Recent Advances From Basic and Clinical Studies of Esophageal Squamous Cell Carcinoma

Plumbagin inhibits the proliferation and survival of esophageal cancer cells by blocking STAT3-PLK1-AKT signaling

Esophageal squamous cell carcinoma (ESCC) is one of the deadliest cancers, and it requires novel treatment approaches and effective drugs. In the present study, we found that treatment with plumbagin, a natural compound, reduced proliferation and survival of the KYSE150 and KYSE450 ESCC cell lines in a dose-dependent manner in vitro. The drug also effectively inhibited the viability of primary ESCC cells from fresh biopsy specimens. Furthermore, plumbagin-induced mitotic arrest and massive apoptosis in ESCC cells. Notably, the drug significantly suppressed the colony formation capacity of ESCC cells in vitro and the growth of KYSE150 xenograft tumors in vivo. At the molecular level, we found that exposure to plumbagin decreased both polo-like kinase 1 (PLK1) and phosphorylated protein kinase B (p-AKT) expression in both ESCC cell lines. Enforced PLK1 expression in ESCC cells not only markedly rescued cells from plumbagin-induced apoptosis and proliferation inhibition but also restored the impaired AKT activity. Furthermore, signal transducer and activator of transcription 3 (STAT3), a transcription factor of PLK1, was also inactivated in plumbagin-treated ESCC cells; however, the overexpression of a constitutively activated STAT3 mutant, STAT3C, reinstated the plumbagin-elicited blockade of PLK1-AKT signaling in ESCC cells. Taken together, these findings indicate that plumbagin inhibits proliferation and potentiates apoptosis in human ESCC cells in vitro and in vivo. Plumbagin may exert these antitumor effects by abrogating STAT3-PLK1-AKT signaling, which suggests that plumbagin may be a novel, promising anticancer agent for the treatment of ESCC.

Platelet to lymphocyte ratio is a predictive marker of prognosis and therapeutic effect of postoperative chemotherapy in non-metastatic esophageal squamous cell carcinoma

Increasing evidence has indicated that inflammatory biomarkers, including the neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), and prognostic nutritional index (PNI), can be used as prognostic indicators in esophageal squamous cell carcinoma (ESCC). However, the best predictor for prognosis in ESCC remains controversial. Few studies have focused on the association between inflammatory biomarkers and postoperative chemotherapy. A cohort of 515 non-metastatic ESCC patients was retrospectively reviewed. Harrell's concordance index (c-index) was used to identify the optimal cut-off values of the inflammatory markers, and their prognostic value was compared. Cox multivariate analysis indicated that, among these inflammatory biomarkers, PLR (≥133 vs. <133) was the only independent prognostic factor for poor OS [hazard ratio = 1.370, 95% confidence intervals = 1.076-1.745, p = .011]. The c-index values of PLR were higher compared with NLR and PNI. For patients with PLR < 133, the surgery plus chemotherapy group had significantly longer OS than the surgery group alone (p = .004), but the significant difference of OS between these two groups was not observed in patients with PLR ≥ 133 (p = .624). PLR is a predictive marker of prognosis and therapeutic effect of postoperative chemotherapy in non-metastatic ESCC.

Rabdocoestin B exhibits antitumor activity by inducing G2/M phase arrest and apoptosis in esophageal squamous cell carcinoma

PURPOSE

Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive squamous cell carcinomas and is generally resistant to chemotherapy. In the present study, the cytotoxic activity of Rabdocoestin B (Rabd-B) against ESCC and the underlying mechanisms were investigated.

METHODS

The inhibitory effect of Rabd-B on KYSE30 and KYSE450 was evaluated by Cell Counting Kit-8 (CCK8) and colony formation assays in vitro. The cell cycle distribution and apoptosis of cells treated with Rabd-B were determined by flow cytometry. The mechanisms underlying the effects of Rabd-B were systematically examined by Western blot. The in vivo anti-tumor ability of Rabd-B was measured in mouse xenograft models and cisplatin (DDP) was used as positive control.

