Esophageal Cancer Tissues Research Articles

MicroRNA-186-5p Inhibits Proliferation And Metastasis Of Esophageal Cancer By Mediating HOXA9.

ObjectiveMicroRNA (miRNA) is an endogenous, non-coding small RNA that plays a key role in regulating organism biology and pathology. The aim of this study was to investigate the expression characteristics of microRNA-186-5p in esophageal cancer (ECa) and its correlation with clinical progression and prognosis, and to further explore its underlying mechanisms.MethodsReal-time quantitative PCR (qRT-PCR) was used to detect microRNA-186-5p level in 45 pairs of ECa tissue samples and adjacent ones, and to analyze the expression of microRNA-186-5p and clinical progression of ECa and prognosis. The relationship between microRNA-186-5p level in ECa cell lines was further verified by qRT-PCR. Finally, the potential mechanism was explored using luciferase reporter gene assay and cell recovery experiment.ResultsQRT-PCR results revealed that the expression of microRNA-186-5p in ECa tissues was remarkably lower than that in adjacent tissues, and the difference was statistically significant. Compared with patients with high expression of microRNA-186-5p, patients with low expression of microRNA-186-5p had higher incidence of pathological stage and lower overall survival rate. Besides, compared with the miR-NC group, the microRNA-186-5p mimics group had a significant decrease in proliferation and metastasis ability of ECa cells. Subsequent qRT-PCR validation in ECa cell lines and tissues indicated a significant increase in HOXA9 expression and a negative correlation with microRNA-186-5p.ConclusionThe expression of microRNA-186-5p was remarkably decreased in ECa, which was remarkably correlated with pathological stage, distant metastasis and poor prognosis of ECa. The results suggested that microRNA-186-5p may inhibit cell proliferation of ECa by regulating HOXA9.

Expression of neuritin in human lung squamous cell carcinoma.

BackgroundThis study aimed to investigate the expression of neuritin in four common cancers, and to explore the association between neuritin expression and the occurrence and development of cancer.MethodsWe initially examined neuritin expression in human cervical, endometrial, oesophageal, and lung cancer tissues by immunohistochemistry (IHC). Based on these results, we further examined its expression in lung squamous cell carcinoma (LUSC) tissues by IHC and reverse transcription-polymerase chain reaction (RT-PCR).ResultsNeuritin expression levels were higher in all cancer tissues compared with normal control tissues. Neuritin protein and gene expression levels were significantly higher in LUSC tissues compared with normal lung tissues (P<0.001), according to IHC and RT-PCR, respectively. Neuritin expression levels decreased significantly with increased clinical TNM stage (I-IV) and distant metastasis (P<0.05).ConclusionNeuritin may have clinical value as a novel diagnostic and prognostic marker in patients with LUSC.

RPL34-AS1 functions as tumor suppressive lncRNA in esophageal cancer

Ribosomal protein L34 antisense RNA 1 (RPL34-AS1) is novel long non-coding RNA, and was found to be down-regulated in colorectal cancer and gastric cancer. The role of RPL34-AS1 was still unknown in esophageal cancer. In our study, we found RPL34-AS1 expression levels in esophageal cancer tissue and specimens and cell lines were lower than in adjacent normal tissue specimens and normal esophageal cell line, respectively. In addition, esophageal cancer patients with Ⅲ-Ⅳ, T3-T4 or positive lymph node metastasis had lower RPL34-AS1expression levels than esophageal cancer patients with Ⅰ-Ⅱ, T1-T2 or negative lymph node metastasis, respectively. In survival analysis suggested esophageal cancer patients with low RPL34-AS1 expression had short overall survival than those with high RPL34-AS1 expression. Our in vitro experiments suggested RPL34-AS1 inhibits esophageal cancer cell proliferation, migration and invasion through down-regulating RPL34 expression. In conclusion, RPL34-AS1 functions as tumor suppressor in esophageal cancer.

