Alarmin S100A8 imparts chemoresistance of esophageal cancer by reprogramming cancer-associated fibroblasts

Chemotherapy remains the first-line treatment for advanced esophageal cancer. However, durable benefits are achieved by only a limited subset of individuals due to the elusive chemoresistance. Here, we utilize patient-derived xenografts (PDXs) from esophageal squamous-cell carcinoma to investigate chemoresistance mechanisms in preclinical settings. We observe that activated cancer-associated fibroblasts (CAFs) are enriched in the tumor microenvironment of PDXs resistant to chemotherapy. Mechanistically, we reveal that cancer-cell-derived S100A8 triggers the intracellular RhoA-ROCK-MLC2-MRTF-A pathway by binding to the CD147 receptor of CAFs, inducing CAF polarization and leading to chemoresistance. Therapeutically, we demonstrate that blocking the S100A8-CD147 pathway can improve chemotherapy efficiency. Prognostically, we found the S100A8 levels in peripheral blood can serve as an indicator of chemotherapy responsiveness. Collectively, our study offers a comprehensive understanding of the molecular mechanisms underlying chemoresistance in esophageal cancer and highlights the potential value of S100A8 in the clinical management of esophageal cancer.

Collagen 1-mediated CXCL1 secretion in tumor cells activates fibroblasts to promote radioresistance of esophageal cancer

Esophageal squamous-cell carcinoma (ESCC) is commonly treated with radiotherapy; however, radioresistance hinders its clinical effectiveness, and the underlying mechanism remains elusive. Here, we develop patient-derived xenografts (PDXs) from 19 patients with ESCC to investigate the mechanisms driving radioresistance. Using RNA sequencing, cytokine arrays, and single-cell RNA sequencing, we reveal an enrichment of cancer-associated fibroblast (CAF)-derived collagen type 1 (Col1) and tumor-cell-derived CXCL1 in non-responsive PDXs. Col1 not only promotes radioresistance by augmenting DNA repair capacity but also induces CXCL1 secretion in tumor cells. Additionally, CXCL1 further activates CAFs via the CXCR2-STAT3 pathway, establishing a positive feedback loop. Directly interfering with tumor-cell-derived CXCL1 or inhibiting the CXCL1-CXCR2 pathway effectively restores the radiosensitivity of radioresistant xenografts in vivo. Collectively, our study provides a comprehensive understanding of the molecular mechanisms underlying radioresistance and identifies potential targets to improve the efficacy of radiotherapy for ESCC.

Cost-effectiveness analysis of serplulimab plus chemotherapy in the first-line treatment for PD-L1-positive esophageal squamous cell carcinoma in China

Objective

The ASTRUM-007 trial (NCT03958890) demonstrated that serplulimab plus chemotherapy administered every 2-week significantly improved progression-free and overall survival in patients with previously untreated, programmed death-ligand 1 (PD-L1) positive advanced esophageal squamous-cell carcinoma (ESCC). This study was aimed to investigate the cost-effectiveness of serplulimab plus chemotherapy in the first-line treatment of PD-L1-positive advanced ESCC.

Methods

A partitioned survival model with a 2-week cycle and a 10-year time horizon was constructed from the Chinese healthcare system perspective. The survival data, direct medical costs and utilities were derived from the ASTRUM-007 trial, YAOZHI database and published sources. Total costs, quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios (ICERs) were calculated. Scenario, one-way and probabilistic sensitivity analyses were performed to assess the uncertainty around model parameters.

Results

Compared with chemotherapy, serplulimab plus chemotherapy provided additional 0.27 QALYs with an incremental cost of $33,460.86, which had an ICER of $124,483.07 per QALY. The subgroup analyses revealed that the ICERs of serplulimab plus chemotherapy were $134,637.42 and $105,589.71 in advanced ESCC patients with 1 ≤ CPS < 10 and CPS ≥ 10, respectively. The price of serplulimab, patient weight, utility values and discount rate were the most influential parameters on base-case results. At a willingness-to-pay threshold of three times per capita GDP ($40,587.59) in 2022, the probability of serplulimab plus chemotherapy being cost-effective was 0% compared with chemotherapy. When the price of serplulimab decreased by 70%, the probabilities of serplulimab plus chemotherapy being cost-effective were 81.42%, 67.74% and 96.75% in advanced ESCC patients with PD-L1-positive, PD-L1 1≤CPS<10 and CPS≥10, respectively.