RESULTS

Rabd-B efficiently induced G2/M phase arrest in ESCC cells by upregulating the Chk1/Chk2-Cdc25C axis to inhibit the G2→M transition facilitated by Cdc2/Cyclin B1. Furthermore, Rabd-B suppressed ATM/ATR phosphorylation, thereby inhibiting BRCA1-mediated DNA repair, which resulted in mitotic catastrophe and induced cell apoptosis. Rabd-B also decreased the activity of the Akt and NF-κB survival signaling pathways and ultimately initiated the caspase-9-dependent intrinsic apoptotic pathway in ESCC cells. The apoptosis induced by Rabd-B could be partially reversed by a caspase-9-specific inhibitor (Z-LEHD-FMK) and a pan-caspase inhibitor (Z-VAD-FMK). Moreover, Rabd-B effectively suppressed tumor growth in mouse xenografts which was comparable to that of DDP without significant injuries to the mice.

CONCLUSION

Taken together, these findings indicate that Rabd-B is a promising precursor compound that may be useful as a treatment for ESCC and thus warrants further investigation.

Inhibition of the development of N-nitrosomethylbenzylamine-induced esophageal tumors in rats by strawberries and aspirin, alone and in combination

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is one of two subtypes of esophageal cancer, with high incidence and mortality rates in developing countries.

OBJECTIVE

The current study investigated the potential chemoprotective effects of strawberries and aspirin against the development of rat esophageal papillomas, the precursors to ESCC.

METHODS

Using a prevention model, we administered study diets to rats before, during, and after N-nitrosomethylbenzylamine (NMBA) treatment. The effects of the four diets were evaluated: the control diet, 5% strawberry powder in the control diet, 0.01% aspirin in the drinking water, and the combination of strawberries and aspirin. At week 25, we euthanized all the rats and collected their esophagi to quantify tumor incidence, multiplicity, and burden, as well as for molecular analysis.

RESULTS

Both strawberries and aspirin significantly decreased esophageal tumor multiplicity, with the combination causing the most robust suppression. Aspirin alone and the combination decreased the total tumor burden in the esophagus. None of the diets had a significant effect on tumor incidence or the expression of COX-1 and COX-2. Strawberries and aspirin, alone and in combination, significantly suppressed squamous epithelial cell proliferation (PCNA).

CONCLUSIONS

Strawberries, aspirin, and their combination exhibit chemoprotective effects against NMBA-induced esophageal tumors in rats.

Epidemiology of Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) accounts for about 90% of the 456,000 incident esophageal cancers each year. Regions of high incidence include Eastern to Central Asia, along the Rift Valley in East Africa, and into South Africa. There are many causes of ESCC, which vary among regions. Early studies in France associated smoking cigarettes and heavy alcohol consumption with high rates of ESCC, but these factors cannot explain the high incidence in other regions. We discuss other risk factors for ESCC, including polycyclic aromatic hydrocarbons from a variety of sources, high-temperature foods, diet, and oral health and the microbiome-all require further research. A growing list of defined genomic regions affects susceptibility, but large genome-wide association studies have been conducted with ethnic Chinese subjects only; more studies are called for in the rest of Asia and Africa. ESCC has been understudied, but growing infrastructure in more high-incidence countries will allow rapid progress in our understanding.

The prognostic value of TP53 mutations in hypopharyngeal squamous cell carcinoma

Background

TP53 is the most frequently mutated gene in human cancers. Previous studies reported that TP53 mutations correlated with poor prognoses in patients with head and neck squamous cell carcinoma (HNSCC). However, the relationship between TP53 mutations and hypopharyngeal squamous cell carcinoma (HPSCC) is not known. The current study aimed to evaluate TP53 mutation status as a predictive biomarker in patients with HPSCC.

Methods

We retrospectively reviewed the clinical charts of 57 HPSCC patients treated with initial surgery between 2008 and 2014. TP53 mutation status was determined by Sanger sequencing, and patients were classified into wild-type, missense mutation, and truncating mutation groups. Additionally, p53 expression was determined using immunohistochemistry in surgical specimens.

Results

TP53 mutations were identified in 39 (68%) patients. The 3-year disease-specific survival (DSS) rate of wild-type, missense mutation, and truncating mutation group were 94%, 61%, and 43%, respectively. The TP53 mutation group displayed significantly worse DSS and overall survival rates than the wild-type group (P = 0.01 and P = 0.007, respectively). Multivariate analyses revealed that the presence of TP53 mutations and ≥4 metastatic lymph nodes were independent adverse prognostic factors for HPSCC. p53 immunopositivity was detected in 22 patients, including 5 (28%) and 17 (71%) patients in the wild-type and missense mutation groups, whereas none of the patients with truncating mutation exhibited p53 immunopositivity (P = 0.0001).