X-linked inhibitor of apoptosis protein accelerates migration by inducing epithelial\u2013mesenchymal transition through TGF-\u03b2 signaling pathway in esophageal cancer cells

BackgroundThe prognosis of esophageal cancer is still dismal because of its high probability of metastasis that is likely related to the cellular process of epithelial–mesenchymal transition (EMT). Recent studies have shown a novel role of X-linked inhibitor of apoptosis protein (XIAP) in regulating the migration process of cancer cells and, therefore, linking to progression and poor prognosis of cancer.MethodsThe expression of XIAP in esophageal squamous cell cancer (ESCC) tissues was determined by immunohistochemistry assay. Cell migration was analyzed by wound healing assay and Transwell assay. The expression of EMT markers (E-cadherin, N-cadherin and Vimentin) was revealed by immunofluorescence assay. Quantitative real‑time PCR analysis and Western blot analysis were used to detect the expression of XIAP and EMT markers as well as transforming growth factor-β (TGF-β) at mRNA and protein level, respectively.ResultsWe found that the expression of XIAP closely correlated to the probability of lymphatic metastasis in patients and that ESCC patients with the high XIAP expression were associated with worse overall survival (OS). Univariate and multivariate analysis also revealed XIAP as an independent prognostic factor for overall survival in ESCC patients. In both EC9706 and TE13 cell lines, knockdown of XIAP decreased the migration of cancer cells by inhibiting EMT process through regulating the TGF-β signaling pathway, pinpointing a regulatory role of XIAP in migratory process upon TGF-β activation.ConclusionsTaken together, our results suggest XIAP as a important prognostic and regulative factor in ESCC patients. XIAP may promote migration of esophageal cancer cells through the activation of TGF-β mediated EMT.

Effect and mechanism of microRNA-10b on proliferation and invasion of esophageal cancer cells.

MicroRNA (miR)-10b is highly expressed in esophageal cancer tissues and is associated with poor prognosis of esophageal cancer. However, the role and mechanism of miR-10b in esophageal cancer cells remains unclear, therefore, the present study aimed to investigate this. Esophageal cancer cells, TE-1 and EC9706, were transfected with miR-10b mimic, miR-10b inhibitor or incubated with transforming growth factor-β (TGF-β). MTT and EdU assays were used to detect cell proliferation. Flow cytometry was used to determine cell cycle analysis and apoptosis. Cell migration and invasion were also analyzed. Western blot analysis was used to detect protein levels and reverse transcription-quantitative PCR was used to analyze miR-10b expression. The present results demonstrated that, compared with the control group, miR-10b significantly promoted TE-1 and EC9706 cell proliferation. Compared with miR-10b inhibitor group and control group, miR-10b mimic promoted esophageal cancer cell cycle progression, inhibited apoptosis of esophageal cancer cells and promoted the migration and invasion of cells. The proliferation of esophageal cancer cells increased in a dose-dependent manner with TGF-β concentration. TGF-β treatment induced high expression of miR-10b in both cell lines. The miR-10b mimic + TGF-β group further promoted the migration and invasion of esophageal cancer cells. Western blot analysis determined that, compared with the control group, miR-10b mimic increased TGF-β expression. miR-10b mimic also inhibited the expression of phosphatase and tensin homolog (PTEN) in tumor cells. Compared with the control group, TGF-β inhibited the expression of PTEN with the miR-10b mimic + TGF-β group further inhibiting the PTEN. miR-10b inhibitor + TGF-β reversed the effect of TGF-β and miR-10b on PTEN. In conclusion, miR-10b promoted cell cycle progression, inhibited apoptosis and promoted the migration and invasion of esophageal cancer cells. The mechanism may be related to the upregulation of TGF-β and the downregulation of PTEN. The present findings suggested that miR-10b might be a potential therapeutic target for esophageal cancer.

Prognostic significance of TPX2 and NIBP in esophageal cancer.

