Reversal of multidrug resistance in drug-resistant human gastric cancer cell line SGC7901/VCR by antiprogestin drug mifepristone

Table 1 Effects of of mifepristone on intracellular VCR accumulation and rhodamine 123 retention in drug-resistant human gastric cancer cell line SGC7901/VCR and its parental counterpart SGC7901

Mifepristone	Intracellular [3H]VCR accumulation (pmol/mg protein)		Fluorescent intensity of intracellular rhodamine 123
(μmol/L)	SGC7901	SGC7901/VCR	SGC7901	SGC7901/VCR
0 (control)	3.36 ± 0.54	0.98 ± 0.20	82.36 ± 4.23	22.32 ± 3.14
1	3.41 ± 0.49	1.31 ± 0.29a	83.21 ± 5.50	28.89 ± 4.25a
5	3.54 ± 0.68	2.24 ± 0.62b	85.12 ± 4.89	45.63 ± 6.34b
10	3.65 ± 0.87	3.05 ± 0.75b	86.01 ± 6.12	68.69 ± 7.40b
20	3.84 ± 0.79	3.64 ± 0.84b	88.20 ± 6.45	82.10 ± 9.21b

^aP < 0.05,

^bP < 0.01 vs control group.

Table 2 Flow cytometric analysis of Bcl-2 and Bax expression in human gastric cancer cell line SGC7901 and its drug-resistant counterpart SGC7901/VCR

Cell line	Bcl-2 (%)	Bax (%)
SGC7901	17.23 ± 0.86	5.85 ± 0.56
SGC7901/VCR	25.32 ± 1.44a	1.24 ± 0.78a

^aP < 0.05 vs SGC7901 cell line.

Table 3 Effect of mifepristone on Bcl-2 and Bax expression in SGC7901/VCR cells

Mifepristone (μmol/L)	Bcl-2 (%)	Bax (%)
0 (control)	25.32 ± 1.44	1.24 ± 0.78
10	9.21 ± 0.65a	19.69 ± 1.13a

^aP < 0.05 vs control group.

Table 4 Effects of mifepristone on the sensitivity of SGC7901 cells and its drug-resistant counterpart SGC7901/VCR to VCR

Mifepristone	SGC7901		SGC7901/VCR
(μmol/L)	IC50	Reversal fold	IC50	Reversal fold
0 (control)	4.23 ± 1.02		46.36 ± 5.14
1	4.19 ± 1.00	1.01	45.23 ± 4.21	1.02
5	4.05 ± 0.94	1.04	6.45 ± 1.23b	7.19
10	3.81 ± 0.89	1.11	3.61 ± 0.87b	12.84
20	3.49 ± 0.74	1.21	2.19 ± 0.54a	21.17

Data represent IC₅₀ values of VCR (nmol/L) expressed as mean ± SD of 3 independent experiments.

^aP < 0.005,

^bP < 0.01, vs control group.