Conclusion

The TP53 mutation status correlated with poor prognosis in surgically treated HPSCC patients. Specifically, truncating mutations which were not detected by p53 immunohistochemistry were predictive of worst survival.

Alcohol consumption and bladder cancer risk with or without the flushing response: The Japan Public Health Center-based Prospective Study

The association between alcohol consumption and bladder cancer risk has been insufficiently investigated in East Asian populations, who frequently have the inactive enzyme for metabolizing acetaldehyde. Given that acetaldehyde associated with alcohol consumption is assessed as a carcinogen, consideration of differences in acetaldehyde exposure would aid accuracy in assessing the bladder cancer risk associated with alcohol consumption. Here, we conducted a population-based cohort study in Japan to examine this association, including information on the flushing response as a surrogate marker of the capacity of acetaldehyde metabolism. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated using multivariate Cox proportional hazard models. During follow up from 1990 through 2012 for the 95,915 subjects (45,649 men and 50,266 women, aged 40-69 years), 354 men and 110 women were newly diagnosed with bladder cancer. No significant association between alcohol consumption and bladder cancer risk was observed in the overall analysis. Among male flushers, HRs were 1.04 (95% CI 0.70-1.54), 1.67 (1.16-2.42), 1.02 (0.62-1.67) and 0.63 (0.33-1.20) for alcohol consumption of 1-150, 151-300, 301-450, >450 g/week of pure ethanol compared with non-drinkers and occasional drinkers, respectively, indicating an inverted U-shaped association between alcohol consumption and bladder cancer risk. In contrast, no significant association was identified among male non-flushers. The marginally significant interaction between alcohol consumption and the flushing response (p for interaction = 0.083) may support our hypothesis that acetaldehyde derived from alcohol consumption is associated with bladder cancer risk. A prospective study considering polymorphisms of genes involved in acetaldehyde metabolism is warranted.

PRSS8 methylation and its significance in esophageal squamous cell carcinoma

Esophageal cancer is one of the most common cancers worldwide, and the incidence and mortality is increasing rapidly in recent years in China, but the underlying mechanisms are largely unclear. Herein we found that the expression of PRSS8, a serine protease prostasin, is significantly decreased in esophageal squamous cell carcinomas (ESCC) at mRNA and protein levels. The reduction of PRSS8 was well correlated with poor differentiation and shorter survival time. Interestingly, ESCC stromal expression of PRSS8 was significantly correlated with stromal lymphocyte infiltration and cancer progression. Methylation specific PCR showed that PRSS8 was hypermethylated in ESCC tissues and ESCC cell lines, which was linked to the downregulation of PRSS8 expression and decreased activities of PRSS8 promoter. De-methylation agent decitabine was able to restore PRSS8 expression, leading to the inhibition of cancer cell proliferation, motility, migration and cell cycle arrest. However, the restored PRSS8 and its tumor inhibition could be reversed by small interfering RNA targeting PRSS8. Mechanistic study showed that tumor inhibition of PRSS8 may be associated with proliferation- and epithelial mesenchymal transition - related proteins in ESCC cells. In conclusion, our finding showed that PRSS8 methylation and its stromal expression had important clinical significance in ESCC.

Downregulation of KLK13 promotes the invasiveness and metastasis of oesophageal squamous cell carcinoma

KLK13 downregulation occurs in tumour tissues in comparison with adjacent normal tissues from patients with oesophageal squamous cell carcinoma (OSCC). KLK13 mRNA levels were tested in OSCC tumour tissues and adjacent noncancerous tissues from 138 patients. In addition, the correlation between KLK13 mRNA levels and OSCC clinicopathologic features was analysed. KLK13 mRNA levels decreased notably in tumour tissues compared with those in adjacent noncancerous tissues. And decreased KLK13 mRNA levels indicated significant correlations with higher tumour grade, elevated TNM (UICC, 2009) stage classification, deeper infiltration and more lymph node metastases. And thus KLK13 may be a promising diagnostic marker. Decreased KLK13 mRNA levels also correlate with poor survival, which indicates that KLK13 mRNA expression may be a potential prognostic marker, although it could not be an independent prognostic factor by multivariate analysis. In vitro experiments of the OSCC cell lines KYSE150 and KYSE450 demonstrated that overexpression of KLK13 inhibits cell invasion and migration. Thus, KLK13 is a unique novel molecule useful for monitoring OSCC progression. Full elucidation of the role of KLK13 in OSCC may reveal avenues for investigating the molecule's functional potential as a novel therapeutic drug for targeting OSCC.

