Esophageal Squamous Cell Carcinoma Tumor Research Articles

A novel amino acid metabolism-related gene signature to predict the overall survival of esophageal squamous cell carcinoma patients.

Esophageal squamous cell carcinoma (ESCC) has a poor early detection rate, prognosis, and survival rate. Effective prognostic markers are urgently needed to assist in the prediction of ESCC treatment outcomes. There is accumulating evidence of a strong relationship between cancer cell growth and amino acid metabolism. This study aims to determine the relationship between amino acid metabolism and ESCC prognosis. This study comprehensively evaluates the association between amino acid metabolism-related gene (AAMRG) expression profiles and the prognosis of ESCC patients based on data from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to verify the expression of prognosis-related genes. A univariate Cox regression analysis of TCGA data identified 18 prognosis-related AAMRGs. The gene expression profiles of 90 ESCC tumor and normal tissues were obtained from the GSE20347 and GSE67269 datasets. Two differently expressed genes (DEGs) were considered as ESCC prognosis-related genes; and they were branched-chain amino acid transaminase 1 (BCAT1) and methylmalonic aciduria and homocystinuria type C protein (MMACHC). These two AAMRGs were used to develop a novel AAMRG-related gene signature to predict 1- and 2-year prognostic risk in ESCC patients. Both BCAT1 and MMACHC expression were verified by RT-qPCR. A prognostic nomogram that incorporated clinical factors and BCAT1 and MMACHC gene expression was constructed, and the calibration plots showed that it had good prognostic performance. The AAMRG signature established in our study is efficient and could be used in clinical settings to predict the early prognosis of ESCC patients.

Prognostic prediction and diagnostic role of Rspondin 1 expression in esophageal squamous cell carcinoma.

Rspondin 1 (Rspo1), a protein family member featuring secreted furin-like domains, plays a pivotal role in cancer development and exhibits a positive correlation with tumor progression. However, its expression in esophageal squamous cell carcinoma (ESCC) is still unknown. Here, we assessed the correlation between Rspo1 and clinicopathological features of ESCC patients, and further investigated the potential role of Rspo1 in ESCC development and clinical outcomes. This was a pilot study. A total of 112 paraffin-embedded tumor samples from patients with ESCC, including 68 matched adjacent normal tissues, were collected post-surgery. Subsequently, tissue microarray (TMA) and immunohistochemistry (IHC) techniques were employed to assess the protein levels of Rspo1. All statistical analyses were performed with SPSS 20.0 (SPSS, Inc., Chicago, IL). We found that Rspo1 expression was significantly higher in ESCC than in adjacent normal tissues (P < 0.0001). Moreover, Rspo1 was highly expressed in ESCC tumor specimens and showed a significant correlation with the T classification of ESCC (P < 0.05). Additionally, our findings indicate a positive relationship between Rspo1 and survival time in ESCC. Patients exhibiting moderate to high levels of Rspo1 expression demonstrated superior survival outcomes compared to those with low expression (P = 0.0002). Our investigation has demonstrated that Rspo1 is upregulated in ESCC and exhibits a positive correlation with disease progression. Furthermore, we have observed a significant association between Rspo1 overexpression and improved patient survival rates, indicating its potential as a prognostic marker and therapeutic target for ESCC treatment.

CD24 promotes metastasis and chemoresistance by directly targeting Arf6-ERK pathway in esophageal squamous cell carcinoma

Increasing evidence suggests the importance of CD24 in tumor progression, but its role and mechanism in esophageal squamous cell carcinoma (ESCC) remain unclear. The present study aims to explore the potential of CD24 as a novel predictive biomarker in ESCC, as well as its mechanism and therapeutic implications in metastasis and 5-FU chemoresistance. By using tissue microarray and immunohistochemistry, we found that CD24 expression was higher in ESCC tumor tissues than paired non-tumor tissues, further indicating that CD24 was markedly associated with poor prognosis. CD24 significantly promoted metastasis and 5-FU chemoresistance in vitro and in vivo. Mechanistically, CD24 competes with GIT2 to bind to Arf6, and stabilizes Arf6-GTP to activate the subsequent ERK pathway, thus promoting cancer progression. In addition, a significant positive correlation between CD24 and p-ERK was observed in clinical ESCC tissues. In summary, this study not only reveals CD24 as a regulatory factor for Arf6 activity, but also uncovers CD24-Arf6-ERK signaling axis as a novel mechanism of ESCC progression. Our findings suggest CD24 as a promising biomarker and therapeutic target in ESCC.

