Esophageal Squamous Cell Carcinoma Cancer Cells Research Articles

Lysophosphatidic acid promotes ESCC progression by increasing the level of CCL2 secreted by esophageal epithelial cells.

Lysophosphatidic acid (LPA) is a small bioactive lipid which acts as a potent regulator in various tumor progressions through six G-protein-coupled receptors (LPA1-LPA6). Our previous study demonstrated that the LPA-producing enzyme, autotaxin (ATX), was upregulated in esophageal squamous cell carcinoma (ESCC) and ATX high expression levels indicated a poor prognosis. Esophageal squamous cell carcinoma is a type of malignant tumor which originates from epithelial cells. Its progression can be affected by the interaction between cancer cells and normal cells. However, the impact of LPA on the interaction between esophageal epithelial cells and cancer cells in the development of ESCC remains uncertain. MTS and Edu assays were performed to determine ESCC cell proliferation in culture medium (CM) derived from LPA-stimulated esophageal epithelial cells (Het-1a). A wound healing assay, transwell migration and an invasion assay were performed to assess the metastatic ability of ESCC cells. Cytokine array analysis was conducted to detect the differentially secreted cytokines in CM. The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases were utilized to uncover the pathways and cytokines that are influenced by LPA in ESCC. Immunohistochemical staining was employed to measure the expression of ATX and CCL2 in early-stage ESCC. Quantitative real-time PCR, western blot, enzyme-linked immunosorbent assay and an antibody neutralization assay were employed to measure the mechanism of LPA-mediated communication between epithelial cells and cancer cells. Functional experiments showed that exposing ESCC cancer cells to CM from LPA-treated Het-1a results in promoting proliferation, migration, invasion and epithelial-mesenchymal transition processes. Using cytokine array analysis, we discovered that LPA triggers the release of multiple cytokines from epithelial cells. After screening of the TCGA and GEO databases, CCL2 was identified and found to be correlated with ATX expression in ESCC. Furthermore, CCL2 levels in both mRNA expression and secretion were observed to be upregulated in epithelial cells upon stimulation with LPA. Blocking CCL2 effectively reduced the pro-migration influence of CM derived from LPA-treated Het-1a. Mechanism studies have demonstrated that LPA activated the NF-κB signaling pathway through LPA1/3, ultimately causing an increase in CCL2 expression and secretion in Het-1a. Our findings, taken together, demonstrate that CM from LPA-treated esophageal epithelial cells plays a significant role in promoting the progression of ESCC, with CCL2 acting as the primary regulator.

Preclinical efficacy of NXP900, a YES1/SRC kinase inhibitor in esophageal squamous cancer models.

e15133 Background: NXP900 (eCF506) is a novel potent and selective SRC family kinase (SFK) inhibitor, (IC50 of 0.47 nM against YES1). NXP900 locks its target into its native “closed” conformation (type 1.5 inhibitor), thereby inhibiting both kinase activity and complex formation with protein partners (Temps et al. Cancer Res. 2021, 81, 5438-5450). In contrast, multi-kinase inhibitors, including dasatinib and bosutinib, block SRC in the active “open” conformation (type 1 inhibitors) promoting the association of SFK and signaling partners via allosteric facilitation of conformational protein activation (Higuchi et al. Cell Rep 2021, 34, 108876). YES1 gene amplification is prevalent in several squamous cancers including esophageal squamous cell carcinoma (ESCC), lung SCC, head and neck SCC, and bladder cancer, indicating that YES1 would be an attractive target in these cancer types. Moreover, crosstalk between YES1 and the Hippo pathway suggests that NXP900 may have a therapeutic potential in squamous cancers with Hippo pathway alterations. Methods: Animal strain: CD1 Nude mice (Charles River). Human ESCC cancer cell lines: KYSE70, OE21, KYSE410, KYSE30 and OE19 cells (Sigma), TE5, and TE14 (Riken). Xenograft tumors were generated by subcutaneous implantation on the right lower flank of the thigh at a cell density of 2x106 to 1x107 cells/mouse at 0.1 mL Matrigel/cell dilution volume per injection. Experiment groups: Vehicle, NXP900 (40 mg/kg); treatment: QD for 28 days, oral gavage. Colony formation assay: 500 cells of 4 cell lines (KYSE70, OE21, KYSE410 and KYSE30) and 1500 cells of 3 cell lines (OE19, TE5 and TE14) were seeded in 24 well plates in triplicates; and treated with NXP900 for 14 days followed by staining with crystal violet. Results: NXP900 strongly inhibited cell proliferation of KYSE70, KYSE410, KYSE30, OE21, OE19, TE5 and TE14 in a colony formation assay. NXP900 significantly inhibited the activating phosphorylation of SRC in KYSE70 cells at 10 nM, while no effect was observed on the inhibitory tyrosine residues on YES1/FYN at 250 nM. Oral administration of NXP900 in a KYSE70 xenograft mouse model with YES1 gene amplification, resulted in an average decrease of tumor volume of 71% while in the vehicle control group tumor volume increased by 472% (p ≤ 0.001), demonstrating significant tumor regression. On Day 27, a mean increase from baseline in body weight of 2.0% and 3.5% was seen in the NXP900 and control groups respectively, indicating good tolerability. Conclusions: NXP900 is a novel potent and selective YES1/SRC kinase inhibitor with subnanomolar IC50 against YES1. NXP900 has marked antitumor efficacy in esophageal carcinoma models in vitro and in vivo providing substantial proof of concept for targeting solid tumors with YES1 and Hippo pathway alterations. IND enabling studies for NXP900 have been completed.

