Study of abnormal chromosome regions in esophageal squamous cell carcinoma by comparative genomic hybridization: relationship of lymph node metastasis and distant metastasis to selected abnormal regions

PRKCI Mediates Radiosensitivity via the Hedgehog/GLI1 Pathway in Cervical Cancer

Objective

Insensitivity to radiotherapy accounts for the majority of therapeutic failures in cervical cancer (CC) patients who undergo radical radiotherapy. We aimed to elucidate the molecular mechanisms underlying radiosensitivity to identify methods to improve the overall 5-year survival rate. The atypical protein kinase C iota (aPKCι) gene PRKCI exhibits tumor-specific copy number amplification (CNA) in CC. We investigated how PRKCI decreases radiosensitivity in CC and assessed the interplay between PRKCI and the Hedgehog (Hh)/GLI1 pathway in the present research.

Methods

The biological functions of PRKCI in CC radiosensitivity were explored through immunohistochemistry, colony formation, Cell Counting Kit-8 (CCK-8), cell cycle, apoptosis assays, and xenograft models. qRT-PCR, Western blotting analysis, and immunofluorescence assays were utilized to evaluate the interplay between PRKCI and the Hh/GLI1 pathway and its mechanism in PRKCI-decreased radiosensitivity in CC. Furthermore, the effect of auranofin (AF), a selective inhibitor of PKCι, on CC cells was explored through biochemical assays in vitro and in vivo.

Results

We found that high PRKCI expression was responsible for decreased survival in CC. PRKCI was intimately associated with radiation-triggered alterations in proliferation, the cell cycle, apoptosis, and xenograft growth. The Hh/GLI1 pathway was activated when PRKCI expression was altered. PRKCI functions downstream of the Hh/GLI1 pathway to phosphorylate and activate the transcription factor GLI1. AF acts as a radiosensitizer and showed biological effects in vitro and in vivo.

Conclusions

PRKCI is a therapeutic target for regulating radiosensitivity in CC. This molecule regulates radiosensitivity by modulating GLI1 relocalization and phosphorylation in CC via the Hh/GLI1 pathway.

Long non-coding RNA expression profiles and related regulatory networks in areca nut chewing-induced tongue squamous cell carcinoma

Areca nut chewing is an important risk factor for developing tongue squamous cell carcinoma (TSCC), although the underlying molecular mechanism is unknown. To determine the potential molecular mechanisms of areca nut chewing-induced TSCC, the present study performed whole-genome detection with five pairs of TSCC and adjacent normal tissues, via mRNA- and long non-coding (lnc)RNA-gene chip analysis. A total of 3,860 differentially expressed genes were identified, including 2,193 lncRNAs and 1,667 mRNAs. Gene set-enrichment analysis revealed that the differentially expressed mRNAs were enriched in chromosome 22q13, 8p21 and 3p21 regions, and were regulated by nuclear factor kappa B (NF-κB) and interferon regulatory factors (IRFs). The results of ingenuity pathway analysis revealed that these mRNAs were significantly enriched for inflammatory immune-related signaling pathways. A co-expression network of mRNAs and lncRNAs was constructed by performing weighted gene co-expression network analysis. The present study focused on NF-κB-, IRF- and Th cell-signaling pathway-related lncRNAs and the corresponding mRNA-lncRNA regulatory networks. To the best of our knowledge, the present study was the first to investigate differential mRNA- and lncRNA-expression profiles in TSCCs induced by areca nut chewing. Inflammation-related mRNA-lncRNA regulatory networks driven by IRFs and NF-κB were identified, as well as the Th cell-related signaling pathways that play important carcinogenic roles in areca nut chewing-induced TSCC. These differentially expressed mRNAs and lncRNAs, and their regulatory networks provide insight for further analysis on the molecular mechanism of areca nut chewing-induced TSCC, candidate molecular markers and targets for further clinical intervention.

