Heterogeneity In Esophageal Squamous Cell Carcinoma Research Articles

Immune-tumor interaction dictates spatially directed evolution of esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) is a poor-prognostic cancer type with extensive intra- and inter-patient heterogeneity in both genomic variations and tumor microenvironment (TME). However, the patterns and drivers of spatial genomic and microenvironmental heterogeneity of ESCC remain largely unknown. Here, we generated a spatial multi-omic atlas by whole-exome, transcriptome, and methylome sequencing of 507 tumor samples from 103 patients. We identified a novel tumor suppressor PREX2, accounting for 22% of ESCCs with frequent somatic mutations or hyper-methylation, which promoted migration and invasion of ESCC cells in vitro. Analysis of the TME and quantification of subclonal expansion indicated that ESCCs undergo spatially directed evolution, where subclones mostly originated from the tumor center but had a biased clonal expansion to the upper direction of the esophagus. Interestingly, we found upper regions of ESCCs often underwent stronger immunoediting with increased selective fitness, suggesting more stringent immune selection. In addition, distinct TMEs were associated with variable genomic and clinical outcomes. Among them, hot TME was associated with high immune evasion and subclonal heterogeneity. We also found that immunoediting, instead of CD8+ T cell abundance, acts as an independent prognostic factor of ESCCs. Importantly, we found significant heterogeneity in previously considered potential therapeutic targets, as well as BRCAness characteristics in a subset of patients, emphasizing the importance of focusing on heterogeneity in ESCC targeted therapy. Collectively, these findings provide novel insights into the mechanisms of the spatial evolution of ESCC and inform precision therapeutic strategies.

Abstract 5674: Characterizing Cellular Heterogeneity and Identifying Potential Biomarkers in Esophageal Squamous Cell Carcinoma (ESCC) Using Single-Cell RNA Sequencing

Abstract Esophageal squamous cell carcinoma (ESCC) exhibits significant cellular heterogeneity, rendering it susceptible to developing radioresistance and recurring tumors. Single-cell RNA sequencing (scRNA-seq) is an advanced technique that allows for the exploration of distinct gene expression profiles in individual cells. To investigate cellular heterogeneity in ESCC, scRNA-seq analysis was performed on tumor tissues from ten ESCC patients, as well as adjacent non-malignant esophageal tissues. The cellular composition revealed 19 distinct cell clusters, further categorized into seven cell populations: 69.31% Fibroblast, 15.36% T cell, 5.30% Monocytes, 5.26% Endothelial cells, 2.68% plasma cell, 1.91% Epithelial cells, and 0.18% ambiguous. Notably, Fibroblast and Endothelial cells were more prevalent in non-malignant tissues, while the remaining cell types were enriched in tumor tissues. Differential gene expression analysis identified 49 genes with higher expression in tumor cells and 37 genes with lower expression. Gene Set Enrichment Analysis (GSEA) revealed the top three most relevant GO Biological Processes pathways: positive regulation of immune response, regulation of T cell activation, and positive regulation of cell migration. Furthermore, in post-treatment follow-up, four patients were observed to develop metastasis within one year. Comparative analysis between metastatic and non-metastatic patients unveiled 9 Differentially Expressed Genes (DEGs), including KRT6A and AKR1B10, which exhibited specific expression in Epithelial cells and were highly expressed in tumor tissues. Additionally, IGLC2, IGHG4, and IGHG1 demonstrated specific expression in plasma cells, with elevated expression in tumor tissues. These findings suggest that KRT6A, AKR1B10, IGLC2, IGHG4, and IGHG1 may serve as potential biomarkers for predicting post-chemotherapy metastasis in ESCC patients. Citation Format: Tzu-Hung Hsiao, Chih-Hung Lin, Ting-Shuan Wu, Li-Wen Lee, Chung-Ping Hsu. Characterizing Cellular Heterogeneity and Identifying Potential Biomarkers in Esophageal Squamous Cell Carcinoma (ESCC) Using Single-Cell RNA Sequencing [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 5674.

Innovative prognostic modeling in ESCC: leveraging scRNA-seq and bulk-RNA for dendritic cell heterogeneity analysis.