Nur77-IRF1 axis inhibits esophageal squamous cell carcinoma growth and improves anti-PD-1 treatment efficacy

The nuclear receptor Nur77 plays paradoxical roles in numerous cancers. However, whether Nur77 inhibits esophageal squamous cell carcinoma (ESCC) growth and affects immunological responses against ESCC has not been determined. The functional role of Nur77 in ESCC was investigated in this study using human ESCC cell lines, quantitative real-time polymerase chain reaction (PCR), cell proliferation and colony formation assays, flow cytometry analysis, western blotting and animal models. The target gene controlled by Nur77 was verified using dual-luciferase reporter assays, chromatin immunoprecipitation analysis and functional rescue experiments. To examine the clinical importance of Nur77, 72 human primary ESCC tissues were subjected to immunohistochemistry. Taken together, these findings showed that, both in vitro and in vivo, Nur77 dramatically reduced ESCC cell growth and triggered apoptosis. Nur77 directly interacts with the interferon regulatory factor 1 (IRF1) promoter to inhibit its activity in ESCC. Pharmacological induction of Nur77 using cytosporone B (CsnB) inhibited ESCC cell proliferation and promoted apoptosis both in vitro and in vivo. Furthermore, CsnB increased CD8+ T-cell infiltration and cytotoxicity to inhibit the formation of ESCC tumors in an immunocompetent mouse model. In ESCC tissues, Nur77 expression was downregulated, and IRF1 expression was increased; moreover, their expression levels were negatively related. IRF1 and Nur77 were strongly correlated with overall survival. These findings suggested that Nur77 targets and regulates the IRF1/PD-L1 axis to serve as a tumor suppressor in ESCC.Graphical abstract of the regulatory mechanism of Nur77 overexpression downregulates IRF1 in the inhibition of ESCC progression and enhance anti-PD-1 therapy efficacy.

Circ_0000592 facilitates the progression of esophageal squamous cell carcinoma via miR-155-5p/FZD5 axis.

Esophageal squamous cell carcinoma (ESCC) is one of the gastrointestinal malignancies with high prevalence and poor prognosis. Previous reports suggested that circular ribose nucleic acidsmight exert regulatory functions in ESCC. This study aims to explore the role of circ_0000592 in ESCC progression, providing novel insights into the diagnosis and therapeutic avenues for ESCC. The GSE131969 data set was utilized to assess circ_0000592 expression in ESCC. The validation was performed in the tumorous tissues of ESCC patients (n = 80) and human-immortalized ESCC cell lines. The correlation between circ_0000592 expression and prognosis was analyzed. The impact of circ_0000592 on ESCC cell activity was evaluated through downregulating circ_0000592, as well as encompassing cell viability, migration, and invasion abilities. The downstream pathway of circ_0000592 was explored by binding site prediction from the TargetScan database, followed by in vitro and in vivo experiments. An in vivo xenograft tumor model was established to highlight the role of circ_0000592 in ESCC. Patients with ESCC exhibited higher circ_0000592 expression levels compared to noncancerous patients, which were associated with reduced survival time, higher TNM stage, and increased lymph node metastasis. The circ_0000592 downregulation suppressed cell viability, migration, and invasion abilities in vitro. Mechanistically, circ_0000592 countered the inhibitory effects on the target gene Frizzled 5 (FZD5) through interactions with miR-155-5p. The overexpression of miR-155-5p curtailed the luciferase activity of circ_0000592 in ESCC cells, inhibiting downstream molecule FZD5 protein expression and subsequently mitigating the detrimental consequences of escalated circ_0000592 expression in ESCC cells. Consistently, circ_0000592 downregulation curbed proliferation and metastasis of ESCC tumors in vivo. In summary, circ_0000592 promoted the progress of ESCC by counteracting the inhibitory impact on FZD5 through its interaction with miR-155-5p. Together, our findings highlighted circ_0000592 as a prospective therapeutic target for ESCC.