ANO1 reprograms cholesterol metabolism and the tumor microenvironment to promote cancer metastasis.

Tumor metastasis is a complex process. A better understanding of the mechanistic underpinnings of the metastatic cascade could uncover approaches to better prevent and target metastases. Here, we integrated transcriptomic profiling in primary esophageal squamous cell carcinoma (ESCC) and matched lymph node metastatic tissues and genome-wide CRISPR/Cas9 functional screening to identify the key drivers of cancer metastasis. Anoctamin 1 (ANO1) expression was found to be elevated in primary tumors and further increased in metastatic tissues. High expression of ANO1 was associated with poor patient survival, and ANO1 overexpression promoted cancer invasion and metastasis. Mechanistically, ANO1 inactivated the LXR pathway and increased intracellular cholesterol accumulation by interacting with JUN to repress the transcription of cholesterol hydroxylase, CYP27A1. In a paracrine manner, interleukin 1β (IL-1β) secreted from ANO1-expressing ESCC cancer cells activated NFκB signaling in fibroblasts to stimulate production of the chemokine CCL1, which in turn enhanced invasion of ESCC cancer cells. Furthermore, molecular docking and in silico screening of 1,500,000 small molecules identified K786-4469 as a lead compound that targeted ANO1 and suppressed cancer metastasis in vitro and in vivo. Overall, these findings uncover a non-canonical function of ANO1 in regulating cholesterol metabolism and fibroblast function, revealing ANO1 as a potential prognostic biomarker and therapeutic target for metastatic ESCC.

CPT1A promotes anoikis resistance in esophageal squamous cell carcinoma via redox homeostasis

Anoikis resistance was a prominent hallmark of cancer metastasis, and lipo-genic characteristics have been identified as another metabolic alteration during tumorigenesis. However, their crosstalk has not been fully elucidated, especially in advanced esophageal squamous cell carcinoma (ESCC). In this study, we showed, for the first time, that the key enzyme carnitine O-palmitoyl transferase 1 (CPT1A), which is involved in fatty acid oxidation (FAO), was markedly upregulated in ESCC cells upon detached culture via a metabolism PCR array. Overexpression of CPT1A was associated with poor survival of ESCC patients and could protect ESCC cells from apoptosis via maintaining redox homeostasis through supply of GSH and NADPH. Mechanistically, detached culture conditions enhanced the expression of the transcription factor ETV4 and suppressed the expression of the ubiquitin enzyme RNF2, which were responsible for the elevated expression of CPT1A at the mRNA and protein levels, respectively. Moreover, genetic or pharmacologic disruption of CPT1A switched off the NADPH supply and therefore prevented the anchorage-independent growth of ESCC cells in vitro and lung metastases of xenografted tumor models in vivo. Collectively, our results provide novel insights into how ESCC cancer cells exploit metabolic switching to form distant metastases and some evidence for the link between anoikis and FAO.

