Clinical characteristics
TCGA provided the clinical histories of 379 patients, including age, race, Federation International of Gynecology and Obstetrics(FIGO) stage, primary therapeutic outcome, histologic grade, venous invasion, lymphatic invasion, and tumor residual, as well as Overall survival(OS), disease-specific survival(DSS), and progression-free interval(PFI) events. The details ware presented in Table 1.
Table 1
Clinical Characteristics of The EOC Patients Based on TCGA
Characteristic
|
Level
|
Low expression of MMP17(n=189)
|
High expression of MMP17(n=190)
|
FIGO stage, n (%)
|
Stage I
|
1 (0.3%)
|
0 (0%)
|
|
Stage II
|
11 (2.9%)
|
12 (3.2%)
|
|
Stage III
|
145 (38.6%)
|
150 (39.9%)
|
|
Stage IV
|
31 (8.2%)
|
26 (6.9%)
|
Primary therapy outcome, n (%)
|
PD
|
7 (2.3%)
|
20 (6.5%)
|
|
SD
|
11 (3.6%)
|
11 (3.6%)
|
|
PR
|
15 (4.9%)
|
28 (9.1%)
|
|
CR
|
125 (40.6%)
|
91 (29.5%)
|
Race, n (%)
|
Asian
|
4 (1.1%)
|
8 (2.2%)
|
|
Black or African American
|
14 (3.8%)
|
11 (3%)
|
|
White
|
166 (45.5%)
|
162 (44.4%)
|
Age, n (%)*
|
<=60
|
113 (29.8%)
|
95 (25.1%)
|
|
>60
|
76 (20.1%)
|
95 (25.1%)
|
Histologic grade, n (%)
|
G1
|
0 (0%)
|
1 (0.3%)
|
|
G2
|
22 (6%)
|
23 (6.2%)
|
|
G3
|
160 (43.4%)
|
162 (43.9%)
|
|
G4
|
1 (0.3%)
|
0 (0%)
|
Venous invasion, n (%)
|
No
|
23 (21.9%)
|
18 (17.1%)
|
|
Yes
|
29 (27.6%)
|
35 (33.3%)
|
Lymphatic invasion, n (%)
|
No
|
28 (18.8%)
|
20 (13.4%)
|
|
Yes
|
49 (32.9%)
|
52 (34.9%)
|
Tumor residual, n (%)
|
NRD
|
32 (9.6%)
|
35 (10.4%)
|
|
RD
|
131 (39.1%)
|
137 (40.9%)
|
OS event, n (%)
|
Alive
|
79 (20.8%)
|
68 (17.9%)
|
|
Dead
|
110 (29%)
|
122 (32.2%)
|
DSS event, n (%)
|
Alive
|
83 (23.4%)
|
71 (20.1%)
|
|
Dead
|
94 (26.6%)
|
106 (29.9%)
|
PFI event, n (%)
|
Alive
|
50 (13.2%)
|
52 (13.7%)
|
|
Dead
|
139 (36.7%)
|
138 (36.4%)
|
Age, meidan (IQR)
|
|
58 (50, 66)
|
60.5 (51, 71)
|
PD,progressive disease;SD,stable disease; PR,partial response; CR,complete response; RD,radical resection;IQR, interquartile range;*p < 0.05. |
Expression profiles of MMP17 in different cancers and related differentially expressed genes in EOC
Using the TCGA database, MMP17 was found to be significantly over expressed in 13 of the 33 cancer types investigated, as shown in Figure 1A. MMP17 expression was much higher in EOC patients than in pericarcinous tissues (P< 0.001, Figure 1B).
Based on median MMP17 expression in EOC, 427 OC patients were split into two groups: high- and low-MMP17 expression groups. Following that, we looked at the mRNA expression of two separate groups. Volcano plots (Figure 1C) indicated 753 mRNAs (641 upregulated and 112 downregulated) that were recognized as DEGs (absolute value of fold change >1.0, P<0.05). In addition, a heatmap was employed to depict representative DEGs (Figure 1D).
Functional annotation of MMP17 Associated differentially expressed genes in EOC
Several EOC-related pathways were enhanced, as shown in Figures 2A-C, including extracellular matrix organization (GO:0030198), skeletal system development (GO:0001501), blood vessel development (GO:0001568), and cell substrate adhesion (GO:0001568) (GO: 0031589).Furthermore, MMP17-associated DEGs were significantly enriched in cell extracellular matrix (ECM) clusters (Figures 3A–F), including extracellular matrix organization [normalized enrichment score (NES) = 2.889, adjusted P = 0.011], ECM receptor interaction (NES = 2.797, adjusted P = 0.011), ECM degradation (NES = 2.752, adjusted P = 0.011), EMC proteoglycans (NES = 2.691, adjusted P = 0.011),EMC glycoproteins (NES = 2.683, adjusted P = 0.011) and collagen degradation(NES = 2.675, adjusted P = 0.011).We also constructed a PPI network to illustrate the MMP17 served as the hub gene related to another ten genes(Figure 4).