LINC00330/CCL2 axis-mediated ESCC TAM reprogramming affects tumor progression

BackgroundTumor-associated macrophages (TAMs) significantly influence the progression, metastasis, and recurrence of esophageal squamous cell carcinoma (ESCC). The aberrant expression of long noncoding RNAs (lncRNAs) in ESCC has been established, yet the role of lncRNAs in TAM reprogramming during ESCC progression remains largely unexplored.MethodsESCC TAM-related lncRNAs were identified by intersecting differentially expressed lncRNAs with immune-related lncRNAs and performing immune cell infiltration analysis. The expression profile and clinical relevance of LINC00330 were examined using the TCGA database and clinical samples. The LINC00330 overexpression and interference sequences were constructed to evaluate the effect of LINC00330 on ESCC progression. Single-cell sequencing data, CIBERSORTx, and GEPIA were utilized to analyze immune cell infiltration within the ESCC tumor microenvironment and to assess the correlation between LINC00330 and TAM infiltration. ESCC-macrophage coculture experiments were conducted to investigate the influence of LINC00330 on TAM reprogramming and its subsequent effect on ESCC progression. The interaction between LINC00330 and C–C motif ligand 2 (CCL2) was confirmed through transcriptomic sequencing, subcellular localization analysis, RNA pulldown, silver staining, RNA immunoprecipitation, and other experiments.ResultsLINC00330 is significantly downregulated in ESCC tissues and strongly associated with poor patient outcomes. Overexpression of LINC00330 inhibits ESCC progression, including proliferation, invasion, epithelial–mesenchymal transition, and tumorigenicity in vivo. LINC00330 promotes TAM reprogramming, and LINC00330-mediated TAM reprogramming inhibits ESCC progression. LINC00330 binds to the CCL2 protein and inhibits the expression of CCL2 and downstream signaling pathways. CCL2 is critical for LINC00330-mediated TAM reprogramming and ESCC progression.ConclusionsLINC00330 inhibited ESCC progression by disrupting the CCL2/CCR2 axis and its downstream signaling pathways in an autocrine fashion; and by impeding CCL2-mediated TAM reprogramming in a paracrine manner. The new mechanism of TAM reprogramming mediated by the LINC00330/CCL2 axis may provide potential strategies for targeted and immunocombination therapies for patients with ESCC.Graphical

HLA-A+ tertiary lymphoid structures with reactivated tumor infiltrating lymphocytes are associated with a positive immunotherapy response in esophageal squamous cell carcinoma.

Immune checkpoint blockade (ICB) therapy provides remarkable clinical benefits for multiple cancer types. However, the overall response rate to ICB therapy remains low in esophageal squamous cell carcinoma (ESCC). This study aimed to identify biomarkers of ICB therapy for ESCC and interrogate its potential clinical relevance. We investigated gene expression in 42 treatment-naïve ESCC tumor tissues and identified differentially expressed genes, tumor-infiltrating lymphocytes and immune-related genes signatures associated with differential immunotherapy responses. We systematically assessed the tumor microenvironment using the NanoString GeoMx digital spatial profiler, single-cell RNA-seq and multiplex immunohistochemistry in ESCC. Finally, we evaluated the associations between HLA-A-positive tertiary lymphoid structures (TLSs) and patients' responses to ICB in 60 ESCC patients. Tumor infiltrating B lymphocytes and several immune-related gene signatures, such as the antigen presenting machinery (APM) signature, are significantly elevated in ICB treatment responders. Multiplex immunohistochemistry identified the presence of HLA-A+ TLSs and showed that TLS-resident cells increasingly express HLA-A as TLSs mature. Most TLS-resident HLA-A+ cells are tumor-infiltrating T (TIL-T) or tumor-infiltrating B (TIL-B) lymphocytes. Digital spatial profiling of spatially distinct TIL-T lymphocytes and single-cell RNA-seq data from 60 ESCC tumor tissues revealed that CXCL13-expressing exhausted TIL-Ts inside TLSs are reactivated with elevated expression of the APM signature as TLSs mature. Finally, we demonstrated that HLA-A+ TLSs and their major cellular components, TIL-Ts and TIL-Bs, are associated with a clinical benefit from ICB treatment for ESCC. HLA-A+ TLSs are present in ESCC tumor tissues. TLS-resident TIL-Ts with elevated expression of the APM signature may be reactivated. HLA-A+ TLSs and their major cellular components, TIL-Ts and TIL-Bs, may serve as biomarkers for ICB-treated ESCC patients.

Development of a Specific Aptamer-Modified Nano-System to Treat Esophageal Squamous Cell Carcinoma.

Esophageal squamous cell carcinoma (ESCC) is a prevalent gastrointestinal cancer characterized by high mortality and an unfavorable prognosis. While combination therapies involving surgery, chemotherapy, and radiation therapy are advancing, targeted therapy for ESCC remains underdeveloped. As a result, the overall five-year survival rate for ESCC is still below 20%. Herein, ESCC-specific DNA aptamers and an innovative aptamer-modified nano-system is introduced for targeted drug and gene delivery to effectively inhibit ESCC. The EA1 ssDNA aptamer, which binds robustly to ESCC cells with high specificity and affinity, is identified using cell-based systematic evolution of ligands by exponential enrichment (cell-SELEX). An EA1-modified nano-system is developed using a natural egg yolk lipid nanovector (EA1-EYLNs-PTX/siEFNA1) that concurrently loads paclitaxel (PTX) and a small interfering RNA of Ephrin A1 (EFNA1). This combination counters ESCC's proliferation, migration, invasion, and lung metastasis. Notably, EFNA1 is overexpressed in ESCC tumors with lung metastasis and has an inverse correlation with ESCC patient prognosis. The EA1-EYLNs-PTX/siEFNA1 nano-system offers effective drug delivery and tumor targeting, resulting in significantly improved therapeutic efficacy against ESCC tumors. These insights suggest that aptamer-modified nano-systems can deliver drugs and genes with superior tumor-targeting, potentially revolutionizing targeted therapy in ESCC.

