selected resistant cells

Treatment	IC50 ± SDa (μM) (Resistant fold) b
	H460	H460/MX20
Mitoxantrone	0.021± 0.005(1.0) b	1.533 ± 0.245 (73.1)
+ Cabo 2.5 μM	0.022 ± 0.007(1.0)	0.175 ± 0.021(8.3)*
+ Cabo 5 μM	0.021 ± 0.004(1.0)	0.083 ± 0.032(3.9)*
+ FTC 5 μM	0.022 ± 0.003(1.0)	0.027 ± 0.012(1.3)*
SN-38	0.032 ± 0.002 (1.0)	2.273 ± 0.165(71.0)
+ Cabo 2.5 μM	0.029± 0.005(0.9)	0.342 ± 0.031(10.7)*
+ Cabo 5 μM	0.027 ± 0.003(0.8)	0.075 ± 0.006(2.3)*
+ FTC 5 μM	0.029 ± 0.008(0.9)	0.034 ± 0.003(1.0)*
Topotecan	0.077 ± 0.013(1.0)	2.618 ± 0.167(43.23)
+ Cabo 2.5 μM	0.076 ± 0.008(1.0)	0.531 ± 0.017(3.17)*
+ Cabo 5 μM	0.071 ± 0.005(0.9)	0.195 ± 0.014(2.5)*
+ FTC 5 μM	0.070 ± 0.004(0.9)	0.080 ± 0.009(1.03)*
Cisplatin	2.077± 0.142(1.0)	2.043 ± 0.293(1.0)
+ Cabo 2.5 μM	1.973 ± 0.178(0.9)	1.973 ± 0.193(1.0)
+ Cabo 5 μM	2.104 ± 0.138(1.0)	2.312 ± 0.132(1.1)
+ FTC 5 μM	2.014 ± 0.291(1.0)	1.991 ± 0.189(1.0)

Cell survival was determined by MTT assay as described in Material and Methods.

^aIC₅₀ values are represented as the mean ± standard deviation (SD).

^bResistance fold was calculated by the IC₅₀ values for different substrates, and cisplatin of H460 cell lines with cabozantinib or fumitremorgin C (FTC), or the resistant cell line H460/MX20 in the presence or absence of cabozantinib or FTC, divided by the IC₅₀ values for different substrates, and cisplatin of H460 without the reversing agents.

^*P<0.05, versus the control group.