Search

Squamous cell carcinomas (SCCs) comprise one of the most common histologic types of human cancer. Transcriptional dysregulation of SCC cells is orchestrated by tumor protein p63 (TP63), a master transcription factor (TF) and a well-researched SCC-specific oncogene. In the present study, both Gene Set Enrichment Analysis (GSEA) of SCC patient samples and in vitro loss-of-function assays establish fatty-acid metabolism as a key pathway downstream of TP63. Further studies identify sterol regulatory element binding transcription factor 1 (SREBF1) as a central mediator linking TP63 with fatty-acid metabolism, which regulates the biosynthesis of fatty-acids, sphingolipids (SL), and glycerophospholipids (GPL), as revealed by liquid chromatography tandem mass spectrometry (LC-MS/MS)-based lipidomics. Moreover, a feedback co-regulatory loop consisting of SREBF1/TP63/Kruppel like factor 5 (KLF5) is identified, which promotes overexpression of all three TFs in SCCs. Downstream of SREBF1, a non-canonical, SCC-specific function is elucidated: SREBF1 cooperates with TP63/KLF5 to regulate hundreds of cis-regulatory elements across the SCC epigenome, which converge on activating cancer-promoting pathways. Indeed, SREBF1 is essential for SCC viability and migration, and its overexpression is associated with poor survival in SCC patients. Taken together, these data shed light on mechanisms of transcriptional dysregulation in cancer, identify specific epigenetic regulators of lipid metabolism, and uncover SREBF1 as a potential therapeutic target and prognostic marker in SCC., The relevance and underlying molecular mechanisms of epigenetic regulation in squamous cell carcinomas (SCC) await further characterization. Here, the authors show a transcriptional regulatory loop involving SREBF1, TP63 and KLF5 driving tumourigenesis in SCC through fatty acid, ERBB and mTOR pathway regulation.

Neuropilin-1 (NRP1) is a non-kinase receptor recently implicated in tumor progression. Here we revealed that over-expression of NRP1 correlates with poor prognosis in esophageal squamous cell carcinoma (ESCC). NRP1-knockdown suppressed ESCC cell proliferation and xenograft tumor growth. Reduced NRP1 expression downregulated P65 mRNA and protein expression, and ectopic expression of P65-restored cell proliferation in NRP1-silenced cells. NRP1 regulates P65 transcription by activating cAMP responsive element binding protein (CREB). NRP1 interacted with and activated epidermal growth factor receptor (EGFR), and b1/b2 domain of NRP1 is responsible for the activation of EGFR. We also found that EGFR regulated CREB transcriptional activity via AKT. These data suggest that NRP1 is an upstream regulator in the P65-dependent proliferation signaling pathway and a candidate therapeutic target for ESCC.

ObjectivesOesophageal squamous cell carcinoma (OSCC) and adenocarcinoma (OAC) are distinct cancers in terms of a number of clinical and epidemiological characteristics, complicating the design of clinical trials and biomarker developments. We analysed 1048 oesophageal tumour-germline pairs from both subtypes, to characterise their genomic features, and biological and clinical significance.DesignPreviously exome-sequenced samples were re-analysed to identify significantly mutated genes (SMGs) and mutational signatures. The biological functions of novel SMGs were investigated using cell line and xenograft models. We further performed whole-genome bisulfite sequencing and chromatin immunoprecipitation (ChIP)-seq to characterise epigenetic alterations.ResultsOSCC and OAC displayed nearly mutually exclusive sets of driver genes, indicating that they follow independent developmental paths. The combined sample size allowed the statistical identification of a number of novel subtype-specific SMGs, mutational signatures and prognostic biomarkers. Particularly, we identified a novel mutational signature similar to Catalogue Of Somatic Mutations In Cancer (COSMIC)signature 16, which has prognostic value in OSCC. Two newly discovered SMGs, CUL3 and ZFP36L2, were validated as important tumour-suppressors specific to the OSCC subtype. We further identified their additional loss-of-function mechanisms. CUL3 was homozygously deleted specifically in OSCC and other squamous cell cancers (SCCs). Notably, ZFP36L2 is associated with super-enhancer in healthy oesophageal mucosa; DNA hypermethylation in its super-enhancer reduced active histone markers in squamous cancer cells, suggesting an epigenetic inactivation of a super-enhancer-associated SCC suppressor.ConclusionsThese data comprehensively contrast differences between OSCC and OAC at both genomic and epigenomic levels, and reveal novel molecular features for further delineating the pathophysiological mechanisms and treatment strategies for these cancers.

// Li Shang 1, * , Jia-Jie Hao 1, * , Xue-Ke Zhao 3, * , Jian-Zhong He 4, * , Zhi-Zhou Shi 1 , Hui-Juan Liu 5 , Li-Fei Wu 6 , Yan-Yi Jiang 1 , Feng Shi 1 , Hai Yang 1 , Yu Zhang 1 , Yi-Zhen Liu 1 , Tong-Tong Zhang 1 , Xin Xu 1 , Yan Cai 1 , Xue-Mei Jia 5 , Min Li 6 , Qi-Min Zhan 1 , En-Min Li 4 , Li-Dong Wang 3 , Wen-Qiang Wei 2 , Ming-Rong Wang 1 1 State Key Laboratory of Molecular Oncology, Cancer Institute (Hospital), Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100021, China 2 Department of Cancer Epidemiology, Cancer Institute (Hospital), Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100021, China 3 Henan Key Laboratory for Esophageal Cancer Research of the First Affiliated Hospital, Zhengzhou University, Zhengzhou 450000, China 4 Department of Biochemistry and Molecular Biology, Shantou University Medical College, Shantou 515041, China 5 Department of Histology and Embryology, Anhui Medical University, Hefei 230032, China 6 Department of Gastroenterology, Anqing City Hospital, Affiliated Anqing Hospital of Anhui Medical University, Anqing 246003, China * These authors have contributed equally to this work Correspondence to: Ming-Rong Wang, e-mail: wangmr2015@126.com Wen-Qiang Wei, e-mail: weiwq@cicams.ac.cn Li-Dong Wang, e-mail: ldwang2007@126.com En-Min Li, e-mail: nmli@stu.edu.cn Keywords: ANO1, esophageal squamous cell carcinoma, precancerous lesions, biomarker, prognosis Received: September 17, 2015 Accepted: March 01, 2016 Published: March 21, 2016 ABSTRACT Objectives: Anoctamin 1 (ANO1) has been found to be overexpressed in esophageal squamous cell carcinoma (ESCC) in our previous study. Herein we showed the clinical relevance of ANO1 alterations with ESCC and esophageal precancerous lesion progression. Results: ANO1 was detected in 38.1% (109/286) and 25.4% (77/303) of tumors in the two cohorts, but in none of morphologically normal operative margin tissues. ANO1 expression was significantly associated with a shorter overall survival (OS), especially in patients with moderately differentiated and stage IIA tumors. In 499 iodine-unstained biopsies from the endoscopic screening cohort in 2005-2007, all the 72 pathologically normal epithelial mucosa presented negative immunostaining, whereas ANO1 expression was observed in 3/11 tumors and 5/231 intraepithelial lesions. 7/8 ANO1-positive cases had developed unfavorable outcomes revealed by endoscopic follow-up in 2012. Analysis of another independent cohort of 148 intraepithelial lesions further confirmed the correlation between ANO1 expression and progression of precancerous lesions. 3/4 intraepithelial lesions with ANO1 expression had developed ESCC within 4-9 years after the initial endoscopic examination. Methods: Immunohistochemistry (IHC) was performed to examine ANO1 expression in surgical ESCC specimens and two independent cohorts of esophageal biopsies from endoscopic screening in high-incidence area of ESCC in northern China. Association between ANO1 expression, clinico-pathologic parameters, and the impact on overall survival was analyzed. Conclusions: Positive ANO1 is a promising biomarker to predict the unfavorable outcome for ESCC patients. More importantly, it can predict disease progression of precancerous lesions.