Dexrazoxane inhibits the growth of esophageal squamous cell carcinoma by attenuating SDCBP/MDA-9/syntenin-mediated EGFR-PI3K-Akt pathway activation

Syndecan-binding protein (SDCBP) was reported to stimulate the advancement of esophageal squamous cell carcinoma (ESCC) and could potentially be a target for ESCC treatment. There is a growing corpus of research on the anti-tumor effects of iron chelators; however, very few studies have addressed the involvement of dexrazoxane in cancer. In this study, structure-based virtual screening was employed to select drugs targeting SDCBP from the Food and Drug Administration (FDA)-approved drug databases. The sepharose 4B beads pull-down assay revealed that dexrazoxane targeted SDCBP by interacting with its PDZ1 domain. Additionally, dexrazoxane inhibited ESCC cell proliferation and anchorage-independent colony formation via SDCBP. ESCC cell apoptosis and G2 phase arrest were induced as measured by the flow cytometry assay. Subsequent research revealed that dexrazoxane attenuated the binding ability between SDCBP and EGFR in an immunoprecipitation assay. Furthermore, dexrazoxane impaired EGFR membrane localization and inactivated the EGFR/PI3K/Akt pathway. In vivo, xenograft mouse experiments indicated that dexrazoxane suppressed ESCC tumor growth. These data indicate that dexrazoxane might be established as a potential anti-cancer agent in ESCC by targeting SDCBP.

Integrating bulk and single-cell sequencing data to construct a Scissor+ dendritic cells prognostic model for predicting prognosis and immune responses in ESCC

Esophageal squamous cell carcinoma (ESCC) is characterized by molecular heterogeneity with various immune cell infiltration patterns, which have been associated with therapeutic sensitivity and resistance. In particular, dendritic cells (DCs) are recently discovered to be associated with prognosis and survival in cancer. However, how DCs differ among ESCC patients has not been fully comprehended. Recently, the advance of single-cell RNA sequencing (scRNA-seq) enables us to profile the cell types, states, and lineages in the heterogeneous ESCC tissues. Here, we dissect the ESCC tumor microenvironment at high resolution by integrating 192,078 single cells from 60 patients, including 4379 DCs. We then used Scissor, a method that identifies cell subpopulations from single-cell data that are associated bulk samples with genomic and clinical information, to stratify DCs into Scissorhi and Scissorlow subtypes. We applied the Scissorhi gene signature to stratify ESCC scRNAseq patient, and we found that PD-L1, TIGIT, PVR and IL6 ligand-receptor-mediated cell interactions existed mainly in Scissorhi patients. Finally, based on the Scissor results, we successfully developed a validated prognostic risk model for ESCC and further validated the reliability of the risk prediction model by recruiting 40 ESCC clinical patients. This information highlights the importance of these genes in assessing patient prognosis and may help in the development of targeted or personalized therapies for ESCC.

Abstract LB083: Near-infrared light-triggered tumor pyroptosis potentiates PD-1 immunotherapy in esophageal cancer

