Esophageal Squamous Cell Lines Research Articles

TET2 Is Downregulated in Early Esophageal Squamous Cell Carcinoma and Promotes Esophageal Squamous Cell Malignant Behaviors.

To explore the expression of the ten eleven translocation (TET) 2 protein in early esophageal squamous cell carcinoma (EESCC), precancerous lesions, and cell lines and to evaluate the effect of TET2 on the functional behavior of EC109 esophageal cancer cells. Thirty-one samples of EESCC and precancerous lesions collected via endoscopic submucosal dissection at Taihe Hospital, Shiyan, from February 1, 2017, to February 1, 2019, were analyzed. The study involved evaluating TET2 expression levels in lesion tissue and adjacent normal epithelium, correlating these with clinical pathological features. Techniques including 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide, cell scratch assays, flow cytometry for propidium iodide (PI) staining, Hoechst 333258/PI double staining, and nude mouse tumorigenesis experiments were employed to assess the effect of TET2 on the proliferation, migration, cell cycle, apoptosis, and tumorigenic ability of esophageal cancer cells. TET2 expression was notably reduced in early esophageal cancer tissue and correlated with tumor invasion depth (P < 0.05). Overexpression of TET2 enhanced the proliferation and migration of esophageal cancer cells, increased the cell population in the G0 phase, decreased it in the S phase, and intensified cell necrosis (P < 0.05). There was a partial increase in tumorigenic ability (P = 0.087). TET2 downregulation in ESCC potentially influences the necrosis, cell cycle, and tumorigenic ability of esophageal cancer cells, suggesting a role in the onset and progression of esophageal cancer.

Raltitrexed enhanced antitumor effect of anlotinib in human esophageal squamous carcinoma cells on proliferation, invasiveness, and apoptosis

BackgroundAnlotinib is a multi-targeted receptor tyrosine kinase inhibitor (TKI) which has exhibited encouraging clinical activity in advanced non-small cell lung cancer (NSCLC) and soft tissue sarcoma. Raltitrexed is well known to be effective in the treatment of colorectal cancer in China. The present study aims to investigate the combinatory antitumor effect of anlotinib and raltitrexed on human esophageal squamous carcinoma cells and further explore the molecular mechanisms in vitro.MethodsHuman esophageal squamous cell lines KYSE-30 and TE-1 were treated with anlotinib or raltitrexed, or both, then cell proliferation was measured by MTS and colony formation assay; cell migration and invasion were detected by wound-healing and transwell assays; cell apoptosis rate was studied by flow cytometry and the transcription of apoptosis-associated proteins were monitored by quantitative polymerase chain reaction (qPCR) analysis. Finally, western blot was performed to check phosphorylation of apoptotic proteins after treatment.ResultsTreatment with raltitrexed and anlotinib showed enhanced inhibitory effects on cell proliferation, migration and invasiveness compared with raltitrexed or anlotinib monotherapy. Meanwhile, raltitrexed combined with anlotinib strongly increased cell apoptosis percentage. Moreover, the combined treatment down-regulated mRNA level of the anti-apoptotic protein Bcl-2 and invasiveness-associated protein matrix metalloproteinases-9 (MMP-9), while up-regulated pro-apoptotic Bax and caspase-3 transcription. Western blotting showed that the combination of raltitrexed and anlotinib could inhibit the expression of phosphorylated Akt (p-Akt), Erk (p-Erk) and MMP-9.ConclusionsThis study indicated that raltitrexed enhanced the antitumor effects of anlotinib on human ESCC cells by down-regulating phosphorylation of Akt and Erk, providing a novel treatment option for patients with esophageal squamous cell carcinoma (ESCC).

Abstract 5407: Targeting NRF2 using specific inhibitor brusatol sensitized esophageal adenocarcinoma cells to cisplatin through inducing ferroptosis

Abstract Background: The incidence rate of the esophageal adenocarcinoma (EAC) has increased rapidly among men during the past four decades in the USA and western countries while the 5 year survival rate is still below 20%. Traditional chemotherapy is still the main stream strategy in treatment of EAC patients. However, chemo-resistance usually develops that finally leads to failure of treatments. NFE2-related factor 2 (NRF2) is the master regulator of cellular anti-oxidant properties that maintains cell viability and cellular homeostasis. Overexpression of NRF2 in human cancers are associated with drug-resistance and poor prognosis. Methods and Results: NRF2 protein levels are higher in several EAC cell lines, as compared to BE cell lines (CPA, BAR10T) and normal esophageal squamous cell lines, using Western blot analysis. We confirmed NRF2 overexpression in primary EAC samples, using immunohistochemistry on a tissue microarray that contained 76 EACs. Brusatol is an NRF2 specific inhibitor originated from natural plant. Administration of Brusatol in EAC cells significantly inhibited NRF2 ARE luciferase activity and reduced gene expression of NRF2 target genes such as GR, HO1, GSTM2, GPX3 and GPX4, resulting in a significant increase in cellular ROS levels, which were further increased by treatment with CDDP with subsequent increase in cancer cell death. Further investigation revealed that Brusatol significantly increased lipid peroxidation levels as detected by immunofluorescence assay and flow cytometry and resulted in significant ferroptosis, in particular in combination with CDDP treatments. We confirmed that Brusatol in combination with CDDP significantly suppressed tumor growth in a xenografting mice model. Conclusion: Constitutive overexpression of NRF2 in EAC cells favors tumor cell survival and drug resistance. NRF2 specific inhibitor may synergize with traditional chemotherapeutic drugs by inducing lipid peroxidation and ferroptosis in EAC. Citation Format: Dunfa Peng, Tianling Hu, Lei Chen, Heng Lu, Shoumin Zhu, Wael El-Rifai. Targeting NRF2 using specific inhibitor brusatol sensitized esophageal adenocarcinoma cells to cisplatin through inducing ferroptosis [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 5407.

