SPI1-Mediated Upregulation of the CST1 Gene as an Independent Poor Prognostic Factor Accelerates Metastasis in Esophageal Squamous Cell Carcinoma (ESCC) by Interacting with MMP2.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is a highly lethal tumor type, but studies on the ESCC tumor microenvironment are limited. We found that cystatin SN (CST1) plays an important role in the ESCC tumor microenvironment. CST1 has been reported to act as an oncogene in multiple human cancers, but its clinical significance and underlying mechanism in ESCC remain elusive. METHODS: We performed ESCC gene expression profiling with data from RNA-sequencing and public databases and found CST1 upregulation in ESCC. Then, we assessed CST1 expression in ESCC by RT‒qPCR and Western blot analysis. In addition, immunohistochemistry (IHC) and enzyme-linked immunosorbent assay (ELISA) were used to estimate the expression of CST1 in ESCC tissue and serum. Moreover, further functional experiments were conducted to verify that the gain and loss of CST1 in ESCC cell lines significantly influenced the proliferation and metastasis of ESCC. Mass spectrometry, coimmunoprecipitation, and gelatin zymography experiments were used to validate the interaction between CST1 and matrix metalloproteinase 2 (MMP2) and the mechanism of CST1 influence on metastasis in ESCC. RESULTS: Here, we found that CST1 expression was significantly elevated in ESCC tissues and serum. Moreover, compared with patients with low CST1 expression, patients with high CST1 expression had a worse prognosis. Overall survival (OS) and disease-free survival (DFS) were significantly unfavorable in the high CST1 expression subgroup. Likewise, the CST1 level was significantly increased in ESCC serum compared with healthy control serum, indicating that CST1 may be a potential serum biomarker for diagnosis, with an area under the curve (AUC) = 0.9702 and p < 0.0001 by receiver operating curve (ROC) analysis. Furthermore, upregulated CST1 can promote the motility and metastatic capacity of ESCC in vitro and in vivo by influencing epithelial mesenchymal transition (EMT) and interacting with MMP2 in the tumor microenvironment (TME). CONCLUSIONS: Collectively, the results of this study indicated that high CST1 expression mediated by SPI1 in ESCC may serve as a potentially prognostic and diagnostic predictor and as an oncogene to promote motility and metastatic capacity of ESCC by influencing EMT and interacting with MMP2 in the TME.

EXOC3L1: A Novel Prognostic Biomarker Correlated with Immune Infiltration in Esophageal Squamous Cell Carcinoma.

BACKGROUND Exocyst complex component 3-like 1 (EXOC3L1) is ubiquitously present in multiple organs. However, its role in esophageal squamous cell carcinoma (ESCC) remains unknown. The aim of this study was to explore the relationship between EXOC3L1 and ESCC. MATERIAL AND METHODS A total of 652 normal samples and 82 ESCC samples obtained from the University of California Santa Cruz (UCSC) Xena were applied to detect the expression difference of EXOC3L1. GSE53625 with 179 paired samples and GSE161533 with 28 paired samples were used for validation. The correlation between clinicopathological features and EXOC3L1 expression was calculated. Kaplan-Meier method was employed to assess the prognostic value of EXOC3L1 in ESCC. Univariate and multivariate Cox regression analyses were carried out to screen the factors contributing to the prognosis of ESCC. In addition, functional enrichment analysis, protein-protein interaction (PPI) network analysis, and immune infiltration analysis were conducted to identify the significantly involved functions of EXOC3L1. RESULTS EXOC3L1 was significantly overexpressed in ESCC compared to normal samples. High expression of EXOC3L1 was associated with worse prognosis, and univariate and multivariate Cox regression analysis demonstrated that EXOC3L1 was an independent prognostic predictor of ESCC. Functional enrichment analysis and immune infiltration analysis disclosed that the expression of EXOC3L1 was correlated with the abundance of several types of immune cells. CONCLUSIONS EXOC3L1 plays a crucial role in the prognosis of ESCC, and it may serve as a reliable biomarker for predicting the survival and a potential therapeutic target for ESCC.

A comprehensive prognostic and immune infiltration analysis of EXOC3L1 in pan-cancer.