Abstract Background: Esophageal cancer remains a lethal malignancy accounting for 604,000 new cases and 544,000 cancer-related modalities worldwide. To date, the clinical outcomes for patient with esophageal cancer are severely limited by the lack of effective treatment modalities. Moreover, the intrinsic and acquired resistances to chemotherapy and radiotherapy, stemming from DNA damage responses, inevitably exacerbates the disease progression. Pyroptosis is a proinflammatory programmed cell death (PCD) that is causally linked to anti-tumor immune responses, but the development of pyroptosis-based therapy has been limited by the lack of effective inducers to mediate pyroptotic cell death in a tumor-specific and controllable manner. Herein, we establishes that near-infrared light-triggered tumor pyroptosis (NIR-pyroptosis) is a novel non-apoptotic anticancer modality, providing a promising opportunity to overcome apoptosis resistance in current esophageal cancer therapies. Method: In this study, a novel esophageal cancer-targeted, NIR-pyroptosis antibody-drug conjugates (ADC) was established by covalently conjugating IRDye700, a photosensitizer, with ICAM1 antibody using thiol-maleimide click chemistry. This antibody-photosensitizer conjugate (ICAM1-IRDye700) functions as a potent NIR-pyroptosis inducer in multiple preclinical models of esophageal squamous cell carcinoma (ESCC). The in vitro potency of ICAM1-IRDye700 was determined by flow cytometry, immunofluorescent co-localization, and high-content imaging. Transmission electron microscopy (TEM) further characterized pyroptosis-related morphological changes in ICAM1-IRDye700-treated ESCC cells. To elucidate its underlying mechanism, transcriptomic and immune-blot analyses were performed to identify the molecular signaling cascades of NIR-pyroptosis ignited by ICAM1-IRDye700. Results: Under minimal doses (2ug/ml) of near-infrared light stimulation, ICAM1-IRDye700 rapidly triggered pyroptosis in ESCC cells, achieving approximately 95% cell death within 2 hours. Importantly, the potency of NIR-pyroptosis predominantly depends on the spatio. At different stages of drug accumulation on the cell membrane, in endosomes, and lysosomes, the time of pyroptosis induction varied. Transmission electron microscopy further observed pyroptosis-related morphological changes, and immunoblot analysis and sequencing results also provided supporting evidence, demonstrating the activation of the subcellular depositing locations of ICAM1-IRDye700 upon NIR irradiation. Further biomechanistic studies reveal that ICAM1-IRDye700 potently activates NLRP1-CASP1-GSDMD signaling axis, leading to a boosted antitumor immunity in vivo. This antitumor immunity activation was independent from reactive oxygen species (ROS). Furthermore, NIR-pyroptosis works in synergy with PD-1 immunotherapy by improving adaptive antitumor immunity in immunocompetent tumor models. Conclusion: Collectively, we established ICAM1-IRDye700 as a concept-of-proof ADC for NIR-pyroptosis therapy. Mechanistically, we explored the biomechanism of how ICAM1-IRDye700 igniting NIR-pyroptosis in ESCC tumors. This novel ADC boosts innate and adaptive immunity, resulting in potent and sustained tumor attenuations in combination with PD-1 checkpoint immunotherapy. Citation Format: Xue-Fei Tian, Fan Chen, Xi-Ru Xue, Yang Yang, Peng Guo. Near-infrared light-triggered tumor pyroptosis potentiates PD-1 immunotherapy in esophageal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB083.

Long non-coding RNA SRA1 suppresses radiotherapy resistance in esophageal squamous cell carcinoma by modulating glycolytic reprogramming.

Esophageal squamous cell carcinoma (ESCC), a highly aggressive subtype of esophageal cancer, is characterized by late-stage diagnosis and limited treatment options. Recent advancements in transcriptome sequencing technologies have illuminated the molecular intricacies of ESCC tumors, revealing metabolic reprogramming as a prominent feature. Specifically, the Warburg effect, marked by enhanced glycolysis, has emerged as a hallmark of cancer, offering potential therapeutic targets. In this study, we comprehensively analyzed bulk RNA-seq data from ESCC patients, uncovering elevated SRA1 expression in ESCC development and a poorer prognosis. Silencing of SRA1 led to a modulation of glycolysis-related products and a shift in PKM2 expression. Our findings shed light on the intricate molecular landscape of ESCC, highlighting SRA1 as a potential therapeutic target to disrupt glycolysis-dependent energy production. This metabolic reprogramming may hold the key to innovative treatment strategies for ESCC, ultimately improving patient outcomes.

Single-cell transcriptome sequencing analysis reveals intra-tumor heterogeneity in esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) is a prevalent malignant tumor of the digestive system that poses a significant threat to human life and health. It is crucial to thoroughly investigate the mechanisms of esophageal carcinogenesis and identify potential key molecular events in its carcinogenesis. Single-cell transcriptome sequencing is an emerging technology that has gained prominence in recent years for studying molecular mechanisms, which may help to further explore the underlying mechanisms of the ESCC tumor microenvironment in depth. The single-cell dataset was obtained from GSE160269 in the Gene Expression Omnibus database, including 60 tumor samples and four paracancer samples. The single-cell data underwent dimensional reduction clustering analysis to identify clusters and annotate expression profiles. Subcluster analysis was conducted for each cellular taxon. Copy number variation analysis of tumor cell subpopulations was performed to primarily identify malignant cells within them. A proposed chronological analysis was performed to obtain the process of cell differentiation. In addition, cell communication, transcription factor analysis, and tumor pathway analysis were also performed. Relevant risk models and key genes were established by univariate COX regression and LASSO analysis. The key genes obtained from the screen were subjected to appropriate silencing and cellular assays, including CCK-8, 5-ethynyl-2'-deoxyuridine, colony formation, and western blot. Single-cell analysis revealed that normal samples contained a large number of fibroblasts, T cells, and B cells, with fewer other cell types, whereas tumor samples exhibited a relatively balanced distribution of cell types. Subclassification analysis of immune cells, fibroblasts, endothelial cells, and epithelial cells revealed their specific spatial characteristics. The prognostic risk model, we constructed successfully, achieved accurate prognostic stratification for ESCC patients. The screened key gene, UPF3A, was found to be significantly associated with the development of ESCC by cellular assays. This process might be linked to the phosphorylation of ERK and P38. Single-cell transcriptome analysis successfully revealed the distribution of cell types and major expressed factors in ESCC patients, which could facilitate future in-depth studies on the therapeutic mechanisms of ESCC.

