Table 1. Effect of let-7b restoration on the cytotoxicity of paclitaxel and gemcitabine in KRAS mutant (MT) and wide-type (WT) cell lines.

	IC50 of Paclitaxel			IC50 of Gemcitabine
	+ scramble	+ let-7b	CI	+ scramble	+ let-7b	CI
A549 (KRAS MT)	21 ± 1 nM	4 ±1 nM	0.46	92 ± 2 nM	25 ± 1 nM	0.57
H1975 (KRAS WT)	11 ± 1 nM	9 ±1 nM	1.04	48 ± 1 nM	37 ± 1 nM	0.98
Panc-1 (KRAS MT)	25 ± 1 nM	8 ± 1 nM	0.36	36 ± 1 μM	17 ± 1 μM	0.47
BxPC-3 (KRAS WT)	22 ± 1 nM	17 ±1 nM	1.01	30 ± 1 nM	22 ± 1 nM	0.96

CI: combination index; CI < 0.9 indicates synergism; CI = 0.9–1.1 indicates additivity, and CI > 1.1 indicates antagonism.