Interplay between Notch1 and Notch3 promotes EMT and tumor initiation in squamous cell carcinoma

Notch1 transactivates Notch3 to drive terminal differentiation in stratified squamous epithelia. Notch1 and other Notch receptor paralogs cooperate to act as a tumor suppressor in squamous cell carcinomas (SCCs). However, Notch1 can be stochastically activated to promote carcinogenesis in murine models of SCC. Activated form of Notch1 promotes xenograft tumor growth when expressed ectopically. Here, we demonstrate that Notch1 activation and epithelial–mesenchymal transition (EMT) are coupled to promote SCC tumor initiation in concert with transforming growth factor (TGF)-β present in the tumor microenvironment. We find that TGFβ activates the transcription factor ZEB1 to repress Notch3, thereby limiting terminal differentiation. Concurrently, TGFβ drives Notch1-mediated EMT to generate tumor initiating cells characterized by high CD44 expression. Moreover, Notch1 is activated in a small subset of SCC cells at the invasive tumor front and predicts for poor prognosis of esophageal SCC, shedding light upon the tumor promoting oncogenic aspect of Notch1 in SCC.

Notch receptors can exert different roles in cancer. In this manuscript, the authors reveal that Notch1 activation and EMT promote tumor initiation and cancer cell heterogeneity in squamous cell carcinoma, while the repression of Notch3 by ZEB1 limits Notch1-induced differentiation, permitting Notch1-mediated EMT.

Factors associated with the high prevalence of oesophageal cancer in Western Kenya: a review

Oesophageal carcinoma (OC) is highly prevalent in Western Kenya especially among the members of the Kalenjin community who reside in the Northern and Southern areas of the Rift Valley. Previous authors have suggested potential association of environmental and genetic risk factors with this high prevalence. The environmental factors that have been suggested include contamination of food by mycotoxins and/or pesticides, consumption of traditional alcohol (locally referred to “Busaa” and “Chan’gaa”), use of fermented milk (“Mursik”), poor diet, tobacco use and genetic predisposition. The aim of this paper is to critically examine the potential contribution of each of the factors that have been postulated to be associated with the high prevalence of the disease in order to establish the most likely cause. We have done this by analyzing the trends, characteristics and behaviours that are specifically unique in the region, and corroborated this with the available literature.

From our findings, the most plausible cause of the high incidence of OC among the Kalenjin community is mycotoxins, particularly fumonisins from the food chain resulting from poor handling of cereals; particularly maize combined with traditional alcohol laced with the toxins interacting synergistically with other high-risk factors such as dietary deficiencies associated alcoholism and viral infections, especially HPV. Urgent mitigating strategies should be developed in order to minimize the levels of mycotoxins in the food chain.

Targeted next-generation sequencing supports epidermoid metaplasia of the esophagus as a precursor to esophageal squamous neoplasia