Single-cell profiling of response to neoadjuvant chemo-immunotherapy in surgically resectable esophageal squamous cell carcinoma

BackgroundThe efficacy of neoadjuvant chemo-immunotherapy (NAT) in esophageal squamous cell carcinoma (ESCC) is challenged by the intricate interplay within the tumor microenvironment (TME). Unveiling the immune landscape of ESCC in the context of NAT could shed light on heterogeneity and optimize therapeutic strategies for patients.MethodsWe analyzed single cells from 22 baseline and 24 post-NAT treatment samples of stage II/III ESCC patients to explore the association between the immune landscape and pathological response to neoadjuvant anti-PD-1 combination therapy, including pathological complete response (pCR), major pathological response (MPR), and incomplete pathological response (IPR).ResultsSingle-cell profiling identified 14 major cell subsets of cancer, immune, and stromal cells. Trajectory analysis unveiled an interesting link between cancer cell differentiation and pathological response to NAT. ESCC tumors enriched with less differentiated cancer cells exhibited a potentially favorable pathological response to NAT, while tumors enriched with clusters of more differentiated cancer cells may resist treatment. Deconvolution of transcriptomes in pre-treatment tumors identified gene signatures in response to NAT contributed by specific immune cell populations. Upregulated genes associated with better pathological responses in CD8 + effector T cells primarily involved interferon-gamma (IFNγ) signaling, neutrophil degranulation, and negative regulation of the T cell apoptotic process, whereas downregulated genes were dominated by those in the immune response-activating cell surface receptor signaling pathway. Natural killer cells in pre-treatment tumors from pCR patients showed a similar upregulation of gene expression in response to IFNγ but a downregulation of genes in the neutrophil-mediated immunity pathways. A decreased cellular contexture of regulatory T cells in ESCC TME indicated a potentially favorable pathological response to NAT. Cell–cell communication analysis revealed extensive interactions between CCL5 and its receptor CCR5 in various immune cells of baseline pCR tumors. Immune checkpoint interaction pairs, including CTLA4-CD86, TIGIT-PVR, LGALS9-HAVCR2, and TNFSF4-TNFRSF4, might serve as additional therapeutic targets for ICI therapy in ESCC.ConclusionsThis pioneering study unveiled an intriguing association between cancer cell differentiation and pathological response in esophageal cancer patients, revealing distinct subgroups of tumors for which neoadjuvant chemo-immunotherapy might be effective. We also delineated the immune landscape of ESCC tumors in the context of clinical response to NAT, which provides clinical insights for better understanding how patients respond to the treatment and further identifying novel therapeutic targets for ESCC patients in the future.

Abstract 1892: KK2260: A fully human tetravalent bispecific antibody targeting TfR1 and EGFR for the treatment of EGFR-expressing tumors

