3.1 Patient characteristics
Totally 349 cases with clinical data were downloaded from TCGA in January 2021. 136 (39.0%) cases were male. 47 (13.5%) patients were with stage I disease, 110 (31.5%) patients were with stage II disease, 155 (44.4%) patients were with stage III disease and 37 (10.6%) patients were with stage IV disease. T1, T2, T3, T4 diseases were found in 17 (4.9%), 72 (20.6%), 168 (48.1%), 92 (26.4%) patients, respectively. 67.9% of the patients had lymph node invasion. Of which, 91 cases were N1 disease, 75 cases were N2 disease, 71 cases were N3 disease. 24(6.9%) patients had distant metastases. Clinical characteristics of patients were shown in table 1.
Table 1. Patient characteristics of gastric cancer
Characteristic
|
|
N(total=349)
|
%
|
Age
|
≤65
|
160
|
45.8
|
|
>65
|
189
|
54.2
|
Gender
|
male
|
136
|
39.0
|
|
female
|
213
|
61.0
|
Grade
|
G1
|
6
|
1.7
|
|
G2
|
120
|
34.4
|
|
G3
|
223
|
63.9
|
Clinical stage
|
I
|
47
|
13.5
|
|
II
|
110
|
31.5
|
|
III
|
155
|
44.4
|
|
IV
|
37
|
10.6
|
T stage
|
1
|
17
|
4.9
|
|
2
|
72
|
20.6
|
|
3
|
168
|
48.1
|
|
4
|
92
|
26.4
|
N stage
|
0
|
112
|
32.1
|
|
1
|
91
|
26.1
|
|
2
|
75
|
21.5
|
|
3
|
71
|
20.3
|
M stage
|
0
|
325
|
93.1
|
|
1
|
24
|
6.9
|
3.2 GUCY1A2 expression was increased in gastric carcinoma patients
Data of 343 gastric carcinoma samples and 30 normal samples with GUCY1A2 expression information were downloaded from TCGA database in January 2021. GUCY1A2 expression level were compared in normal samples and tumors samples. In comparison to normal samples, GUCY1A2 expression was significantly increased in tumor samples (Fig. 1A and 1B).
3.3 Increased GUCY1A2 was associated with poor overall survival
Patients with complete survival information and GUCY1A2 expression information were included in survival analysis. As shown in Fig. 2A, patients with high GUCY1A2 expression showed a worse prognosis than patients with low GUCY1A2 expression. We also analyzed the association between GUCY1A2 expression and other clinical characteristics. Results showed that expression level of GUCY1A2 was correlated to histological grade, T stage. Patients who with higher histological grade and T stage had higher GUCY1A2 level. But GUCY1A2 expression was independent of age, gender, clinical stage, lymph node invasion or distant metastasis (Fig. 2B-2H).
3.4 GUCY1A2 was an independent prognostic factor in gastric carcinoma
Univariate cox regression analysis showed that age, stage, distant metastasis and high GUCY1A2 expression level was correlated significantly with poor survival. HR was1.44 and 95% confidence intervals was1.03-2.02 (p=0.03) (Tab. 2). Age, gender, clinical stage and increased GUCY1A2 expression level remained associated with survival at multivariate analysis (Tab. 3 and Fig. 3).
Table 2. Association of clinical characteristics and survival by univariate cox regression
Characteristic
|
HR(95%CI)
|
p value
|
Age
|
1.03(1.01-1.05)
|
0.004*
|
Gender
|
1.50(0.98-2.30)
|
0.062
|
Grade
|
1.25(0.85-1.84)
|
0.252
|
Clinical stage
|
1.51(1.20-1.91)
|
0.001*
|
T stage
|
1.28(1.00-1.63)
|
0.050
|
M stage
|
2.07(1.07-3.98)
|
0.030*
|
N stage
|
1.54(0.97-2.45)
|
0.070
|
GUCY1A2
|
1.44(1.03-2.02)
|
0.034*
|
HR: Hazard Ratio, CI: confident interval
Table 3. Association of clinical characteristics and survival by Multivariate analysis
Characteristic
|
HR(95%CI)
|
p value
|
Age
|
1.05(1.02-1.07)
|
0.000*
|
Gender
|
1.57(1.01-2.44)
|
0.045*
|
Grade
|
1.33(0.89-1.99)
|
0.167
|
Clinical stage
|
1.71(1.09-2.69)
|
0.019*
|
T stage
|
1.03(0.73-1.45)
|
0.086
|
M stage
|
1.83(0.80-4.16)
|
0.150*
|
N stage
|
0.69(0.34-1.38)
|
0.292
|
GUCY1A2
|
1.76(1.20-2.56)
|
0.004*
|
HR: Hazard Ratio, CI: confident interval
3.5 GUCY1A2 related signaling pathways identified by GSEA
We performed GSEA to found out signaling pathways which are differentially activated between low GUCY1A2 expression and high GUCY1A2 expression data sets in gastric carcinoma. Differences in enrichment of KEGG pathways (c2.cp.kegg.v7.2.symbols) were analyzed. The enriched pathways were selected according to the normalized enrichment score (NES) (Tab.4). Pathways of adherens junction, calcium signaling pathway, cell adhesion molecules cams, ECM receptor interaction, focal adhesion, MAPK signaling pathway, TGF-β signaling pathway, Wnt signaling pathway were enriched in GUCY1A2 high expression group (Fig. 4).
Table 4. Gene set enriched in HIST1H1D high phenotype
Gene Set Name
|
NES
|
NOM p-val
|
KEGG_CALCIUM_SIGNALING_PATHWAY
|
2.08
|
0.000
|
KEGG_FOCAL_ADHESION
|
2.06
|
0.002
|
KEGG_ECM_RECEPTOR_INTERACTION
|
2.23
|
0.000
|
KEGG_TGF_BETA_SIGNALING_PATHWAY
|
1.80
|
0.016
|
KEGG_MAPK_SIGNALING_PATHWAY
|
1.76
|
0.008
|
KEGG_ADHERENS_JUNCTION
|
1.68
|
0.032
|
KEGG_CELL_ADHESION_MOLECULES_CAMS
|
1.65
|
0.048
|
KEGG_WNT_SIGNALING_PATHWAY
|
1.59
|
0.038
|
NES: Normalized enrichment score; NOM: Nominal. Gene sets with NOM p-val<0.05 were considered as significant.