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Dysregulated expression of S100A7 is found in several cancers and plays an important role in tumor progression; however, its carcinogenic role in esophageal squamous carcinoma (ESCC) is still poorly understood. Here, we identified that the levels of S100A7 were remarkably upregulated in 341 tumor tissues (P <.001) and 274 serum samples (P <.001) of ESCC patients compared with normal control. It was an independent prognostic factor (P =.026). Furthermore, a new diagnostic model for ESCC based on serum S100A7, SCC, and crfra21‐1 was established with area under curve (AUC) up to 0.863 (95% CI: 0.802‐0.925). Mechanically, we found upregulated S100A7 could promote cell migration and proliferation through intracellular binding to JAB1 and paracrine interaction with RAGE receptors and then activates the downstream signaling pathways. In addition, exocrine S100A7 could promote M2 macrophage infiltration and polarization by up‐regulating M2 macrophage associated proteins, and tumor angiogenesis by enhancing the activation of p‐ErK and p‐FAK pathways. Further animal experiments confirmed the role of S100A7 in promoting M2 macrophage infiltration and angiogenesis in ESCC. In conclusion, these findings highlighted the potential diagnostic and prognostic value of S100A7 in patients with ESCC. Meanwhile, our results reveal that S100A7 promotes tumor progression by activating oncogenic pathways and remodeling tumor microenvironment, which paving the way for the progress of S100A7 as a therapeutic target for cancer treatment. [ABSTRACT FROM AUTHOR]

Alternative splicing (AS), a major mechanism for the enhancement of transcriptome and proteome diversity, has been widely demonstrated to be involved in the full spectrum of oncogenic processes. High-throughput sequencing technology and the rapid accumulation of clinical data sets have provided an opportunity to systemically analyze the association between messenger RNA AS variants and patient clinical outcomes. Here, we compared differentially spliced AS transcripts between esophageal carcinoma (ESCA) and non-tumor tissues, profiled genome-wide survival-associated AS events in 87 patients with esophageal adenocarcinoma (EAC) and 79 patients with esophageal squamous cell carcinoma (ESCC) using The Cancer Genome Atlas (TCGA) RNA-seq data set, and constructed predictive models as well as splicing regulation networks by integrated bioinformatic analysis. A total of 2326 AS events in 1738 genes and 1812 AS events in 1360 genes were determined to be significantly associated with overall survival (OS) of patients in the EAC and ESCC cohorts, respectively, including some essential participants in the oncogenic process. The predictive model of each splice type performed reasonably well in distinguishing good and poor outcomes of patients with esophageal cancer, and values for the area under curve reached 0.942 and 0.815 in the EAC exon skip predictive model and the ESCC alternate acceptor site predictive model, respectively. The splicing regulation networks revealed an interesting correlation between survival-associated splicing factors and prognostic AS genes. In summary, we created prognostic models for patients with esophageal cancer based on AS signatures and constructed novel splicing correlation networks. [ABSTRACT FROM AUTHOR]

Abstract: The long non‐coding RNA GAS5 has been reported as a tumor suppressor in many cancers. However, its functions and mechanisms remain largely unknown in esophageal squamous cell carcinoma (ESCC). In this study, we found that GAS5 was over‐expressed in ESCC tissue compared with that in normal esophageal tissue in a public database. Functional studies showed that GAS5 could inhibit ESCC cell proliferation, migration and invasion in vitro. Further analysis revealed that GAS5 was regulated by interferon (IFN) responses via the JAK‐STAT pathway. Moreover, as an IFN‐stimulated gene (ISG), GAS5 was a positive regulator of IFN responses. The feedback loop between GAS5 and the IFN signaling pathway plays an important antitumor role in ESCC, thus providing novel potential therapeutic targets. [ABSTRACT FROM AUTHOR]

