Table 2.

Ability of RA to promote chemosensitivity in osteosarcoma MDR cell lines

	KHOSR IC50(µM)	U2OSR IC50(µM)
Doxorubicin	1.820 ± 0.071	3.202 ± 0.083
plus RA 0.2µM	0.630 ± 0.141	1.433 ± 0.012
plus RA 0.5µM	0.601 ± 0.085	1.256 ± 0.092
plus RA 1µM	0.396 ± 0.016	0.981 ± 0.016
plus RA 2µM	0.094 ± 0.014	0.374 ± 0.073
plus RA 5µM	NA	0.065 ± 0.059

*IC₅₀ is the concentration of drug (μM) that produced 50% inhibition of cell growth.