COX-2 strengthens the effects of acid and bile salts on human esophageal cells and Barrett esophageal cells

AimsInvestigate the effect and mechanism of COX-2 on viability, intestinal metaplasia, and atypia in human esophageal squamous and Barrett esophageal cell lines.MethodsHuman esophageal squamous and Barrett esophageal cell lines were transfected with a COX-2 expression vector and a COX-2 siRNA, and then were treated with acid, bile salts, and a mixture of both. Cell viability, the expression of COX-2, NF-κB(p65), CDX-2, MUC2, c-myb, and BMP-4, and the morphology and microstructure of cells were then observed.ResultsThe viability of COX-2 overexpressed cells was significantly higher than that of control cells, while the viability of COX-2 siRNA-treated cells was significantly lower than that of control cells. Intestinal metaplasia and atypia were observed in cells overexpressing COX-2. Acid, bile salts, and their mixture inhibited the viability of these two cell lines, but the inhibitory effect of the mixture was stronger than a single treatment in either. SiRNA mediated knockdown of COX-2 strengthened the antiproliferative effects of the mixture on HET-1A and BAR-T cells. The expression of p-p65, CDX-2, and BMP-4 was positively correlated with COX-2 expression, while the expression levels of p65, MUC2, and c-myb remained unchanged.ConclusionCOX-2 may influence the viability, atypia, and intestinal metaplasia of human esophageal cells and Barrett esophageal cells. Activation of the p-p65, CDX-2, and BMP-4 signaling pathways by COX-2 may be part of this mechanism.

Knockdown of EphB3 inhibits cell proliferation partly through the AKT signaling pathway and represses epithelial-mesenchymal transition in esophageal squamous cell carcinoma.

BackgroundTo investigate the role and mechanism of erythropoietin-producing hepatocyte receptor B3 (EphB3) in cancer of esophageal squamous cells.MethodsEphB3 expression in esophageal carcinoma squamous tissue and cell lines was determined by immunohistochemistry, western blotting and qRT-PCR. The viability, invasion and migration of cells were assessed by Transwell assay, formation of colonies, CCK-8, and healing of wounds, respectively. Flow cytometry analysis was employed to evaluate the actions of EphB3 on the activity of the cell cycle and the degree of apoptosis. The activity of EphB3 on the growth of tumors in vivo was examined in a mouse xenograft model.ResultsEphB3 was highly expressed in esophageal squamous cell cancer tissue and was positively correlated with cell differentiation, metastasis in lymph node and the TNM stage. Patients with higher EphB3 expression had poorer prognosis in 3-year overall survival rate. EphB3 also overexpressed in esophageal squamous cell cancer cell lines. Knock down of EphB3 expression suppressed proliferation, migration and the invasion of cells in vitro and was shown to delay the growth of tumors in vivo. Silencing of EphB3 reduced the expression of pAKT, cyclinD1 and altered the epithelial-mesenchymal transition (EMT) process. Furthermore, AKT signal pathway agonist SC79 reversed EphB3 downregulation-mediated inhibition of cell proliferation, migration, invasion and EMT process.ConclusionsEphB3 knockdown inhibited the proliferation of esophageal squamous cell cancer partly through the AKT signaling pathway and repressed cell migration and invasion via EMT reversion. The findings of the study suggested that EphB3 might be a novel target for the therapy of esophageal carcinoma.

Galangin Enhances Anticancer Efficacy of 5-Fluorouracil in Esophageal Cancer Cells and Xenografts Through NLR Family Pyrin Domain Containing 3 (NLRP3) Downregulation.

