Table 1.

Mutations found in HPRT cDNAs prepared from 6-TG–resistant colonies of T47D, HCT116, and MDA-MB-231 cells

Cell lines	Treatment	Number of clones analyzed	Clones without mutation in the coding sequence	Clones with frameshift mutation(s)	Clones with deletion(s)	Clones with only a single deletion	Clones with one or more exons lacking	Clones with other types of deletions	Clones with insertion(s)	Clones with transition(s)	Clones with transversion(s)
T47D	Mock	24	0	12	14	17	24	4	1	4	0
							Del ex. 3: 11	Del 1: 7	ins 1: 1	Transitions: 5
							Del ex. 2+3: 9
							Del ex. 4+5: 4
T47D	LSMCM	40	0	20	40	25	38	11	3	7	1
							Del l ex. 3: 14	Del 17: 3	Ins 1: 3	Transitions: 7	Transitions: 3
							Del ex. 2+3: 16
							Del ex. 4 + 5: 5
							Del ex. 2+3+4: 1	Del 1: 21
							Del ex. 6+7+8: 1
							Del ex. 5: 1
HCT116	− Doxycycline	14	1	13	13	0	0	13	4	0	2
								Del 2: 1	Ins 1: 5	Transitions: 7	Transversions: 3
								Del 1: 12
HCT116	− Doxycycline	14	1	13	13	0	0	13	4	0	2
								Del 2: 1	Ins 1: 5	Transversions: 2
Del 1: 12
HCT116	+ Doxycycline	25	4	18	11	0	2	9	13	6	6
							Del ex. 3: 1	Del 1: 16	Ins 1: 17	Transitions: 6	Transversions: 8
							Del ex. 2+3: 1
MDA-MB-231	− Doxycycline	11	3	8	10	5	8	3	0	1	0
							Del ex. 2+3: 1	Del 1: 5	Transitions: 1
							Del ex. 7: 8
MDA-MB-231	+ Doxycycline	24	2	17	21	11	17	9	0	4	2
							Del ex. 2: 1	Del 1: 17	Transitions: 6	Transversions: 2
							Del ex. 2 + 3: 1
							Del ex. 7: 16

Ex., exon; LSMCM, LPS-stimulated macrophage-conditioned medium; Mock, unstimulated macrophage-conditioned medium.