Squamous cell carcinomas (SCCs) are aggressive malignancies. Previous report demonstrated that master transcription factors (TFs) TP63 and SOX2 exhibited overlapping genomic occupancy in SCCs. However, functional consequence of their frequent co-localization at super-enhancers remains incompletely understood. Here, epigenomic profilings of different types of SCCs reveal that TP63 and SOX2 cooperatively and lineage-specifically regulate long non-coding RNA (lncRNA) CCAT1 expression, through activation of its super-enhancers and promoter. Silencing of CCAT1 substantially reduces cellular growth both in vitro and in vivo, phenotyping the effect of inhibiting either TP63 or SOX2. ChIRP analysis shows that CCAT1 forms a complex with TP63 and SOX2, which regulates EGFR expression by binding to the super-enhancers of EGFR, thereby activating both MEK/ERK1/2 and PI3K/AKT signaling pathways. These results together identify a SCC-specific DNA/RNA/protein complex which activates TP63/SOX2-CCAT1-EGFR cascade and promotes SCC tumorigenesis, advancing our understanding of transcription dysregulation in cancer biology mediated by master TFs and super-enhancers., Master regulator transcription factors TP63 and SOX2 have been reported to overlap in genomic occupancy in squamous cell carcinomas (SCCs). Here, the authors demonstrate that TP63 and SOX2 promote co-operatively long non-coding RNA CCAT1 expression through activating its super-enhancer, and CCAT1 forms a complex with TP63 and SOX2, which regulates EGFR super-enhancers and enhances both the MEK/ERK1/2 and PI3K/AKT signaling pathways in SCC.

Background At present no objective prognostic biomarkers have been established in esophageal squamous cell carcinoma (ESCC). Objective To identify the genomic biomarkers associated with clinicopathological factors and prognosis of ESCCs. Methods Real-time PCR was used to analyze the copy number change and mRNA expression of genes. The survival curves were plotted according to Kaplan-Meier method and checked by log-rank test. Results We revealed the copy number increase of CACNA1C (12p13.33) and MRPL21 (11q13.2) as well as decrease of VIPR2 (7q36.3) and MAP3K7 (6q15) in ESCC by Real-time PCR, and also found that MRPL21 was significantly overexpressed and VIPR2 was underexpressed in ESCC. Gain of CACNA1C was significantly associated with differentiation (P = 0.043), and loss of VIPR2 was significantly linked with good prognosis (P = 0.016). Most importantly, we revealed that loss of MAP3K7 was significantly correlated with good prognosis in ESCC patients (n = 159, P = 0.004), especially in Grade II and pN0 patients (n = 76, P = 0.005 and n = 74, P = 0.024). Multivariate analysis confirmed that MAP3K7 loss provided prognostic information in ESCC (HR, 0.454; 95% CI: 0.208-0.995; P = 0.048). Conclusions Loss of MAP3K7 may be a candidate prognostic factor in ESCC.

Cisplatin resistance frequently occurs in esophageal squamous cell carcinoma (ESCC). The underlying mechanism for cisplatin resistance in ESCC remains largely obscure. Here we report that entinostat reversed cisplatin resistance in ESCC both in vitro and in vivo by induction of apoptosis and inhibition of cell proliferation, accompanied by a decrease of multidrug resistance gene 1 (MDR1), P-Src, Mcl-1, Cyclin D1 and an increase of cleaved PARP. MDR1 expression was associated with worsen survival of ESCC patients with cisplatin-based chemotherapy. Dasatinib potentiated entinostat to overcome cisplatin resistance. By inhibiting Src, dasatinib reduced the expression of MDR1 and Mcl-1. Furthermore, Obatoclax, an inhibitor of Mcl-1, obviously decreased the expression of MDR1, suggesting that entinostat might surmount cisplatin resistance in ESCC via a Src-Mcl-1-MDR1 pathway. Interestingly, cisplatin also enhanced the effect of entinostat both in vitro and in vivo. Our data disclose a molecular basis that entinostat reverses cisplatin resistance, and provide a promising strategy with combinatorial drugs to treat cisplatin resistant ESCC patients.

Genomic aberration is a common feature of human cancers and also is one of the basic mechanisms that lead to overexpression of oncogenes and underexpression of tumor suppressor genes. Our study aims to identify frequent genomic changes and candidate copy number driving genes in esophageal squamous cell carcinoma (ESCC). We used array comparative genomic hybridization to identify recurrent genomic alterations and screened the candidate targets of selected amplification regions by quantitative and semi-quantitative RT-PCR. Thirty-four gains and 16 losses occurred in more than 50 % of ESCCs. High-level amplifications at 7p11.2, 8p12, 8q24.21, 11q13.2-q13.3, 12p11.21, 12q12 and homozygous deletions at 2q22.1, 8p23.1-p21.2, 9p21.3 and 14q11.2 were also identified. 11q13.2 was a frequent amplification region, in which five genes including CHKA, GAL, KIAA1394, LRP5 and PTPRCAP were overexpressed in tumor tissues than paracancerous normal tissues. The expression of ALG3 at 3q27.1 was higher in ESCCs, especially in patients with lymph node metastasis. Target gene identification of amplifications or homozygous deletions will help to reveal the mechanism of tumor formation and explore new therapy method.

The study aims to find candidate probes of fluorescence in situ hybridization (FISH) for detection of lung cancer with bronchial brushings and to evaluate whether the accuracy of diagnosing lung cancer by cytological deviant and genetic abnormalities is greater than that of cytology alone.Centromeric enumeration probes (CEPs) for chromosomes 2, 3, 6, 7, 8, 9, 11, 12, and 17 were analyzed using FISH in 74 surgical resection tissues, 32 operative margin tissues without tumor involvement of lung cancer, and 174 bronchial brushings.The aneuploidy rates of the tested probes were 61.7, 89.1, 80.0, 92.7, 65.0, 70.4, 66.7, 71.8, 68.9 % in tumor tissues, and 29.3, 58.9, 33.3, 69.6, 67.0, 40.3, 38.0, 49.3, 35.1 % in bronchial brushings. The combination of cytology and FISH using the three-probe set for chromosomes 3+7+8 significantly improved the sensitivity of bronchial brushing examination for lung cancer detection (P = 0.00003), especially squamous cell carcinoma (SCC), which increased from 78.0 to 98.2 %. The specificity of the 3+7+8 probe set was 94.6 %. Moreover, a high aneuploidy rate of the probe set in bronchial brushings was detected more often in SCCs (P = 0.029) and late-stage non-small-cell lung cancer (NSCLC) (P = 0.044). Kaplan-Meier curves indicated that adenocarcinoma (ADC) patients with high aneuploidy rate of CEP3 in tissue samples exhibited poorer overall survival (P = 0.016).FISH performed on cytology preparations is useful for confirmation of cancer diagnosis. The three-probe set, 3+7+8, has potential value for the detection of SCCs in bronchial brushings.

Purpose: To investigate the molecular mechanisms through which polo-like kinase-1 (PLK1) takes part in anoikis resistance of esophageal squamous cell carcinoma (ESCC) cells. Experimental Design: The role of PLK1 in cell anoikis resistance was examined by ectopic gene expression and siRNA-mediated knockdown. Glutathione S-transferase pull-down and co-immunoprecipitation assays were utilized to investigate PLK1-interacting proteins. Electrophoretic mobility shift assay, chromatin immunoprecipitation, and reporter gene assays were carried out to identify the transcription factors responsible for PLK1 expression during anoikis resistance. Results: We found that detachment of ESCC cells triggers the upregulation of PLK1. Elevated PLK1 expression contributes to protection against anoikis in cancer cells through the regulation of β-catenin expression. Moreover, we showed that, through direct binding to the PLK1 promoter, the NF-κB subunit RelA transcriptionally activates PLK1, which inhibits the ubiquitination and degradation of β-catenin. Inhibition of the NF-κB pathway restores the sensitivity of cancer cells to anoikis by downregulating PLK1/β-catenin expression. In addition, RelA gene amplification and protein overexpression was significantly correlated with PLK1 expression in ESCC tissues. Conclusions: Our findings suggest that upregulation of PLK1 triggered by cell detachment is regulated by RelA at the transcriptional level. PLK1 protects esophageal carcinoma cells from anoikis through modulation of β-catenin protein levels by inhibiting their degradation. Taken together, this study reveals critical mechanisms involved in the role of RelA/PLK1/β-catenin in anoikis resistance of ESCC cells. Clin Cancer Res; 17(13); 4285–95. ©2011 AACR.