BackgroundGalangin is believed to exert antioxidant effects by inhibition of the NLR family pyrin domain containing 3 (NLRP3) inflammasome, which has been linked to chemotherapy sensitivity in cancers. In this study, we explored the synergistic effect of galangin in combination with the chemotherapy agent 5-fluorouracil (5-FU) in esophageal cancer cells and xenografts.Material/MethodsThe esophageal squamous epithelium cell line Het-1A and 2 human esophageal cancer cell lines (Eca109, OE19) were used to investigate the effect of galangin with or without 5-FU in vitro through proliferation and invasion analyses, while apoptosis was analyzed in cancer cells. Furthermore, a subcutaneous xenograft tumor model in mice was used to study cancer development in vivo.ResultsCompared with 5-FU monotherapy, combined galangin and 5-FU treatment reduced human esophageal cancer cell growth activities and invasion abilities. The results suggested that galangin had a chemotherapy-sensitized synergistic antitumor effect induced by 5-FU. The susceptibility of cancer cells to apoptosis, which is linked with chemotherapy sensitivity, was induced by 5-FU and further enhanced by galangin. NLRP3 was identified as being significantly activated by 5-FU, but galangin treatment reversed the effect and inhibited NLRP3 expression, which was accompanied by downregulated interleukin-1β levels. Further investigation showed that the induced apoptotic cascade can be mostly reversed by incubation with an NLRP3 activator, irrespective of AKT signaling. Using xenograft mouse models, we found that galangin exposure further restrained cancer development after 5-FU treatment and increased sensitivity to chemotherapy by suppressing the NLRP3 inflammasome pathway.ConclusionsOur results indicated that galangin played a synergistic anticancer role through NLRP3 inflammasome inhibition when paired with FU-5.

Forkhead box F1 induces columnar phenotype and epithelial-to-mesenchymal transition in esophageal squamous cells to initiate Barrett's like metaplasia

Multiple genome-wide association studies (GWAS) have linked Forkhead Box F1 (FOXF1) to Barrett's esophagus (BE). Understanding whether FOXF1 is involved in initiation of Barrett's metaplasia could allow FOXF1 to be used for risk stratification and for therapy. Two-dimensional cell cultures and three-dimensional organoid cultures and well-annotated human biopsies were used to determine the role of FOXF1 in BE pathogenesis. Multiple established esophageal squamous and BE cell lines were tested in gain- and loss-of-function studies. Initiation of a BE-like metaplastic change was evaluated by measuring characteristic cytokeratins and global gene expression profiling and by culturing organoids. Epithelial–mesenchymal transition (EMT) was evaluated by immunostaining for E-cadherin, vimentin and Snail, and by cell motility assay. Columnar esophageal epithelium of BE patients exhibited higher expression of FOXF1 compared to normal squamous esophageal epithelium of GERD patients (P < 0.001). Acidic bile salts induced nuclear FOXF1 in esophageal squamous cells. FOXF1 overexpression in normal esophageal squamous cells: (a) increased columnar cytokeratins and decreased squamous cytokeratins, (b) converted squamous organoids to glandular organoids, and (c) switched global gene profiles to resemble that of human BE epithelium (P = 2.1685e − 06 for upregulated genes and P = 8.3378e − 09 for downregulated genes). FOXF1 inhibition in BE cell lines led to loss of BE differentiation markers, CK7, and mucin 2. Also, FOXF1 induced EMT and promoted cell motility in normal esophageal squamous epithelial cells. FOXF1-induced genes mapped to pathways such as Cancer, Cellular Assembly and Organization, DNA Replication, Recombination, and Repair. In conclusion, FOXF1 promotes a BE-like columnar phenotype and cell motility in esophageal squamous epithelial cells, which may have a critical role in BE development. FOXF1 should be studied further as a biomarker for BE and as a target for BE treatment.

[Effect of miR-146a on biological behavior of esophageal squamous cell carcinoma cells and its mechanism].

Objective: To investigate the effects and mechanisms of miR-146a on the proliferation, invasion, migration, apoptosis and cell cycle of esophageal squamous cell carcinoma cells. Methods: The expressions of miR-146a in 3 esophageal squamous carcinoma cell lines (Eca109, KYSE140, KYSE150) were detected by real-time quantitative polymerase chain reaction (RT-qPCR). MiR-146a mimics was transfected into Eca109 to up-regulate the expression of miR-146a. Effects of miR-146a on cell proliferation, invasion and migration were evaluated by cell counting kit 8 (CCK-8), Transwell assay and wound-healing assay, respectively. The cell apoptosis and cycle were assessed by flow cytometry (FCM). Finally, relevant bioinformatics techniques were used to predict the target gene of miR-146a. Dual luciferase reporter assay was used to identify the interaction of 3' terminal untranslated region (3' UTR) of miR-146a and its target gene, interleukin-1 receptor-associated kinase (IRAK1). RT-qPCR and western blot were used to detect the mRNA and protein expressions of IRAK1, respectively. Results: The relative expressions of miR-146a in 3 esophageal squamous cell carcinoma cells (Eca109, KYSE140, KYSE150) were 0.36±0.05, 0.16±0.06 and 0.09±0.02, respectively, all of which were significantly lower than 1±0.05 of normal esophageal epithelial cells (HEEC) (P<0.01). The model of esophageal squamous cell carcinoma cells was constructed by transfecting miR-146a mimics into Eca109 cells. The results showed that the ability of absorbance value, the number of transmembrane cells (52±18), the reduced scratch distances at 48 hours and 72 hours after transfection [(25.29±0.77) μm, (30.66±0.91) μm] were significantly lower than those of the negative control group and blank control group (all P<0.01). The early apoptosis rate was (6.13±0.91)%, higher than (2.50±0.68)% of the negative control group (P<0.01) and (1.70±0.20)% of blank control group (P<0.01). The percentage of cells in G(1) phase [(44.74±6.76)%] was decreased while the G(2)/M phase [(41.88±2.88)%] was increased when compared with the negative control group and the blank control group (P<0.05 and P<0.01, respectively). The results of dual luciferase reporter gene assay showed that luciferase activity in the group co-transfected with IRAK1-wild-type and miR-146a mimics was significantly lower than that in the control groups (P<0.01). The results of RT-qPCR and western blot showed that the mRNA and protein expressions of IRAK1 in the co-transfected group were 1.02±0.28 and 1.00±0.05, respectively, both lower than those in the negative control group and the blank control group (P<0.01). Conclusions: The expressions of miR-146a are decreased in the esophageal squamous cell lines, which plays a role as tumor suppressor gene. MiR-146a can inhibit the proliferation, invasion and migration of esophageal squamous cell cells, promote apoptosis, and block the cell cycle at G(2)/M stage. MiR-146a may mediate the malignant biological behavior of esophageal cancer cells through the regulation of IRAK1.

