The overmethylated genes in Helicobacter pylori-infected gastric mucosa are demethylated in gastric cancers

BMC Gastroenterology

Table 3 Comparison of the frequency of over- and undermethylated genes detected in the gastric non-cancerous and cancerous tissues

Gene	Noncancerous tissue		Microsatellite genotype of gastric cancers (%)				Bone marrow
	H. pylorinegative (n = 100)	H. pyloripositive (n = 100)	LOH-B (n = 13)	LOH-L (n = 29)	LOH-H (n = 24)	MSI (n = 4)	(n = 18) (%)
Overmethylation frequency
CDH1	21	77*	0 (0)*	7 (24)	3 (13)	0 (0)	0 (0)
ARRDC4	20	62*	3 (23)	8 (28)	1 (4)*	1 (25)	0 (0)
PPARG	40	82*	5 (38)	7 (24)	6 (25)	1 (25)	0 (0)
CDKN2A	46	90*	9 (69)	16 (55)	9 (38)	2 (50)	4 (22)
TRAPPC2L	6	21*	6 (46)*	8 (28)*	1 (4)	1 (25)	0 (0)
DUSP6	12	36*	3 (23)	3 (10)	1 (4)	2 (50)	0 (0)
MLH1	19	37*	4 (31)	17 (59)*	11 (46)	3 (75)	0 (0)
RUNX3	42	85*	10 (77)	26 (90)*	19 (79)*	4 (100)	18 (100)
PGA5	12	13	5 (38)	8 (28)	1 (4)	0 (0)	0 (0)
PGC	4	10	4 (31)	4 (14)	5 (21)	1 (25)	18 (100)
TFF1	37	52	5 (38)	3 (10)*	3 (13)*	0 (0)	18 (100)
TFF2	4	3	4 (31)	4 (14)	1 (4)	0 (0)	2 (11)
MSLN	12	11	8 (62)*	16 (55)*	6 (25)	1 (25)	18 (100)
KRT6A	18	16	4 (31)	16 (55)*	4 (17)	3 (75)	3 (17)
Undermethylation frequency
CDH1	0	0	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)
ARRDC4	0	0	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)
PPARG	0	0	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)
CDKN2A	0	0	0 (0)	0 (0)	0 (0)	0 (0)	0 (0)
TRAPPC2L	13	11	1 (8)	2 (7)	7 (29)	1 (25)	16 (89)
DUSP6	26	25	3 (23)	13 (45)	12 (50)	2 (50)	18 (100)
MLH1	20	18	7 (54)	6 (21)	9 (38)	1 (25)	17 (94)
RUNX3	5	1	0 (0)	1 (3)	2 (8)	0 (0)	0 (0)
PGA5	10	14	0 (0)	3 (10)	5 (21)	0 (0)	0 (0)
PGC	29	18	4 (31)	8 (28)	5 (21)	2 (50)	0 (0)
TFF1	11	1*	7 (54)	19 (66)*	17 (71)*	3 (75)	0 (0)
TFF2	36	26	4 (31)	11 (38)	8 (33)	3 (75)	13 (72)
MSLN	0	0	0 (0)	1 (3)	1 (4)	2 (50)	0 (0)
KRT6A	17	16	3 (23)	3 (10)	3 (13)	1 (25)	5 (28)

The gastric cancers were categorized into baseline-level LOH (LOH-B), low-level LOH (LOH-L), high-level LOH (LOH-H) and microsatellite instability (MSI). The details are described in the material and methods section.
*H. pylori-positive gastric mucosa and gastric cancers were compared with H. pylori-negative gastric mucosa. Significant differences were determined using Fisher's exact test (P < 0.01).

ISSN: 1471-230X