Risk assessment of esophageal squamous cell carcinoma (ESCC) is currently based on clinicopathological parameters. To identify genomic markers that can predict overall survival in ESCC, we performed array comparative genomic hybridization (array CGH) on a screening set of 35 tumor samples from ESCC patients. Prognosis association of the genes selected on the basis of the array CGH results was further validated by real-time PCR in two independent sample sets (n = 151 and 84). Genomic analysis revealed seven high-level amplifications and two homozygous deletions. Gain of 11q13.2 and loss of 7q34 and 18q21.1-q23 were associated with poor outcome. Gain of 11q13.2 was an independent prognostic factor and was selected for further validation. In both validation sets of samples, copy number increase of CPT1A in 11q13.2 was correlated with short overall survival (P = 0.015, n = 151 and P = 0.044, n = 84). Multivariate analysis confirmed that CPT1A gain provided prognostic information in ESCC (HR, 1.643; 95% CI: 1.076-2.509; P = 0.022; HR, 2.488; 95% CI: 1.235-5.013; P = 0.011). Immunohistochemistry showed significant correlation between strong expression of CPT1A protein and poor outcome of ESCC patients (P = 0.018, n = 73). Our data suggest that gain of CPT1A may be a candidate prognostic factor.

Esophageal squamous cell carcinoma (ESCC) is the predominant histological subtype of esophageal cancer in Asia, characterized by high incidence and mortality rate. Although significant progress has been made in surgery and adjuvant chemoradiotherapy, the prognosis of the patients with this cancer still remains poor. Investigation into protein alterations that occurred in tumors can provide clues to discover new biomarkers for improving diagnosis and guiding targeted therapy. Hundreds of papers have appeared over the past several decades concerning protein alterations in ESCC. This review summarizes all the dysregulated proteins investigated in the disease from 187 published papers and analyzes their contributions to tumor development and progression. We document protein alterations associated with tumor metastasis and the transition from normal esophageal epithelia to dysplasia in order to reveal the most useful markers for prediction of clinical outcome, early detection, and identification of high-risk patients for targeted therapies. In particular, we discuss the largest and most rigorous studies on prognostic implications of proteins in ESCC, in which cyclin D1, p53, E-cadherin and VEGF appeared to have the strongest evidence as independent predictors of patient outcome.

The gene of SKP2, located on chromosome 5p13, plays a critical role in cell cycle progression, especially at the G1-S transition, putatively through its control of several cell cycle regulator proteins including p27kip1, p21cip1, p57kip2, p130, cyclin E, and c-Myc. Previous studies in this laboratory revealed that gain of chromosome 5p was often seen in esophageal squamous cell carcinoma (ESCC). In the present study, we examined the amplification status and expression level of SKP2 in ESCC and investigated its clinicopathologic significance. Amplification and elevated expression of SKP2 correlated significantly with tumor stage and positive lymph node metastasis (P < 0.05). The SKP2 protein expression level as determined by immunohistochemical staining showed a significant inverse correlation with p27 protein. In vivo assay showed that inhibition of SKP2 expression also decreased tumor growth and lung metastasis of ESCC cells. At the molecular level, knockdown of SKP2 by RNA interference inhibited cell migration and invasion ability. Knockdown of SKP2 expression sensitized cancer cells to anoikis, and a wobble mutant of SKP2 that is resistant to SKP2 small interfering RNA can rescue this effect. Expression level of pAkt decreased after SKP2 knockdown. Treatment of cells with phosphoinositidyl 3-kinase inhibitor (LY294002) and constitutively activator (insulin-like growth factor I) had significant effects on the anoikis of SKP2 RNA interference cells. These results show for the first time that SKP2 is amplified and overexpressed in ESCC. Elevated expression of SKP2 protected cancer cells from anoikis, and this effect was mediated, at least in part, by the phosphoinositidyl 3-kinase-Akt pathway. (Mol Cancer Res 2009;7(1):12–22)

Chromosome aberrations are distinctive features of human malignant tumors. Analysis of chromosomal changes can illuminate the molecular mechanisms underlying the development and progression of cancer. To establish the technique of multicolor fluorescence in situ hybridization (M-FISH) for identifying chromosome aberrations in esophageal carcinoma cell line KYSE 410-4, four pools of 6-color whole-chromosome painting probes have been designed and hybridized on the same metaphase spread by four rounds of repetitive FISH. Repetitive 6-color M-FISH was successfully established and the cytogenetic abnormalities in KYSE 410-4 cells were characterized. Chromosome gains occurred at 2q, 3, 8, 17p, and X. An isochromosome 3q was visualized in the cell line, which might be one intermediate mechanism leading to 3p losses and/or 3q gains. Furthermore, 16 structural arrangements were detected, including four derivative chromosomes. The rearrangement of the centromeric regions accounted for approximately 44% of all rearrangements. The results added a more complete and accurate information of the genetic alterations to the classical cytogenetic description of KYSE 410-4 and provided a detailed cytogenetic background data for appropriate use of the cell line. The established 6-color M-FISH was useful for analyzing chromosomes in the whole genome of human tumors.

Background Esophageal cancer is one of the most common malignancies in the world. In order to identify the proteins associated with esophageal squamous cell carcinomas (ESCC), we analyzed the protein profiles of ESCC cases with tumor and matched adjacent normal tissues. Methods Two-dimensional electrophoresis (2-DE) was carried out to analyze the protein profiles. Dysregulated protein spots were identified by Matrix-Assisted Laser Desorption Ionization Time-of-Flight (MALDI-TOF) and verified by liquid chromatography/electrospray ionization ion trap-mass spectrometry/mass spectrometry (LC-ESI-IT MS). RT-PCR and immunohistochemistry on tissue microarray were performed to confirm the gene dysregulation in esophageal cancerous tissues. RNA interference (RNAi) was used to knock down the gene expression in ESCC cell lines. Apoptosis assay with annexin V-FITC/PI staining was conducted and cells were analyzed by flow cytometry. Results 2-DE showed that two protein spots with approximate molecular weights and different pI were elevated in 12 out of 18 ESCCs as compared to the corresponding normal tissues. Both the two spots were identified as MnSOD by MALDI-TOF and were verified by LC-ESI-IT MS. MnSOD overexpression was detected in 14 tumors out of 24 cases by RT-PCR and 52 tumors out of 116 cases by immunohistochemistry comparing to normal epithelia. siRNA-mediated silencing of MnSOD in KYSE450 and KYSE150 cell lines revealed that MnSOD protected ESCC cells from apoptosis induced by ultraviolet (UV) and doxorubicin (DOX). Conclusions These findings suggest that there existed two isoforms of MnSOD protein in normal and tumor esophageal tissues. MnSOD was overexpressed in ESCC and its up-regulation in esophageal cancer cells was associated with apoptosis resistance.

Cell invasion and migration significantly contribute to tumor metastasis. Microtubule-associated protein 4 (MAP4) protein is one member of microtubule-associate proteins family. It is responsible for stabilization of microtubules by modulation of microtubule dynamics. However, there is little information about the involvement of MAP4 in human cancer. Here we show that MAP4 serves as a regulator of invasion and migration in esophageal squamous cancer cells. By activating the ERK-c-Jun-vascular endothelial growth factor A signaling pathway, MAP4 promotes cell invasion and migration in vitro, tumor growth and metastasis in mouse models. Immunohistochemical staining of operative tissues indicated that MAP4 expression was associated with tumor stage, lymph node metastasis and shorter survival of the patients with esophageal squamous cell carcinoma (ESCC). Multivariate Cox regression analysis showed that MAP4 is an independent prognostic indicator. In the serial sections of ESCC tissues, there was a positive correlation between MAP4 and vascular endothelial growth factor A expression. Notably, an intratumoral injection of MAP4-small interfering RNA (siRNA) remarkably inhibited the growth of the tumors that formed by the MAP4-expressing ESCC cells in nude mice, and a combination of MAP4-siRNA and Bevacizumab significantly enhanced the inhibition effect. Our data suggest that MAP4 is probably a useful prognostic biomarker and a potential therapeutic target for the disease.

