Promoter Region Hypermethylation and mRNA Expression of MGMT and p16 Genes in Tissue and Blood Samples of Human Premalignant Oral Lesions and Oral Squamous Cell Carcinoma
Table 3
Correlation of promoter methylation with risk factors in different groups.
Genes
Risk factors
Methylated
Control ()
PMOLs ()
OSCC ()
P valuea
MGMT
Tobacco chewers (N)
N
9
51
59
Tissue
2 (22%)
24 (47%)
52 (88%)
0.041
Blood
1 (11%)
14 (27%)
39 (66%)
0.015
Alcohol consumers (N)
N
5
12
19
Tissue
0 (0%)
8 (67%)
10 (53%)
0.1588
Blood
0 (0%)
7 (58%)
7 (37%)
0.259
Pan masala (N)
N
3
25
23
Tissue
1 (33%)
15 (60%)
14 (61%)
0.877
Blood
0 (0%)
8 (32%)
14 (61%)
0.236
Bidi smokers (N)
N
10
35
43
Tissue
2 (20%)
20 (57%)
38 (88%)
0.038
Blood
1 (10%)
15 (43%)
33 (77%)
0.048
p16
Tobacco chewers (N)
N
9
51
59
Tissue
2 (22%)
25 (49%)
51 (86%)
0.049
Blood
0 (0%)
18 (35%)
50 (85%)
0.088
Alcohol consumers (N)
N
5
12
19
Tissue
0 (0%)
8 (67%)
11 (58%)
0.124
Blood
0 (0%)
6 (50%)
8 (42%)
0.278
Pan masala (N)
N
3
25
23
Tissue
2 (67%)
19 (76%)
18 (78%)
0.015
Blood
0 (0%)
11 (44%)
17 (74%)
0.107
Bidi smokers (N)
N
10
35
43
Tissue
2 (20%)
29 (83%)
40 (93%)
0.007
Blood
0 (0%)
15 (43%)
38 (88%)
0.071
Chi-square test; n = total number of samples in the group; N = number of individuals exposed to risk factors in different groups. Significant P value represented with bold.