Conclusion

Serplulimab plus chemotherapy in the first-line treatment for PD-L1-positive advanced ESCC might not be cost-effective in China.

Cost-effectiveness analysis of PD-1 inhibitors combined with chemotherapy as first-line therapy for advanced esophageal squamous-cell carcinoma in China

Objective: This study was aimed to investigate the cost-effectiveness of all available programmed death 1 (PD-1) inhibitors combined with chemotherapy in the first-line treatment of advanced esophageal squamous-cell carcinoma (ESCC) from the Chinese healthcare system perspective. Methods: A partitioned survival model with a 3-week cycle and a 10-year time horizon was constructed based on a network meta-analysis. The survival data and utility values were derived from clinical trials, and the direct medical costs were collected from public drug bidding database and published literature. Total costs, quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios (ICERs) were calculated. Scenario, one-way and probabilistic sensitivity analyses were performed to assess the uncertainty around model parameters. Results: Compared with mono-chemotherapy, toripalimab, sintilimab and camrelizumab plus chemotherapy were cost-effective treatment regimens, while serplulimab, pembrolizumab and nivolumab plus chemotherapy were not cost-effective options. Toripalimab plus chemotherapy provided the highest QALYs of 0.95 with the lower cost of $8,110.53 compared to other competing alternatives. The robustness of the base-case results was confirmed by scenario and one-way sensitivity analysis. At a willingness-to-pay threshold of three times per capita gross domestic product ($38,351.20) in 2021, the probability of toripalimab plus chemotherapy being the optimal option was 74.25% compared with other six competing alternatives. Conclusion: Toripalimab plus chemotherapy represented the most cost-effective option as the first-line therapy for advanced ESCC patients in China.

LncRNA SNHG6 Inhibits Apoptosis by Regulating EZH2 Expression via the Sponging of MiR-101-3p in Esophageal Squamous-Cell Carcinoma

Background

The long non-coding RNA (lncRNA) SNHG6 was significantly upregulated in esophageal squamous-cell carcinoma (ESCC), and it promoted ESCC cell proliferation, invasion, and migration. However, the effects of SNHG6 on cell apoptosis and the corresponding underlying mechanisms have not yet reported.

Methods

Apoptosis was detected by flow cytometric analysis. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were used for mRNA and protein quantification, respectively. A luciferase reporter assay was performed to verify downstream target genes for SNHG6 and miR-101-3p.

Results

Dysregulation of SNHG6 inhibited apoptosis in ESCC cells and regulated the expression of apoptosis-related proteins such as Bcl-2, Mcl-1, Bax and Caspase-3. Functionally, miR-101-3p could compete binding with 3′-untranslated region of SNHG6 and downregulation of miR-101-3p reversed its effect on cell apoptosis in SNHG6 knockdown cells. EZH2 was confirmed as a downstream target gene of miR-101-3p, silencing EZH2 expression had the same effect on apoptosis and protein expression as knocking down SNHG6. Overexpression of EZH2 reversed the effects of miR-101-3p overexpression on cell apoptosis in ESCC cells.

Conclusion

In this study, we found that upregulation of the lncRNA SNHG6 inhibited apoptosis via miR-101-3p/EZH2 axis in ESCC. These findings may contribute to the diagnosis and treatment of ESCC.

LincRNA-p21 leads to G1 arrest by p53 pathway in esophageal squamous cell carcinoma

Background: Esophageal squamous cell carcinoma (ESCC) is the fourth most common cause of cancer death in China. Long noncoding RNAs have emerged as critical regulators in cancer. Long intergenic noncoding RNA-p21, a kind of Long noncoding RNAs, LincRNA-p21 have been discussed dysregulated in several cancers, but its role in ESCC remains unknown. This study investigated the role of LincRNA-p21 in ESCC.