Gain of chromosome 11q13 is a common event in esophageal squamous cell carcinoma (ESCC). The cortactin gene (CTTN, also EMS1), located at 11q13, plays a pivotal role in coupling membrane dynamics to cortical actin assembly. This gene has been implicated in the motility of several types of cells. In the present study, we found that the amplification and overexpression of the CTTN gene was associated with lymph node metastasis in ESCC. Functional analysis by small interfering RNA–mediated silencing of CTTN revealed that in addition to the effect on cell migration, CTTN influenced cell invasiveness by anoikis resistance. In vivo assay showed that inhibition of CTTN expression also decreased tumor growth and lung metastasis of ESCC cells. At the molecular level, we showed for the first time that the protective role of CTTN in anoikis resistance was correlated with the activation of the phosphatidylinositol 3-kinase/Akt pathway. Overall, the data suggest that CTTN is an oncogene in the 11q13 amplicon and exerts functions on tumor metastasis in ESCC. (Cancer Res 2006; 66(24): 11690-9)

The genetic bases underlying esophageal tumorigenesis are poorly understood. Our previous studies have shown that coordinated deletion of the Smad4 and PTEN genes results in accelerated hair loss and skin tumor formation in mice. Herein, we exemplify that the concomitant inactivation of Smad4 and PTEN accelerates spontaneous forestomach carcinogenesis at complete penetrance during the first 2 months of age. All of the forestomach tumors were invasive squamous cell carcinomas (SCCs), which recapitulated the natural history and pathologic features of human esophageal SCCs. A small population of the SCC lesions was accompanied by adenocarcinomas at the adjacent submucosa region in the double mutant mice. The rapid progression of forestomach tumor formation in the Smad4 and PTEN double knockout mice corresponded to a dramatic increase in esophageal and forestomach epithelial proliferation. The decreased expression of p27, p21, and p16 together with the overexpression of cyclin D1 contributed cooperatively to the accelerated forestomach tumorigenesis in the double mutant mice. Our results point strongly to the crucial relevance of synergy between Smad4 and PTEN to suppress forestomach tumorigenesis through the cooperative induction of cell cycle inhibitors. (Cancer Res 2006; 66(14): 6972-81)

Allelic loss on chromosome 3p occurs frequently in esophageal cancer. The human ribosomal protein L14 gene (RPL14) is located on chromosome 3p21.3. In the present study, we investigated alteration of RPL14 at both the genomic DNA and RNA levels in 129 Chinese esophageal squamous cell carcinomas (ESCC) and 17 dysplasia adjacent to tumor tissues by a combination of tissue microdissection, microsatellite analysis of the intragenic marker, reverse transcriptase-polymerase chain reaction (RT-PCR) and direct sequencing. In the tested informative cases, loss of heterozygosity (LOH) of RPL14 was observed in 29 out of 68 (43%) tumors. Decreased expression of the gene was detected in 31 out of 49 (63%) carcinomas. No mutation was found in the remaining RPL14 allele of the tumors with LOH. We examined subsequently the allelic status of RPL14 in the dysplasia (preneoplastic lesions) between malignant tissues and histologically normal epithelia. Of 17 tested dysplasia in which the tumors showed LOH, eight (47%) displayed the same allelic loss as their corresponding tumors, seven (41%) exhibited microsatellite instability (MSI), and only two retained both the RPL14 alleles. The data suggest that alteration of RPL14 occurred frequently in ESCC and might be an earlier event in the tumorigenesis of the esophagus. Analysis to RPL14 gene may contribute to the early detection of ESCC as a potential molecular marker.

Our previous work has shown that a number of genes locating on 1q21 were down-regulated in esophageal squamous cell carcinomas (ESCC) and they may involve in carcinogenesis. To determine whether chromosome 1q LOH occurs in ESCC, we analyzed LOH in 61 ESCCs using 18 microsatellite markers on chromosome 1q. Forty-six of 61 (75.4%) tumors presented LOH at one or more loci. A significant association was found between chromosome 1q LOH and histopathological grade. LOH on D1S3466 had a negative correlation with family history, whereas LOH on D1S2777 positively correlated with smoking. These results suggest this region harbor putative tumor suppressor gene(s) contributing to tumorigenesis and differentiation in ESCC.

Migration inhibitory factor-related protein 14 (MRP14) is one of calcium-binding proteins, referred as S100A9. The heterodimeric molecule formed by MRP14 with its partner MRP8 (S100A8) is the major fatty acid carrier in neutrophils. The MRP8/14 complex has been also implicated in the intracellular transport of arachidonic acid and its precursors in keratinocytes. We show here the involvement of MRP14 in human esophageal cancer. In an initial study, mRNA differential display-reverse transcription polymerase chain reaction (DD-PCR) was performed with two esophageal carcinomas, one esophageal adenocarcinoma and matched normal adjacent mucosa. DD-PCR with the arbitrary primer OPA3 showed that one cDNA band was highly expressed in normal tissues, but disappeared or substantially decreased in tumor counterparts. It was later identified to be the 3'-end of migration inhibitory factor-related protein 14 (MRP14). Northern blotting, RT-PCR and Western blotting corroborated the down-regulation of MRP14 in 58/64 squamous cell carcinomas and 2/2 adenocarcinomas as compared with adjacent normal epithelia of the esophagus. MRP14 was undetectable in 3/3 esophageal-carcinoma cell lines. Immunochemistry demonstrated that expression of MRP14 was restricted to normal esophageal epithelia. No mutation was found in the genomic DNA of the MRP14 gene by PCR and directed DNA sequencing. Our finding suggested that the reduction of MRP14 expression is a frequent event in Chinese human esophageal cancer.

Allelic loss on chromosome 13 occurs frequently in esophageal squamous cell carcinomas. To define minimal deletion intervals and find candidate tumor suppressor gene(s), we conducted a study of loss of heterozygosity (LOH) in 59 esophageal squamous cell carcinomas from northern China using a panel of ten microsatellite markers on chromosome 13q. The results showed that 12 of 59 (20%) cases presented allelic loss in three or more consecutive adjacent chosen markers, suggesting loss of larger fragments on chromosome 13q. Two minimal deletion regions of overlap were found: one was located on band 13q12.3 from markers D13S171 to D13S267, and the other on band 13q14.1-q14.3 from markers D13S263 to D13S168. The latter was a new deletion region that was never reported in esophageal squamous cell carcinomas. More frequent LOH was observed in higher pathological grade of esophageal cancer at loci D13S171, D13S263 and in later stage of esophageal cancer at D13S263. The data suggest the possibility that one or more unknown tumor suppressor gene(s) on 13q may play an important role in the development of esophageal squamous cell carcinomas.

Esophageal squamous cell carcinoma (ESCC) is a world-wide prevalent cancer, which is particularly common in certain regions of Asia. Here we report the whole-exome or targeted deep sequencing of 139 paired ESCC cases, and analysis of somatic copy number variations (SCNV) of over 180 ESCCs. We identified novel significantly mutated genes such as FAT1, FAT2, ZNF750 and KMT2D, in addition to previously discovered ones (TP53, PIK3CA and NOTCH1). Further SCNV evaluation, immunohistochemistry and biological analysis suggested their functional relevance in ESCC. Notably, RTK-MAPK-PI3K pathways, cell cycle and epigenetic regulation are frequently dysregulated by multiple molecular mechanisms in this cancer. Moreover, our approaches uncovered many novel druggable candidates, and XPO1 was further explored as a therapeutic target because of its mutation and protein overexpression. Together, our integrated study unmasks a number of novel genetic lesions in ESCC and provides an important molecular foundation for understanding esophageal tumors and developing therapeutic targets.

Esophageal squamous cell carcinoma (ESCC) is a common cancer type in China. In this study, we aimed to develop aneuploidy markers for diagnosis and prognosis of ESCC. Chromosomal aneuploidies were detected in 493 primary tumors and 61 precancerous lesions by fluorescence in situ hybridization with chromosome enumeration probes (CEP), and cut-off values were set by receiver operating characteristic (ROC) curves. According to the cut-off values, chromosomes 3, 8, 10, 12, 17 and 20 presented frequent gains, with rates of 70.1, 69.7, 58.9, 66.9, 67.5 and 77.2 % in tumors and of 32.1, 26.8, 33.9, 41.2, 44.0 and 42.0 % in precancerous lesions. Loss of chromosome Y was detected in 72.0 % of male patients. An optimal four-probe panel CEP3/12/17/20 was established for detecting ESCC (sensitivity: 86.1 %), and CEP3/10/12/20 for precancerous lesions (sensitivity: 48.0 %). Gain of CEP8 was significantly correlated with lymph node metastasis (LNM) and late stages (P = 0.002 and 0.001), and loss of CEPY with age (P = 0.002, male). Kaplan–Meier survival curves indicated that patients with positive CEP10/17 (pT1 + T2, P = 0.041) and CEP8/17 (stages IIb + III + IV, P = 0.002) had poor overall survival. Combinations of LNM/stage and CEP panels could divide patients into more subgroups, including LNM + CEP3/17, LNM + CEP10/17, LNM + CEP3/10/17, stage + CEP3/17, stage + CEP10/17 and stage + CEP3/10/17 (P = 0.0004, 0.0003, 0.0001, 0.005, 0.001 and 0.0008, respectively). Multivariate Cox regression analysis confirmed that the above combinational models were independent prognostic factors. Our data suggest that the combinational probe sets may have potential for detection and prognostic prediction of ESCC.