Globally, esophageal squamous cell carcinoma (ESCC) stands out as a common cancer type, characterized by its notably high rates of occurrence and mortality. Recent advancements in treatment methods, including immunotherapy, have shown promise, yet the prognosis remains poor. In the context of tumor development and treatment outcomes, the tumor microenvironment (TME), especially the function of dendritic cells (DCs), is significantly influential. Our study aims to delve deeper into the heterogeneity of DCs in ESCC using single-cell RNA sequencing (scRNA-seq) and bulk RNA analysis. In the scRNA-seq analysis, we utilized the SCP package for result visualization and functional enrichment analysis of cell subpopulations. CellChat was employed to identify potential oncogenic mechanisms in DCs, while Monocle 2 traced the evolutionary trajectory of the three DC subtypes. CopyKAT assessed the benign or malignant nature of cells, and SCENIC conducted transcription factor regulatory network analysis, offering a preliminary exploration of DC heterogeneity. In Bulk-RNA analysis, we constructed a prognostic model for ESCC prognosis and immunotherapy response, based on DC marker genes. This model was validated through quantitative PCR (qPCR) and immunohistochemistry (IHC), confirming the gene expression levels. In this study, through intercellular communication analysis, we identified GALECTIN and MHC-I signaling pathways as potential oncogenic mechanisms within dendritic cells. We categorized DCs into three subtypes: plasmacytoid (pDC), conventional (cDC), and tolerogenic (tDC). Our findings revealed that pDCs exhibited an increased proportion of cells in the G2/M and S phases, indicating enhanced cellular activity. Pseudotime trajectory analysis demonstrated that cDCs were in early stages of differentiation, whereas tDCs were in more advanced stages, with pDCs distributed across both early and late differentiation phases. Prognostic analysis highlighted a significant correlation between pDCs and tDCs with the prognosis of ESCC (P< 0.05), while no significant correlation was observed between cDCs and ESCC prognosis (P = 0.31). The analysis of cell malignancy showed the lowest proportion of malignant cells in cDCs (17%), followed by pDCs (29%), and the highest in tDCs (48%), with these results being statistically significant (P< 0.05). We developed a robust ESCC prognostic model based on marker genes of pDCs and tDCs in the GSE53624 cohort (n = 119), which was validated in the TCGA-ESCC cohort (n = 139) and the IMvigor210 immunotherapy cohort (n = 298) (P< 0.05). Additionally, we supplemented the study with a novel nomogram that integrates clinical features and risk assessments. Finally, the expression levels of genes involved in the model were validated using qPCR (n = 8) and IHC (n = 16), thereby confirming the accuracy of our analysis. This study enhances the understanding of dendritic cell heterogeneity in ESCC and its impact on patient prognosis. The insights gained from scRNA-seq and Bulk-RNA analysis contribute to the development of novel biomarkers and therapeutic targets. Our prognostic models based on DC-related gene signatures hold promise for improving ESCC patient stratification and guiding treatment decisions.

Prognostic Risk Models Using Epithelial Cells Identify β-Sitosterol as a Potential Therapeutic Target Against Esophageal Squamous Cell Carcinoma.

Esophageal squamous cell carcinoma (ESCC) is an aggressive and fatal malignancy that leads to epithelial cancer. The association between epithelial cell heterogeneity, prognosis, and immune response in this cancer remains uncertain. This study aimed to investigate epithelial cell heterogeneity in ESCC and develop a predictive risk model using the identified cell types. Single-cell RNA sequencing (scRNA-seq) and differential ESCC gene data were accessed from the Gene Expression Omnibus. Functional enrichment analysis, inferCNV, cell development trajectories, and intercellular communication were analyzed following epithelial cell characterization. Differentially expressed ESCC (n = 773) and epithelial cell marker genes (n = 3407) were intersected to obtain core genes, and epithelial cell-related prognostic genes were identified. LASSO regression analysis was used to construct a prognostic model. The external dataset GSE53624 was used to further validate the stability of the model. Drug sensitivity predictions, and immune cell infiltration were analyzed. Molecular docking clarified the possible therapeutic role of β-sitosterol in ESCC. Finally, wound healing assay, cell colony, and transwell assay were constructed to detect the effects of the core gene PDLIM2 on ESCC cell proliferation, invasion, and migration. Eight cell clusters were identified, and epithelial cells were categorized into tumor and paratumor groups. The tumor group possessed more chromosomal variants than the paratumor group. Epithelial cells were associated with multiple cell types and significantly correlated with the Wnt, transforming growth factor, and epidermal growth factor signaling pathways. From 231 intersected genes, five core genes were screened for use in the risk model: CTSL, LAPTM4B, MYO10, NCF2, and PDLIM2. These genes may contribute to the cancerous transformation of normal esophageal epithelial cells and thereby act as biomarkers and potential therapeutic targets in patients with ESCC. β-Sitosterol furthermore displayed excellent docking potential with these genes. Meanwhile, further experiments demonstrated that the gene PDLIM2 plays a major role in the progression of oesophageal squamous carcinoma. We successfully developed a risk model for the prognosis of ESCC based on epithelial cells that addresses the response of ESCC to immunotherapy and offers novel cancer treatment options.