Materials and methods: The LincRNA-p21 expression level and its association with esophageal cancer was determined in 64 tumor tissues of esophageal squamous cell carcinoma patients and cells using quantitative real-time reverse transcription PCR. Fluorescence in situ hybridization of single-RNA molecular probes was used to determine subcellular localization of LincRNA-p21. CCK8 and EdU assays were used for proliferation assay, flow cytometry was performed for apoptosis and cell-cycle distribution, and 24-well Mill cell chamber was made for measuring the abilities of migration and invasion after transfected with lentivirus-expressing LincRNA-p21 in EC109 cells. Then, quantitative real-time reverse transcription PCR and Western blot detected the expression of p21. Further, UC2288, an inhibitor of p21, was used to decrease the level of p21, and flow cytometry was used to detect cell cycle. Finally, screening for differential pathways from microarray analysis and expression of p53 and cyclin D were detected by Western blot.

Results:LincRNA-p21 expression level was remarkably lower in tumor tissues versus nontumor tissues and lower in EC109 cells versus Het-1A cells. Statistical analysis found that LincRNA-p21 might enhance the risk of ESCC. We observed that LincRNA-p21 was expressed both in the nucleus and cytoplasm, and a larger proportion of LincRNA-p21 was observed in the cytoplasm. The results demonstrated that upregulating the expression of LincRNA-p21 could inhibit cell proliferation, migration, invasion, and the transition of cell cycle from G1 and promoted apoptosis of EC109. Then, we found that LincRNA-p21 promotes the expression of p21. Decreasing the level of p21 revealed that cell-cycle arrest was restored. Pathway analysis found p53 pathway was downregulated, and upregulation of LincRNA-p21 inhibited the expression of cyclin D.

Conclusion: Our study suggests that LincRNA-p21 plays as a tumor inhibitor in ESCC development and LincRNA-p21 might induce G1 arrest through p53 signal pathway.

Downregulation of microRNA-4324 promotes the EMT of esophageal squamous-cell carcinoma cells via upregulating FAK

Background: Esophageal squamous-cell carcinoma (ESCC) metastasis is the major cause of death of this severe and common malignancy. Focal adhesion kinase (FAK) is one of the key components of the focal adhesion complex, which is a multi-protein structure that controls cell adhesion, migration and invasion and regulates tumor metastasis. Purpose: To identify the roles and mechanisms of FAK in the regulation of Epithelial-to-mesenchymal transition (EMT) of ESCC cells. Methods: The expression of FAK and miR-4324 in both ESCC tissues and cells were evaluated by qRT-PCR and Immunohistochemistry analysis. Dual luciferase assays were performed for the confirmation of miR-4324's specific binding to 3'UTR of FAK mRNA. Besides, the trans-well assays and wound healing assays were employed to evaluate the effects of FAK /miR-4324 axis on the EMT regulation of ESCC cells. Furthermore, the relationship between miR-4374/FAK expression and clinical pathologic parameters & patient survival were also statistically analyzed. Results: In this study, we identified the upregulation of FAK and downregulation of miR-4324 in both ESCC cells and tissues. Overexpression of miR-4324 mimic, which significantly decreased cellular FAK levels, can impair the invasion potential and migration ability of ESCC cells. Besides, co-transfection of FAK can attenuate the function of miR-4324 mimic. Further experimental results demonstrated that miR-4324 mimic remarkably downregulated epithelial-to-mesenchymal transition (EMT) phenotype, which can also be effectively prevented by overexpressing FAK in ESCC cells. What's more, low miR-4324 and high FAK tissue levels have significant association with poor cell differentiation, tumor size and invasion depth as well as overall number of metastatic lymph nodes. Patients with high miR-4324 and low FAK levels in tumoral tissues lived longer than their counterparts, respectively. Conclusions: In conclusion, miR-4324/FAK axis could be a promising therapeutic target and potential prognostic biomarker for ESCC, which deserves further investigation in the clinic.

Cytoskeleton-associated protein 4 is a novel serodiagnostic marker for esophageal squamous-cell carcinoma

Background

Recent years have witnessed significant progress in the treatment of esophageal squamous-cell carcinoma (ESCC); however, the prognosis of ESCC is still unsatisfactory. Bio-markers are required to improve identification of high-risk populations and help management of ESCC. This study was to evaluate the role of serum CKAP4 in ESCC.

Methods

This longitudinal study recruited 207 ESCC patients and age-/sex-matched healthy controls. Circulating levels of CKAP4 were measured using ELISA kits, while the expression of CKAP4 in esophageal tissue was evaluated using Western blotting.