To detect the expression of phosphorylated-signal transducer and activator of transcription 3 (p-Stat3) and myeloid leukemia-1 (Mcl-1) as well as their correlation, and to investigate the functional role of Stat3 and Mcl-1 in the pathogenesis of esophageal squamous cell carcinoma (ESCC).Stat3 activity in ESCC cells was inhibited with JAK/Stat3 inhibitors (AG490 or JSI-124). Specific siRNA was used to inhibit the Stat3 expression. Cell apoptosis was detected by flow cytometry. Expression of Mcl-1 protein was determined by Western blotting. Expression of phospho-Stat3 (Tyr705) and myeloid leukemia-1 (Mcl-1) proteins in ESCC tissues was detected by tissue microarray and immunohistochemistry. The relationship between p-Stat3 or Mcl-1 aberrant expression and clinicopatholohical features of ESCC was analyzed. The correlation of their expression was also analyzed.Suppression of the Stat3 signaling activation in ESCC cells led to marked apoptosis, and dramatic reduction of Mcl-1 protein. The positive rate of phospho-Stat3 (Tyr705) expression was 45.0% in 50/111 of the ESCC tissue samples. The lower the degree of tumor differentiation, the higher the positive rate of phospho-Stat3 (Tyr705), showing a significant difference (P = 0.018). The positive rate of Mcl-1 protein expression was 72.1% (80/111), and the lower the degree of tumor differentiation was, the higher there was the positive rate of Mcl-1, with a significant difference (P = 0.026). There was a positive correlation between the expressions of p-Stat3 and Mcl-1 proteins (P = 0.012).In a subset of ESCC tissues, p-Stat3 (Tyr705) and Mcl-1 are overexpressed and positively correlated with each other, and both are correlated with tumor differentiation. Persistent activation of Stat3 contributes to apoptotic resistance in ESCC cells, and may be at least partly mediated through upregulation of Mcl-1.

CTTN (EMS1) : an oncogene contributing to the metastasis of esophageal squamous cell carcinoma

Calreticulin (CRT) is a Ca2+-binding chaperone protein that alters cellular Ca2+-homeostasis in the endoplasmic reticulum (ER). Previously it was shown that CRT was overexpressed in esophageal squamous cell carcinoma (ESCC), and elevated CRT expression promoted the migration and invasion of ESCC cells. In the present study, the mechanisms underlying the role of CRT in esophageal carcinoma progression were investigated. Critically, depletion of CRT or protein-tyrosine phosphatase 1B (PTP1B) reduced ESCC cell migration and metastasis to the lung, whereas restoration of PTP1B protein levels rescued cell migration in CRT-silenced cells. Knockdown of CRT decreased PTP1B protein expression by reducing phosphorylation at the Y694 site of STAT5A, whereas knockdown of PTP1B reduced ERK1/2 phosphorylation at T204. Immunohistochemical analysis of CRT and PTP1B expression in ESCC patient tissues was strongly correlated. Importantly, PTP1B expression was associated with poor survival in patients with CRT overexpression. Overall, these data indicate a novel signaling pathway connecting CRT, STAT5A, PTP1B, and ERK1/2 in the regulation of ESCC cell migration. Implications: These findings suggest that PTP1B is a downstream effector of CRT signaling, promotes tumor progression, and can potentially be used as a new drug target for ESCC. Mol Cancer Res; 11(9); 986–94. ©2013 AACR.

Background Chromosomal and genomic aberrations are common features of human cancers. However, chromosomal numerical and structural aberrations, breakpoints and disrupted genes have yet to be identified in esophageal squamous cell carcinoma (ESCC). Methods Using multiplex-fluorescence in situ hybridization (M-FISH) and oligo array-based comparative hybridization (array-CGH), we identified aberrations and breakpoints in six ESCC cell lines. Furthermore, we detected recurrent breakpoints in primary tumors by dual-color FISH. Results M-FISH and array-CGH results revealed complex numerical and structural aberrations. Frequent gains occurred at 3q26.33-qter, 5p14.1-p11, 7pter-p12.3, 8q24.13-q24.21, 9q31.1-qter, 11p13-p11, 11q11-q13.4, 17q23.3-qter, 18pter-p11, 19 and 20q13.32-qter. Losses were frequent at 18q21.1-qter. Breakpoints that clustered within 1 or 2 Mb were identified, including 9p21.3, 11q13.3-q13.4, 15q25.3 and 3q28. By dual-color FISH, we observed that several recurrent breakpoint regions in cell lines were also present in ESCC tumors. In particular, breakpoints clustered at 11q13.3-q13.4 were identified in 43.3% (58/134) of ESCC tumors. Both 11q13.3-q13.4 splitting and amplification were significantly correlated with lymph node metastasis (LNM) (P = 0.004 and 0.022) and advanced stages (P = 0.004 and 0.039). Multivariate logistic regression analysis revealed that only 11q13.3-q13.4 splitting was an independent predictor for LNM (P = 0.026). Conclusions The combination of M-FISH and array-CGH helps produce more accurate karyotypes. Our data provide significant, detailed information for appropriate uses of these ESCC cell lines for cytogenetic and molecular biological studies. The aberrations and breakpoints detected in both the cell lines and primary tumors will contribute to identify affected genes involved in the development and progression of ESCC.

Atypical protein kinase Cι (PKCι) has been identified as an oncoprotein in esophageal squamous cell carcinomas. However, the mechanisms underlying the role of PKCι in this disease remain unclear. In the present work, we found that inhibition of PKCι expression by RNAi induced apoptosis via the down-regulation of β-catenin in esophageal cancer cells. Furthermore, we found that PKCι regulated β-catenin in an autophagy dependent way. Since down-regulation of β-catenin induced by knockdown of PKCι could be rescued by autophagy inhibition; knockdown of PKCι activated autophagy and promoted the recruitment of β-catenin into autophagosome. These results suggested that PKCι positively regulated β-catenin through negatively regulated autophagy and depletion of PKCι promoted apoptosis via autophagic degradation of β-catenin in esophageal cancer cells. These data provide new insights into PKCι signaling in human cancer.

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignancies with poor prognosis in China. Patients with ESCC may present with vague symptoms in early stage and most of the cases are diagnosed at advanced stage, without the chance of optimal therapy. In the development and progression of ESCC, cytogenetic and molecular aberrations are frequently observed. This review is to summarize the advances in the chromosomal and genomic alterations of ESCC reported recently.

Anoikis is a kind of programmed cell death induced by loss of extracellular matrix (ECM) adhesion, which is one of key factors for homestasis. Resistance to anoikis is required for tumor cell metastasis. We have previously shown several anoikis-resistance genes in esophageal squamous cell carcinoma (ESCC). In order to find novel anoikis-resistant genes in ESCC, we constructed retroviral cDNA library using total RNA from ESCC cell lines. NIH 3T3 cells, which are sensitive to anoikis, were infected with the library constructed. The cells were cultured in soft agar, and the clones which can survive in detached states were selected. The cDNAs inserted into the anoikis-resistant NIH3T3 clones were amplified using retroviral specific primers. Sequencing analysis showed that a cDNA fragment inserted into the anoikis-resistant clone contains full coding sequence (ORF) of human UBCH7/UBE2L3 gene. By infection with retrovirus encoding UBCH7 ORF (pMSCV-UBCH7), forced expression of UBCH7 increased the anoikis-resistance of NIH3T3 cells. More importantly, knockdown of UBCH7 expression by siRNA transfection reduced the anoikis-resistant ability of esophageal cancer MLuC1 cells. The data suggest that UBCH7/UBE2L3 gene would be involved in anoikis-resistance in ESCC.

