Reversal of multidrug resistance in vincristine-resistant human gastric cancer cell line SGC7901/VCR by LY980503

Table 1 Effect of LY980503 on the sensitivity of SGC7901 and SGC7901/VCR cells to DOX (mean ± SD)

LY980503(μmol/L)	IC50 (μmol/L)
	SGC7901(RF)	SGC7901/VCR (RF)
0	0.068 ± 0.0081	1.6 ± 0.12
1	0.060 ± 0.0048 (1.1)	1.3 ± 0.19 (1.3)
2	0.049 ± 0.0058 (1.4)a	0.55 ± 0.024 (2.9)c
4	0.037 ± 0.0027 (1.8)b	0.25 ± 0.032 (6.4)d
10	0.021 ± 0.0029 (3.2)b	0.11 ± 0.015 (14.5)d

^aP < 0.05,

^bP < 0.01 vs SGC7901 cells in the absence of LY980503;

^cP < 0.05,

^dP < 0. 01 vs SGC7901/VCR cells in the absence of LY980503.

Table 2 Effect of LY980503 on the growth of SGC7901 and SGC7901/VCR cells (mean ± SD)

LY980503	Survival rate (%)
(μmol/L)	SGC7901	SGC7901/VCR
2	97 ± 8.6	103 ± 9.7
4	94 ± 7.8	98 ± 8.3
10	89 ± 6.5	87 ± 8.9
20	61 ± 4.6	67 ± 6.8
40	34 ± 4.5	39 ± 3.9