Esophageal epidermoid metaplasia is a rare condition that involves the proximal-to-middle third of the esophagus. It is sharply demarcated and defined histologically by epithelial hyperplasia, a prominent granular cell layer, and superficial hyperorthokeratosis. In addition, preliminary studies have suggested an association between esophageal epidermoid metaplasia and esophageal squamous neoplasia (squamous dysplasia and esophageal squamous cell carcinoma). To further characterize esophageal epidermoid metaplasia and better define its relationship to squamous neoplasia of the esophagus, we performed targeted next-generation sequencing on uninvolved esophageal squamous mucosa and matching esophageal epidermoid metaplasia specimens from 18 patients. Further, we evaluated both synchronous and metachronous high-grade squamous dysplasia/esophageal squamous cell carcinoma by next-generation sequencing from 5 of the 18 (28%) patients, and compared these findings to corresponding esophageal epidermoid metaplasia specimens. Targeted next-generation sequencing revealed 12 of 18 (67%) esophageal epidermoid metaplasia specimens' harbored alterations in genes often associated with esophageal squamous cell carcinoma. The most frequently mutated genes consisted of TP53 (n=10), PIK3CA (n=2), EGFR (n=2), MYCN (n=1), HRAS (n=1), and the TERT promoter (n=1). Sequencing of synchronous and metachronous high-grade squamous dysplasia/esophageal squamous cell carcinoma identified shared genetic alterations with corresponding esophageal epidermoid metaplasia specimens that suggests a clonal relationship between these entities. In addition, the presence of a TP53 mutation in esophageal epidermoid metaplasia specimens correlated with concurrent or progression to high-grade squamous dysplasia/esophageal squamous cell carcinoma. No genetic alterations were detected in uninvolved esophageal squamous mucosa. On the basis of these findings, we conclude esophageal epidermoid metaplasia is a precursor to in situ and invasive esophageal squamous neoplasia. Further, the detection of TP53 mutations in esophageal epidermoid metaplasia specimens may serve as an early detection biomarker for high-grade squamous dysplasia/esophageal squamous cell carcinoma.

A novel long noncoding RNA linc00460 up-regulated by CBP/P300 promotes carcinogenesis in esophageal squamous cell carcinoma

Esophageal cancer is one of the leading causes of cancer-related mortality because of poor prognosis. Long noncoding RNAs (lncRNAs) have been gradually demonstrated to play critical roles in cancer development. We identified a novel long noncoding RNA named linc00460 by microarray analysis using esophageal squamous cell carcinoma (ESCC) clinical samples, which has not been studied before. Our research indicated that linc00460 was overexpressed in the majority of tumor tissues and ESCC cell lines. Linc00460 expression was positively correlated with ESCC TNM stage, lymph node metastasis, and predicted poor prognosis. In vitro experiments showed that linc00460 depletion suppressed ESCC cell growth through regulating cell proliferation and cell cycle; in additional, linc00460 depletion accelerated ESCC cell apoptosis. We further revealed that linc00460 overexpression was manipulated by transcriptional co-activator CBP/P300 through histone acetylation. Given the high expression and important biological functions of linc00460, we suggest that linc00460 works as an oncogene and might be a valuable prognostic biomarker for ESCC diagnosis and treatment.

Neutrophil to Lymphocyte Ratio as Prognostic Indicator for Patients with Esophageal Squamous Cell Cancer

Background

This study aimed to evaluate the correlation between neutrophil to lymphocyte ratio (NLR) with overall survival (OS) of esophageal squamous cell carcinoma (ESCC) patients.

Method

Records of patients with diagnosed ESCC were reviewed. Leukocyte counts and patients' characteristics were extracted from their clinical records to calculate NLR. Correlation between NLR and baseline characteristics with overall survival (OS) was then analyzed using Cox regression. The patients were then separated into higher and lower NLR groups according to median NLR. OS was further compared between the 2 groups.

Results

A total of 1281 patients were included in the study. Cox regression analysis showed a significant correlation of NLR with OS of ESCC patients. The median pretreatment NLR was identified as 2.86. Higher NLR was associated with worse prognosis in terms of OS.

Conclusions

Pretreatment NLR is independently associated with OS of ESCC patients. Therefore, NLR may be used as a predictive indicator for pretreatment evaluation and adjustment of treatment regimen.

Sporamin suppresses growth of human esophageal squamous cell carcinoma cells by inhibition of NF‑κB via an AKT‑independent pathway

The aim of the present study was to determine whether sporamin, a trypsin inhibitor, suppresses the growth of human esophageal squamous cell carcinoma (ESCC) cells in vitro. Sporamin treatment led to the suppression of viability and proliferation of human ESCC cell lines, EC9706 and EC109, as determined by MTT and [3H] thymidine incorporation assays, respectively. Flow cytometry and fluorescence microscopy demonstrated that sporamin significantly induced apoptosis in EC9706 and EC109 cells. Western blotting demonstrated that sporamin downregulated the expression of Bcl‑2 and Bcl‑2 like 1, and upregulated the expression of Bcl‑2‑associated X in EC9706 and EC109 cells. In addition, marked inhibition of nuclear factor (NF)‑κB activation was observed in sporamin‑treated EC9706 and EC109 cells by an electrophoretic mobility shift assay. Sporamin treatment also resulted in reduced expression levels of phosphorylated (p)‑NF‑κB inhibitor α and nuclear NF‑κB p65. However, the expression levels of p‑protein inase (AKT) and its downstream target, p‑p70 S6 kinase, were not markedly altered following sporamin treatment. In conclusion, sporamin may suppress the growth of human ESCC cells via NF‑κB‑dependent and AKT‑independent mechanisms and may act as a promising natural therapeutic agent for the treatment of human ESCC.