Chromosomal rearrangements and involved genes have been reported to play important roles in the development and progression of human malignancies. But the gene rearrangements in esophageal squamous cell carcinoma (ESCC) remain to be identified. In the present study, array-based comparative genomic hybridization (array-CGH) was performed on the ESCC cell line KYSE150. Eight disrupted genes were detected according to the obviously distinct unbalanced breakpoints. The splitting of these genes was validated by dual-color fluorescence in-situ hybridization (FISH). By using rapid amplification of cDNA ends (RACE), genome walking and sequencing analysis, we further identified gene disruptions and rearrangements. A fusion transcript DTL-1q42.2 was derived from an intrachromosomal rearrangement of chromosome 1. Highly amplified segments of DTL and PTPRD were self-rearranged. The sequences on either side of the junctions possess micro-homology with each other. FISH results indicated that the split DTL and PTPRD were also involved in comprising parts of the derivative chromosomes resulted from t(1q;9p;12p) and t(9;1;9). Further, we found that regions harboring DTL (1q32.3) and PTPRD (9p23) were also splitting in ESCC tumors. The data supplement significant information on the existing genetic background of KYSE150, which may be used as a model for studying these gene rearrangements.

To identify potential biomarkers for the prognosis of non-small cell lung cancer (NSCLC) patients by using bronchial brushing specimens.The expression of MCM7, Ki67 and EGFR was evaluated in 494 NSCLC tissues and 174 bronchial brushings using immunohistochemical and immunocytochemical techniques. Associations between protein expression and clinico-pathologic parameters were assessed, and the impact on overall survival (OS) was analyzed.High expression of MCM7, Ki67 and EGFR was detected in 33.3%, 23.5% and 12.7% of tissues and in 52.4%, 52.7% and 20.6% of bronchial brushings, respectively. Expression of MCM7 and Ki67 was associated with squamous cell carcinoma (SCC) in both tissues and bronchial brushings (MCM7: P = 0.0007, 0.00003; Ki67: P0.00001, 0.00001). Overexpression of MCM7 in tumor tissues was detected more frequently in poorly differentiated tumors (P = 0.0120) and non-bronchioloalveolar carcinomas (non-BACs) (P = 0.0238). EGFR overexpression was observed in tissues of larger tumors (P = 0.00004) and in bronchial brushings at later stage (P = 0.0262). Kaplan-Meier curves indicated that patients with overexpression of MCM7 or Ki67 had a poorer OS compared to those with low expression for all stages (P0.00001, 0.0233) and early-stages (P0.00001, 0.0032). In particular, the patients with MCM7 overexpression in bronchial brushings had a poorer prognosis (P = 0.0045). Multivariate Cox regression analysis showed that MCM7 was an independent prognostic indicator both in tissue samples and bronchial brushings.Our data suggest that MCM7 and Ki67 in tumor tissues may be potential markers of a poor prognosis for NSCLC patients. MCM7 in bronchial brushings also showed an independent prognostic value, which may be useful when biopsies are unavailable.

Protein kinase Cι (PKCι) is an atypical PKC isoform and participates in multiple aspects of the transformed phenotype in human cancer cells. We previously reported that frequent amplification and overexpression of PKCι were correlated with lymph node metastasis in primary esophageal squamous cell carcinomas (ESCC). In the present study, short interfering RNA–mediated silencing of PKCι revealed that this enzyme was required for cell migration, invasion, and resistance to anoikis. In vivo experiments showed that PKCι suppression decreased tumor growth in esophageal cancer xenografts and lung metastases in nude mice. At the molecular level, knockdown of PKCι in suspended ESCC cells caused a decrease in S-phase kinase-associated protein 2 (SKP2) that had been reported to promote resistance to anoikis via the PI3K/AKT pathway. AKT phosphorylation was abolished after PKCι suppression, but AKT activation could be refreshed by PKCι upregulation, suggesting that PKCι enhanced cell resistance to anoikis via the PKCι-SKP2-PI3K/AKT pathway. Addition of the proteasome inhibitor MG132 prevented the decrease of SKP2 in PKCι silenced cells, and polyubiquitin-SKP2 was elevated after PKCι depletion, showing that PKCι might regulate the expression of SKP2 through the ubiquitin-proteasome pathway in suspended cells. Furthermore, overexpression of SKP2 in PKCι-downregulated cells restored cell resistance to anoikis. Most importantly, PKCι expression significantly correlated with SKP2 in 133 ESCC tissues (P = 0.031). Taken together, our data show that PKCι promotes tumorigenicity and metastasis of human esophageal cancer and that SKP2 is a candidate downstream effector of PKCι signaling in ESCC. Mol Cancer Res; 9(4); 390–402. ©2011 AACR.

Dysregulation of cell cycle control, especially G1/S phase transition, is implicated in the pathogenesis of most human cancers, including esophageal squamous cell carcinoma (ESCC). However, the clinicopathological significance of aberrant expression of G1/S phase-related proteins in ESCC remains unclear. In the present study, cyclin D1, p21WAF1/Cip1 and p53 protein expression were examined in 148 ESCC cases using immunohistochemistry combined with tissue microarray. We then analyzed the correlations between their expression and clinicopathological parameters and found that overexpression of p53 was associated with lymph node metastasis (P=0.001). p21WAF1/Cip1 down-regulation was an independent prognostic factor by multivariate analysis (RR=0.418, P0.001). Further more, array-CGH results revealed that cyclin D1 gene was amplified in 45.4% of ESCC patients. This study confirms that dysregulation of G1/S related genes is common in ESCC and reduced expression of p21WAF1/Cip1 protein can predict shorter overall survival time of patients with ESCC.

We have shown earlier that overexpression of Calreticulin (CRT) contributed to a poor prognosis for patients with esophageal squamous cell carcinoma (ESCC). Here, we have shown an important role of CRT in tumorigenesis through enhancing cell motility and anoikis resistance. SiRNA-mediated knockdown of CRT caused impaired cell migration, invasion and resistance to anoikis. Notably, CRT downregulation decreased the expression of Cortactin (CTTN), which has been previously reported as a candidate oncogene associated with anoikis through the PI3K–Akt pathway. In addition, Akt phosphorylation was abolished after CRT downregulation and its activation can be refreshed by CRT upregulation, suggesting that CRT-enhanced cell resistance to anoikis through the CRT–CTTN–PI3K–Akt pathway. Moreover, the CTTN mRNA level was decreased in CRT–siRNA cells, coupled with the inactivation of STAT3. Expression of both CTTN and p-STAT3 was reduced in tumor cells following incubation with the JAK-specific inhibitor, AG490. Chromatin immunoprecipitation assay showed direct binding of p-STAT3 to the conservative STAT3-binding sequences in CTTN promoter. Furthermore, overexpression of CTTN in CRT-downregulated ESCC cells restored its motility and resistance to anoikis. This study not only reveals a role of CRT in motility promotion and anoikis resistance in ESCC cells, but also identifies CRT as an upstream regulator in the CRT–STAT3–CTTN–Akt pathway.

Although the diagnostic and therapeutic modalities of esophageal squamous cell carcinoma (ESCC) have been improved considerably, the five-year survival rate is still not satisfied. To detect the numberial aberrations of the chromosomes in ESCC, fluorescence in situ hybridization (FISH) was performed on interphase nuclei prepared from 220 esophageal carcinoma tissues with specific centromeric probes for chromosomes 3, 8, 10, 20 and Y. The main aberrations of the euchromosomes was chromosome gain, including trisome, tetrasome, and polysome. The gain rates of the four euchromosome were 84.9%, 77.5%, 63.7% and 83.2%, and the frequencies of polysome for each euchromosome were 24.6%, 34.9%, 23.4% and 31.7%, respectively. Loss of chromosome Y was observed in 61.2% of male patients. The combination of the four chromosome probes 3, 8, 10 and 20 detected 74.5% of ESCC and the combination of 3, 8, 20 and Y detected 85.0%. These results indicated that both sets of the four centromeric probe combinations provide candidate biomarkers for the diagnosis of esophageal squamous cell carcinoma.