The expression of targeting protein for Xenopus kinesin-like protein 2 (TPX2) and NIK-IKK-β binding protein (NIBP) in patients with esophageal cancer were investigated. A total of 250 samples of cancer tissue and 250 samples of adjacent normal tissue were collected from 250 patients who underwent radical resection of esophageal cancer in Weihai Central Hospital from March 2011 to February 2014. RT-qPCR was used to detect the relative expression of TPX2 and NIBP. The relative expression of TPX2 and NIBP in esophageal cancer tissues was statistically higher than those in adjacent normal tissues (P<0.05). TPX2 and NIBP levels in tumor tissues with lymph node metastasis were significantly higher than those in tissues without lymph node metastasis (P<0.05). There was a significant difference in the relative expression of TPX2 and NIBP in different degrees of infiltration (P<0.05). Tissues with a TPX2 level equal to or higher than the average TPX2 level (1.465) were divided into TPX2 high expression group, while tissues with a TPX2 level below the average were divided into TPX2 low expression group. The 5-year overall survival rate of TPX2 high expression group was significantly lower than that of TPX2 low expression group (P<0.05). Tissues with a NIBP level equal to or higher than the average NIBP level (0.498) were included in the NIBP high expression group, while tissues with a NIBP level below the average were included in the NIBP low expression group. The 5-year overall survival rate of NIBP high expression group was significantly lower than that of NIBP low expression group (P<0.05). TPX2, NIBP, TNM staging, lymph node metastasis, and degree of infiltration were independent prognostic factors affecting overall survival (P<0.05). In conclusion, owing to their high expression in esophageal cancer tissues, TPX2 and NIBP are potentially important biomarkers for the evaluation of TNM stage, metastasis, and prognosis of esophageal cancer.

Dual effects of an anti-CD147 antibody for Esophageal cancer therapy

ABSTRACTBackground: Esophageal cancer is a highly aggressive neoplasm. Targeted therapy has been proven to be a promising way for cancer therapy. Here, we report a novel anti-CD147 antibody for esophageal cancer therapy, which is a chimeric antibody with modified glycoform in Fc region.Methods: ADCC assay was used to explore the antitumor efficacy of Metuzumab against esophageal cancer in vitro. Wound healing assay and Boyden Chamber invasion assay were performed to explore whether Metuzumab could inhibit migration and invasion of esophageal cancer in vitro. Insulin-like growth factors 1 (IGF-1) and PI3k/Akt was assayed for elaborating antagonistic mechanism of Metuzumab in migration and invasion of esophageal cancer cells. Subcutaneous xenograft nude mouse model was used to investigate the antitumor efficacy of Metuzumab against esophageal cancer in vivo. The esophageal cancer tissue microarrays (TMA) was examined for identification of association of CD147 with lymph node metastasis, and the footpad xenograft nude mouse model was used to explore whether Metuzumab could inhibit lymph node metastasis of esophageal cancer in vivo.Results: The results showed that Metuzumab exhibited higher ADCC compared to the wild type antibody cHAb18. Metuzumab inhibited migration and invasion of esophageal cancer through blockade of CD147 in vitro. The results of Western blot showed Metuzumab might inhibit migration and invasion of esophageal cancer cells through suppressing activation of PI3k/Akt and expression of IGF-1. Experiments in vivo showed that Metuzumab exhibited significant antitumor efficacy and inhibited lymph node metastasis of esophageal cancer in xenograft models. The immunochemical staining of TMA showed CD147 was high-expressed on various kinds of esophageal cancer tissues and associated with the grade of lymph node-metastasis.Conclusions: The in vitro and in vivo study demonstrated dual effects of Metuzumab in effectively mediating ADCC by activating effector cells, and inhibiting metastasis of esophageal cancer through blockade the function of CD147, providing justification for moving Metuzumab forward to clinical development in esophageal cancer.

Clinical Application of Long Non-Coding RNA-UCA1 as a Candidate Gene in Progression of Esophageal Cancer

Esophageal cancer (EC) is known as one of the most prevalent gastrointestinal cancers, and results in the seventh highest number of cancer-relevant deaths. Long non-coding RNAs (lncRNAs) have substantial roles in several biological processes. LncRNA human urothelial carcinoma associated 1 (UCA1) is announced to be enhanced in multiple types of human cancers. This survey was carried out to identify the potential role of the lncRNA-UCA1 in the progression of EC. A case-control investigation was performed on 140 FFPE tissues of EC patients consisting of 70 cancerous tissues and 70 marginal tissues samples. To determine the lncRNA-UCA1 gene expression changes, quantitative reverse-transcription polymerase chain reaction (qRT-PCR) method was utilized. In addition, the associations between the lncRNA-UCA1 gene expression and clinicopathological parameters were assessed. Our findings revealed that the lncRNA-UCA1 was notably up-regulated in EC tissues compared to adjacent normal tissues (P< 0.05). LncRNA-UCA1 expression was substantially correlated to alcohol drinking (P= 0.008) and socioeconomic status (P= 0.001), while shared no correlation with age, hot drinking status and stage (P> 0.05). Our data indicated that the lncRNA-UCA1 play an important role in the progression of EC and may be considered as a candidate gene in the pathogenesis of EC patients.