Pseudolaric Acid B Inhibits Proliferation, Invasion, and Angiogenesis in Esophageal Squamous Cell Carcinoma Through Regulating CD147.

BackgroundEsophageal squamous cell carcinoma (ESCC) is a common malignant tumor of the digestive system. Studies have shown that pseudolaric acid B (PAB) has several pharmacological effects like anti-microtubule, anti-angiogenesis, and antitumor functions, while the effect and mechanism of PAB on esophageal cancer are still unclear. This study was designed to investigate the effects of PAB on ESCC.MethodsTo study the effects of PAB on the biological function through a series of in vitro and in vivo experiments.ResultsThe results revealed that PAB inhibited the proliferation, invasion, and migration, but promoted the apoptosis of ESCC. Moreover, PAB restrained the growth of cancer cells in vivo and inhibited the angiogenesis of HUVEC in mice with ESCC. CD147 expression was increased in the esophageal squamous cell lines, and interference with CD147 hindered the proliferation, invasion, and migration of ESCC cells, and inhibited the growth and angiogenesis of the esophageal squamous cell line. PAB reduced the expression of CD147 in vivo and in vitro. The expression of MMP2, 3, and 9 was increased after overexpression of CD147, which provided the opportunity to reverse the role of PAB in inhibiting proliferation, invasion, migration, and angiogenesis of ESCC.DiscussionThe results revealed that PAB inhibited the proliferation, invasion, migration, and angiogenesis of ESCC in vitro and in vivo by CD147. PAB is a promising monomer for therapy of ESCC, providing references for future research on ESCC treatment.

Sox2 induces tumorigenesis and angiogenesis of early-stage esophageal squamous cell carcinoma through secretion of Suprabasin.

Early stage of esophageal squamous cell carcinoma (ESCC) is known to be accompanied by angiogenesis and morphological changes of microvessels. Transcription factor Sox2 is amplified in various cancers including ESCC, but the role of Sox2 in the carcinogenesis and angiogenesis has not been determined. Hence, we aimed to investigate the role of Sox2 in the early stage of ESCC. We found that the expression of Sox2 was significantly higher in early-stage ESCC tissues than that in their adjacent normal tissues. We then established Sox2-inducible normal human esophageal squamous cell line (HetSox2) to investigate the role of Sox2 in esophageal carcinogenesis and angiogenesis in vitro. Sox2 overexpression led to increased cell proliferation and spheroid formation. The culture supernatant of Sox2-overexpressing HetSox2 induced migration and sprouting of endothelial cell line HUVEC (human umbilical vein endothelial cell). As for the mechanism, we found that the expression of secreted protein Suprabasin was directly induced by Sox2. Suprabasin enhanced proliferation of normal human esophageal squamous cells when added to the culture. Moreover, Suprabasin enhanced migration and sprouting of HUVEC cells, which were observed with the culture supernatant of Sox2-overexpressing HetSox2. This angiogenic effect of Suprabasin was abolished by inhibiting AKT phosphorylation, which suggested its dependence on AKT signaling. Finally, we showed that Suprabasin expression and the density of microvessels were significantly higher in ESCC tissues with high Sox2 expression. Our study suggested that increased Sox2 expression in esophageal squamous cells induced Suprabasin expression, and as a result initiated the carcinogenesis via increased cell proliferation and angiogenesis.

PTK7 promotes the malignant properties of cancer stem-like cells in esophageal squamous cell lines.