Methylation decreases the Bin1 tumor suppressor in ESCC and restoration by decitabine inhibits the epithelial mesenchymal transition

Bridging integrator-1 (Bin1), as a tumor suppressor, is frequently attenuated or even abolished in multiple primary cancers. A reduced expression of Bin1 caused by DNA methylation, has been reported in breast and prostate cancers. However, the methylation status of Bin1 and potent biological functions in esophageal squamous cell carcinoma (ESCC) remain unclear. In a previous study, we showed that the Bin1 expression was low in ESCC tissues. Herein, we further characterized this mechanism, confirming that gene hypermethylation was significantly correlated with the aberrant attenuation of Bin1. In addition, the Bin1 hypermethylation was associated with the poorer clinical parameters and shorter survival times of ESCC patients. Methylation-specific reverse transcription-polymerase chain reaction (MS-RT-PCR) showed that Bin1 was hypermethylated in several ESCC cell lines, which might be the main cause of reduced Bin1 expression. In addition, treatment with the de-methylation agent Decitabine (DAC) could restore Bin1 expression and evidently restrained ESCC cell malignant behaviors, particularly the epithelial mesenchymal transition (EMT) via reactivating the PTEN/AKT signaling pathway to inhibit matrix metalloproteinase (MMP)-2 and MMP-9 expression in vitro and in vivo. In conclusion, these results demonstrated that Bin1 methylation could augment the malignant biological behaviors of ESCC and predict the poor prognosis for ESCC patients, thus indicating the potential clinical application value of DAC-based de-methylation therapy in ESCC.

Racial Disparity in Gastrointestinal Cancer Risk

Cancer from the gastrointestinal tract and its associated excretory organs will occur in more than 300,000 Americans in 2017, with colorectal cancer responsible for >40% of that burden; there will be more than 150,000 deaths from this group of cancers in the same time period. Disparities among subgroups related to the incidence and mortality of these cancers exist. The epidemiology and risk factors associated with each cancer bear out differences for racial groups in the United States. Esophageal adenocarcinoma is more frequent in non-Hispanic whites, whereas esophageal squamous cell carcinoma with risk factors of tobacco and alcohol is more frequent among blacks. Liver cancer has been most frequent among Asian/Pacific Islanders, chiefly due to hepatitis B vertical transmission, but other racial groups show increasing rates due to hepatitis C and emergence of cirrhosis from non-alcoholic fatty liver disease. Gastric cancer incidence remains highest among Asian/Pacific Islanders likely due to gene-environment interaction. In addition to esophageal squamous cell carcinoma, cancers of the small bowel, pancreas, and colorectum show the highest rates among blacks, where the explanations for the disparity are not as obvious and are likely multifactorial, including socioeconomic and health care access, treatment, and prevention (vaccination and screening) differences, dietary and composition of the gut microbiome, as well as biologic and genetic influences. Cognizance of these disparities in gastrointestinal cancer risk, as well as approaches that apply precision medicine methods to populations with the increased risk, may reduce the observed disparities for digestive cancers.