Down-regulation of long non-coding RNA HOTAIR inhibits invasion and migration of oesophageal cancer cells via up-regulation of microRNA-204.

Oesophageal cancer is a progressive tumour with high mortality. However, therapies aimed at treating oesophageal cancer remain relatively limited. Accumulating studies have highlighted long non‐coding RNA (lncRNA) HOX transcript antisense RNA (HOTAIR), microRNA‐204 (miR‐204) and homeobox C8 (HOXC8) in the progression of oesophageal cancer. Herein, we tried to demonstrate the function of HOTAIR, miR‐204 and HOXC8 in oesophageal cancer and their relationship. Differentially expressed genes involved in oesophageal cancer were identified. The endogenous expression of HOTAIR and miR‐204 in oesophageal cancer cell lines was altered to elucidate their effects and to identify the interaction among HOTAIR, miR‐204 and HOXC8. We also explored the underlying regulatory mechanisms of HOTAIR and miR‐204 with siRNA against HOTAIR, miR‐204 mimic or miR‐204 inhibitor. Cell proliferation, migration, invasion and apoptosis were subsequently detected. Xenograft in nude mice was induced to evaluate tumourigenicity. miR‐204 was down‐regulated, while HOTAIR and HOXC8 were up‐regulated in the oesophageal cancer tissues. HOTAIR could competitively bind to miR‐204 and miR‐204 could further target HOXC8. The oesophageal cancer cells treated with si‐HOTAIR or miR‐204 mimic exhibited decreased expression levels of HOXC8, Vimentin and MMP‐9, but increased E‐cadherin level. Silenced HOTAIR or elevated miR‐204 inhibited proliferation, migration and invasion, along with stimulated apoptosis of oesophageal cancer cells. In summary, our results show that lncRNA HOTAIR could specifically bind to miR‐204 as a competing endogenous RNA and regulate miR‐204 and HOXC8. Hence, down‐regulation of HOTAIR could inhibit progression of oesophageal cancer, indicating a novel target for oesophageal cancer treatment.

Downregulated lncRNA UCA1 acts as ceRNA to adsorb microRNA-498 to repress proliferation, invasion and epithelial mesenchymal transition of esophageal cancer cells by decreasing ZEB2 expression

ABSTRACT Objective Esophageal cancer (EC) is one of the most general malignant tumors in humans. There were few studies researching the connections between lncRNA UCA1 and EC. This study is to research the effect of lncRNA UCA1 adsorbing microRNA-498 (miR-498) as a ceRNA to regulate ZEB2 expression on epithelial mesenchymal transition (EMT), invasion and migration of EC cells. Methods UCA1, miR-498 and ZEB2 expression in EC tissues and cells was detected by RT-qPCR or western blot analysis. EC cells were transfected with siRNA-UCA1, miR-498 mimics or their controls to determine cell colony, proliferation, cycle distribution, apoptosis, migration and invasion by colony formation assay, CCK-8 assay, flow cytometry, and Transwell assay, respectively. The protein expression of PCNA, c-Myc, E-cadherin, N-cadherin, MMP-2 and MMP-9 was detected by Western blot analysis. The growth rate and weight of transplanted tumor in nude mice were observed. Results There were overly expressed UCA1 and ZEB2 and lowly expressed miR-498 in EC tissues and cells. LncRNA UCA1 acted as ceRNA to inhibit miR-498 expression and thereby increasing ZEB2 expression. With down-regulated UCA1 and up-regulated miR-498, ZEB2 expression, cell proliferation, colony formation, invasion, migration ability, EMT, tumor growth rate and weight in nude mice were apparently reduced. Conclusion This study demonstrates that inhibited UCA1 up-regulated miR-498 and down-regulated ZEB2, thereby repressing proliferation activity, invasion, migration, and EMT of EC cells.