Multifunctional gold nanoparticle based selective detection of esophageal squamous cell carcinoma cells using resonance Rayleigh scattering assay

Esophageal squamous cell carcinoma (ESCC) is one of the most common cancers in China. Early and accurate diagnosis is the key to effective treatment of this disease. In this work, a resonance Rayleigh scattering (RRS) strategy was established to determine the concentration of epidermal growth factor receptor (EGFR) over-expressed ESCC cancer cells, which based on the selective binding of the anti-EGFR aptamer (Apt) and anti-EGFR antibody (Ab) multi-functionalized gold nanoparticles (AuNPs) probe (Apt-AuNPs-Ab) to the EGFR-positive cancer cell. When the probe was mixed with the Eca109 ESCC cancer cell, a distinct RRS intensity increase was observed. The probe possesses a dynamic range from 1.0 × 102-5.0 × 105 cell·mL−1 for Eca109 cells, and the detection limit is 20 cell·mL−1. Experimental results with the A2780 ovarian cancer cells line, as well as with the Eca109 ESCC cancer cell line, clearly demonstrated that the RRS assay was sensitive and selective to Eca109 than the other cancer cell lines that express a low level of EGFR. The proposed RRS assay provided a novel platform for detection of EGFR-positive cancer cells and shown the good potential for clinical diagnostics.

Arsenic nano complex induced degradation of YAP sensitized ESCC cancer cells to radiation and chemotherapy

BackgroundIncreased reactive oxygen species (ROS) production by arsenic treatment in solid tumors showed to be effective to sensitize cancer cells to chemotherapies. Arsenic nano compounds are known to increase the ROS production in solid tumors.MethodsIn this study we developed arsenic–ferrosoferric oxide conjugated Nano Complex (As2S2–Fe3O4, AFCNC) to further promote the ROS induction ability of arsenic reagent in solid tumors. We screen for the molecular pathways that are affect by arsenic treatment in ESCC cancer cells. And explored the underlying molecular mechanism for the arsenic mediated degradations of the key transcription factor we identified in the gene microarray screen. Mouse xenograft model were used to further verify the synthetic effects of AFCNC with chemo and radiation therapies, and the molecular target of arsenic treatment is verified with IHC analysis.ResultsWith gene expression microarray analysis we found Hippo signaling pathway is specifically affected by arsenic treatment, and induced ubiquitination mediated degradation of YAP in KYSE-450 esophageal squamous cell carcinoma (ESCC) cells. Mechanistically we proved PML physically interacted with YAP, and arsenic induced degradation PML mediated the degradation of YAP in ESCC cells. As a cancer stem cell related transcription factor, YAP 5SA over expressions in cancer cells are correlated with resistance to chemo and radiation therapies. We found AFCNC treatment inhibited the increased invasion and migration ability of YAP 5SA overexpressing KYSE-450 cells. AFCNC treatment also effectively reversed protective effects of YAP 5SA overexpression against cisplatin induced apoptosis in KYSE-450 cells. Lastly, with ESCC mouse xenograft model we found AFCNC combined with cisplatin treatment or radiation therapy significantly reduced the tumor volumes in vivo in the xenograft ESCC tumors.ConclusionsTogether, these findings suggested besides ROS, YAP is a potential target for arsenic based therapy in ESCC, which should play an important role in the synthetic effects of arsenic nano complex with chemo and radiation therapy.

RACGAP1 is transcriptionally regulated by E2F3, and its depletion leads to mitotic catastrophe in esophageal squamous cell carcinoma.

BackgroundRACGAP1 has significant involvement in tumorigenesis of cancers, including liver cancer, stomach cancer, and colon cancer. However, the role and the exact mechanism of RACGAP1 in esophageal squamous cell carcinoma (ESCC) has not been explored.MethodsQPCR and Western blots analysis was performed to analyze the expression of RACGAP1 in ESCC. MTT assays and colony formation assays were performed to explore the functional role of RACGAP1 in ESCC. Cell cycle analysis and immunofluorescence assays were used to investigate the function of RACGAP1 involvement in mitotic catastrophe. At last, we conducted the public datasets mining to explore the expression status and prognosis value of RACGAP1 as well as the correlation between RACGAP1 and E2F3 in various cancers.ResultsThe high abnormal expression of RACGAP1 is observed in ESCC and associated with worse clinical outcomes of patients with ESCC. RACGAP1, a novel cell cycle associated gene regulated by E2F3, acts as an oncogenic driver in ESCC cell lines. Notably, for the first time, RACGAP1 depletion induced severe mitotic catastrophe, followed by massive cell death.ConclusionsOur findings showed the essential role of RACGAP1 in ESCC cancer cell survival and the therapeutic potential of RACGAP1 as a molecular target for ESCC.

Characterization of super-enhancer-associated functional lncRNAs acting as ceRNAs in ESCC.