This study was performed to investigate the role of PTK7 in esophageal squamous cell carcinoma (ESCC) stem-like cells (CSCs). PTK7 expression in ESCCs identified by RT-qPCR, and CSC-like cells were isolated from populations of NEC and TE-1 cells. The CSC-like cells were verified by flow cytometric analyses performed using CD34 and CD133 antibodies, and RT-qPCR and western blot assays were used to examine the self-renewal capability of CSC-like cells. CSC-like cells treated with PTK7 siRNA or a P53-specific inhibitor (PFTα) were analyzed for their sphere formation capacity and their apoptosis and migration/invasion capabilities by sphere formation, flow cytometry, and transwell assay, respectively. Their levels of P53, MKK3, and cleaved caspase 3 expression were examined by western blot analysis. Our results revealed that a majority of the isolated CSC-like cells were CD34+/CD133+ double positive cells. Nango, Sox2, and OCT4 were dramatically increased in the separated CSC-like cells, which had the pluripotency and self-renewal properties of stem cells. Additional, PTK7 was dramatically upregulated in the ESCC tissues and CSC-like cells. An investigation of the function of CSC-like cells revealed that knockdown of PTK7 reduced their sphere formation, promoted apoptosis, and suppressed their migration and invasion abilities, all of which could be significantly reversed by PFTα. Mechanistic studies showed that PFTα could attenuate the upregulation of P53, MKK3, and cleaved caspase 3 expression that was induced by PTK7 knockdown in CSC-like cells. PTK7 increased the malignant behaviors of CSC-like cells derived from ESCC cells by regulating p53. Therefore, this study suggests PTK7 as an underlying target for therapy against ESCC.

Effect of HMGB1 knockdown by RNA interference on cell proliferation and migration of esophageal squamous cell carcinoma after X-ray radiation

Objective To evaluate the effect of X-ray radiation on cell proliferation, migration, survival ability and cell cycle of human esophageal squamous cell carcinoma after RNA interference-mediated down-regulation of HMGB1 gene expression. Methods The expression of HMGB1 at mRNA and protein levels in the human esophageal squamous cell carcinoma cell lines ECA109 and KYSE30 was determined using RT-PCR and Western blot assays. MTS and Transwell assays were employed to examine the proliferation and migration of ECA109 and KYSE30 cell lines. The cellular survival ability in vitro was assessed by clone formation assay. The cell cycle after X-ray radiation in different groups was detected by flow cytometry. Results The expression of HMGB1 at mRNA and protein levels in ECA109 and KYSE30 cells were markedly higher in a dose-dependent and time-dependent manner in the radiation group than that in the control group (all P<0.05). MTS results demonstrated that the proliferation of ECA109 and KYSE30 cells was obviously lower at each time point after radiation than that in the group without radiation (all P<0.01). The expression of HMGB1 at mRNA and protein levels was significantly inhibited in the HMGB1 siRNA group than those in the control and NC groups (both P<0.01). The data from the clone formation assay revealed that the radiosensitivity was significantly increased after down-regulation of HMGB1 expression (P<0.01). Transwell migration assay revealed that the number of migrating cells at the fourth hour after X-ray irradiation in the HMGB1 siRNA group was significantly lower than those in the control and negative groups (both P<0.01). In the HMGB1 siRNA group, the percentage of cells at G0/G1 phase was obviously higher, whereas the percentage of S phase was significantly lower than those in the control and NC groups, and the trend was even more significant after X-ray radiation (all P<0.01). Conclusion Inhibition of HMGB1 expression by siRNA can suppress the proliferation and migration of ECA109 and KYSE30 cells and enhance the radiosensitivity by increasing the cell cycle arrest at G0/G1 stage after X-ray irradiation in vitro. Key words: HMGB1 gene; Cell proliferation and migration; Cell cycle; Radiosensitivity

Molecular effects of tobacco smoke and bile reflux in Barrett’s esophagus in vitro

Background: Chronic gastroesophageal-reflux disease creates an environment of high oxidative stress believed to contribute to the carcinogenic transformation from reflux esophagitis to the premalignant condition Barrett’s esophagus (BE). BE ultimately progresses to esophageal adenocarcinoma (EAC). The aim of this study was to confirm the molecular effects of tobacco smoke and bile reflux in the molecular carcinogenesis of Barrett’s adenocarcinoma. Methods: Tobacco smoke condensate (4,000 ng/mL and dilutions) and a standardized bile acid (0.4 mM) were used to determine effects on a human hTERT-immortalized non-neoplastic Barrett’s esophageal cell line (BarT) and a human esophageal squamous cell line (Het-1a). Fourteen clinically relevant genes were evaluated via relative quantification real-time PCR analysis. Results: There was a synergistic relationship regarding the effects of bile acids and smoke condensate on both the BarT and Het-1a cell lines. Genes for inflammatory mediators COX2, IL1β, IL6, and IL8 were significantly up-regulated by combination smoke and bile treatment in both cell lines, while genes vital for cellular protection such as superoxide dismutase genes, MUC family of genes, CDX2 and CYP3A4 had varying expression changes. Conclusions: Tobacco smoke may enhance harmful effects of bile-acid refluxate on esophageal mucosa and is a significant factor in EAC carcinogenesis.

