Comprehensive bioinformatics analysis of co-mutation of FLG2 and TP53 reveals prognostic effect and influences on the immune infiltration in ovarian serous cystadenocarcinoma

Abstract

Background: Ovarian cancer remains one of the most lethal gynecological malignancies, characterized by late-stage diagnosis and high rates of recurrence. The present study aims to explore the prognostic and immunological implications of FLG2 and TP53, the two genes exhibiting a high mutation frequency across various cancer types, in the context of ovarian serous cystadenocarcinoma (OV).

Methods: The study systematically analyzed and discussed the potential implications of co-mutation of FLG2 and TP53 on prognosis and immune response using a cohort of 585 ovarian cancer samples. The differentially expressed genes (DEGs) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed on 300 ovarian cancer samples with RNA sequencing (RNA-seq) data.

Results: The co-mutation of FLG2 and TP53 was identified in the 585 ovarian cancer cohort, and the group with co-mutation exhibited improved outcomes in terms of overall survival (OS), progression-free survival (PFS), and disease-specific survival (DSS). Additionally, the co-mutation (FLG2 ⁺/TP53 ⁺) group demonstrated higher scores in tumor mutation burden (TMB) comparing to that of the other three groups. The score of microsatellite instability (MSI) in the co-mutant group was only higher than that of the co-wild-type (FLG2 ^-/TP53 ^-). A total of 327 DEGs were identified in both the co-mutation and non-co-mutation (NCM) groups using limma analysis in the subgroup of 300 patients with RNA-seq data. Subsequent KEGG analysis revealed that these DEGs were implicated in various biological processes, including thermogenesis, Parkinson's disease (PD), and oxidative phosphorylation signaling pathways. Additionally, the co-mutation group exhibited elevated levels of various immune cells. Furthermore, a nomogram with high predictive accuracy was developed by integrating co-mutation status with clinical characteristics.

Conclusions: In the context of OV, the concurrent mutation of FLG2 and TP53 not only induces immune activation, but also helps identify a subset of patients with a more favorable prognosis.

Keywords: FLG2/TP53; Ovarian serous cystadenocarcinoma (OV); co-mutation; immune infiltration; prognosis.

Figure 1

The mutational landscape in 585 OV patients. (A) Waterfall chart for genetic mutation analysis. (B,C) Mutation diagram of TP53 and FLG2 across protein domains. #, numbers; OV, ovarian serous cystadenocarcinoma.

Figure 2

Analysis of the survival status of the OV samples. (A-C) Analysis of TP53 gene mutation on OS, PFS, and DSS. (D-F) Kaplan-Meier survival curves were established by FLG2 mutation on OS, PFS, and DSS. (G-I) The survival curve of pairwise comparison of four groups (FLG2⁺/TP53⁺, FLG2⁺/TP53⁻, FLG2⁻/TP53⁺, FLG2⁻/TP53⁻) in OS, PFS, DSS. (J-L) The survival curve of comparison of co-mutation group and NCM group in OS, PFS, DSS. *, P<0.05; **, P<0.01; ***, P<0.001. FLG2⁺/TP53⁺, group of patients with FLG2 and TP53 mutation; FLG2⁺/TP53⁻, group of patients with FLG2 mutation and TP53 wild-type; FLG2⁻/TP53⁺, group of patients with FLG2 wild-type and TP53 mutation; FLG2⁻/TP53⁻, group of patients with FLG2 and TP53 wild-type. NCM, non-co-mutation; OV, ovarian serous cystadenocarcinoma; OS, overall survival; PFS, progression-free survival; DSS, disease-specific survival.

Figure 3

The correlation between FLG2/TP53 mutation status and TMB and MSI. (A) The comparison of TMB between TP53- and FLG2-mutated groups. (B,C) FLG2/TP53 mutation status was correlated in TMB of four groups (B) and two groups (C). (D-F) The survival curve between high- and low-TMB in terms of co-mutation samples, NCM samples, and all samples. (G,H) The analysis of FLG2/TP53 mutation status MSI between four and two groups. (I) Comparison of prognosis between high and low MSI of co-mutation samples. ***, P<0.001; ****, P<0.0001; ns, no significance. FLG2⁺/TP53⁺, group of patients with FLG2 and TP53 mutation; FLG2⁺/TP53⁻, group of patients with FLG2 mutation and TP53 wild-type; FLG2⁻/TP53⁺, group of patients with FLG2 wild-type and TP53 mutation; FLG2⁻/TP53⁻, group of patients with FLG2 and TP53 wild-type. TMB, tumor mutation burden; NCM, non-co-mutation; L, low; H, high; MSI, microsatellite instability.

Figure 4

DEGs analysis between the group of co-mutation and the NCM in 300 RNA-seq OV samples. (A) Volcano plot showing DEGs. (B) Heatmap of DEGs between co-mutation and NCM groups. (C) GO/KEGG enrichment analyses based on DEGs. (D) Heatmap depicts consensus clustering solution (k=2) for 327 DEGs in OV samples. (E) PCA analysis of cluster 1 and 2. (F) Kaplan-Meier curves of OS in two clusters. NCM, non-co-mutation; CC, cellular component; KEGG, Kyoto Encyclopedia of Genes and Genomes; C1, cluster 1; C2, cluster 2; PCA, principal component analysis; DEGs, differential expressed genes; RNA-seq, RNA sequencing; OV, ovarian serous cystadenocarcinoma; GO, Gene Ontology; OS, overall survival.

Figure 5

The analysis of immune characteristics between the group of co-mutation and the NCM. (A) The analysis of immune cell proportions in 300 OV samples. (B) The correlation between 22 immune cells. (C,D) The correlation between the co-mutation and NCM in immune cells (C), and immunomodulatory genes (D). *, P<0.05; **, P<0.01; ***, P<0.001; ****, P<0.0001; –, no significance. NCM, non-co-mutation; OV, ovarian serous cystadenocarcinoma.

Figure 6

Relationship between FLG2/TP53 mutation status and other clinical information. (A) Nomogram for predicting the probability of 1-, 3-, and 5-year OS for OV patients. (B) Calibration plot of the nomogram for predicting the probability of OS at 1, 3, and 5 years. (C) Kaplan-Meier curves of OS in nomogram risk score. (D) Time-dependent ROC curve analyses of the nomogram model. (E-G) DCA in 1-, 3-, and 5-year OS. FLG2⁺/TP53⁺, group of patients with FLG2 and TP53 mutation; FLG2⁺/TP53⁻, group of patients with FLG2 mutation and TP53 wild-type; FLG2⁻/TP53⁺, group of patients with FLG2 wild-type and TP53 mutation; FLG2⁻/TP53⁻, group of patients with FLG2 and TP53 wild-type. TMB, tumor mutation burden; L, low; H, high; AUC, area under the curve; CI, confidence interval; OS, overall survival; OV, ovarian serous cystadenocarcinoma; ROC, receiver operating characteristic curve; DCA, decision curve analysis.