Long noncoding RNAs (lncRNAs) have important regulatory roles in cancer biology. Although some lncRNAs have well‐characterized functions, the vast majority of this class of molecules remains functionally uncharacterized. To systematically pinpoint functional lncRNAs, a computational approach was proposed for identification of lncRNA‐mediated competing endogenous RNAs (ceRNAs) through combining global and local regulatory direction consistency of expression. Using esophageal squamous cell carcinoma (ESCC) as model, we further identified many known and novel functional lncRNAs acting as ceRNAs (ce‐lncRNAs). We found that most of them significantly regulated the expression of cancer‐related hallmark genes. These ce‐lncRNAs were significantly regulated by enhancers, especially super‐enhancers (SEs). Landscape analyses for lncRNAs further identified SE‐associated functional ce‐lncRNAs in ESCC, such as HOTAIR, XIST, SNHG5, and LINC00094. THZ1, a specific CDK7 inhibitor, can result in global transcriptional downregulation of SE‐associated ce‐lncRNAs. We further demonstrate that a SE‐associated ce‐lncRNA, LINC00094 can be activated by transcription factors TCF3 and KLF5 through binding to SE regions and promoted ESCC cancer cell growth. THZ1 downregulated expression of LINC00094 through inhibiting TCF3 and KLF5. Our data demonstrated the important roles of SE‐associated ce‐lncRNAs in ESCC oncogenesis and might serve as targets for ESCC diagnosis and therapy.

Abstract 4472: Downregulation of POTEG predicts poor prognosis in esophageal squamous cell carcinoma

Abstract POTE ankyrin domain family, member G (POTEG) belongs to POTE family. The POTE gene family encodes very closely related proteins that are highly expressed in prostate, ovary, testis, and placenta. Recent studies indicated that the POTE proteins have a pro-apoptotic function. To examine whether POTEG also underwent apoptosis in ESCC cancer cells and the functions of POTEG in the development of esophageal squamous cell carcinoma (ESCC), we determined the location and expression of POTEG in ESCC cancer cells. Clinical association studies determined that POTEG downregulation was associated with poor clinical outcomes. Ectopic re-expression of POTEG effectively suppressed the tumorigenesis and metastasis of ESCC cells in vitro and in vivo, including the inhibition of cell growth rate, foci formation, soft agar colony formation, migration, invasion and tumor formation in nude mice. Molecular analyses revealed that POTEG downregulated CDKs, leading to subsequent inhibition of Rb phosphorylation, and consequently arrested Cell Cycle at G1/S Checkpoint. Prospectively, POTEG can reduce the level of anti-apoptotic proteins, while promote the level of proapoptotic proteins and inducing apoptosis. On the other side, POTEG inhibit metastasis by reducing epithelial-mesenchymal transition in ESCCs. Taken together, our results revealed that POTEG has a pivotal function in ESCC pathogenesis, with possible use as a biomarker and intervention point for new therapeutic strategies. Citation Format: Yan Li. Downregulation of POTEG predicts poor prognosis in esophageal squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4472.

ADAMTS-6 is a predictor of poor prognosis in patients with esophageal squamous cell carcinoma

BackgroundA disintegrin and metalloprotease with thrombospondin motif (ADAMTS) enzymes play important roles in cell functions including adhesion, invasion, migration, and proliferation. ADAMTS-6 is a member of the ADAMTS family; reports of its relationship with esophageal squamous cell carcinoma (ESCC) progression are rare. It is unclear whether ADAMTS-6 could be an independent ESCC biomarker. MethodsADAMTS-6 expression was detected by immunohistochemistry (IHC) in 171 paraffin-embedded ESCC specimens; relationships with patients' clinicopathological features and Twist-1 expression were analyzed by the Pearson Chi-square method, respectively. Overall survival (OS) and disease-free survival (DFS) were determined using the Kaplan–Meier method and compared using the long-rank test. ResultsADAMTS-6 was expressed mainly in the cytoplasm and nucleus; the expression was significantly higher in tumor tissues. Increased expression of ADAMTS-6 correlated with clinical stage (P = 0.009), pT stage (P = 0.042), lymph node metastasis (P = 0.014) and recurrence (P = 0.033). There were no significant correlations between ADAMTS-6 expression and other clinicopathological parameters including age, sex, tumor size, distant metastasis, differentiation, …chemotherapy, radiotherapy, CD68 expression and epithelial mesenchymal transition (EMT) status. Kaplan–Meier survival curves revealed that upregulated expression of ADAMTS-6 indicated short OS (P = 0.001) and DFS (P = 0.002). Multivariate analysis confirmed that high ADAMTS-6 expression was an independent factor for ESCC prognosis. ADAMTS-6 expression was significantly correlated with Twist-1 expression in ESCC cancer cells (P = 0.007) and stromal cells (P < 0.001). Patients with ESCC revealing expression of both ADAMTS-6 and Twist-1 exhibited significantly reduced OS and DFS rates than other patients. ConclusionsHigh ADAMTS-6 expression is a useful marker of poor prognosis in patients with ESCC.