Abstract: The transforming growth factor β (TGF-β) signaling pathway plays anti- and pro-tumoral roles in the vast majority of cancers, and long noncoding RNAs have been reported to play key roles in the highly contextual response process. However, the roles of long noncoding RNAs (lncRNAs) in TGF-β signaling in esophageal squamous cell carcinoma (ESCC) remain unknown. In this study, we performed RNA-seq to compare lncRNAs expression levels between TGF-β1-treated and untreated ESCC cells and observed that NF-kappaB-interacting lncRNA (NKILA) was remarkably upregulated by the classical TGF-β signaling pathway. RNA profiling of 39 pairs ESCC tumor and adjacent nontumor samples using RT-qPCR demonstrated that NKILA is significantly downregulated in ESCC tumor tissues, and NKILA expression levels were significantly decreased in advanced tumor tissues (III and IV) compared to early stages (I and II) (p < 0.01). Gain- and loss-of-function assays showed that NKILA inhibited ESCC cell metastasis in vitro and in vivo, and mechanism studies showed that NKILA repressed MMP14 expression by inhibiting IκBα phosphorylation and NF-κB activation. Collectively, these findings suggest that the TGF-β-induced lncRNA NKILA has potential as an antimetastasis therapy.Key messages: Long noncoding RNA NKILA could be remarkably upregulated by classical TGF-β signal pathway in ESCC.NKILA was significantly downregulated in esophageal squamous cell carcinoma and negatively correlated with TNM stage.NKILA inhibits ESCC cell metastasis via repressing MMP14 expression by suppressing the phosphorylation of IκBα and NF-κB activation. [ABSTRACT FROM AUTHOR]

Understanding interactions between tumor and the host immune system holds great promise to uncover biomarkers for targeted therapies and clinical outcomes. However, systematical analysis of immune signatures in esophageal squamous cell carcinoma (ESCC) remains largely unstudied. In this study, immune signatures containing 708 immune related genes were curated from mRNA microarray data with tumor and paired normal tissues from 119 ESCC patients. Differential expression and survival analysis were performed with validations from Human Protein Atlas and an independent cohort of 110 ESCC patients by immunohistochemistry staining. We identified a total of 186 significantly dysregulated genes in ESCC, including downregulated genes SPINK5, IL1RN and upregulated genes SPP1 and PLAU, which were further confirmed in Human Protein Atlas data. Moreover, nine immune related genes (ABL1, ATF2, ATG5, C6, CD38, HMGB1, ICOSLG, IL12RB2 and PLAU) were significantly associated with patients' overall survival, among which, prognostic model was built including three independent factors ABL1, CD38 and ICOSLG. Validation by immunohistochemistry staining suggested that combination with tumor infiltrated CD4+ and CD8+ T lymphocytes would yield higher performance in distinguishing cases as high or low risk of unfavorable prognosis. In summary, we profiled the immune status in ESCC and established predictive and prognostic factors for ESCC, which could reflect immune disorders within tumor microenvironments and independently distinguish patients with a high risk of reduced survival, providing novel predictive and therapeutic targets for ESCC patients in the future. [ABSTRACT FROM PUBLISHER]

Interferons (IFNs) play crucial roles in the development and treatment of cancer. Long non-coding RNAs (lncRNAs) are emerging molecules involved in cancer progression. Here, we identified and characterized an IFN-inducible nuclear lncRNA IRF1-AS (Interferon Regulatory Factor 1 Antisense RNA) which was positively correlated with IRF1 expression. IFNs upregulate IRF1-AS via the JAK-STAT pathway. Knockdown and overexpression of IRF1-AS revealed that IRF1-AS inhibits oesophageal squamous cell carcinoma (ESCC) proliferation and promotes apoptosis in vitro and in vivo. Mechanistically, IRF1-AS activates IRF1 (Interferon Regulatory Factor 1) transcription through interacting with ILF3 (Interleukin Enhancer Binding Factor 3) and DHX9 (DExH-Box Helicase 9). In turn, IRF1 binds to the IRF1-AS promoter directly and activates IRF1-AS transcription. Global analysis of IRF1-AS-regulated genes indicated that IRF1-AS activates the IFN response in vitro and in vivo. IRF1 knockdown in IRF1-AS-overexpressing cells abolished the antiproliferative effect and activation of the IFN response. Furthermore, IRF1-AS was downregulated in ESCC tissues, and low expression correlated with poor prognosis. In conclusion, the interferon-inducible lncRNA IRF1-AS represses esophageal squamous cell carcinoma progression by promoting interferon response through a positive regulatory loop with IRF1. [ABSTRACT FROM AUTHOR]