Association of MMP17 and immune cell infiltration in EOC
The ssGSEA method was used to determine the infiltration of 24 immune cell types in EOC, and then Spearman's analysis was used to evaluate the relationship between MMP17 and immune cell infiltration. Tem(R = 0.357, P 0.001), macrophages(R = 0.333, P 0.001), and NK cells (R = 0.389, P 0.001) were all strongly linked with MMP17 expression, as shown in Figure 5A. Th17 cells (R = -0.195, P 0.001) and NK CD56bright cells (R = -0.107, P =0.037) were found to have a negative relationship with MMP17. We assessed at the levels of infiltration of the most important immune cells (Figure 5B,C) in different MMP17 groups, and the results were consistent with those in Figure 5A.
Predictive value of MMP17 for EOC diagnosis and prognosis
The evaluation of MMP17 on discriminating EOC diagnosis was demonstrated using a ROC curve. MMP17 has a high sensitivity and specificity for EOC diagnosis, with an area under the curve (AUC) of 0.988. (Figure 6A). Following that, K-M analyses were used to confirm MMP17's prediction of clinical outcomes. Overall survival (HR: 1.69, P 0.001), progression-free interval (HR: 1.42, P =0.004), and disease-specific survival (HR: 1.72, P 0.001) for high-MMP17 exprssion groups were all substantially worse than for low-MMP17 groups, as illustrated in Figures 6B–D.
We also ran a multivariate Cox regression analysis to see if MMP17 had any predictive value for clinical outcomes. In multivariate Cox regression, MMP17 expression was found to be an independent risk factor for overall survival (HR: 1.488, P 0.001), progression-free interval (HR: 1.347, P 0.01), and disease-specific survival (HR: 1.548, P 0.01), however, FIGO stage, age, and race showed no prognostic advantages for clinical outcomes,As shown in Table 2.
Each multivariate Cox regression analysis' statistically significant prognostic factors were then utilized to design a prognostic nomogram, and a calibration curve was constructed to assess the nomogram's effectiveness. FIGO stage, age, and race, as well as MMP17, were included into the nomogram to predict OS(C-index of 0.694 )(Figure 7A)], DSS(C-index of 0.701 )(Figure 7C)], and PFI(C-index of 0.653 )(Figure 7E)].The calibration curves for the three nomograms for 1-, 3-, and 5-year clinical outcomes all showed promising results, with the exception of the 3- and 5-year predictions for DSS and forecast PFI, which were lacking in data (Figures 7B,D,F)
TABLE 2
Cox regression analysis for clinical outcomes in EOC patients.
|
|
Characteristics
|
HR for overall survival (95% CI)
|
HR for progression-free interval (95% CI)
|
HR for disease-specific survival (95% CI)
|
|
|
Univariate
|
Multivariate
|
Univariate
|
Multivariate
|
Univariate
|
Multivariate
|
|
Age (>60 vs. ≤60 years)
|
1.355*
|
1.316
|
1.255
|
NA
|
1.255
|
NA
|
|
FIGO stage(I&II vs. III&IV)
|
2.115
|
2.602
|
1.573
|
1.558
|
2.276
|
2.474
|
|
Primary therapy outcome (PD&SD vs. PR&CR)
|
0.301***
|
0.317***
|
0.457 ***
|
0.507***
|
0.294***
|
0.33***
|
|
MMP17(high vs. low)
|
1.639***
|
1.488 ***
|
1.39**
|
1.347**
|
1.693***
|
1.548**
|
|
Race (White vs. Black or African American and Asian)
|
0.637
|
0.61
|
0.843
|
NA
|
0.592*
|
0.601
|
|
HR, hazard ratio; EOC, Epithelial Ovarian Caner; CI, confidence interval. *P < 0.05; **P < 0.01; ***P < 0.001.
|
|
Prognostic performance of MMP17 in EOC subgroups
The next step was to see if MMP17 had any prognostic value for clinical outcomes in a variety of clinicopathological categories. In certain subgroups, we ran Cox regression analysis, and the results were shown as forest plots (Figure 8). In patients with tumor (HR = 1.76, P = 0.000), FIGO stage III-IV (HR =1.72, P = 0.000), histology G3-4 (HR = 1.77, P = 0.000), and tumor residual (HR = 1.60, P = 0.001), MMP17 was a significant risk factor for overall survival(Figure 8A). Figure 8B shows similar findings for disease-specific survival and progression-free intervals (Figure 8C). MMP17 was also found to be an independent risk factor for all ages and anatomic subdivisions.
In addition, we reported K-M analyses for clinical outcomes (overall survival, progression-free interval, and disease-specific survival) in four representative subgroups: age under 60, tumor status, and anatomic neoplasm subdivision (Figure 9). All of these findings showed that the low-MMP17 expression groups had considerably superior clinical outcomes.