NKILA inhibits NF-κB signaling and suppresses tumor metastasis.

The long non-coding RNA (lncRNA) NKILA (nuclear transcription factor NF-κB interacting lncRNA) functions as a suppressor in human breast cancer and tongue cancer. However, the clinical significance and biological roles of NKILA in esophageal squamous cell carcinoma (ESCC) remain unknown. In this study, we showed that NKILA was downregulated in ESCC tissues and cancer cells compared with their normal counterparts. Low NKILA expression correlated with large tumor size and advanced TNM stage, and predicted poor overall and disease-free survival of ESCC patients. Further loss- and gain-of-function assays indicated that NKILA inhibited proliferation and migration of ESCC cells in vitro, suppressed tumor growth and lung metastasis in vivo. Mechanistically, NKILA could inhibit phosphorylation of IκBα, suppress p65 nuclear translocation and downregulate the expression of NF-κB target genes in ESCC cells. These results suggest NKILA could suppress malignant development of ESCC via abrogation of the NF-κB signaling and may potentially serve as a prognostic marker for ESCC.

Abstract 2538: MiR-638 promotes autophagy and malignant phenotypes of cancer cells via directly suppressing DACT3

Abstract Dyregulation of autophagy is implicated in human cancers and the mechanism details remains largely unclear. Herein we report the regulatory role of miR-638 in autophagy of esophageal squamous cell carcinoma (ESCC) and breast cancer cells. We found that miR-638 overexpression promotes starvation- and rapamycin-induced autophagy. In ESCC and breast cancer cells, miR-638 acts as an oncogene and promote cell proliferation, migration, as well as invasion in vitro and in vivo. In accordance with this, we observed significantly higher miR-638 expression in ESCC and breast cancer tissues compared to normal tissues. To further elucidate regulatory mechanisms of miR-638 in autophagy, we performed a computational nomination of its target genes through intersecting the results of multiple prediction algorithms. DACT3, a key regulator of Wnt/β-catenin signaling, was predicted to be regulated by miR-638 by all programs and confirmed by experimental results. Depletion of DACT3 phenocopied effects of miR-638 overexpression, demonstrating its importance in autophagy. These results elucidate that the miR-638-DACT3 axis might be an important molecular pathway in controlling and autophagy and tumorigenesis. Our data in clinical tissue samples highlight miR-638 and DACT3 with histological marker for cancer detection and potentially therapeutic implications. Citation Format: Ming Yang. MiR-638 promotes autophagy and malignant phenotypes of cancer cells via directly suppressing DACT3 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2538. doi:10.1158/1538-7445.AM2017-2538

Regulation of SPOCK1 by dual strands of pre-miR-150 inhibit cancer cell migration and invasion in esophageal squamous cell carcinoma.

Analysis of our microRNA (miRNA) expression signatures of human cancers based on RNA sequencing have shown that both strands of pre-miR-150, miR-150-5p (the guide strand) and miR-150-3p (the passenger strand), are significantly reduced in cancer tissues. We have investigated the functional significance of both strands of pre-miR-150 in cancer cells. The aim of this study was to investigate the antitumor function of these miRNAs and how these miRNAs regulated oncogenic targets in esophageal squamous cell carcinoma (ESCC). Ectopic expression studies demonstrated that both strands of pre-miR-150 miRNA inhibited ESCC cancer cell migration and invasion, indicating that both miR-150-5p and miR-150-3p acted as antitumor miRNAs. A combination of genome-wide gene expression analyses and in silico database searches showed that SPOCK1 (SPARC/osteonectin, cwcv and kazal-like domains proteoglycan 1) was a candidate target of miR-150-5p and miR-150-3p in ESCC cells. Luciferase reporter assays showed that SPOCK1 was directly regulated by these miRNAs. Silencing of SPOCK1 by small interfering RNA inhibited cancer cell migration and invasion. Overexpression of SPOCK1/SPOCK1 was confirmed by real-time PCR methods and immunohistochemistry. Taken together, downregulation of both strands of pre-miR-150 and overexpression of SPOCK1 are involved in ESCC pathogenesis. The involvement of passenger strand miRNAs in the regulation of cancer cell aggressiveness is a novel concept in RNA research.