Identification of key candidate genes and pathways in endometrial cancer: Evidence from bioinformatics analysis

Endometrial cancer (EC) is the fourth most common cancer in women worldwide. Although researchers are exploring the biological processes of tumorigenesis and development of EC, the gene interactions and biological pathways of EC are not accurately verified. In the present study, bioinformatics methods were used to screen for key candidate genes and pathways that were associated with EC and to reveal the possible mechanisms at molecular level. Microarray datasets (GSE63678, GSE17025 and GSE3013) from the Gene Expression Omnibus database were downloaded and 118 differentially expressed genes (DEGs) were selected using a Venn diagram. Functional enrichment analyses were performed on the DEGs. A protein-protein interaction network was constructed, including the module analysis. A total of 11 hub genes were identified from the DEGs, and functional enrichment analyses were performed to clarify their possible biological processes. A total of 118 DEGs were selected from three mRNA datasets. Functional enrichment demonstrated 27 downregulated genes that were primarily involved in the positive regulation of transcription from RNA polymerase II promoter, protein binding and the nucleus. A total of 91 upregulated DEGs were mainly associated with cell division, protein binding and the nucleus. Pathway analysis indicated that the downregulated DEGs were mainly enriched in pathways associated with cancer, and the upregulated DEGs were mainly enriched in the cell cycle. The 11 hub genes were primarily enriched in the cell cycle, oocyte meiosis, progesterone-mediated oocyte maturation, the p53 signaling pathway and viral carcinogenesis. The integrated analysis showed that cyclin B1, ubiquitin conjugating enzyme E2 C and cell division cycle 20 may participate in the tumorigenesis, development and invasion of EC. In conclusion, the hub genes and pathways identified in the present study contributed to the understanding of carcinogenesis and progression of EC at the mechanistic and molecular-biological level. As candidate targets for the diagnosis and treatment of EC, these genes deserve further investigation.

High TSTA3 Expression as a Candidate Biomarker for Poor Prognosis of Patients With ESCC

Esophageal squamous cell carcinoma is the sixth most lethal cancer worldwide and the fourth most lethal cancer in China. Tissue-specific transplantation antigen P35B codifies the enzyme GDP-d-mannose-4,6-dehydratase, which participates in the biosynthesis of GDP-l-fucose. GDP-l-fucose is an important substrate involved in the biosynthesis of many glycoproteins. Cancer cells are often accompanied by the changes in glycoprotein structure, which affects the adhesion, invasion, and metastasis of cells. It is not clear whether tissue-specific transplantation antigen P35B has any effect on the development of esophageal squamous cell carcinoma. We used an immunohistochemical method to assess the expression of tissue-specific transplantation antigen P35B in 104 esophageal squamous cell carcinoma samples. The results showed tissue-specific transplantation antigen P35B expression was associated with some clinical features in patients, such as age (P = .017), clinical stage (P = .010), and lymph node metastasis (P = .043). Kaplan-Meier analysis and log-rank test showed that patients with esophageal squamous cell carcinoma having high tissue-specific transplantation antigen P35B expression had a worse prognosis compared to the patients with low expression (P = .048). Multivariate Cox proportional hazards regression model showed that high expression of tissue-specific transplantation antigen P35B could predict poor prognosis for patients with esophageal squamous cell carcinoma independently. In conclusion, abnormal fucosylation might participate in the progress of esophageal squamous cell carcinoma and tissue-specific transplantation antigen P35B may serve as a novel biomarker for prognosis of patients with esophageal squamous cell carcinoma.

PIK3CA copy number aberration and activation of the PI3K-AKT-mTOR pathway in varied disease states of penile cancer

BACKGROUND

Therapeutic targeting of the PI3K-AKT-mTOR pathway may benefit patients with advanced penile squamous cell carcinoma (PSCC).

OBJECTIVES

To determine the prevalence of PIK3CA copy number gain and correlate this with the activity status of PI3K-AKT-mTOR pathway in pre-malignant penile intraepithelial neoplasia (PeIN) and invasive PSCC.

MATERIALS AND METHODS

Archival tissue blocks were obtained from 58 PeIN and 244 primary PSCC patients treated at St George's Hospital. PIK3CA copy number status (CNS) was assessed by fluorescence in-situ hybridisation. High-risk HPV DNA was detected with INNO-LiPA assay. p16INK4A, p-AKT and p-mTOR protein expression were assessed using immunohistochemistry (IHC).

RESULTS

Increased prevalence of PIK3CA copy number gain was seen in PSCC in comparison to PeIN (84/199 (42%) vs. 10/58 (17%); p = 0.0009). Analysis of the p-AKT and p-mTOR revealed a tendency to a more common expression of cytoplasmic p-AKT (p = 0.1318), nuclear p-AKT (p<0.0001) and cytoplasmic mTOR (p = 0.0006) in PeIN than PSCC. A significant association between p-AKT cytoplasmic immunoexpression and PIK3CA CNS (p = 0.0404) was found in PeIN.