Abstract 6270: Integrating spatial transcriptomics and single-cell RNA-seq reveal the tumorigenesis and heterogeneity of esophageal squamous cell carcinoma

Abstract Background: Esophageal cancer is the sixth leading cause of cancer death globally and esophageal squamous cell carcinoma (ESCC) is the major histological type in China. The heterogeneity of ESCC resulted in poor therapeutic effect and tumor recurrence. To investigate the heterogeneity of ESCC at the single-cell level and the oncogenic evolution, we performed single-cell RNA-seq and spatial transcrtiptomics analysis in ESCC samples from different patients and position. Methods: We performed single-cell RNA-seq of tumor, adjacent normal tissue and the junction of cancer and normal tissues from 4 ESCC patients. We also performed spatial transcriptomics of paired cancer, normal and junction of ESCC patients. Unsupervised clustering was performed to find different cell clusters of ESCC and marker genes of different clusters were determined. Inferred copy number variation was performed to identify malignant cells and pseudotime analysis to investigate the development of different cell clusters. Combined analysis of single-cell and spatial data was performed to reveal the spatial characteristics of different cell types. Results: We successfully determined different cell types including epithelial cells, immune cells, fibroblasts, myeloid cells and so on. And we also reclustered epithelial, myeloid and T/NK cells to investigate different subtypes and their marker genes. We also distinguished malignant cells from heterogeneous cellular populations using inferred copy number variation analysis. Pseudotime analysis revealed the evolution of different cell types of ESCC. We identified key signatures associated with oncogenic evolution of ESCC and the spatial characteristics of key cell clusters. Conclusion: These findings reveal the heterogenesis of ESCC and key signatures in ESCC tumorigenesis. Keywords: ESCC, single cell sequencing, spatial transcriptomics, heterogeneity, tumorigenesis Citation Format: Xiaoyang Yin, Baosheng Li. Integrating spatial transcriptomics and single-cell RNA-seq reveal the tumorigenesis and heterogeneity of esophageal squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6270.

Multi-region sequencing reveals genetic correlation between esophageal squamous cell carcinoma and matched cell-free DNA

PurposeThis study aimed to determine if both ubiquitous and heterogeneous somatic mutations could be detected in circulating cell-free DNA (cfDNA) in patients with esophageal squamous cell carcinoma (ESCC). MethodsPaired multi-regional tumor tissues, cfDNA, and white blood cells (WBCs) were collected from five ESCC patients before treatment, as part of an ongoing prospective study (NCT02395705). Samples from Cohort 1 were sequenced by whole-exome sequencing and samples from Cohort 2 were sequenced by targeted capture sequencing. Somatic single-nucleotide variations (SNVs) were detected by comparing solid tumor or cfDNA with matched WBCs, with a minimum variant allele frequency (VAF) of 0.1% and P value <0.05. ResultsGenomic DNA (gDNA) and plasma-derived cfDNA from 26 samples were sequenced successfully. In Cohort 1, a significant linear relationship between the tumor and cfDNA VAFs (R2= 0.78, P < 0.0001) was found. In Cohort 2, cfDNA could recover an average of 60.7% (31/51; range, 35.7–76.2%) of somatic mutations present in matched solid tumors. There was a significant positive correlation in VAFs between cfDNA and matched solid tumor tissues (R2= 0.92, P < 0.0001). ConclusionsBoth sequencing approaches revealed high intratumoral heterogeneity in ESCC, and enabled the detection of both ubiquitous and heterogeneous mutations in cfDNA.

Dissecting the single-cell transcriptome network underlying esophagus non-malignant tissues and esophageal squamous cell carcinoma.

BackgroundEsophageal squamous cell carcinoma (ESCC) is among the most prevalent causes of cancer-related death in adults. Tumor microenvironment (TME) has been associated with therapeutic failure and lethal outcomes for patients. However, published reports on the heterogeneity and TME in ESCC are scanty.MethodsFive tumor samples and five corresponding non-malignant samples were subjected to scRNA-seq analysis. Bulk RNA sequencing data were retrieved in publicly available databases.FindingsFrom the scRNA-seq data, a total of 128,688 cells were enrolled for subsequent analyses. Gene expression and CNV status exhibited high heterogeneity of tumor cells. We further identified a list of tumor-specific genes and four malignant signatures, which are potential new markers for ESCC. Metabolic analysis revealed that energy supply-related pathways are pivotal in cancer metabolic reprogramming. Moreover, significant differences were found in stromal and immune cells between the esophagus normal and tumor tissues, which promoted carcinogenesis at both cellular and molecular levels in ESCC. Immune checkpoints, regarded as potential targets for immunotherapy in ESCC were significantly highly expressed in ESCC, including LAG3 and HAVCR2. Eventually, we constructed a cell-to-cell communication atlas based on cancer cells and immune cells and performed the flow cytometry, qRT-PCR, immunofluorescence, and immunohistochemistry analyses to validate the results.InterpretationThis study demonstrates a widespread reprogramming across multiple cellular elements within the TME in ESCC, particularly in transcriptional states, cellular functions, and cell-to-cell interactions. The findings offer an insight into the exploration of TME and heterogeneity in the ESCC and provide new therapeutic targets for its clinical management in the future.