Twist1 is highly expressed in cancer-associated fibroblasts of esophageal squamous cell carcinoma with a prognostic significance.

Cancer-associated fibroblasts (CAFs) play important roles in cancer progression. Twist1 was recently reported to be a key regulator of CAFs in gastric cancer, but its role in other types of cancer remains unclear, especially for esophageal squamous cell carcinoma (ESCC). We assessed the Twist1 expression on stromal fibroblasts using immunohistochemistry in 169 tissue specimens from ESCC patients, and performed in vitro and in vivo experiments to confirm the role of Twist1 in CAFs of ESCC. And we investigated the biological pathways that are activated in Twist1-high ESCC using The Cancer Genome Atlas (TCGA) data. The expression of Twist1 in stromal fibroblasts was observed in 89.9% of ESCC patients and positively associated with the increased depth of tumor invasion, lymph node metastasis, and advanced clinical stage, and a significant adverse prognostic factor in overall survival. Twist1-expressing stromal fibroblasts also expressed representative CAF markers, and co-localization of Twist1 and CAF markers were confirmed by confocal immunofluorescence imaging. Bioinformatic analysis of mRNA expression data of esophageal cancer from TCGA revealed that gene sets of CAFs were highly enriched in Twist1-high ESCC. Depletion of Twist1 in ex vivo cultured ESCC CAFs induced significant decrease in migration, invasion, colony formation, sphere formation, and contractibility of ESCC cancer cells compared to control CAFs. Furthermore, Twist1-expressing fibroblasts remarkably enhanced the in vivo tumorigenicity of ESCC in a xenograft model. In conclusion, Twist1 could be a novel CAF marker for the prognostic evaluation of ESCC patients as well as a potent therapeutic target for ESCC.

Association between periostin and epithelial-mesenchymal transition in esophageal squamous cell carcinoma and its clinical significance.

The present study aimed to investigate the association between periostin (POSTN), epithelial cadherin (E-cad) and vimentin (Vim) expression levels in esophageal squamous cell carcinoma (ESCC) tissues, and its clinicopathological significance. A total of 58 patients with esophageal cancer were enrolled. Immunohistochemistry was performed to quantify the expression levels of POSTN, E-cad and Vim. E-cad expression was reduced in ESCC tissue, which was associated with severe tumor node metastasis (TNM) stage (P<0.001), lymphatic metastasis (P<0.001) and vascular invasion (P=0.026). Conversely, Vim expression was found to be increased in ESCC tissues, and had associations with TNM stage (P=0.039) and lymphatic metastasis (P=0.039). POSTN overexpression observed in ESCC cells was associated with attenuation of E-cad expression (P<0.001) and elevated expression levels of Vim (P<0.001). Additionally, significant correlations between the overexpression of POSTN in ESCC cells and clinicopathological variables including TNM staging (P=0.009), degree of differentiation (P<0.001), lymphatic metastasis (P=0.009) and vascular invasion (P=0.002) were verified. Multivariate analysis revealed that overexpression of POSTN in ESCC cancer cells is able to predict the poor prognosis of patients independently of overall survival (P=0.022) and disease free survival (P=0.019). The preliminary findings of the present study demonstrate that POSTN is involved in the epithelial-mesenchymal transition of ESCC cells, and may therefore be a predictive factor for tumor invasion and metastasis, as well as an indicator of poor prognosis for patients with ESCC.

MiRNA-638 promotes autophagy and malignant phenotypes of cancer cells via directly suppressing DACT3

Dyregulation of autophagy is implicated in human cancers and the mechanism details remains largely unclear. Herein we report the regulatory role of miR-638 in autophagy of esophageal squamous cell carcinoma (ESCC) and breast cancer cells. We found that miR-638 overexpression promotes starvation- and rapamycin-induced autophagy. In ESCC and breast cancer cells, miR-638 acts as an oncogene and promotes cell proliferation, migration, as well as invasion in vitro and in vivo. In accordance with this, we observed significantly higher miR-638 expression in ESCC and breast cancer tissues compared to normal tissues. To further elucidate regulatory mechanisms of miR-638 in autophagy, we performed a computational nomination of its target genes through intersecting the results of multiple prediction algorithms. DACT3, a key regulator of Wnt/β-catenin signaling, was predicted to be regulated by miR-638 by all programs and confirmed by experimental results. Depletion of DACT3 phenocopied effects of miR-638 overexpression, demonstrating its importance in autophagy. These results elucidate that the miR-638-DACT3 axis might be an important molecular pathway in controlling autophagy and tumorigenesis. Our data in clinical tissue samples highlight miR-638 and DACT3 as histological marker for cancer detection and their potentially therapeutic implications.