CONCLUSION

Overall, PIK3CA copy number gain correlated with activation of the PI3K-AKT-mTOR pathway in PeIN and activation of this pathway is primarily involved in early penile carcinogenesis. Based on these results therapeutic targeting of this pathway in advanced PSCC is unlikely to produce significant clinical benefit. Future studies will need to focus on alternative therapeutic targets.

UBE2C Is a Transcriptional Target of the Cell Cycle Regulator FOXM1

FOXM1 (forkhead box protein M1) is a transcription factor that participates in all stages of tumor development, mainly through the control of cell cycle and proliferation, regulating the expression of genes involved in G1/S and G2/M transition and M phase progression. The ubiquitin conjugating enzyme E2 (UBE2C) is a member of the anaphase promoting complex/cyclosome, promoting the degradation of several target proteins along cell cycle progression, during metaphase/anaphase transition. FOXM1 and UBE2C have been found overexpressed in a wide range of different solid tumors. Therefore, the aim of this study was to investigate whether UBE2C is a transcriptional target of FOXM1, using esophageal squamous cell carcinoma (ESCC) as a model, in addition to several cancer-deposited data. Our results show that FOXM1 and UBE2C expression present a positive correlation in normal tissues and in 25 distinct tumor types, including ESCC, where these genes are overexpressed. Moreover, FOXM1 binds to UBE2C promoter region in ESCC cell line and transcriptionally activates it, leading to UBE2C upregulation. In conclusion, this study provides evidences that FOXM1 transcriptionally regulates UBE2C expression in ESCC and their deregulation may be a general phenomenon in human neoplasias.

African-American esophageal squamous cell carcinoma expression profile reveals dysregulation of stress response and detox networks

BACKGROUND

Esophageal carcinoma is the third most common gastrointestinal malignancy worldwide and is largely unresponsive to therapy. African-Americans have an increased risk for esophageal squamous cell carcinoma (ESCC), the subtype that shows marked variation in geographic frequency. The molecular architecture of African-American ESCC is still poorly understood. It is unclear why African-American ESCC is more aggressive and the survival rate in these patients is worse than those of other ethnic groups.

METHODS

To begin to define genetic alterations that occur in African-American ESCC we conducted microarray expression profiling in pairs of esophageal squamous cell tumors and matched control tissues.

RESULTS

We found significant dysregulation of genes encoding drug-metabolizing enzymes and stress response components of the NRF2- mediated oxidative damage pathway, potentially representing key genes in African-American esophageal squamous carcinogenesis. Loss of activity of drug metabolizing enzymes would confer increased sensitivity of esophageal cells to xenobiotics, such as alcohol and tobacco smoke, and may account for the high incidence and aggressiveness of ESCC in this ethnic group. To determine whether certain genes are uniquely altered in African-American ESCC we performed a meta-analysis of ESCC expression profiles in our African-American samples and those of several Asian samples. Down-regulation of TP53 pathway components represented the most common feature in ESCC of all ethnic groups. Importantly, this analysis revealed a potential distinctive molecular underpinning of African-American ESCC, that is, a widespread and prominent involvement of the NRF2 pathway.

CONCLUSION

Taken together, these findings highlight the remarkable interplay of genetic and environmental factors in the pathogenesis of African-American ESCC.

DNA Copy Number Aberrations, and Human Papillomavirus Status in Penile Carcinoma. Clinico-Pathological Correlations and Potential Driver Genes

Penile squamous cell carcinoma is a rare disease, in which somatic genetic aberrations have yet to be characterized. We hypothesized that gene copy aberrations might correlate with human papillomavirus status and clinico-pathological features. We sought to determine the spectrum of gene copy number aberrations in a large series of PSCCs and to define their correlations with human papillomavirus, histopathological subtype, and tumor grade, stage and lymph node status. Seventy formalin-fixed, paraffin embedded penile squamous cell carcinomas were centrally reviewed by expert uropathologists. DNA was extracted from micro-dissected samples, subjected to PCR-based human papillomavirus assessment and genotyping (INNO-LiPA human papillomavirus Genotyping Extra Assay) and microarray-based comparative genomic hybridization using a 32K Bacterial Artificial Chromosome array platform. Sixty-four samples yielded interpretable results. Recurrent gains were observed in chromosomes 1p13.3-q44 (88%), 3p12.3-q29 (86%), 5p15.33-p11 (67%) and 8p12-q24.3 (84%). Amplifications of 5p15.33-p11 and 11p14.1-p12 were found in seven (11%) and four (6%) cases, respectively. Losses were observed in chromosomes 2q33-q37.3 (86%), 3p26.3-q11.1 (83%) and 11q12.2-q25 (81%). Although many losses and gains were similar throughout the cohort, there were small significant differences observed at specific loci, between human papillomavirus positive and negative tumors, between tumor types, and tumor grade and nodal status. These results demonstrate that despite the diversity of genetic aberrations in penile squamous cell carcinomas, there are significant correlations between the clinico-pathological data and the genetic changes that may play a role in disease natural history and progression and highlight potential driver genes, which may feature in molecular pathways for existing therapeutic agents.