Abstract 783: miR-375 downregulates VEGFA via YAP1-EBRR2 pathway in esophageal cancer

Abstract Esophageal cancer (EC), including esophageal squamous cell carcinoma (ESCC) and adenocarcinoma (EAC), is one of the deadliest cancers with extremely aggressive nature and poor survival rate. Diagnostic methods for EC mainly include endoscopy, barium swallow and ultrasound, which are either invasive or lack of sensitivity and specificity at early stages. Therefore, the development of a non-invasive and reliable diagnostic method with high sensitivity and specificity is crucial in improving early detection, diagnosis and treatment. microRNAs (miRNAs) are small RNA molecules that regulate the expression of protein-coding genes by directly binding to target mRNAs in a sequence-specific manner. The aim of this study is to identify novel miRNA biomarkers for EC diagnosis. By cross-referencing our data with others’ from NCBI, we identified a list of dysregulated miRNAs in EC, including miR-375. We assessed the expression of miR-375 in EC cell lines and tissues using real-time reverse transcriptase-polymerase chain reaction (qRT-PCR). We found that miR-375 expression is significantly decreased in human EC cell lines (KEYS-70, KEYS-180, FLO-1 and JHU-ad1) compared to the normal esophageal squamous cell line, Het-1A. Using microdissection technique, we isolated normal epithelium, dysplasia, and invasive EC components from formalin-fixed, paraffin-embedded (FFPE) tissue followed by qRT-PCR analysis. Decreased expression of miR-375 was detected in 12 of 14 EC tissue samples (86%) compared to the matched normal tissues. MTT and Matrigel invasion assay demonstrated that forced expression of miR-375 suppressed the proliferation and invasion in EC cell lines. TargetScanS and miRanda were used to identify potential target genes of miR-375, which includes epidermal growth factor receptor 2 (HER2) and YES-associated protein (YAP1), both of them act as oncogenes in EC development. Interestingly, forced expression of miR-375 resulted in significantly reduced expression of human vascular endothelial growth factor-A (VEGF-A) gene, which is a downstream target gene of YAP1/ERBB2 pathway involving in tumor angiogenesis in EC cell lines. More functional analysis is under way. These findings suggest that miR-375 may act as a tumor suppressor, and could serve as a marker for EC diagnosis and management. Citation Format: Shuchang Ren, Xiaohui Tan, Xiaoling Wu, Tao Chen, Patricia Latham, Sidney W. Fu. miR-375 downregulates VEGFA via YAP1-EBRR2 pathway in esophageal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 783.

Expression of maternal embryonic leucine zipper kinase in esophageal squamous cell carcinoma and its significance

Objective To investigate the expression of maternal embryonic leucine zipper kinase (MELK) in esophageal squamous cell carcinoma and its significance. Methods The surgical resection specimens of 139 patients with esophageal squamous cell carcinoma who were admitted to Peking University Cancer Hospital from August 2009 to July 2013 were selected. MELK expression in esophageal squamous cell cancer tissues was detected by immunohistochemistry. The relationship between MELK expression and clinicopathological characteristics of patients was analyzed. MELK expression in 6 esophageal squamous cell carcinoma cell lines (ECA109, KYSE150, KYSE30, KYSE70, KYSE180 and KYSE510) was tested by Western blot, and the cell line with high MELK expression was selected, and the expression of MELK was knocked down by lentiviral infection. The effect of MELK on tumor cell migration and invasion was examined by Transwell method, and the effect of MELK on cell proliferation was verified by CCK-8 method. Results MELK is highly expressed in 100 cases (71.9%) of esophageal squamous cell carcinoma, and the positive expression rate of MELK in patients with stage T3-T4 was higher than that in patients with stage T1-T2 (χ 2= 4.702, P=0.030). The poor differentiation and lymph node metastasis inclined to higher MELK positive expression rate, but the difference was not statistically significant (χ 2=2.761, P=0.097; χ2=0.994, P=0.319). MELK was highly expressed in ECA109 and KYSE150 cells. The Transwell test results showed that the number of migrating cells of EEL109 and KYSE150 cells in the MELK knockdown group was decreased when compared with the negative control group [(77±10) cells vs. (126±8) cells, t=6.56, P < 0.05; (37±4) cells vs. (105±3) cells, t=24.27, P < 0.05], and the number of invading cells was decreased [(47±7) cells vs. (154±9) cells, t=17.08, P < 0.05; (37±2) cells vs. (184±4) cells, t=54.09, P < 0.05]. CCK-8 proliferation studies showed that the proliferation of ECA109 and KYSE150 cells in the MELK knockdown group was inhibited (both P < 0.05). Conclusions The high MELK expression in patients with esophageal squamous cell carcinoma is associated with T stage. High expression of MELK can promote the proliferation and invasion of tumor cells in esophageal squamous cell carcinoma. Key words: Esophageal neoplasms; Carcinoma, squamous cell; Maternal embryonic leucine zipper kinase; Invasiveness

Recurrent activations of transient receptor potential vanilloid-1 and vanilloid-4 promote cellular proliferation and migration in esophageal squamous cell carcinoma cells.