Abstract Background: TfR1 is a transmembrane glycoprotein involved in iron uptake and regulation of cell growth. High TfR1 expression has been reported in different types of cancers, therefore recognized as a target molecule for cancer therapy. Despite the promise of potent efficacy of TfR1-targeted agents, there is a risk of side effects (i.e., severe anemia), since TfR1 is also highly expressed in certain normal cells (e.g., reticulocytes). KK2260 is a fully human tetravalent bispecific antibody (bsAb) based on REGULGENTTM technology targeting TfR1 and EGFR. This bsAb was designed for EGFR-expressing cell selective anti-cancer drug which could not be achieved by conventional monospecific Ab. In this study, we evaluated the mechanism of action (MOA), anti-cancer effect, and toxicity of KK2260. Methods: Binding activity of KK2260 to TfR1 and EGFR was evaluated by surface plasmon resonance method. Ligand blocking activity was evaluated by binding competition on esophageal squamous cell carcinoma (ESCC) OE21 cells. Growth inhibitory activity of KK2260 on cancer cells or hematopoietic progenitor cells was evaluated by proliferation inhibition assay. In some studies, excessive iron or anti-EGFR parent Ab was added. Effect on the cell surface target expression levels was evaluated by flow cytometry. The intracellular iron level was evaluated by cell imaging. Effect on EGF induced EGFR phosphorylation was evaluated by Western blotting. The in vivo efficacy of KK2260 was evaluated in cell line-derived and patient-derived xenograft (PDX) models of ESCC selected for high EGFR expression level. The toxicity of KK2260 was evaluated in cynomolgus monkeys. Results: KK2260 bound to TfR1 and EGFR with no ligand binding inhibition. KK2260 inhibited cell growth of moderate to high EGFR-expressing cancer cells, but not against EGFR-negative cancer cells or hematopoietic progenitor cells. KK2260 downregulated TfR1 expression on OE21 cells and the intracellular iron level decreased, but no effect was observed on EGFR phosphorylation. The growth inhibitory activity of KK2260 was abolished by adding excessive amounts of iron or reduced by inhibiting the binding to EGFR. Potent anti-tumor activity was observed in the ESCC PDX models with tumor regression. In the intermittent-dose toxicity study of cynomolgus monkeys, KK2260 was well-tolerated. Conclusions: KK2260 demonstrated potent anti-cancer effect both in vitro and in vivo. Intriguingly, KK2260 did not inhibit EGFR phosphorylation while EGFR-binding dependent TfR1 downregulation resulted in intracellular iron deficiency, which was considered as the MOA of KK2260. KK2260 was well tolerated in non-human primates. These preclinical data suggest the unique property of KK2260 is expected to provide significant benefit to patients with advanced ESCC and other EGFR-expressing tumors and Phase 1 study is currently on going in Japan (jRCT2031230372). Citation Format: Keisuke Mitamura, Hironori Otsuki, Keiko Nakahashi, Ayaka Kitagawa, Masayo Kamigaki, Yohei Kurio, Miho Inoue, Yasunori Uemura. KK2260: A fully human tetravalent bispecific antibody targeting TfR1 and EGFR for the treatment of EGFR-expressing tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1892.

Lymphatic endothelial cell-mediated accumulation of CD177+Treg cells suppresses antitumor immunity in human esophageal squamous cell carcinoma

ABSTRACT Regulatory T (Treg) cells are critical in shaping an immunosuppressive microenvironment to favor tumor progression and resistance to therapies. However, the heterogeneity and function of Treg cells in esophageal squamous cell carcinoma (ESCC) remain underexplored. We identified CD177 as a tumor-infiltrating Treg cell marker in ESCC. Interestingly, expression levels of CD177 and PD-1 were mutually exclusive in tumor Treg cells. CD177+ Treg cells expressed high levels of IL35, in association with CD8+ T cell exhaustion, whereas PD-1+ Treg cells expressed high levels of IL10. Pan-cancer analysis revealed that CD177+ Treg cells display increased clonal expansion compared to PD-1+ and double-negative (DN) Treg cells, and CD177+ and PD-1+ Treg cells develop from the same DN Treg cell origin. Importantly, we found CD177+ Treg cell infiltration to be associated with poor overall survival and poor response to anti-PD-1 immunotherapy plus chemotherapy in ESCC patients. Finally, we found that lymphatic endothelial cells are associated with CD177+ Treg cell accumulation in ESCC tumors, which are also decreased after anti-PD-1 immunotherapy plus chemotherapy. Our work identifies CD177+ Treg cell as a tumor-specific Treg cell subset and highlights their potential value as a prognostic marker of survival and response to immunotherapy and a therapeutic target in ESCC.

Contrasting Roles of Programmed Death-Ligand 1 Expression in Tumor and Stroma in Prognosis of Esophageal Squamous Cell Carcinoma.

The assessment of programmed death-ligand 1 (PD-L1) expression in esophageal squamous cell carcinoma (ESCC) has become increasingly important with the rise of immune checkpoint inhibitors (ICIs). However, challenges persist, including subjective interpretation and the unclear significance of staining intensity, as well as contrasting roles in tumoral and stromal regions. Our study enhances the understanding of PD-L1 in ESCCs by analyzing its expression in tumors and stroma with H-scores, highlighting its distinct clinicopathological impacts. In a retrospective cohort of 194 ESCC specimens from surgical resection, we quantified PD-L1 expression in tumoral and stromal compartments using H-scores, analyzing whole slide images with digital pathology analysis software. Kaplan-Meier analysis demonstrated that higher PD-L1 expression is significantly associated with improved postoperative overall survival (OS) and recurrence-free survival (RFS) in both tumoral and stromal areas. Multivariable analysis identified high tumoral PD-L1 expression as an independent prognostic factor for prolonged OS and RFS (HR = 0.47, p = 0.007; HR = 0.54, p = 0.022, respectively). In a separate analysis, high stromal PD-L1 expression was found to correlate with less advanced pathological stages and a prolonged response to cytotoxic chemotherapy, with no similar correlation found for ICI treatment response. This study reveals PD-L1's contrasting role in the ESCC tumor immune microenvironment, impacting prognosis, tumor stage, and treatment response.

