In this study, we recruited 351 endometrial cancer patients and 344 healthy controls, the age of cases and controls were matched (p = 0.923). There were significant differences in CEA, CA125 and AFP quantity in serum between cases and controls (p < 0.001; p = 0.048; p < 0.001). All of three clinical indicators were higher quantity in cases than controls (Table 1).
In Table 3, we listed the basic information of the SNPs which including the chromosome, position, minor and common allele, the HWE p-value of all SNPs were greater than 0.05, we calculated the minor allele frequency (MAF) of cases and controls. We found compared with common G allele, the rs118050317 C allele were significant increased 0.46-fold endometrial cancer risk (OR = 1.46, 95% CI = 1.04 – 2.06, p = 0.028).
In table 4, we calculated the genotype distribution in cases and controls under four different genotype model (co-dominant, dominant, recessive and log-additive) before and after adjustment the age. After adjusted the age, compared with GG genotype carriers, the rs118050317 CC genotype carriers were significant increased the endometrial cancer risk under co-dominant model (OR = 8.43, 95% CI = 1.05 – 67.89, p = 0.045), the results also significant under log-additive model (OR = 1.47, 95% CI = 1.04 – 2.07, p = 0.029).
In the association analysis between different SNPs and different clinical index, we found there was significant difference between rs7307242 different genotype and CEA and AFP quantity (p = 0.021, p < 0.001), genotype AA corresponding to the highest quantity, followed by TT and AT genotype. Rs75750647 different genotypes were significant associated with CA125 and CA199 quantity (p = 0.032, p = 0.033), the AA genotype carriers had the highest CA125 and CA199 quantity. SNP loci rs11610368 different genotypes were significant associated with HE4 quantity (p = 0.010), genotype AA corresponding to the highest quantity, followed by GG and AG (Table 5).
Table 1 The basic information of cases and controls
Variable
|
Cases (n=351)
|
Controls (n=344)
|
p
|
Age (Mean±SD)
|
55.66 ± 8.46
|
55.60 ± 8.43
|
0.923
|
≤55
|
184
|
178
|
|
>55
|
167
|
166
|
|
Clinical index
|
|
|
|
CEA
|
305
|
105
|
|
Quantity in serum(ng/ml)
|
12.55 ± 3.95
|
2.24 ± 3.14
|
<0.001*
|
CA125
|
299
|
105
|
|
Quantity in serum (U/ml)
|
24.23 ± 56.30
|
13.25 ± 11.52
|
0.048*
|
CA199
|
285
|
95
|
|
Quantity in serum (U/ml)
|
21.21 ± 58.23
|
13.91 ± 11.62
|
0.226
|
AFP
|
303
|
105
|
|
Quantity in serum (ng/ml)
|
9.75 ± 5.28
|
2.77 ± 0.97
|
<0.001*
|
CEA: Carcinoembryonic antigen; CA: Carbohydrate antigen; AFP: Alpha fetoprotein
*p <0.05 indicates statistical significance
Table 2 Primers used in this study
SNPs
|
2nd-PCRP
|
1st-PCRP
|
UEP_SEQ
|
rs118050317
|
ACGTTGGATGGTGTAGTGATTGACACCTG
|
ACGTTGGATGACAGGAGCTGGTCATGTTGC
|
ggggtGCCGATGGGGAAGGATTAG
|
rs75750647
|
ACGTTGGATGTGTTCGCTGTGTACTGGATG
|
ACGTTGGATGCCCCCACAAAATTACAAACC
|
CTAAAGCAGGGTGGAG
|
rs7307242
|
ACGTTGGATGAAATGCTTCTCCTGGAAGTC
|
ACGTTGGATGGCCCTAGCCTGTTTCTTTAG