Results

Serum CKAP4 levels were higher in ESCC patients (380.2±171.3 pg/mL) than healthy controls (271.8±97.4 pg/mL; P<0.001). The area under the receiver-operating characteristic curve of serum CKAP4 levels to identify the presence of ESCC was 0.675 (95% CI 0.622–0.728; P<0.001). According to Youden’s index, the best cutoff value was 429.1 pg/mL (sensitivity 0.415 and specificity 0.995). Furthermore, after follow-up, multivariate analyses identified that pathological lymph node metastases were the poorest prognostic factor (HR 1.862, 95% CI 1.093–3.173; P=0.022), followed by serum CKAP4 (HR 1.437, 95% CI 1.025–2.014; P=0.035). When stratified by tertiles of serum CKAP4, subjects in the first tertile presented a mean survival time of 75.4 months (95% CI 68.0–81.9), which decreased significantly in the second tertile (73.8 months, 95% CI 61.4–86.3) and the third tertile (59.9 months, 95% CI 49.8–70.0, log-rank χ²=8.235; P=0.016).

Conclusion

These results suggested that serum CKAP4 could be a potential biomarker for clinical management of ESCC.

Identification of key genes and pathways for esophageal squamous cell carcinoma by bioinformatics analysis

The aim of the present study was to identify the differentially expressed genes (DEGs) in esophageal squamous-cellcarcinoma (ESCC) and provide potential therapeutic targets. The microarray dataset GSE20347 was downloaded from the Gene Expression Omnibus (GEO) database, and included 17 tissue samples and 13 normal adjacent tissue samples from patients with ESCC. A total of 22,277 DEGs were identified. A heat map for the DEGs was constructed with the Morpheus online tool and the top 200 genes (100 upregulated and 100 downregulated) were selected for further bioinformatics analysis, including analysis of gene ontology (GO) terms, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, protein-protein interaction networks and Spearman's correlation tests. The results of the GO analysis indicated that the upregulated DEGs were most significantly enriched in membrane-bounded vesicles in the cellular component (CC) category, but were not significantly enriched in any GO terms of the categories biological process (BP) or molecular function (MF); furthermore, the downregulated DEGs were most significantly enriched in regulation of DNA metabolic processes, nucleotide binding and chromosomes in the categories BP, MF and CC, respectively. The KEGG analysis indicated that the downregulated DEGs were enriched in the regulation of cell cycle pathways. The top 10 hub proteins in the protein-protein interaction network were cyclin-dependent kinase 4, budding uninhibited by benzimidazoles 1, cyclin B2, heat shock protein 90AA1, aurora kinase A, H2A histone family member Z, replication factor C subunit 4, and minichromosome maintenance complex component 2, −4 and −7. These proteins are mainly involved in regulating tumor progression. The genes in the four top modules were mainly implicated in regulating cell cycle pathways. Secreted Ly-6/uPAR-related protein (SLURP) was the hub gene, and SLURP and its interacting genes were most enriched in the chromosomal part in the CC category, organelle organization in the BP category and protein binding in the MF category, and were involved in pathways including DNA replication, cell cycle and P53 signaling. The expression of SLURP-1 in fifteen patients with esophageal carcinoma was detected using quantitative polymerase chain reaction analysis, and the results indicated that SLURP-1 expression was significantly decreased in the tumor samples relative to that in normal adjacent tissues. These results suggest that several hub proteins and the hub gene SLURP-1 may serve as potential therapeutic targets, and that gene dysfunction may be involved in the tumorigenesis of ESCC.

Tumor suppressor miR-128-3p inhibits metastasis and epithelial-mesenchymal transition by targeting ZEB1 in esophageal squamous-cell cancer

MicroRNAs (miRNAs) are some short RNAs that regulate multiple biological functions at post-transcriptional levels, such as tumorigenic processes, inflammatory lesions and cell apoptosis. Zinc finger E-box binding homeobox factor 1 (ZEB1) is a crucial mediator of epithelial-mesenchymal transition (EMT). It induces malignant progression of various cancers including human esophageal squamous-cell carcinoma (ESCC). In this study, we found that miR-128-3p was downregulated in ESCC tissues and cells by using PCR. Moreover, down-regulated expression of miR-128-3p was testified to be associated with poor prognosis of ESCC patients and might be regarded as an independent prognostic factor. Then, we examined the role of miR-128-3p in ESCC cells, and found that miR-128-3p could suppress the cell migration and invasion in vitro. Furthermore, ZEB1 was confirmed to be a direct target of miR-128-3p by luciferase reporter assay. Rescue experiments proved that EMT was regulated by miR-128-3p via suppression of ZEB1. Taken all together, we conclude that miR-128-3p suppresses EMT and metastasis via ZEB1, and miR-128-3p may be a critical mediator in ESCC.