Amplification and overexpression of CTTN and CCND1 at chromosome 11q13 in Esophagus squamous cell carcinoma (ESCC) of North Eastern Chinese Population

Esophageal squamous cell carcinoma (ESCC) is a genetically complex tumor type and is a major cause of cancer-related mortality. The combination of genetics, diet, behavior, and environment plays an important role in the carcinogenesis of ESCC. To characterize the genomic aberrations of this disease, we investigated the genomic imbalances in 19 primary ESCC cases using high-resolution array comparative genomic hybridization (CGH). All cases showed either loss or gain of whole chromosomes or segments of chromosome(s) with variable genomic sizes. The copy number alterations per case affected the median 34% (~ 1,034Mb/3,000Mb) of the whole genome. Recurrent gains were 1q21.3-qter, 3q13.11-qter, 5pter-p11, 7pter-p15.3, 7p12.1-p11.2, 7q11-q11.2, 8p12-qter, 11q13.2-q13.3, 12pter-p13.31, 17q24.2, 20q11.21-qter, and 22q11.21-q11.22 whereas the recurrent losses were 3pter-p11.1, 4pter-p12, 4q28.3-q31.22, 4q31.3-q32.1, 9pter-p12, 11q22.3-qter and 13q12.11-q22.1. Amplification of 11q13 resulting in overexpression of CTTN/CCND1 was the most prominent finding, which was observed in 13 of 19 ESCC cases. These unique profiles of copy number alteration should be validated by further studies and need to be taken into consideration when developing biomarkers for early detection of ESCC.

The chromosome 3q26 OncCassette: A multigenic driver of human cancer

Recurrent copy number variations (CNVs) are genetic alterations commonly observed in human tumors. One of the most frequent CNVs in human tumors involves copy number gains (CNGs) at chromosome 3q26, which is estimated to occur in >20% of human tumors. The high prevalence and frequent occurrence of 3q26 CNG suggest that it drives the biology of tumors harboring this genetic alteration. The chromosomal region subject to CNG (the 3q26 amplicon) spans from chromosome 3q26 to q29, a region containing ∼200 protein-encoding genes. The large number of genes within the amplicon makes it difficult to identify relevant oncogenic target(s). Whereas a number of genes in this region have been linked to the transformed phenotype, recent studies indicate a high level of cooperativity among a subset of frequently amplified 3q26 genes. Here we use a novel bioinformatics approach to identify potential driver genes within the recurrent 3q26 amplicon in lung squamous cell carcinoma (LSCC). Our analysis reveals a set of 35 3q26 amplicon genes that are coordinately amplified and overexpressed in human LSCC tumors, and that also map to a major LSCC susceptibility locus identified on mouse chromosome 3 that is syntenic with human chromosome 3q26. Pathway analysis reveals that 21 of these genes exist within a single predicted network module. Four 3q26 genes, SOX2, ECT2, PRKCI and PI3KCA occupy the hub of this network module and serve as nodal genes around which the network is organized. Integration of available genetic, genomic, biochemical and functional data demonstrates that SOX2, ECT2, PRKCI and PIK3CA are cooperating oncogenes that function within an integrated cell signaling network that drives a highly aggressive, stem-like phenotype in LSCC tumors harboring 3q26 amplification. Based on the high level of genomic, genetic, biochemical and functional integration amongst these 4 3q26 nodal genes, we propose that they are the key oncogenic targets of the 3q26 amplicon and together define a "3q26 OncCassette" that mediates 3q26 CNG-driven tumorigenesis. Genomic analysis indicates that the 3q26 OncCassette also operates in other major tumor types that exhibit frequent 3q26 CNGs, including head and neck squamous cell carcinoma (HNSCC), ovarian serous cancer and cervical cancer. Finally, we discuss how the 3q26 OncCassette represents a tractable target for development of novel therapeutic intervention strategies that hold promise for improving treatment of 3q26-driven cancers.