|
CCAGATCACTAGCTCTGA
|
rs10849390
|
ACGTTGGATGTCACACAATCTCACAGGGAC
|
ACGTTGGATGGAAATCAGTACTGCCTGTGC
|
tcgccCAGGGACAGCCCGCTGCC
|
rs11610368
|
ACGTTGGATGTCTGTGACTCCTTGCCAATG
|
ACGTTGGATGCTCTGCAATGTTACACAGCC
|
CCTTGCCAATGGATAGAATAGAA
|
UEP SEQ: unextended mini‐sequencing primer
Table 3 Basic information of candidate SNPs in this study
SNPs
|
Chromosome
|
Gene
|
Position
|
Minor allele
|
Common allele
|
HWE p-Value
|
MAF
|
OR (95%CI)
|
p
|
Case
|
Control
|
rs118050317
|
12
|
NINJ2
|
634980
|
C
|
G
|
0.336
|
0.129
|
0.092
|
1.46 (1.04 - 2.06)
|
0.028*
|
rs75750647
|
12
|
NINJ2
|
638831
|
A
|
G
|
0.617
|
0.333
|
0.314
|
1.09 (0.87 - 1.37)
|
0.440
|
rs7307242
|
12
|
NINJ2
|
641529
|
A
|
T
|
0.197
|
0.138
|
0.149
|
0.92 (0.68 - 1.24)
|
0.576
|
rs10849390
|
12
|
NINJ2
|
646086
|
G
|
A
|
0.638
|
0.372
|
0.360
|
1.05 (0.85 - 1.31)
|
0.646
|
rs11610368
|
12
|
NINJ2
|
662624
|
A
|
G
|
0.053
|
0.127
|
0.130
|
0.97 (0.71 - 1.33)
|
0.869
|
SNP: single nucleotide polymorphisms; HWE: Hardy-Weinberg equilibrium; MAF: minor allele frequency; OR: odds ratio; 95% CI: 95% confidential interval
*p <0.05 indicates statistical significance
Table 4 Genotype frequencies of the SNPs and their associations with risk of endometrial cancer
SNP
|
Model
|
Genotype
|
Case
|
Control
|
Without adjustment
|
With adjustment of age
|
OR (95% CI)
|
p
|
OR (95% CI)
|
p
|
rs118050317
|
Co-dominant
|
GG
|
268
|
282
|
1
|
|
1
|
|
|
|
CG
|
74
|
61
|
1.28 (0.87 - 1.86)
|
0.206
|
1.28 (0.88 - 1.87)
|
0.202
|
|
|
CC
|
8
|
1
|
8.42 (1.05 - 67.76)
|
0.045*
|
8.43 (1.05 - 67.89)
|
0.045*
|
|
Dominant
|
GG
|
268
|
282
|
1
|
|
1
|
|
|
|
CG+CC
|
82
|
62
|
1.39 (0.96 - 2.01)
|
0.080
|
1.40 (0.96 - 2.02)
|
0.078
|
|
Recessive
|
GG+CG
|
342
|
343
|
1
|
|
1
|
|
|
|
CC
|
8
|
1
|
8.02 (1.00 - 64.50)
|
0.050
|
8.03 (1.00 - 64.52)
|
0.050
|
|
Log-additive
|
—
|
—
|
—
|
1.46 (1.04 - 2.06)
|
0.029*
|
1.47 (1.04 - 2.07)
|
0.029*
|
OR: odds ratio; 95% CI: 95% confidential interval
*p <0.05 indicates statistical significance
Table 5 The association between SNPs of NINJ2 and clinical index of endometrial cancer
SNP
|
Clinical Index
|
Genotype
|
Number in cases
|
Quantity in blood
(Mean ± SD)
|
p
|
rs7307242
|
CEA (ng/ml)
|
AA
|
7
|
14.94 ± 3.97
|
0.021*
|
|
|
AT
|
69
|
11.56 ± 3.55
|
|
|
|
TT
|
229
|
12.78 ± 4.01
|
|
|
AFP (ng/ml)
|
AA
|
7
|
19.55 ± 21.16
|
<0.001*
|
|
|
AT
|
69
|
9.23 ± 3.82
|
|
|
|
TT
|
227
|
9.61 ± 4.23
|
|
rs75750647
|
CA125 (U/ml)
|
AA
|
35
|
46.51 ± 131.23
|
0.032*
|
|
|
AG
|
129
|
24.09 ± 44.88
|
|
|
|
GG
|
135
|
18.6 ± 24.39
|
|
|
CA199 (U/ml)
|
AA
|
31
|
46.19 ± 163.92
|
0.033*
|
|
|
AG
|
124
|
15.9 ± 14.45
|
|
|
|
GG
|
130
|
20.32 ± 28.95
|
|
rs11610368
|
HE4 (pg/ml)
|
AA
|
3
|
295.38 ± 390.97
|
0.010*
|
|
|
AG
|
65
|
90.37 ± 99.74
|
|
|
|
GG
|
233
|
91.49 ± 113.83
|
|
CEA: Carcinoembryonic antigen; CA: Carbohydrate antigen; HE4: Human epididymis protein 4; AFP: Alpha fetoprotein; SF: Serum ferritin; TNF: Tumor necrosis factor
*p <0.05 indicates statistical significance