Annular Stenotic Oesophageal Squamous Cell Carcinoma in Cattle Exposed Naturally to Bracken Fern (Pteridium arachnoideum)

Oesophageal squamous cell carcinomas (SCCs) may be observed as exophytic masses or ulcerative or infiltrative endophytic neoplasms. However, in cattle, there is also an uncommon gross presentation as an annular stenotic thickening of the oesophageal wall. Thirteen cases of annular stenotic oesophageal SCC in cattle grazing in bracken fern (Pteridium arachnoideum) areas are reported. The lesions consisted of endophytic masses, focally extensive, firm and circumferential (annular) in the oesophageal wall. Pronounced wrinkling of the mucosa, with retracted uneven areas and subsequent luminal narrowing (stenosis), was observed in all cases. Papillomas and squamous intraepithelial lesions also were observed in these cases. The SCCs were graded as well differentiated (n = 7), moderately differentiated (n = 5) or poorly differentiated (n = 1). The neoplastic keratinocytes were surrounded by moderate to abundant fibrous connective tissue (a desmoplastic reaction), that was better demonstrated by Masson's trichrome stain. Picrosirius red-stained sections showed abundant collagen type I fibres, which contributed to the stenosing characteristics of this tumour. Although it might be easily misdiagnosed as oesophageal scar tissue, the oesophageal SCCs of cattle grazing bracken fern may have a distinctive gross appearance that should be included in the differential diagnosis of oesophageal stenosis.

Molecular Mechanisms of Acetaldehyde-Mediated Carcinogenesis in Squamous Epithelium

Acetaldehyde is a highly reactive compound that causes various forms of damage to DNA, including DNA adducts, single- and/or double-strand breaks (DSBs), point mutations, sister chromatid exchanges (SCEs), and DNA-DNA cross-links. Among these, DNA adducts such as N²-ethylidene-2'-deoxyguanosine, N²-ethyl-2'-deoxyguanosine, N²-propano-2'-deoxyguanosine, and N²-etheno-2'-deoxyguanosine are central to acetaldehyde-mediated DNA damage because they are associated with the induction of DNA mutations, DNA-DNA cross-links, DSBs, and SCEs. Acetaldehyde is produced endogenously by alcohol metabolism and is catalyzed by aldehyde dehydrogenase 2 (ALDH2). Alcohol consumption increases blood and salivary acetaldehyde levels, especially in individuals with ALDH2 polymorphisms, which are highly associated with the risk of squamous cell carcinomas in the upper aerodigestive tract. Based on extensive epidemiological evidence, the International Agency for Research on Cancer defined acetaldehyde associated with the consumption of alcoholic beverages as a "group 1 carcinogen" (definite carcinogen) for the esophagus and/or head and neck. In this article, we review recent advances from studies of acetaldehyde-mediated carcinogenesis in the squamous epithelium, focusing especially on acetaldehyde-mediated DNA adducts. We also give attention to research on acetaldehyde-mediated DNA repair pathways such as the Fanconi anemia pathway and refer to our studies on the prevention of acetaldehyde-mediated DNA damage.

A Novel Grading System Based on Tumor Budding and Cell Nest Size Is a Strong Predictor of Patient Outcome in Esophageal Squamous Cell Carcinoma

The determination of prognosis in patients with esophageal squamous cell carcinoma (ESCC) is primarily based on staging according to the TNM-classification, whereas conventional grading is of minor clinical importance because of its deficiencies in prognostic patient stratification. Recently, a novel, highly prognostic grading scheme based on budding activity and cell nest size has been proposed for squamous cell carcinoma (SCC) of both pulmonary as well as oral origin. In order to investigate the utility and transferability of this approach to ESCC, we evaluated budding activity and cell nest size, as well as other histomorphologic characteristics, in a cohort of 135 primarily resected tumors and correlated the results with clinicopathologic and outcome parameters. High budding activity and small cell nest size showed a strong association with reduced overall, disease-specific, and disease-free survival (P<0.001, respectively) in ESCC. The combination of both markers in a 3-step grading system showed excellent prognostic separation of well-differentiated (G1), moderately differentiated (G2), and poorly differentiated (G3) carcinomas (P<0.001). The hazard ratio for disease-free survival in multivariate analysis under inclusion of stage was 2.97 for G2 and 5.42 for G3 ESCC (P<0.001). World Health Organization-based grading had no prognostic impact. Taken together, our data prove the value of tumor budding and cell nest size as excellent outcome predictors in ESCC and validate the utility of a previously established grading scheme proposed for oral and pulmonary SCC in this tumor entity. Ultimately, these combined efforts may result in a universal grading system for SCC regardless of the site of origin.

