Mechanism of 5-fluorouracil required resistance in human hepatocellular carcinoma cell line Bel7402

Table 1 GSH content and GSTs activity in Bel₇₄₀₂ and Bel₇₄₀₂/5-FU cells and the effect of BSO on the intracellular GSH content in Bel₇₄₀₂/5-FU cells

	BSO (μmol·L-1)	Subline
		Bel7402/5-FU	Bel7402
GSH content (mg/mg protein)	-	0.952 ± 0.257	0.322 ± 0.196b
	5	0.520 ± 0.107
	50	0.427 ± 0.200a
	100	0.403 ± 0.135a
GSTs activity (nmol/min/mg protein)	-	19.1 ± 1.9	14.8 ± 1.2c

GSH content was determined in Bel₇₄₀₂/5-FU cells treated with or without BSO for 24 hr and Bel₇₄₀₂ cells. GSTs activity was assayed by the method of Ghalia et al[22] using 30 mmol·L^-1 GSH and 30 mmol·L^-1 CDNB as substrates. Results are presented as mean ± SD from three independent experiments, each per-formed in triplicates. Differences for significance were tested by using a Student’s t-test:

^aP < 0.05,

^bP < 0.01 vs Bel₇₄₀₂/5-FU cells without the addition of BSO;

^cP < 0.05 vs the GSTs activity in Bel₇₄₀₂/5-FU cells