High Expression of LAMP3 Is a Novel Biomarker of Poor Prognosis in Patients with Esophageal Squamous Cell Carcinoma

Lysosomal-associated membrane protein 3 (LAMP3), identified as a molecular marker of mature dendritic cells, is one of the LAMP family members. Its expression was induced by hypoxia, and was associated with hypoxia mediated metastasis in breast and cervical cancers. However, epithelial expression of LAMP3 and its prognostic value in esophageal squamous cell carcinoma (ESCC) is still unknown. In the current study, mRNA expression of LAMP3 in 157 ESCC tissues and 50 adjacent normal tissues was detected by quantitative real-time PCR (qRT-PCR). LAMP3 protein expression in 46 paired cancerous and normal tissues was detected by immunohistochemistry (IHC). Then, DNA copy number was examined to observe its potential correlation with mRNA expression. The results showed that both mRNA and protein expression level of LAMP3 was significantly higher in cancerous tissues compared with normal controls (p < 0.001). LAMP3 DNA copy number was amplified in 70% of ESCC tissues and positive correlated with mRNA expression (p = 0.037). Furthermore, patients with higher LAMP3 expression had worse overall survival (HR = 1.90, 95% CI = 1.17-3.09, p = 0.010) and disease-free survival (HR = 1.80, 95% CI = 1.18-2.74, p = 0.006). In conclusion, our results suggest that epithelial LAMP3 expression is an independent prognostic biomarker for ESCC.

Plasma microRNA profiles: identification of miR-25 as a novel diagnostic and monitoring biomarker in oesophageal squamous cell carcinoma

Background:

Recent studies have demonstrated that microRNAs are stably detectable in plasma/serum because of their binding to specific proteins or being packaged in secretory particles. This study was designed to detect novel microRNAs in plasma for cancer detection and monitoring using microRNA array-based approaches in oesophageal squamous cell carcinoma (ESCC) patients.

Methods:

Through the integration of two Toray 3D-Gene microRNA array-based approaches to compare plasma microRNA levels between ESCC patients and healthy volunteers and between preoperative and postoperative ESCC patients, we identified a novel plasma biomarker in ESCC.

Results:

(1) Eight upregulated and common microRNAs (miR-15b, 16, 17, 25, 19b, 20a, 20b, and 106a) were selected using two high-resolution microRNA array approaches. (2) Test-scale analyses by quantitative RT–PCR validated a significant higher levels of plasma miR-19b (P=0.0020) and miR-25 (P=0.0030) in ESCC patients than controls. However, a significant correlation was observed between plasma miR-19b levels and concentrations of red blood cells (P=0.0073) and haemoglobin (P=0.0072). (3) miR-25 expression was found to be significantly higher in ESCC tissues (P=0.0157) and ESCC cell lines (P=0.0093) than in normal tissues and fibroblasts. (4) In a large-scale validation analysis, plasma miR-25 levels were significantly higher in 105 preoperative (P<0.0001) ESCC patients who underwent curative oesophagectomy and 20 superficial ESCC patients who underwent endoscopic resection (P<0.0001) than in 50 healthy volunteers. (5) Plasma miR-25 levels were significantly reduced in postoperative samples than in preoperative samples (P<0.0005) and were significantly increased during ESCC recurrences (P=0.0145).

Conclusions:

Plasma miR-25 might be a clinically useful biomarker for cancer detection and the monitoring of tumour dynamics in ESCC patients.

Identification of putative target genes for amplification within 11q13.2 and 3q27.1 in esophageal squamous cell carcinoma

BACKGROUND

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).

METHODS

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.

RESULTS

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.

CONCLUSIONS

Target gene identification of amplifications or homozygous deletions will help to reveal the mechanism of tumor formation and explore new therapy method.

Characterization of genetic rearrangements in esophageal squamous carcinoma cell lines by a combination of M-FISH and array-CGH: further confirmation of some split genomic regions in primary tumors

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.

