Table 3.
Methylation Frequencies and Methylation Indices in EBV-Positive and -Negative GCs
| EBV-positive GC (n = 21) | EBV-negative GC (n = 56) | P value* | |
|---|---|---|---|
| THBS1 | 21 (100%) | 31 (55.4%) | <0.001 |
| APC | 20 (95.2%) | 40 (71.4%) | 0.030 |
| p16 | 20 (95.2%) | 20 (35.7%) | <0.001 |
| 14-3-3 sigma | 19 (90.5%) | 35 (62.5%) | 0.024 |
| p14 | 17 (81.0%) | 24 (42.9%) | 0.004 |
| TIMP-3 | 17 (81.0%) | 34 (60.7%) | 0.112 |
| DAP-Kinase | 16 (76.2%) | 27 (48.2%) | 0.039 |
| PTEN | 16 (76.2%) | 14 (25%) | <0.001 |
| E-cadherin | 15 (71.4%) | 38 (67.9%) | 1.000 |
| RASSF1A | 14 (66.7%) | 2 (3.6%) | <0.001 |
| COX2 | 11 (52.4%) | 26 (46.4%) | 0.799 |
| GSTP1 | 8 (38.1%) | 3 (5.4%) | 0.001 |
| MGMT | 8 (38.1%) | 6 (10.7%) | 0.016 |
| hMLH1 | 2 (9.5%) | 11 (19.6%) | 0.496 |
| MINT1 | 19 (90.5%) | 33 (58.9%) | 0.013 |
| MINT25 | 19 (90.5%) | 31 (55.4%) | 0.004 |
| MINT12 | 15 (71.4%) | 14 (25.0%) | <0.001 |
| MINT31 | 13 (61.9%) | 38 (67.9%) | 0.787 |
| MINT2 | 12 (57.1%) | 11 (19.6%) | 0.002 |
| Methylation index† (mean± SD) | 0.70 ± 0.13 | 0.41 ± 0.24 | <0.001 |
*The methylation frequency of each tested gene or locus was compared between EBV-positive and -negative GCs, using a two-tailed Fisher’s exact test. The methylation index was compared using a Student’s t test.
†The methylation index is defined as the total number of genes or loci methylated divided by the total number of genes or loci tested.