The PI3K/AKT/c-MYC Axis Promotes the Acquisition of Cancer Stem-Like Features in Esophageal Squamous Cell Carcinoma.

The importance of intratumoral heterogeneity has been highlighted by the identification and characterization of cancer stem cells (CSCs). Based on the differential responsiveness to a Sox2 reporter, SRR2, we had found a novel dichotomy in esophageal squamous cell carcinoma (ESCC) cells, with reporter-responsive (RR) cells showing more CSC-like features than reporter-unresponsive (RU) cells. Specifically, RR cells exhibited significantly higher tumorsphere formation capacity, proportions of CD44(High) cells, chemoresistance to cisplatin, and tumorigenic potential in vivo. H2 O2 , a potent inducer of oxidative stress and reactive oxygen species, was found to induce a conversion from RU to RR cells; importantly, converted RR cells acquired CSC-like features. The PI3K/AKT/c-MYC signalling axis is important in this context, since pharmacologic blockade of PI3K-AKT or siRNA knockdown of c-MYC effectively inhibited the RR phenotype and its associated CSC-like features, as well as the H2 O2 -induced RU/RR conversion. In a cohort of 188 ESCC patient samples, we found a significant correlation between strong c-MYC expression and a short overall survival (p = .009). In conclusion, we have described a novel intratumoral heterogeneity in ESCC. The identification of the PI3K/AKT/c-MYC axis as a driver of CSC-like features carries therapeutic implications. Stem Cells 2016;34:2040-2051.

Abstract 5194: Notch regulates squamous differentiation, cell plasticity and tumor heterogeneity in esophageal carcinoma

Abstract Introduction: The Notch receptor family regulates cell fates and may act as a tumor suppressor in the squamous epithelia. While squamous differentiation is maintained in esophageal squamous cell carcinoma (ESCC) and its precursor lesions, the roles of Notch in esophageal tumor biology remain elusive. Methods: Transformed human esophageal cells expressing EGFR, p53R175H and cyclin D1 (EPC2-T) and ESCC cell lines were stably transduced with ICN1, an active form of NOTCH1 (N1) in a regulatable manner (Tet-On system). Notch was inhibited by dominant negative mastermind-like1 (DNMAML1), a genetic pan-Notch inhibitor or gamma-secretase inhibitors (GSI). 8xCSL-luciferase reporter was transiently transfected to assess Notch activity. Short hairpin RNA was stably transduced by lentivirus to knockdown ZEB1 and ZEB2. Squamous epithelium was reconstituted in organotypic (3D) culture, a form of tissue engineering. In addition, cell growth was assessed in soft agar and immunodeficient mice. Quantitative RT-PCR, Western blotting, immunohistochemistry (IHC) and flow cytometry were done to determine gene expression. Primary ESCC tissues (n=20) were analyzed by IHC. Results: In primary ESCC, N1 was localized to well-differentiated tumor cell nests expressing involucrin (IVL), a squamous differentiation marker, while downregulated in poorly-differentiated cells lacking IVL within a single tumor tissue, implying N1 in tumor heterogeneity. In cell lines, ICN1 activated Notch-dependent transcription and squamous differentiation in the absence of DNMAML1. In 3D culture, DNMAML1 and GSI not only blocked squamous differentiation but induced massive invasion and epithelial-to-mesenchymal transition (EMT) with Wnt activation as suggested by loss of E-cadherin and nuclear localization of β-catenin. In agreement, DNMAML1 upregulated LEF1, Zinc finger E-box binding proteins ZEB1 and ZEB2, transcription factors all essential in EMT and maintenance of cancer stem cells, facilitating transforming growth factor (TGF)-β1-induced EMT in EPC2-T cells. Moreover, DNMAML1 enriched a unique subset of CD44-bright and CD24-dim cells and augmented colony formation, tumorigenicity as well as chemotherapeutic drug resistance against Cisplatin. Importantly, Cre-mediated removal of chromosomally integrated floxed DNMAML1 reactivated Notch to allow terminal differentiation with IVL induction. Moreover, ZEB knockdown greatly impaired TGF-β-mediated EMT while restoring chemotherapeutic drug sensitivity. Conclusions: These data indicate that Notch activation promotes squamous differentiation whereas Notch inhibition enriches poorly differentiated tumor cells with cancer stem cell potential with drug resistance, which involves ZEB and Wnt activation, thus providing a novel mechanistic insight into how Notch signaling may contribute to tumor heterogeneity in ESCC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5194. doi:10.1158/1538-7445.AM2011-5194