DNA methyltransferase3a expression is an independent poor prognostic indicator in gastric cancer

Table 1 Expression of DNA methyltransferases 1, 3a and 3b between different groups

	Gastric cancer (n = 85)	Control (n = 85)	P value	H. pylori (+) cancer (n = 67)	H. pylori (-) cancer (n = 34)	P value
DNMT1	10 (0-40)	0 (0-5)	< 0.001	20 (0-120)	50 (5-110)	0.302
DNMT3a	80 (5-150)	0 (0-0)	< 0.001	180 (40-210)	155 (58-240)	0.859
DNMT3b	180 (140-240)	90 (0-240)	< 0.001	180 (120-240)	160 (98-210)	0.179

HSCOREs were represented with median (quartile range). H. pylori: Helicobacter pylori; DNMT: DNA methyltransferase.

Table 2 DNA methyltransferases 1, 3a and 3b expression (HSCORE) in gastric cancer according to clinicopathologic parameters

	DNMT1 Median (quantile range)	P value	DNMT3a Median (quantile range)	P value	DNMT3b Median (quantile range)	P value
Gender
Male (n = 227)	10 (0-60)	0.283	90 (0-180)	0.629	210 (120-240)	0.011
Female (n = 73)	20 (0-90)		80 (3-180)		150 (95-240)
Age (yr)
≤ 60 (n = 128)	10 (0-80)	0.839	60 (1-180)	0.101	160 (90-240)	0.003
> 60 (n = 172)	10 (0-60)		100 (1-210)		210 (140-240)
Smoking
Yes (n = 107)	10 (0-70)	0.502	120 (5-210)	0.065	180 (120-240)	0.722
No (n = 193)	10 (0-80)		60 (0-180)		180 (120-240)
Drinking
Yes (n = 72)	10 (0-80)	0.570	120 (40-233)	0.003	195 (125-240)	0.777
No (n = 228)	10 (0-60)		60 (0-180)		180 (120-240)
TNM stage
I (n = 22)	45 (5-93)	0.106	80 (0-180)	0.905	135 (75-240)	0.149
II (n = 51)	20 (0-80)		60 (5-180)		160 (90-240)
III (n = 195)	10 (0-60)		90 (5-180)		210 (140-240)
IV (n = 32)	10 (0-35)		90 (0-180)		170(90-240)
Differentiation
Well + moderate (n = 119)	5 (0-60)	0.051	100 (5-210)	0.158	160 (100-240)	< 0.001
Poor (n = 181)	20 (0-80)		80 (0-180)		240 (150-270)
Lymph-vascular invasion
Absent (n = 138)	10 (0-60)	0.159	60 (0-180)	0.020	180 (120-240)	0.942
Present (n = 162)	10 (0-80)		110 (10-210)		180 (120-240)
Depth of invasion
T1 (n = 8)	80 (13-130)	0.090	130 (20-225)	0.082	185 (128-240)	0.424
T2 (n = 38)	20 (0-98)		60 (0-180)		180 (50-240)
T3 (n = 223)	10 (0-70)		90 (10-210)		180 (120-240)
T4 (n = 31)	10 (0-20)		40 (0-140)		180 (120-240)
Lymph metastasis
N0 (n = 65)	30 (0-80)	0.001	60 (0-170)	0.503	180 (100-240)	0.166
N1 (n = 92)	0 (0-28)		60 (0-203)		210 (140-240)
N2 (n = 78)	20 (0-93)		110 (5-188)		180 (120-240)
N3 (n = 65)	20 (0-70)		90 (15-180)		180 (145-255)
Distant metastasis
Negative (n = 265)	10 (0-80)	0.938	80 (5-180)	0.679	195 (120-240)	0.285
Positive (n = 35)	10 (0-60)		90 (0-210)		160 (90-240)
Survival
Survival (n = 180)	10 (0-80)	0.656	60 (0-180)	0.009	180 (120-240)	0.441
Death (n = 120)	10 (0-60)		120 (13-210)		210 (120-240)

DNMT: DNA methyltransferase.

Table 3 Multivariate analysis of predictors of overall survival in gastric cancer

	HR (95%CI)	P value1
DNMT1 expression
Negative (n = 180)	Reference	0.542
Positive (n = 120)	0.89 (0.60-1.31)
DNMT3a expression
Negative (n = 106)	Reference	0.025
Positive (n = 194)	1.60 (1.06-2.40)
DNMT3b expression
HSCORE ≤ 200 (n = 154)	Reference	0.620
HSCORE > 200 (n = 146)	1.17 (0.63-2.18)
Lymph-vascular invasion
Absent (n = 138)	Reference	0.130
Present (n = 162)	1.36 (0.91-2.03)
TNM stage
I (n = 22)	Reference
II (n = 51)	1.78 (0.50-6.37)	0.379
III (n = 195)	4.11 (1.30-13.05)	0.016
IV (n = 32)	14.55 (4.38-48.31)	< 0.001

¹Cox proportional hazards model, adjusted for gender, age, smoking, drinking, lymph-vascular invasion, and DNMT expression. DNMT: DNA methyltransferase.