In China, endometrial cancer is a common reproductive system tumor, and the main treatment methods are surgical resection, chemotherapy and radiotherapy. Although most early-stage endometrial cancers can be cured, there is still a lack of effective treatment methods for locally advanced and progressive endometrial cancer, especially effective molecular diagnosis and molecular therapy. Therefore, exploring the molecular mechanisms involved in the occurrence and development of endometrial cancer is of great significance. In this study, we used WGCNA to screen potential hub genes related to the prognosis and immunotherapy of UCEC.
A total of 5476 differentially expressed gene, 13 modules and 16 candidate genes identified by WGCNA analysis. Among the 16 candidates genes, AURKA, CCNE1, IQGAP3, TTK and UBE2C were significantly associated with poor prognosis. Therefore, we defined the AURKA, CCNE1, IQGAP3, TTK and UBE2C genes as "final" hub genes.
Aurora kinase A (AURKA) is a member of the serine/threonine kinase family whose activation is required for the process of cell division by regulating mitosis. based on the TCGA database, the expression of AURKA was significantly higher in cancer samples than in normal control samples. AURKA may promotes tumorigenesis via cell proliferation, epithelial-mesenchymal transition (EMT), metastasis, apoptosis and self-renewal of cancer stem cells [18]. AURKA may play a role in impaired cell viability and enhanced apoptosis in UCEC [19]. Further research found that AURKA inhibitor Alisertib may treat UCEC, revealing that AURKA is a promising therapeutic target [20]. Liu found that AURKA is highly expressed in HCC and predicted 8 AURKA-related genes with prognostic value, and then successfully constructed a gene signature. These gene signatures are associated with immune cell infiltration and immune checkpoints shown potential therapeutic point in HCC patients [21].
Interestingly, although this study and Yuan's study [20] analyzed different TCGA data using similar methods and tools, AURKA was screened and identified consistently as a key gene for predicting prognosis in UCEC. This study found that the expression of AURKA was significantly negatively correlated with immune infiltration, T cells regulatory (Tregs) and Dendritic cells resting in UCEC. HMGB1, CD40LG, TNFSF9, ICOS, CD28, CD40, IL2, CCL5, CD80, CXCL10, TNFRSF4 and TNFSF4 may be the stimulatory immune checkpoints of AURKA in UCEC. And EDNRB, C10ORF54, VEGFB, VTCN1, IL13, KIR2DL1, CTLA4 and TGFB1 may be the inhibitory immune checkpoint of AURKA in UCEC.
CCNE1 is a member of the highly conserved cyclin family. In CCNE1-overexpressing tumor cells, aberrant p53 further lost control of the G1-S checkpoint, increasing the dependence on S phase and, more importantly, survival dependence on the G2-M cell cycle checkpoint [22–24]. CCNE1 is an oncogene in many tumors, and its elevated expression was further found to be associated with poor outcomes and platinum resistance [25–27]. In this study, CCNE1 expression was negatively correlated with T cells CD4 memory resting and Neutrophils, but positively correlated with B cells memory and Macrophages M0 in UCEC. HMGB1, CX3CL1, TLR4, ICOS, CD27, BTN3A1, BTN3A2, PRF1, CCL5, TNFRSF9, ICAM1 and IFNA1/2 may be the stimulatory immune checkpoints of CCNE1. And EDNRB, CD276, ADORA2A, IL12A, IL4, KIR2DL1, IL10, SLAMF7, TGFB1, TIGIT and IDO1 may be the inhibitory immune checkpoint of CCNE1 in UCEC.
The protein encoded by IQGAP3 belong to the Rho family, which play critical roles in the development and progression of several cancers. Studies have found that the expression of IQGAP3 is increased in high-grade serous ovarian cancer, and the proliferation, migration and invasion of ovarian cancer cell are inhibited when IQGAP3 is silenced [28]. Interestingly, high expression of IQGAP3 appears to be associated with tumor mutational burden, microsatellite instability, immune cell infiltration, and immunomodulatory agents, with integral roles in the progression and immune response of various human cancers [29]. IQGAP3 expression was negatively correlated with Dendritic cells resting, but positively correlated with B cells naive. HMGB1, ICOSLG, TNFSF9, ICOS, CD28, CD40, BTN3A1/2, IL2, CCL5, TNFRSF9, IL2RA, CXCL9, INF and IFNA2 may be the stimulatory immune checkpoints of IQGAP3. And C10ORF54, CD276, VEGFB, IL4, KIR2DL3, IL10, TIGIT, BTLA and IDO1 may be the inhibitory immune checkpoint of IQGAP3 in UCEC.
TTK encodes a dual-specificity protein kinase that is involved in cell proliferation. The expression of TTK promotes cell proliferation, migration and invasion, suggesting that TTK may be an oncogene [30–31]. Inhibition of TTK expression caused chromosomal missegregation and tumor cell death, conversely, HER2-positive breast and hepatocellular carcinomas were associated with poor prognosis after overexpression of TTK [32–33]. The abnormal expression of TTK is involved in breast cancer cell cycle pathway, DNA replication pathway, and P53 signaling pathway [34]. TTK expression was also negatively correlated with T cells CD8. HMGB1, SELP, CD70, CD28, ICOS, BTN3A2, GZMA, CCL5, IL2RA, CXCL9, IL1A and IFNA1/2 may be the stimulatory immune checkpoints of IQGAP3. And EDNRB, VEGFA, PDCD1, IL13, KIR2DL3 and SLAMF7 may be the inhibitory immune checkpoint of TTK in UCEC.
UBE2C (ubiquitin-conjugating enzyme E2C) encodes a protein that is associated with diseases such as methotrexate-associated lymphoid hyperplasia and complement component 7 deficiency. Gene Ontology (GO) annotations reveals that the main functions of UBE2C are ligase activity and ubiquitin protein ligase binding [35]. The abnormal expression of UBE2C gene has a clear relationship with the prognosis, clinical features, immunity, methylation of pan-cancer, suggest that UBE2C-encoded protein may contribute to cancer progression [36]. Overexpression of UBE2C is associated with breast cancer recurrence and is involved in estrogen-dependent/independent proliferation in early HR+/HER2- breast cancer [37]. UBE2C expression was negatively correlated with T cells CD4 memory resting, Dendritic cells resting and Neutrophils, but positively correlated with Macrophages M0. HMGB1, CD40LG, SELP, ENTPD1, TLR4, ICOSLG, CD40 and IL1A/B may be the stimulatory immune checkpoints of UBE2C. And CD276, LAG3, VEGFA/B, IL12A, IL4 and CTLA4 may be the inhibitory immune checkpoint of UBE2C in UCEC.