PLK1 is essential for the maintenance of genomic stability during mitosis. In our study, we found that overexpression of PLK1 was an independent prognostic factor (RR=4.253, p=0.020) and significantly correlated with survivin, an antiapoptotic protein, in esophageal squamous cell carcinoma (ESCC). Reverse transcription-polymerase chain reaction and fluorescence in situ hybridization (FISH) revealed upregulation of PLK1 mRNA and amplification of PLK1 gene, respectively. Depletion of PLK1 activated the intrinsic apoptotic pathway, which was substantiated by loss of mitochondrial membrane potential, reduction of Mcl-1 and Bcl-2 as well as activation of caspase-9. Coimmunoprecipitation and confocal microscopy displayed that PLK1 was associated with survivin and PLK1 depletion led to downregulation of survivin. Cotransfection of survivin constructs could partially reverse PLK1-depletion-induced apoptosis. These data suggest that PLK1 might be a useful prognostic marker and a potential therapeutic target for ESCC. Survivin is probably involved in antiapoptotic function of PLK1.

Androgen-induced proliferation shutoff gene AS3, also known as APRIN, is a growth inhibitory gene that is initially implicated in prostate cancer. This gene is required for androgen-dependent growth arrest and is a primary target for 1,25(OH)(2)D(3) and androgens. Allelic loss at AS3 locus has been linked to a variety of cancers. However, the correlation of genomic and expression alterations of AS3 with esophageal squamous cell carcinoma (ESCC) is not well established. In this study, the genomic and expression alterations of AS3 in ESCC and their clinical significance are evaluated. Loss of heterozygosity (LOH) analysis using an AS3 intragenic microsatellite marker D13S171 revealed 72% allelic loss at AS3 locus in ESCC, which is significantly correlated with higher pathological grade (P=0.042). RT-PCR examination showed that AS3 mRNA obviously decreased in 44% tumors and its down-regulation was correlated with the sex of patients (P=0.03). Furthermore, the correlation between genomic and expression alterations of AS3 gene was analyzed in 18 ESCC specimens, which indicated that the consistency between allelic loss and decreased mRNA expression of AS3 was relatively poor. The results of this study indicate that the aberrant expression of AS3 may be involved in the tumorigenesis of esophagus and is responsible for the male predominance of ESCC.

DNA amplification is one of the mechanisms to activate genes that are implicated in neoplastic transformation and gain of chromosome band 3q26 is a common event in squamous cell carcinomas. The aim of the present work was to identify the specific target gene from four candidates (MDS1, PRKCI, ECT2, and PIK3CA) located on 3q26 amplification in esophageal squamous cell carcinomas (ESCCs). To assess the prevalence of copy number gains of putative genes, fluorescence in situ hybridization (FISH) was applied on 108 ESCCs and 9 ESCC cell lines. Our data showed that MDS1 and PRKCI were more frequently gained. Positive correlation was found only for PRKCI between amplification and tumor size (P = 0.043), lymph node metastasis (P = 0.015) and clinical stage (P = 0.002). PRKCI gene amplification was highly correlated with protein overexpression (P = 0.009), suggesting that gene amplification is one important mechanism involved in PRKCI overexpression. To investigate further the role of PRKCI alteration in esophageal tumors, a tissue microarray containing samples from 180 ESCCs was used for immunohistochemistry analysis. Statistical analysis revealed that PRKCI overexpression was correlated with lymph node metastasis (P = 0.002) and higher stage (P = 0.004). Performing multivariate logistic regression analysis, a significant association between PRKCI overexpression and presence of lymph node metastasis was found, which was independent of T-stage of the primary tumors (P = 0.004). Our results indicate that PRKCI is an attractive target in the 3q26 amplicon and that it may serve as a molecular marker for metastasis and occult advanced tumor stages in ESCC. © 2007 Wiley-Liss, Inc.

Esophagin/SPRR3 is one of the cornified-envelope structural precursor proteins, which is expressed during epithelia cell differentiation. In 1996, another research group discovered, and our own laboratory subsequently confirmed, frequent and dramatic decreased Esophagin/SPRR3 expression in esophageal squamous cell carcinoma (ESCC). However, the role of Esophagin/SPRR3 in tumorigenesis of esophageal epithelium remains undetermined. In this study, we demonstrate that expression of Esophagin/SPRR3 is frequently downregulated in ESCC. In contrast, no correlations between downregulation of Esophagin/SPRR3 expression and clinicopathologic characteristics were observed. Diminished Esophagin/SPRR3 expression was present in dysplastic epithelia, suggesting that Esophagin/SPRR3 alteration could represent an early event in squamous carcinogenesis of the esophagus. Exogenous expression of Esophagin/SPRR3 significantly suppressed the ability of ESCC cells to form colonies in plastic and soft agar, as well as tumor formation in vivo. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end label assay and immunofluorescence analysis of the active form of Caspase 3 indicated that dysregulated apoptosis might contribute to reduced tumorigenicity. In particular, upregulation of CDK11p46 protein was observed in ESCC cells expressing Esophagin/SPRR3, but not in control cells, indicating that Esophagin/SPRR3-induced apoptosis may be due, at least in part, to increased expression of CDK11p46 protein. These findings suggest that Esophagin/SPRR3 may play a role in the maintenance of normal esophageal epithelial homeostasis, and that aberrant expression of Esophagin/SPRR3 may contribute to the tumorigenesis of ESCC.

To gain insights into metastatic mechanisms in esophageal squamous cell carcinoma (ESCC), we established sublines (MLuB1 and MLuC1) with different capacity of spontaneous lung metastasis by subcutaneous injection of a human ESCC cell line (EC 9706) into nude mices. The incidence of the mice with lung metastasis produced by MLuC1 (87%) was significantly higher than that of MLuB1 (22%). The gene expression profiles of the two sublines were compared with cDNA arrays containing 5,000 known genes, and 47 genes were differentially expressedor =2.0 fold. Laminin-5gamma2 chain (Ln-5gamma2) was one of the up-regulated genes in MLuC1 cells. Proteolytically processed forms of gamma2 are known to promote migration of a multitude of epithelial cells in vitro. Western-blotting analysis revealed that degraded fragments of Ln-5gamma2 and active form of membrane-type matrix metalloproteinase-1 (MT1-MMP) in MLuC1 was significantly higher than those in MLuB1. Expression of MT1-MMP was observed in 60 of 75 Ln-5gamma2-positive carcinoma tissues (80%). Co-expression of the two proteins was significantly associated with depth of invasion (P = 0.012). Moreover, proteolytic fragments of Ln-5gamma2 and active forms of MT1-MMP were frequently found in tumor tissues, whereas in the corresponding normal esophageal tissues there were only intact forms of gamma2 and MT1-MMP. siRNA-mediated silencing of MT1-MMP significantly reduced production of gamma2' and gamma2x in MLuC1 cells and inhibited cell migration. The results suggest that MT1-MMP is an enzyme responsible for Ln-5gamma2 cleavage in ESCC, and interaction between them may play a critical role in promoting invasion and metastasis of human ESCC.

Some researches have showed that chromosomal abnormalities, including chromosomal regions of gains and losses, usually occur in primary esophageal cancer. The comparative genomic hybridization (CGH) technique can show chromosomal abnormality. This study was to analyze the characteristics of chromosomal abnormity in primary esophageal cancer by CGH, and explore its correlation to prognosis.Chromosomal genetic changes in 16 specimens of primary esophageal cancer were detected by CGH. The correlation of chromosomal abnormality to the prognosis was analyzed. Of the 16 patients, 7 died within 2 years after operation (control group), 9 survived over 3 years after operation (survive group).Most of the patients had chromosomal genetic changes. The most frequent changes were gains of chromosome arms or regions 1q/p, 2q/p, 3q, 5q/p, 8q/p, 9q/p, 11q/p, 17, and 20q/p, and losses of chromosome arms or regions 1q/p, 4p, 9p, 18q, and xp. The differences in gains of chromosome arms or regions 7q/p and 19 and losses of chromosome arms or regions 4q/p and 18q between control group and survive group were significant.Abnormal gains and losses of chromosome arms or regions tend to occur in esophageal cancer. The differences between control group and survive group are significant.