Exocyst complex component 3 like 1 (EXOC3L1) is widely present in various human tissues, which mainly regulates insulin secretion. However, its roles in tumors remain unclear. In the present study, we aimed to investigate the roles of EXOC3L1 in pan-cancer, and the data was downloaded from of the University of California Santa Cruz (UCSC) Xena and the Cancer Genome Atlas (TCGA). The expression status of EXOC3L1 was studied in the TCGA_GTEx samples, TCGA samples and paired samples in TCGA, respectively. Subsequently, Kaplan-Meier analysis was applied to 33 kinds of tumors in TCGA, among the cancers that EXOC3L1 can affect prognosis, clinical correlation analysis and univariate Cox regression analysis were performed. Furthermore, representative cancers kidney renal clear cell carcinoma (KIRC) and lung squamous cell carcinoma (LUSC) with a sample size larger than 500 were selected to construct nomogram models to confirm the prognostic value of EXOC3L1 in cancers. Additionally, the associations of EXOC3L1 with immune cell infiltrations were performed as well. Mechanistically, functional enrichment analysis was performed to explore potential signaling pathways that EXOC3L1 may involve in. Our study found that EXOC3L1 was differentially expressed in a variety of tumors and was associated with the clinical outcomes and immune microenvironment of several tumors, it may affect the occurrence and development of tumors through NOTCH signaling pathway, PI3K-AKT signaling pathway and immune-related pathways. In conclusion, we propose that EXOC3L1 may serve as a potential prognostic biomarker and a promising target for cancer immunotherapy in a variety of cancers.

A novel pyroptosis scoring model was associated with the prognosis and immune microenvironment of esophageal squamous cell carcinoma.

The phenotype of pyroptosis has been extensively studied in a variety of tumors, but the relationship between pyroptosis and esophageal squamous cell carcinoma (ESCC) remains unclear. Here, 22 pyroptosis genes were downloaded from the website of Gene Set Enrichment Analysis (GSEA), 79 esophageal squamous cell carcinoma samples and GSE53625 containing 179 pairs of esophageal squamous cell carcinoma samples were collected from the Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO), respectively. Then, pyroptosis subtypes of esophageal squamous cell carcinoma were obtained by cluster analysis according to the expression difference of pyroptosis genes, and a pyroptosis scoring model was constructed by the pyroptosis-related genes screened from different pyroptosis subtypes. Time-dependent receiver operator characteristic (timeROC) curves and the area under the curve (AUC) values were used to evaluate the prognostic predictive accuracy of the pyroptosis scoring model. Kaplan-Meier method with log-rank test were conducted to analyze the impact of the pyroptosis scoring model on overall survival (OS) of patients with esophageal squamous cell carcinoma. Nomogram models and calibration curves were used to further confirm the effect of the pyroptosis scoring model on prognosis. Meanwhile, CIBERSORTx and ESTIMATE algorithm were applied to calculate the influence of the pyroptosis scoring model on esophageal squamous cell carcinoma immune microenvironment. Our findings revealed that the pyroptosis scoring model established by the pyroptosis-related genes was associated with the prognosis and immune microenvironment of esophageal squamous cell carcinoma, which can be used as a biomarker to predict the prognosis and act as a potential target for the treatment of esophageal squamous cell carcinoma.

AKR1C2 acts as a targetable oncogene in esophageal squamous cell carcinoma via activating PI3K/AKT signaling pathway.

The aldo-keto reductases family 1 member C2 (AKR1C2) has critical roles in the tumorigenesis and progression of malignant tumours. However, it was also discovered to have ambiguous functions in multiple cancers and till present, its clinical significance and molecular mechanism in oesophageal squamous cell carcinoma (ESCC) has been unclear. The aim of this study was to explore the role of AKR1C2 in the tumorigenesis of ESCC. Here, we showed that AKR1C2 expression was found to be up-regulated in ESCC tissues and was significantly associated with pathological stage, lymph node metastasis and worse outcomes. Functional assays demonstrated that an ectopic expression of AKR1C2 in ESCC cells resulted in increased proliferation, migration and cisplatin resistance, while knockdown led to inversing effects. Bioinformation analyses and mechanistic studies demonstrated that AKR1C2 activated the PI3K/AKT signalling pathway, furthermore, the inhibitor of PI3K or the selective inhibitor of AKR1C2 enzyme activity could reverse the aggressiveness and showed synergistic antitumour effect when combined with cisplatin, both in vitro and in vivo. In conclusion, Our findings revealed that AKR1C2 could function as an oncogene by activating the PI3K/AKT pathway, as a novel prognostic biomarker and/or as a potential therapeutic target to ESCC.