Response of human REV3 gene to gastric cancer inducing carcinogen N-methyl-N’-nitro-N-nitrosoguanidine and its role in mutagenesis

Table 2 Mutation frequency of SupF tRNA gene in intact plasmid pZ189 after replicated in cultured human cells

Cell line	DMSO			MNNG
	Number of transformant	Number of mutant	Mutation frequency(10-4)	Number of transformant	Number of mutant	Mutation frequency(10-4)
293	7954	1	1.26	12205	9	7.37ab
293-M	15358	2	1.3	12040	7	5.81ab
293-REV3-	39236	9	2.29	19758	3	1.52
FL	13495	7	5.2	13854	38	27.4cd
FL-M	13272	7	5.3	10310	28	27.2cd
FL-REV3-	10967	3	2.7	12609	5	4

^{a, c}χ test P < 0.05 and 0.01 respectively as compared with spontaneous mutation frequency; ^{b, d}χ test P < 0.05 and 0.01 as compared with induced mutation frequency in 293-REV3^- and FL-REV3^- cells respectively.