Abstract 4980: Upregulation of PD-L1 expression by cisplatin in esophageal squamous cell carcinoma cells is independent of interferon/JAK/STAT pathway

Abstract Introduction Blockade of immune check points, especially the program cell death 1 (PD-1) and its major ligand PD-L1 signaling, has become an important mode of therapy against cancers. The upregulation of PD-L1 expression in cancer cells is an important mechanism contributing to immune evasion of cancers. The PD-L1 upregulation in cancer cells could be mediated by intrinsic genetic or signaling alterations, or could be induced in response to specific cytokines, in particular interferon (IFN)-gamma, produced by tumor-infiltrating immune cells. Whether chemotherapy per se has direct impact on PD-L1 expression in cancer cells is currently unclear. Materials and Methods Four esophageal squamous cell carcinoma (ESCC) cell lines, TE5, KYSE70, KYSE270, KYSE510, were included. The expression of PD-L1 in ESCC cells, treated with various concentrations of cisplatin, were evaluated by flow cytometry, Western blotting, and qRT-PCR. To study the potential signaling pathways involved in the PD-L1 upregulation induced by cisplatin, we evaluated the nuclear expression of p-STAT1 and IRF1 (for IFN/JAK/STAT pathway), and p65 and p50 (for NF-kB pathway). Finally, we used BAY-11-7082, an irreversible inhibitor of IKKα, to validate the significance of NF- kB pathway in mediating the PD-L1 upregulation induced by cisplatin. Results Cisplatin at the doses of 5∼ 10 μM increased the proportions of PD-L1-expressing cells detected by flow cytometry in all tested ESCC cells. The folds of increase were 19.29±2.27, 10.13±8.42, 23.19±10.12, 6.20±0.81 for TE5, KYSE70, KYSE270, and KYSE510 treated with 10 μM of cisplatin, respectively. The kinetics of this cisplatin- induced PD-L1 expression, evaluated in TE5 cells, was: after exposure to cisplatin for 24 hours, the PD-L1 expression peaked at 48 hours, and remained elevated at 144 hours after drug exposure. In multiple ESCC cells, exposure to cisplatin did not increase the expression of p-STAT1 and IRF1, suggesting that IFN/JAK/STAT pathway did not involve in the PD-L1 upregulation induced by cisplatin. In co-culture experiments with cisplatin-treated TE5 cells or with condition medium from cisplatin-treated TE5 cells, we confirmed that the PD-L1 upregulation in ESCC cells was not through paracrine manners. In TE5 cells, cisplatin treatment induced nuclear translocation of p65, suggesting that NF-kB pathway was activated. The cotreatment of BAY11-7082 could partially abrogate the PD-L1 upregulation induced by cisplatin in TE5 cells. Conclusion PD-L1 expression in ESCC cancer cells can be up-regulated by cisplatin. Our data indicated that this activation is not mediated through the IFN/JAK/STAT pathway, but may involve in activation of NF-κB signaling. (The study was supported by the grant NTUH 104-M2891 and the grant MOST 104-2314-B-002-111) Citation Format: Ta-Chen Huang, Kuan-Ling Lin, Ann-Lii Cheng, Chih-Hung Hsu. Upregulation of PD-L1 expression by cisplatin in esophageal squamous cell carcinoma cells is independent of interferon/JAK/STAT pathway. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4980.

Establishment of using serum YKL-40 and SCCA in combination for the diagnosis of patients with esophageal squamous cell carcinoma.