Silencing Long Non-Coding RNA AGAP2-AS1 Upregulates microRNA-195-5p to Repress Migration and Invasion of Esophageal Cancer Cells Via the Decrease of FOSL1 Expression

Background: The involvement of long non-coding RNAs (lncRNAs) has been highlighted in multiple cancers including esophageal cancer (EC). Differentially expressed Our study aims to figure out the role of AGAP2-AS1/microRNA-195-5p (miR-195-5p)/FOSL1 in the EC progression. Methods: The expression of AGAP2-AS1, miR-195-5p and FOSL1 in EC tissues and EC cell lines were determined. After that, the ectopic expression and knockdown were applied to explore effect of AGAP2-AS1/miR-195-5p/FOSL1 on EC cell proliferation, cell cycle and apoptosis, as well as invasion and migration. Moreover, xenograft tumor model of nude mice was utilized for verification of the in vitro results. Results: EC tissues and cells were found to contain increased AGAP2-AS1 and FOSL1 and decreased miR-195-5p. AGAP2-AS1 knockdown or miR-195-5p overexpression reduced EC cell proliferation, migration and invasion, blocked cell cycle entry, as well as increased apoptosis. AGAP2-AS1 was observed to down-regulate FOSL1 by binding to miR-195-5p to suppress the development of EC, which was also confirmed in vivo. Conclusions: It was concluded that AGAP2-AS1 downregulation exhibited suppressive effects on the development of EC by decreasing miR-195-5p-dependent FOSL1, highlighting a future direction to develop a novel treatment strategy. Funding: This study was supported by “Ubiquitin-proteasome pathway gene SNPs and paclitaxel sensitivity in advanced esophageal squamous cell carcinoma” (No. 81201954). Declaration of Interest: The authors declare no potential conflicts of interest. Ethical Approval: Written informed consent was obtained from all patients prior to the study. Study protocols were approved by Ethic Committee of Affiliated Cancer Hospital of Zhengzhou University (Henan Cancer Hospital) following the Helsinki Declaration. Animal experiments were conducted in strict accordance with the Guide to the Management and Use of Laboratory Animals issued by the National Institutes of Health. The protocol of animal experiments was approved by the Institutional Animal Care and Use Committee of Affiliated Cancer Hospital of Zhengzhou University (Henan Cancer Hospital).

Roles of the hexosamine biosynthetic pathway and pentose phosphate pathway in bile acid-induced cancer development.

Esophageal squamous cell carcinomas (ESCCs) as well as adenocarcinomas (EACs) were developed in rat duodenal contents reflux models (reflux model). The present study aimed to shed light on the mechanism by which bile acid stimulation causes cancer onset and progression. Metabolomics analyses were performed on samples of neoplastic and nonneoplastic tissues from reflux models, and K14D, cultivated from a nonmetastatic, primary ESCC, and ESCC‐DR, established from a metastatic thoracic lesion. ESCC‐DRtca2M was prepared by treating ESCC‐DR cells with taurocholic acid (TCA) to accelerate cancer progression. The lines were subjected to comprehensive genomic analyses. In addition, protein expression levels of glucose‐6‐phosphate dehydrogenase (G6PD), nuclear factor kappa B (NF‐κB) (p65) and O‐linked N‐Acetylglucosamine (O‐GlcNAc) were compared among lines. Cancers developed in the reflux models exhibited greater hexosamine biosynthesis pathway (HBP) activation compared with the nonneoplastic tissues. Expression of O‐GlcNAc transferase (OGT) increased considerably in both ESCC and EAC compared with nonneoplastic squamous epithelium. Conversely, cell line‐based experiments revealed the greater activation of the pentose phosphate pathway (PPP) at higher degrees of malignancy. G6PD overexpression in response to TCA exposure was observed. Both NF‐κB (p65) and O‐GlcNAc were expressed more highly in ESCC‐DRtca2M than in the other cell lines. Moreover, ESCC‐DRtca2M cells had additional chromosomal abnormalities in excess of ESCC‐DR cells. Overall, glucose metabolism was upregulated in both esophageal cancer tissue and cell lines. While bile acids are not mutagenic, chronic exposure seems to trigger NF‐κB(p65) activation, potentially inducing genetic mutations as well as facilitating carcinogenesis and cancer progression. Glucose metabolism was upregulated in both esophageal cancer tissue and cell lines, and the HBP was activated in the former. The cell line‐based experiments demonstrated upregulation of the pentose phosphate pathway (PPP) at higher degrees of malignancy. While bile acids are not mutagenic, chronic exposure seems to trigger G6PD overexpression and NF‐κB (p65) activation, potentially inducing genetic mutations as well as facilitating carcinogenesis and cancer progression.