Association of ECRG4 with PLK1, CDK4, PLOD1 and PLOD2 in esophageal squamous cell carcinoma

Esophageal cancer-related gene 4 (ECRG4) is a tumor suppressor gene associated with the prognosis of esophageal squamous-cell carcinoma (ESCC). Studies have reported that ECRG4 effectively inhibits the proliferation, migration and invasion of ESCC cells. In the current study, ectopic expression of ECRG4 significantly induced ESCC cell apoptosis. To further understand the molecular profile of ECRG4 overexpression in ESCC cells, tandem mass tag (TMT) labeling followed by LC-MS/MS analysis was applied on samples from ECRG4 overexpressed cells and control cells. Among the identified differentially expressed proteins, four up-regulated proteins (PLK1, CDK4, PLOD1 and PLOD2) associated with cell apoptosis, cell cycle and metastasis were chosen for the further investigation. The effects of ECRG4 protein levels on the expression of these four proteins were validated by manipulating the expression of ECRG4 in ESCC cells followed by Western blotting analysis. The immunohistochemical staining results showed a significant decrease in ECRG4 levels and a notable increase in the four proteins in ESCC samples as compared to matched esophageal tissues (n=75). More importantly, the protein levels of ECRG4 had a negative association with those of PLK1, CDK4, PLOD1 and PLOD2. Thus, our data suggested that the tumor-repressor functions of ECRG4 may be associated with PLK1, CDK4, PLOD1 and PLOD2, providing important insights into the molecular mechanisms of esophageal carcinogenesis.

The role of HGF/MET and FGF/FGFR in fibroblast-derived growth stimulation and lapatinib-resistance of esophageal squamous cell carcinoma

BACKGROUND

Although advanced esophageal squamous-cell carcinoma (ESCC) is treated using a multidisciplinary approach, outcomes remain unsatisfactory. The microenvironment of cancer cells has recently been shown to strongly influence the biologic properties of malignancies. We explored the effect of supernatant from esophageal fibroblasts on the cell growth and chemo-resistance of ESCC cell lines.

METHODS

We used 22 ESCC cell lines, isolated primary human esophageal fibroblasts and immortalized fibroblasts. We first examined cell proliferation induced by fibroblast supernatant. The effect of supernatant was evaluated to determine whether paracrine signaling induced by fibroblasts can influence the proliferation of cancer cells. Next, we examined the effects of adding growth factors HGF, FGF1, FGF7, and FGF10, to the culture medium of cancer cells. These growth factors are assumed to be present in the culture supernatants of fibroblasts and may exert a paracrine effect on the proliferation of cancer cells. We also examined the intrinsic role of HGF/MET and FGFs/FGFR in ESCC proliferation. In addition, we examined the inhibitory effect of lapatinib on ESCC cell lines and studied whether the fibroblast supernatants affect the inhibitory effect of lapatinib on ESCC cell proliferation. Finally, we tested whether the FGFR inhibitor PD-173074 could eliminate the rescue effect against lapatinib that was induced by fibroblast supernatants.

RESULTS

The addition of fibroblast supernatant induces cell proliferation in the majority of cell lines tested. The results of experiments to evaluate the effects of adding growth factors and kinase inhibitors suggests that the stimulating effect of fibroblasts was attributable in part to HGF/MET or FGF/FGFR. The results also indicate diversity in the degree of dependence on HGF/MET and FGF/FGFR among the cell lines. Though lapanitib at 1 μM inhibits cell proliferation by more than 50% in the majority of the ESCC cell lines, fibroblast supernatant can rescue the growth inhibition of ESCC cells. However, the rescue effect is abrogated by co-treatment with FGFR inhibitor.

CONCLUSION

These results demonstrate that cell growth of ESCC depends on diverse receptor tyrosine kinase signaling, in both cell-autonomous and cell-non-autonomous manners. The combined inhibition of these signals may hold promise for the treatment of ESCC.