SENP3 mediates the activation of the Wnt/β-catenin signaling pathway to accelerate the growth and metastasis of oesophagal squamous cell carcinoma in mice.

As a common malignant tumor, esophageal squamous cell carcinoma (ESCC) is occasionally seen in clinical practice. This type of disease has low incidence rate and mortality. The post-translational modification of small ubiquitin like modifiers (SUMO) can play a crucial role in regulating protein function, and can significantly impact the occurrence and development of diseases. SUMO-specific peptidase (SENP) affects cell activity by regulating the biological function of SUMO. SENP3 belongs to the SENP family, and available data indicate that many malignancies are associated with SENPs, it is currently unclear its role in ESCC. This study indicates that there is a high level of SENP3 expression in ESCC tumor cells. If the expression level of this gene is high, it can have a significant impact on ESCC cell lines and affect physiological activities such as invasion of KYSE170 cells. If the gene is knocked out, this situation will not occur. There is also research data indicating that this gene can effectively activate related signaling pathways, thereby promoting the physiological activities of malignant tumor cells. In a nude mouse xenograft tumor model, KYSE170 cells with SENP3 expression knockdown induced a smaller volume and weight of tumor tissue. Therefore, it can be clearly stated that SENP3 can enable Wnt/ β- The catenin signaling pathway is stimulated, which in turn affects the physiological activities of ESCC cells, including the invasion process. The results of this article lay the foundation for clinical staff to carry out clinical management.

Targeting TAOK1 with resveratrol inhibits esophageal squamous cell carcinoma growth in vitro and in vivo.

The worldwide incidence and mortality rates of esophageal squamous cell carcinoma (ESCC) have increased over the last decade. Moreover, molecular targets that may benefit the therapeutics of patients with ESCC have not been fully characterized. Our study discovered that thousand and one amino-acid protein kinase 1 (TAOK1) is highly expressed in ESCC tumor tissues and cell lines. Knock-down of TAOK1 suppresses ESCC cell proliferation in vitro and patient-derived xenograft or cell-derived xenografttumors growth in vivo. Moreover, TAOK1 overexpression promotes ESCC growth in vitro and in vivo. Additionally, we identified that the natural small molecular compound resveratrol binds to TAOK1 directly and diminishes the kinase activity of TAOK1. Targeting TAOK1 directly with resveratrol significantly inhibits cell proliferation, induces cell cycle arrest and apoptosis, and suppresses tumor growth in ESCC. Furthermore, the silencing of TAOK1 or the application of resveratrol attenuated the activation of TAOK1 downstream signaling effectors. Interestingly, combining resveratrol with paclitaxel, cisplatin, or 5-fluorouracil synergistically enhanced their therapeutic effects against ESCC. In conclusion, this work illustrates the underlying oncogenic function of TAOK1 and provides a theoretical basis for the application of targeting TAOK1 therapy to the clinical treatment of ESCC.

Novel oncogenic transcriptional targets of mutant p53 in esophageal squamous cell carcinoma.

Missense mutations in the DNA binding domain of p53 are observed frequently in esophageal squamous cell carcinoma (ESCC). Recent studies have revealed the potentially oncogenic transcriptional networks regulated by mutant p53 proteins. However, majority of these studies have focused on common "hotspot" p53 mutations while rarer mutations are poorly characterized. In this study, we report the characterization of rare, "non-hotspot" p53 mutations from ESCC. In vitro tumorigenic assays performed following ectopic-expression of certain "non-hotspot" mutant p53 proteins caused enhancement of oncogenic properties in squamous carcinoma cell lines. Genome-wide transcript profiling of ESCC tumor samples stratified for p53 status, revealed several genes exhibiting elevated transcript levels in tumors harboring mutant p53. Of these, ARF6, C1QBP, and TRIM23 were studied further. Reverse transcription-quantitative PCR (RT-qPCR) performed on RNA isolated from ESCC tumors revealed significant correlation of TP53 transcript levels with those of the three target genes. Ectopic expression of wild-type and several mutant p53 forms followed by RT-qPCR, chromatin affinity-purification (ChAP), and promoter-luciferase assays indicated the exclusive recruitment of p53 mutants-P190T and P278L, to the target genes leading to the activation of expression. Several functional assays following knockdown of the target genes revealed a significant suppression of tumorigenicity in squamous carcinoma cell lines. Rescue experiments confirmed the specificity of the knockdown. The tumorigenic effects of the genes were confirmed in nude mice xenograft assays. This study has therefore identified novel oncogenic targets of "non-hotspot" mutant p53 proteins relevant for ESCC besides validating the functional heterogeneity of the spectrum of tumor-specific p53 mutations.