Long noncoding RNA HAGLR acts as a microRNA-143-5p sponge to regulate epithelial-mesenchymal transition and metastatic potential in esophageal cancer by regulating LAMP3.

Homeobox D gene cluster antisense growth-associated long noncoding RNA (HAGLR) functions as a crucial regulator in the progression and development of human cancers. We analyzed effects of HAGLR, microRNA (miR)-143-5p and lysosome-associated membrane glycoprotein (LAMP)3 on esophageal cancer (EC) and the related mechanisms. Microarray analysis was used to screen out EC-related genes and the regulation network among HAGLR, miR-143-5p, and LAMP3. The regulatory mechanisms of HAGLR and miR-143-5p in EC were analyzed following the treatment of miR-143-5p mimic, miR-143-5p inhibitor, HAGLR vector, or small interfering RNA against HAGLR in EC cells. The expression of N-cadherin, vimentin, Twist1, Snail1, and E-cadherin as well as the abilities of cell proliferation, invasion, and migration were measured. The effects of the HAGLR/miR-143-5p/LAMP3 axis were determined in vivo by assessing tumor formation in nude mice. The expression of HAGLR and LAMP3 was increased, whereas that of miR-143-5p was diminished in EC tissues and cells. HAGLR could competitively bind to miR-143-5p, and miR-143-5p targeted LAMP3. Down-regulated HAGLR or up-regulated miR-143-5p increased E-cadherin expression and significantly diminished expression of LAMP3, N-cadherin, vimentin, Twist1, and Snail1. Moreover, down-regulated HAGLR inhibited cell proliferation, invasion, migration, epithelial-mesenchymal transition (EMT), and tumor growth. Moreover, down-regulation of HAGLR inhibited LAMP3 expression by sponging miR-143-5p, thereby suppressing the progression of EC. Taken together, our results suggest HAGLR acts as a competing endogenous RNA of miR-143-5p to increase the expression of LAMP3, thus promoting EMT, proliferation, invasion, and migration in EC cells.-Yang, C., Shen, S., Zheng, X., Ye, K., Sun, Y., Lu, Y., Ge, H. Long noncoding RNA HAGLR acts as a microRNA-143-5p sponge to regulate epithelial-mesenchymal transition and metastatic potential in esophageal cancer by regulating LAMP3.

Nuclear magnetic resonance-based metabolomics and metabolic pathway networks from patient-matched esophageal carcinoma, adjacent noncancerous tissues and urine.

BACKGROUNDSeveral studies have demonstrated a correlation between esophageal cancer (EC) and perturbed urinary metabolomic profiles, but none has described the correlation between urine metabolite profiles and those of the tumor and adjacent esophageal mucosa in the same patient.AIMTo investigate how urinary metabolic phenotypes were linked to the changes in the biochemical landscape of esophageal tumors.METHODSNuclear magnetic resonance-based metabolomics were applied to esophageal tumor tissues and adjacent normal mucosal tissues alongside patient-matched urine samples.RESULTSAnalysis revealed that specific metabolite changes overlapped across both metrics, including glucose, glutamate, citrate, glycine, creatinine and taurine, indicating that the networks for metabolic pathway perturbations in EC, potentially involved in but not limited to disruption of fatty acid metabolism, glucose and glycolytic metabolism, tricarboxylic acid cycle and glutaminolysis. Additionally, changes in most urinary biomarkers correlated with changes in biomarker candidates in EC tissues, implying enhanced energy production for rapid cell proliferation.CONCLUSIONOverall, these associations provide evidence for distinct metabolic signatures and pathway disturbances between the tumor tissues and urine of EC patients, and changes in urinary metabolic signature could reflect reprogramming of the aforementioned metabolic pathways in EC tissues. Further investigation is needed to validate these initial findings using larger samples and to establish the underlying mechanism of EC progression.