Some members of the transient receptor potential vanilloid (TRPV) subfamily of cation channels are thermosensitive. Earlier studies have revealed the distribution and functions of these thermo‐TRPVs (TRPV1–4) in various organs, but their expression and function in the human esophagus are not fully understood. Here, we probed for the expression of the thermo‐TRPVs in one nontumor human esophageal squamous cell line and two esophageal squamous cell carcinoma (ESCC) cell lines. TRPV1, TRPV2, and TRPV4 proteins were found to be upregulated in ESCC cells, while TRPV3 was not detectable in any of these cell lines. Subsequently, channel function was evaluated via monitoring of Ca2+ transients by Ca2+ imaging and nonselective cation channel currents were recorded by whole‐cell patch clamp. We found that TRPV4 was activated by heat at 28 °C–35 °C, whereas TRPV1 and TRPV2 were activated by higher, noxious temperatures (44 °C and 53 °C, respectively). Furthermore, TRPV1 was activated by capsaicin (EC 50 = 20.32 μm), and this effect was antagonized by AMG9810; TRPV2 was activated by a newly developed cannabinoid compound, O1821, and inhibited by tranilast. In addition, TRPV4 was activated by hypotonic solutions (220 m Osm), and this effect was abolished by ruthenium red. The effects of TRPV1 and TRPV4 on ESCC were also explored. Our data, for the first time, showed that the overactivation of TRPV1 and TRPV4 promoted the proliferation and/or migration of ESCC cells. In summary, TRPV1, TRPV2, and TRPV4 were functionally expressed in human esophageal squamous cells, and thermo‐TRPVs might play an important role in the development of ESCC.

Overexpression of TAF1L Promotes Cell Proliferation, Migration and Invasion in Esophageal Squamous Cell Carcinoma.

Currently, it reported that TAF1L gene mutation is found in a number of carcinomas, but its pathophysiological function has not been well studied. We focused on investigating expressive levels of TAF1L gene and protein in esophageal squamous cell carcinoma (ESCC) with two tissue microarrays, forty fresh paired ESCC and paracancer samples using immunohistochemistry, real-time PCR or Western blot in this study. Furthermore, we executed TAF1L silence with siRNA in ESCC cell lines to evaluate effects of TAF1L expression on cell proliferation, migration and invasion of ESCC via CCK-8, wound healing and transwell chamber assays. Moreover, key proteins related to ESCC development were also analyzed by Western blot. Results from this study showed that the expression of TAF1L mRNA and protein in ESCC tissues were significantly higher than that in matched paracancer tissues. However, its abnormal expression was not associated with other clinic features, such as the age, gender and pathological grade, except of TNM-N stage. Furthermore, the proliferation, migration and invasion of ESCC cells were inhibited after TAF1L gene silencing. As a consequence, the expression of c-Myc and phosphorylated Akt in esophageal squamous cell line after TAF1L-siRNA treatment were inversely decreased, while p53 was increased significantly, compared those to control group. Taken together, the results from this study suggest that TAF1L gene might be served as an oncogene, and its overexpression could accelerate to the tumorigenesis of ESCC via promoting the malignant cell proliferation and tumor metastasis.

Effects of long noncoding RNA (linc-VLDLR) existing in extracellular vesicles on the occurrence and multidrug resistance of esophageal cancer cells