Overexpression of the DEC1 protein induces senescence in vitro and is related to better survival in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a leading cause of cancer-related death in China and has limited effective therapeutic options except for early surgery, since the underlying molecular mechanism driving its precursor lesions towards invasive ESCC is not fully understood. Cellular senescence is the state of the permanent growth arrest of a cell, and is considered as the initial barrier of tumor development. Human differentiated embryo chondrocyte expressed gene 1 (Dec1) is an important transcription factor that related to senescence. In this study, DEC1 immunohistochemical analysis was performed on tissue microarray blocks constructed from ESCC combined with adjacent precursor tissues of 241 patients. Compared with normal epithelia, DEC1 expression was significantly increased in intraepithelial neoplasia and DEC1 expression was significantly decreased in ESCC in comparison with intraepithelial neoplasia. In vitro, DEC1 overexpression induced cellular senescence, and it inhibited cell growth and colony formation in ESCC cell line EC9706. Fresh esophagectomy tissue sections from five ESCC patients were detected by immunohistochemistry of DEC1 and senescence-associated β-galactosidase (SA-β-Gal) activity, and strongly positive expression of DEC1 was correlated to more senescent cells in these fresh tissue sections. Kaplan – Meier method analysis of the 241 patients revealed that DEC1 expression levels were significantly correlated with the survival of ESCC patients after surgery. The expression levels of DEC1 were also correlated with age, tumor embolus, depth of invasion of ESCC, lymph metastasis status and pTNMs. These results suggest that DEC1 overexpression in precursor lesions of ESCC is a protective mechanism by inducing cellular senescence in ESCC initiation, and DEC1 may be a potential prognostic marker of ESCC.

The role of Pea3 group transcription factors in esophageal squamous cell carcinoma

The transcription factors Pea3, Erm, and Er81 can promote cancer initiation and progression in various types of solid tumors. However, their role in esophageal squamous cell carcinoma (ESCC) has not been elucidated. In this study, we found that the expression levels of Pea3 and Erm, but not that of Er81, were significantly higher in ESCC compared with nontumor esophageal epithelium. A high level of Pea3 expression was significantly correlated with a shorter overall survival in a cohort of 81 patients with ESCC and the subgroup with N1 stage tumor (Wilcoxon-Gehan test, P = 0.016 and P = 0.001, respectively). Pea3 was overexpressed in seven ESCC cell lines compared with two immortalized esophageal cell lines. Pea3 knockdown reduced cell proliferation and suppressed nonadherent growth, migration, and invasion in ESCC cells in vitro. In addition, Pea3 knockdown in ESCC cells resulted in a down-regulation of phospho-Akt and matrix metalloproteinase 13, whereas a significant positive correlation in the expression levels was observed between Pea3 and phospho-Akt (r = 0.281, P < 0.013) and between Pea3 and matrix metalloproteinase 13 in the human specimens (r = 0.462, P < 0.001). Moreover, Pea3 modulated the sensitivity of EC109 cells to doxorubicin, probably via reduced activity of the phosphatidylinositol 3-kinase-Akt-mammalian target of Rapamycin complex 1 pathway on Pea3 knockdown. In conclusion, our results suggest that Pea3 plays an important role in the progression of ESCC.

Common genomic aberrations in basaloid squamous cell carcinoma and carcinosarcoma of the esophagus detected by CGH and array CGH

Basaloid squamous cell carcinoma (BSCC) and carcinosarcoma of the esophagus are rare entities, making up fewer than 2% of esophageal malignancies. Comparative genomic hybridization (CGH) in 1 case of BSCC and 2 cases of carcinosarcoma and subsequent array CGH in 1 case each of BSCC and carcinosarcoma revealed common chromosomal gains at 2p25.3-2p12, 7q21.3-7q22.3, and 11q13.2-11q13.4. Chromosomal losses at 13q31qter were observed in both carcinosarcomas. In addition, progression of genomic instability from in situ to invasive carcinosarcoma could be demonstrated by using array CGH. Our observations suggest a common genetic origin of BSCC and carcinosarcoma.

The p53 target Wig-1: a regulator of mRNA stability and stem cell fate?

Wig-1 is a transcriptional target of the tumor suppressor p53 and encodes an unusual zinc-finger protein involved in post-transcriptional gene regulation. Wig-1 is expressed in all cell types investigated so far, with the highest levels in the brain, and is enriched in stem cells as compared with more differentiated cells of the same lineage. Wig-1 binds to both long double-stranded (ds) RNA and short microRNA-like dsRNA. We have shown that Wig-1 acts in a positive feedback loop that stabilizes p53 mRNA through an AU-rich element (ARE) in the p53 3'untranslated region. Our preliminary data indicate a more general effect of Wig-1 on ARE-containing mRNA. Here we shall summarize current knowledge about Wig-1 and discuss possible implications on p53 function and other cellular processes.