Abstract 2572: Integrated viral sequences in esophageal cancer tissue

Abstract The human genome exhibits a significant degree of invasion by viral genomes. During the course of evolution, several RNA and DNA viruses have become integrated into the vertebrate genome and there is no reason to believe that the process has ended. Integrated viral DNA may account for as much as 10% of the human genome and it is very likely that they may act as carcinogens by altering normal cellular gene expression. In this study we have compared the viral DNA sequences present in normal and tumor tissues from esophageal squamous cell carcinoma (ESCC) samples. DNA was extracted from paired normal and tumor biopsies and subjected to whole genome sequencing. Raw data run folders were converted to FASTQ files and progressed through a QC pipeline. Normal and tumor data sets were then blasted and aligned against an extensive viral sequence database using specialized DRAGEN software, so that all integrated viral DNA fragment sequences were identified. The identified viral sequences were then compared between the paired normal and tumor samples. Using this approach, a large number of viral DNA sequences were identified; these included human papilloma viruses, Herpes simplex viruses, adenoviruses and Hepatitis C viruses. Furthermore, some unexpected viruses of interest were also identified. These include the Autographa Californica Nucleopolyhedrovirus, the Emiliana Huxleyi virus 86, the Gryllus bimaculatus nudivirus and the Trichodysplasia spinulosa-associated polyomavirus, present in different tumour DNA samples. Amplification and rearrangements of endogenous retroviruses such as the Human Endogenous Retrovirus K113 were also observed. Endogenous retroviruses (ERV) can serve as long-lasting viral reservoirs and provide evidence for the coexistence between retroviruses and their hosts over many generations. Defective ERVs can also recombine to affect the expression of adjacent genes. It has been proposed that integrated viral sequences may play a possible role in the etiology and promotion of diseases such as cancer, thus targeted studies of specific viral sequences may elucidate the mechanisms of gene disruption and may ultimately lead to the development of more effective therapeutic interventions. Note: This abstract was not presented at the meeting. Citation Format: Victoria A. Patten, Lamech Mwaphaga, Christopher G. Mathew, Denver T. Hendricks, M. Iqbal Parker. Integrated viral sequences in esophageal cancer tissue [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 2572.

Upregulation of sine oculis homeobox homolog 3 is associated with proliferation, invasion, migration, as well as poor prognosis of esophageal cancer.

Esophageal cancer (EC) is a common cancer worldwide. Sine oculis homeobox homolog (SIX3) is a human transcription factor that regulates the progression of vertebrate eye and fetal forebrain. However, studies on the function of SIX3 in human tumorigenesis remain rare. In this study, we aim to evaluate the role and the significance of SIX3 in EC. The TCGA database and clinical samples were used to assess the expression of SIX3 in EC patients. The Kaplan-Meier method and Cox's proportional hazards model were performed to analyze the correlations between SIX3 expression and EC clinical outcomes. The expressions of SIX3 in EC cells were measured by quantitative reverse transcription PCR analysis. The cell proliferation was detected using cell counting kit-8 and colony formation assay. The migration and invasion capacity of EC cells were evaluated using wound healing and Transwell methods. Western blot assay was used to measure the alterations in some important protein expression levels in the PI3K/Akt signaling pathway. We found that SIX3 was highly expressed in the EC tissues and cells. In addition, high expression of SIX3 was related to poor survival. The knockdown of SIX3 significantly inhibited the proliferation, migration, and invasion of ECA109 cells. A similar pattern was also found in the proliferation and migration of SKGT-4 cell line. The expression levels of some key proteins in the PI3K/Akt signaling pathway were obviously decreased after cells were transfected with si-SIX3, possibly resulting in PI3K/AKT signaling inactivation. In addition, E-cadherin and N-cadherin showed some change. Collectively, the results shed light on a potentially promoting role of SIX3 in human EC. Thus, SIX3 might be considered a novel prognostic biomarker and therapeutic target for EC patients.

The Pseudogene PTTG3P Promotes Cell Migration and Invasion in Esophageal Squamous Cell Carcinoma.