ObjectiveTo investigate the relationship between the expression of linc-VLDLR in extracellular vesicles (EVs) and esophageal carcinomas development and drug resistance. MethodsThe expression of linc-VLDLR and ABCG2 mRNA in 60 cases of esophageal carcinoma tissue, para-carcinoma tissue and the normal esophagus tissue were detected using Fluorescence quantitative reverse transcription polymerase chain reaction (qRT-PCR). Fifty percent inhibiting concentration (IC50) of adriamycin (ADM) to Eca109 cells was detected by MTT assay, after the treatment of different concentrations of adriamycin (ADM) on esophageal squamous cell carcinoma Eca109 cell line for 24 h. EVs were extracted from culture medium after the treatment of three concentrations of ADM (setting based on the IC50) on Eca109 cells for 24 h. Linc-VLDLR expression in EVs was detected by qRT-PCR. After the treatment of the extracted EVs on virgin Eca109 cells for 48 h, then intervening these cells for 24 h by different concentrations of ADM, the new values of IC50 were detected by MTT assay. Cell cycle, cell apoptosis and ABCG2 protein expression of these Eca109 cells were detected by flow cytometry (FCM). Linc-VLDLR and ABCG2 mRNA expression in these Eca109 cells were detected by qRT-PCR. ResultsExpression of linc-VLDLR and ABCG2 mRNA in esophageal squamous cell carcinoma tissue were significantly higher than that in esophageal atypical hyperplasia and normal esophagus tissue, P < 0.01. After the treatment of ADM on Eca109 cells for 24 h, IC50 of Eca109 cells was detected as (0.44 ± 0.02) μg/mL, thus ADM concentrations of 0, 0.2, 0.4 and 0.8 μg/mL were selected to accomplish the following parts of this study. After four groups of Eca109 cells were treated by ADM in different concentrations separately, extracted EVs from the supernatant of all four groups, then labeling these four groups as EVs1, 2, 3 and 4. Linc-VLDLR expression in EVs4 was significantly higher than that in EVs1-3, P < 0.01. After the treatment of EVs1-4 on virgin Eca109 cells for 48 h, new values of IC50 of Eca109 to ADM were detected by MTT. It was found that the IC50 value of group EVs4 was significantly higher than that of other groups, P < 0.05. Flow cytometry results showed that the proliferation index of Eca109 cells in EVs4 was significantly higher than that in EVs1-3 and control groups, P < 0.01. Whereas, there was an obviously downward trend in the apoptosis rate of EVs4, compared to other three groups, P < 0.01. Linc-VLDLR and ABCG2 mRNA and protein expression level in Eca109 cells of EVs4 group were significantly higher than that of EVs1-3 and control groups, P < 0.05. ConclusionsHigh expression of Linc-VLDLR and ABCG2 gene in esophageal cancer cells affected the formation of esophageal cancer drug resistance. EVs released by drug-resistant cells were proved that they could upregulate the expression of ABCG2 in esophageal cancer cells and thus regulate the drug resistance of esophageal cancer cells, which was related to the linc-VLDLR carried by EVs.

Grape Seed Proanthocyanidin Extract Inhibits Human Esophageal Squamous Cancerous Cell Line ECA109 via the NF-κB Signaling Pathway.

Esophageal squamous cell carcinoma is the most common type of squamous cell carcinoma. Grape seed proanthocyanidin extract (GSPE) is considered to exhibit anticancer activity against several different types of cancer. We aimed to determine whether GSPE inhibited esophageal squamous cancerous cells and the possible involvement of NF-κB in this process. The human esophageal squamous cancer cell line ECA109 was treated with GSPE (0–80 μg/mL) and BAY11-7082 (10 μmol/L) for 12, 24, and 48 h. The MTT assay was used to determine cell proliferation; alterations in cell apoptosis were detected by flow cytometry; levels of inflammatory factors interleukin-6 and cyclooxygenase-2 and apoptotic proteins Bax/Bcl-2 were measured by ELISA; qRT-PCR and western blots were used to examine the activation of caspase-3 and NF-κB signaling. GSPE inhibited the proliferation of ECA109 cells and induced cellular apoptosis in a time- and dose-dependent manner. ELISA results showed that GSPE and BAY11-7082 reduced the secretion of inflammatory cytokines interleukin-6 and cyclooxygenase-2. The results of PCR and western blotting indicated that GSPE and BAY11-7082 activated caspase-3 and attenuated the activation of the NF-κB signaling pathway. GSPE induced apoptosis in ECA109 cells and inhibited ECA109 cell proliferation via a reduction in the secretion of inflammatory cytokines. This mechanism may be related to the attenuation of NF-κB activity and the sensitization of caspase-3.

Newly Synthesized Lipid-Porphyrin Conjugates: Evaluation of Their Self-Assembling Properties, Their Miscibility with Phospholipids and Their Photodynamic Activity In Vitro.

Lipid-porphyrin conjugates are considered nowadays as promising building blocks for the conception of supramolecular structures with multifunctional properties, required for efficient cancer therapy by photodynamic therapy (PDT). The synthesis of two new lipid-porphyrin conjugates coupling pheophorbide-a (Pheo-a), a photosensitizer derived from chlorophyll-a, to either chemically modified lyso-phosphatidylcholine (PhLPC) or egg lyso-sphingomyelin (PhLSM) is reported. The impact of the lipid backbone of these conjugates on their self-assembling properties, as well as on their physicochemical properties, including interfacial behavior at the air/buffer interface, fluorescence and absorption properties, thermotropic behavior, and incorporation rate in the membrane of liposomes were studied. Finally, their photodynamic activity was evaluated on esophageal squamous cell carcinoma (ESCC) and normal esophageal squamous epithelium cell lines. The liposome-like vesicles resulting from self-assembly of the pure conjugates were unstable and turned into aggregates with undefined structure within few days. However, both lipid-porphyrin conjugates could be efficiently incorporated in lipid vesicles, with higher loading rates than unconjugated Pheo-a. Interestingly, phototoxicity tests of free and liposome-incorporated lipid-porphyrin conjugates demonstrated a better selectivity in vitro to esophageal squamous cell carcinoma relative to normal cells.