BackgroundElevated serum YKL-40 levels have been observed in various cancers. We evaluated the diagnostic performance of serum YKL-40 alone or in combination with the CEA, CYFRA21-1 and SCCA tumor markers for patients with esophageal squamous cell carcinoma (ESCC).MethodsYKL-40 was detected in ESCC cell lines and tissues by real-time RT-PCR, Western blotting and ELISA. YKL-40 protein expression was determined in 20 ESCC tumor tissues using immunohistochemistry. Serum YKL-40 was measured by ELISA in 126 healthy donors, 59 patients with benign esophageal diseases and 150 patients with ESCC. Serum CEA, CYFRA21-1 and SCCA were determined by electrochemiluminescence.ResultsYKL-40 mRNA and protein were observed in ESCC cancer cell lines, tissues and cell culture media, respectively. YKL-40 expression was observed in 17 of 20 ESCC samples (85%). Serum YKL-40 concentration was significantly elevated in patients with ESCC (Range: 6.95-502.10 ng/ml) compared with patients with benign diseases (Range: 1.21-429.30 ng/ml; P = 0.038) and healthy controls (Range: 2.56-132.26 ng/ml; P < 0.001). ROC curves demonstrated that serum YKL-40 has a sensitivity of 72.70%, a specificity of 84.13% and an AUC of 0.874 for the diagnosis of ESCC, which was superior to CEA (Sen: 8.00%; Spe: 96.80%, AUC = 0.652), CYFRA21-1 (Sen: 40.00%; Spe: 92.06%, AUC = 0.746) and SCCA (Sen: 32.67%; Spe: 94.44%, AUC = 0.789). The YKL-40 and SCCA combination was better for diagnosing ESCC (Sen: 82.00%, Spe: 79.37%, PPV: 82.55 and NPV: 78.74; AUC = 0.917) than the YKL-40 and CEA combination (Sen: 74.00%, Spe: 83.20%, PPV: 84.09 and NPV: 72.73; AUC = 0.877), the YKL-40 and CYFRA21-1 combination (Sen: 82.00%, Spe: 77.78%, PPV: 81.46% and NPV: 78.40%; AUC = 0.897) or the CEA, CYFRA21-1 and SCCA combination (Sen: 56.67%, Spe: 84.80%, PPV: 81.73 and NPV: 61.99; AUC = 0.831). Associations between serum YKL-40 levels and the clinic characteristics of ESCC were not significant, with the exception of age (p = 0.001).ConclusionsESCC tumor cells and tissues express YKL-40. Serum YKL-40 may be a potential biomarker for ESCC. Serum YKL-40 in combination with SCCA significantly increases the sensitivity of detecting ESCC.

TPX2 expression is associated with cell proliferation and patient outcome in esophageal squamous cell carcinoma

The molecular and genetic changes underlying esophageal squamous cell carcinoma (ESCC) tumor formation and rapid progression are poorly understood. Using high-throughput data analysis, we examined molecular changes involved in ESCC pathogenesis and investigated their clinical relevance. Five independent microarray datasets were examined for differentially expressed genes and pathways. For validation, mRNA expression in tumor and matched normal tissues from 16 ESCC cases was examined by cDNA microarray, and protein expression in 97 ESCC specimens was investigated using immunohistochemical stains. The association between clinicopathological parameters and the expression of Aurora kinase A (Aurora-A) and TPX2 was analyzed. The impact of TPX2 expression was also assessed in ESCC cancer cells. AURKA and TPX2, members of the "Role of Ran in mitotic spindle regulation" pathway, were selected for further investigation. Verification by cDNA microarray showed that both genes were overexpressed in tumor tissues, and immunohistochemical staining showed Aurora-A and TPX2 expression in 88.4 and 90.6 % of ESCC specimens, respectively. High TPX2 expression was a significant prognosticator for overall and disease-free survival in univariate analysis and remained an independent prognostic factor in multivariate analysis (HR 1.802, p = 0.037). TPX2 knockdown clones showed inhibited cellular proliferation in growth curve studies and formed fewer colonies in the clonogenic assay. Using bioinformatics resources, which were validated by microarray analysis and immunohistochemistry stains, and manipulation of TPX2 expression in ESCC cell lines, we demonstrated that TPX2 expression is associated with cell proliferation and poor prognosis among patients with resected ESCC.

The enhancement of radiosensitivity in human esophageal squamous cell carcinoma cells by zoledronic acid and its potential mechanism

Esophageal squamous cell carcinoma (ESCC) has a low 5-year patient survival rate. Radiotherapy, as a preoperative or postoperative treatment of surgery, has a crucial role in improving local control and survival of ESCC. Various chemotherapeutic and biologic agents have been used as radio-sensitizers in combination with radiotherapy. Here, we demonstrate that zoledronic acid (ZOL) has a radio-sensitizing effect on ESCC cells. Exposure of ESCC cancer cells to ZOL plus radiation resulted in increased cell death through arresting the cell cycle between S and G2/M phases. ZOL appeared to inhibit proliferation, tube formation and invasion of endothelial cells. These anti-angiogenetic effects were more marked concurrently with irradiation. In addition, synergistic suppressive effects on VEGF expression were observed after combined treatment. Our data suggest that the combination of ZOL and radiation is a promising therapeutic strategy to enhance radiation therapy for ESCC patients.