Pseudogenes are pivotal funtional non-coding RNAs in tumorigenesis. Cumulative evidences have shown that pituitary tumor-transforming 3, pseudogene (PTTG3P), serves as an oncogene in multiple human cancers. However, its expression pattern, biological function, and potential targets in esophageal squamous cell carcinoma (ESCC) remain unknown. Here, by quantitative real-time polymerase chain reaction (qRT-PCR) in 50 cases of ESCC, we found that the expression of PTTG3P, PTTG1 and PTTG2 in esophageal squamous cancer tissues and cell lines were significantly higher than their normal counterparts (P<0.01). Spearman correlation analysis showed that the PTTG3P expression was positively correlated with the PTTG1 and PTTG2 expression in ESCC tissue samples (P<0.05). Additionally, the high expression of PTTG3P in ESCC was significantly correlated with tumor depth, lymph node invasion and TNM stage (P<0.05). We also assessed the function of PTTG3P in vitro by gain-of-function studies. Results showed that enhanced expression of PTTG3P stimulated the migration and invasion of ESCC cells, and promoted the expression level of PTTG1 and PTTG2 in vitro. Furthermore, PTTG3P fulfilled its oncogenic functions by positively regulating its parent gene PTTG1 and PTTG2. Overall, our study indicated that PTTG3P is distinctly overexpressed and exhibited oncogenic role in a PTTG1 and PTTG2 mediated manner in ESCC.

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

Rs1884444 variant in IL23R gene is associated with a decreased risk in esophageal cancer in Chinese population.

Single nucleotide polymorphisms (SNPs) in interleukin-23 receptor (IL23R) are involved in the pathogenesis of many cancers and autoimmune diseases. IL23R gene is still controversial in the study of esophageal cancer. The aim of this research is to investigate the influence of IL23R SNPs on the risk of esophageal cancer. Five hundred six esophageal cancer and 507 controls frequency matched by age and gender were conducted, and the genotypes were determined by the Agena MassARRAY. Logistic regression analysis was used to evaluate the odd ratios (ORs) and 95% confidence intervals (CIs) of rs1884444 and rs6682925 with susceptibility of esophageal cancer. A total of 30 articles are eligible. Pooled ORs and the 95% CI were calculated using the random-effect model. Database predicts the expression of IL23R gene in esophageal cancer. IL23R rs1884444 allele G decreased the risk of esophageal cancer under allele, genotype, and additive models (allele model: OR = 0.82, 95% CI: 0.68-0.98, P = .032; genotype model: OR = 0.65, 95% CI: 0.44-0.97, P = .035; additive model: OR = 0.82, 95% CI: 0.68-0.98, P = .031). Meta-analysis shown that IL23R rs1884444 increased the risk of overall disease in allele model (OR = 1.16, 95% CI: 1.08-1.25, P < .001), and also increased the risk of gastrointestinal tumor (OR = 1.18, 95% CI: 1.05-1.31, P = .005). The database analysis showed that the expression of IL23R gene was upregulated in esophageal cancer tissues. IL23R rs1884444 may play an important role in the susceptibility of esophageal cancer.

PSMD4 regulates the malignancy of esophageal cancer cells by suppressing endoplasmic reticulum stress.

Proteasome 26S subunit non-ATPase 4 (PSMD4) is an important proteasome ubiquitin receptor and plays a key role in endoplasmic reticulum stress (ERS). However, the study of PSMD4 in esophageal cancer (EC) is relatively rare. Here, we found that the expression of PSMD4 was markedly enhanced in EC tissues and cell lines. The cell counting kit-8 (CCK-8) assay showed that overexpression of PSMD4 significantly enhanced Eca109 cell viability, while inhibition of PSMD4 reduced Eca109 cell viability. Knockdown of PSMD4 induced Eca109 cell apoptosis and cell cycle arrest. More importantly, knockdown of PSMD4 significantly enhanced the expression of glucose regulated protein 78, activating transcription factor 6, and p-protein kinase R-like ER kinase, indicating an enhanced ERS response in esophageal cancer cells. Compared with the control cells, brefeldin A significantly inhibited the expression of PSMD4 and increased the expression of p53-upregulated modulator of apoptosis. However, such effects were largely reversed after overexpressing PSMD4 in Eca109 cells, suggesting that silencing PSMD4 could enhance ERS-induced cell apoptosis. In summary, upregulation of PSMD4 promoted the progression of esophageal cancer mainly by reducing ERS-induced cell apoptosis.