Mucosal iodine staining has improved the detection of precancerous lesions of the esophagus. However, this method is unable to exactly evaluate the risk status of the lesions. In the present study, we conducted a molecular analysis combining the iodine staining in esophageal squamous cell carcinomas (ESCC) and different premalignant lesions of the esophagus in order to improve the early diagnosis of ESCC. Tumorous and precancerous lesions were procured as iodine-unstained areas in the resected specimens of ESCC patients by means of Lugol’s iodine staining. Loss of heterozygosity (LOH) was detected with 35 microsatellite markers frequently reported to be deleted in ESCC. The markers with high frequency of LOH in tumorous and precancerous lesions of the same patient were subjected to further detection in iodine-unstained biopsy samples from the population screening in ESCC high-incidence region. Common alterations were observed at D3S3644, D3S1768, D3S3040, D3S4542, RPL14, D9S169, D13S171 and D13S263 in both cancer tissues and precancerous lesions around tumors. Interestingly, D3S3644, D3S1768, D3S3040, D3S4542, RPL14 and D13S263 were also found with high frequency of LOH in iodine-staining abnormal lesions from the population screening. Most importantly, LOH frequency increased with histological severity. Our data suggest that detection of these six markers in combination with iodine staining might contribute to the prediction for the risk of ESCC development and for the diagnosis of patients in preclinical and preneoplastic phase of the disease.

Esophageal squamous cell carcinoma (ESCC) is one of the leading causes of cancer death in China. In the present study, proteins in tumors and adjacent normal esophageal tissues from 41 patients with ESCC were extracted, and two-dimensional electrophoresis (2-DE) was performed using the pH 3-10 and 4-7 immobilized pH gradient strips. The protein spots expressed differentially between tumors and normal tissues were identified by matrix-assisted laser desorption/ionization and liquid chromatography electrospray/ionization ion trap mass spectrometry. A total of 22 proteins differentially expressed between ESCC and normal esophageal tissues were identified, in which 17 proteins were upregulated and 5 downregulated in tumors. Biological functions of these proteins are related to cell signal transduction, cell proliferation, cell motility, glycolysis, regulation of transcription, oxidative stress processes, and protein folding. Some of the proteins obtained were confirmed by Western blotting and immunohistochemical staining. We showed that high expression of calreticulin and 78-kDa glucose-regulated protein (GRP78) were correlated with poor prognosis by Kaplan-Meier analysis and log rank analysis. Zinc finger protein 410, annexin V, similar to the ubiquitin-conjugating enzyme E2 variant 1 isoform c, mutant hemoglobin beta chain, TPM4-ALK fusion oncoprotein type 2, similar to heat shock congnate 71-kDa protein, GRP78, and pyruvate kinase M2 (M2-PK) were for the first time observed to be dysregulated in human ESCC tissues. The proteins here identified will contribute to the understanding of the tumorigenesis and progression of Chinese ESCC and may potentially provide useful markers for diagnosis or targets for therapeutic intervention and drug development.

Analysis of chromosomal changes in esophageal squamous cell carcinoma (ESCC) can illuminate the molecular mechanisms underlying the development and progression of this cancer, which is among the 10 most common malignant tumors. Cell lines are better suited than surgical samples for chromosome analysis in this cancer. This study used multicolor fluorescence in situ hybridization (M-FISH) to characterize the molecular cytogenetics of ESCC in cell line KYSE180. Two pools of 12-color whole-chromosome painting probes were designed, and two rounds of FISH were performed on the same metaphase spreads. Loss of DNA copy number was observed at 4p, 5q, 6q, 9, 10p, 12p, 13, 14p, 15p, 18p, 18q, 20, 22, and Y. Chromosomal gains and translocations occurred at the entire or part of 1, 2p, 3, 4p, 5p, 5q, 6p, 7, 8, 10q, 11, 12q, 14q, 16, 17q, 19, and Xp. Seven derivative chromosomes (5, 8, 12, 14, 14, 14, and 17) presented complex translocations, each involving three or four chromosomes. No chromosomes 9, 13, or Y were detected. These results add significant information to the existing karyotype description of KYSE180 and provide detailed cytogenetic background data for appropriate use of the cell line.

Purpose: Evidence is accumulating that an inverse correlation exists between stefin A level and malignant progression. The aim of this study is to investigate the role of stefin A in human esophageal squamous cell carcinoma cells and to evaluate the possibility of stefin A for cancer therapy. Experimental Design: We stably transfected stefin A cDNA into human EC9706 or KYSE150 esophageal squamous cell carcinoma cells. Subsequently, we evaluated the effect of stefin A overexpression on cell growth, cathepsin B activity, cell motility and invasion, tumor growth, and metastasis. Immunoanalysis was done to assess the expression of factor VIII and to support the localization of stefin A and cathepsin B. We also evaluated the effect of CA074Me, a selective membrane-permeant cathepsin B inhibitor. Results: Both transfection of stefin A and treatment with 10 μmol/L CA074Me significantly reduced cathepsin B activity and inhibited the Matrigel invasion. Combination of both further reduced cathepsin B activity and inhibited the Matrigel invasion. Overexpression of stefin A delayed the in vitro and in vivo growth of cells and significantly inhibited lung metastasis compared with 50% of lung metastasis in xenograft mice from EC9706 or empty vector cells. Transfection with stefin A showed a dramatic reduction of factor VIII staining in the tumors of xenograft mice. Conclusions: Our data strongly indicate that stefin A plays an important role in the growth, angiogenesis, invasion, and metastasis of human esophageal squamous cell carcinoma cells and suggest that stefin A may be useful in cancer therapy.

Chromosome 13 presents frequent allelic loss in esophageal squamous cell carcinomas (ESCC). However, no ESCC suppressor gene has been identified from this chromosome. To define common deletion regions that possibly contain the ESCC suppressor gene(s), we performed a mapping of allelic loss in 50 esophageal squamous cell carcinomas using a panel of 25 microsatellite markers on chromosome 13q21-qter, which has rarely been studied for allelic loss. Loss of heterozygosity (LOH) with high frequencies (> or = 50%) was observed at markers D13S1494, D13S1323, D13S248, D13S1315, D13S285, and D13S1295, in which the peak LOH (69.2%) was at locus D13S248. Seven cases presented LOH at three consecutive markers D13S248, D13S1315 and D13S285, 4 of which also displayed LOH at another adjacent marker D13S1295. This overlapping region of deletion covers an interval of 6.36 Mb at 13q33.1-q34, whose deletion has not previously been reported in ESCC. Tumors of grade II showed significantly more frequent LOH at D13S248 than those of grade I. A significantly higher frequency of allelic loss at D13S152 was also found in tumors with lymph node metastasis compared to those without lymph node metastasis. The present study defined a novel region of allelic loss in 13q33-q34. LOH at D13S248 and D13S152 are associated with higher tumor grade and metastasis, respectively.

To investigate the alteration of the gene HSD17B4 in esophageal squamous cell carcinoma and its potential significance.The mRNA expression and loss of heterozygosity (LOH) of HSD17B4 in 40 primary esophageal tumors were detected by reverse transcriptase-polymerase chain reaction (RT-PCR) and microsatellite analysis with the intragenic marker D5S1384 of the gene.The frequencies of allelic loss of D5S1384 and the rate of down-regulation of gene HSD17B4 were 46.2% and 62.5%, respectively.HSD17B4 may be a candidate tumor suppressor gene associated with esophageal squamous cell carcinoma.

Human MLH1 is one of the DNA mismatch repair genes and located in chromosome 3p21.3. Alterations of the MLH1 were associated with various kinds of human tumors. The present study was to investigate allelic loss of MLH1 and microsatellite instability (MSI) in esophageal squamous cell carcinomas (ESCC), and to estimate the correlation between MSI status and allelic loss of the MLH1 gene. The MSI of 14 microsatellite markers and mRNA expression of MLH1 were assessed in a large cohort of patients with ESCC by using denaturing polyacrylamide gel electrophoresis (PAGE) and reverse transcriptase-polymerase chain reaction (RT-PCR) techniques. Thirty-five percent of tumors displayed MSI in at least one tested marker. MSI in D3S1611, an intragenic marker of the MLH1, was observed in 66.7% of tumors. No down-expression of MLH1 was found at the transcriptional level. The presence of MSI did not correlate with tumor stage, degree of differentiation, lymphonode-metastasis, age and sex of the patients, neither with allelic loss of the MLH1 gene. The data suggested that LOH of MLH1 is common in ESCC, but not lead to the alteration of MLH1 at the level of RNA expression. MSI in tested microsatellite markers occurs frequently in ESCC but is not associated with allelic loss of the MLH1 gene.