Up-regulation of lncRNA CASC9 promotes esophageal squamous cell carcinoma growth by negatively regulating PDCD4 expression through EZH2

Background

Abnormal expression of numerous long non-coding RNAs (lncRNAs) has been reported in esophageal squamous cell carcinoma (ESCC) recently, but the great majority of their roles and mechanisms remain largely unclear. We aim to identify the critical ESCC-associated lncRNAs and elucidate the functions and mechanisms in detail.

Methods

Microarrays were used to analyze the differentially expressed lncRNAs in ESCC tissues. qRT-PCR was used to verify the result of microarrays. The effects of the most up-regulated lncRNA, cancer susceptibility candidate 9(CASC9), on cell growth, proliferation and cell cycle were investigated by in vivo and in vitro assays. Microarrays and recovery tests were used to discover the regulatory targets of CASC9. RNA FISH and subcellular fractionation assays were used to detect the subcellular location of CASC9. Finally, the mechanism of CASC9 regulating PDCD4 was explored by RIP, RNA-protein pull down and ChIP assays.

Results

ESCC tissue microarrays showed that CASC9 was the most up-regulated lncRNA. qRT-PCR analysis indicated that CASC9 expression was positively associated with tumor size and TNM stage, and predicted poor overall survival of ESCC patients. Knockdown of CASC9 inhibited ESCC cell growth in vitro and tumorigenesis in nude mice. Furthermore interfering CASC9 decreased cell proliferation and blocked cell cycle G1/S transition. CASC9-associated microarrays indicated that PDCD4 might be the target of CASC9. Consistent with this, PDCD4 expression was negatively associated with CASC9 expression in ESCC tissues and predicted good prognosis. Manipulating CASC9 expression in ESCC cells altered both PDCD4 mRNA and protein levels and cell cycle arrest caused by CASC9 knockdown could be rescued by suppressing PDCD4 expression. CASC9 located both in the nucleus and cytoplasm. Mechanistically, enhancer of zeste homolog2 (EZH2) could bind to both CASC9 and PDCD4 promoter region. Interfering CASC9 reduced the enrichment of EZH2 and H3K27me3 in the PDCD4 promoter region.

Conclusions

Our study firstly demonstrates that lncRNA CASC9 functions as an oncogene by negatively regulating PDCD4 expression through recruiting EZH2 and subsequently altering H3K27me3 level. Our study implicates lncRNA CASC9 as a valuable biomarker for ESCC diagnosis and prognosis.

Electronic supplementary material

The online version of this article (10.1186/s12943-017-0715-7) contains supplementary material, which is available to authorized users.

Distinct effects of EGFR inhibitors on epithelial- and mesenchymal-like esophageal squamous cell carcinoma cells

Background

Epidermal growth factor receptor (EGFR) plays a pivotal role in the pathophysiology of esophageal squamous cell carcinoma (ESCC). However, the clinical effects of EGFR inhibitors on ESCC are controversial. This study sought to identify the factors determining the therapeutic efficacy of EGFR inhibitors in ESCC cells.

Methods

Immortalized-human esophageal epithelial cells (EPC2-hTERT), transformed-human esophageal epithelial cells (T-Epi and T-Mes), and ESCC cells (TE-1, TE-5, TE-8, TE-11, TE-11R, and HCE4) were treated with the EGFR inhibitors erlotinib or cetuximab. Inhibitory effects on cell growth were assessed by cell counting or cell-cycle analysis. The expression levels of genes and proteins such as involucrin and cytokeratin13 (a squamous differentiation marker), E-cadherin, and vimentin were evaluated by real-time polymerase chain reaction or western blotting. To examine whether mesenchymal phenotype influenced the effects of EGFR inhibitors, we treated T-Epi cells with TGF-β1 to establish a mesenchymal phenotype (mesenchymal T-Epi cells). We then compared the effects of EGFR inhibitors on parental T-Epi cells and mesenchymal T-Epi cells. TE-8 (mesenchymal-like ESCC cells)- or TE-11R (epithelial-like ESCC cells)-derived xenograft tumors in mice were treated with cetuximab, and the antitumor effects of EGFR inhibitors were evaluated.

Results

Cells were classified as epithelial-like or mesenchymal-like phenotypes, determined by the expression levels of E-cadherin and vimentin. Both erlotinib and cetuximab reduced cell growth and the ratio of cells in cell-cycle S phase in epithelial-like but not mesenchymal-like cells. Additionally, EGFR inhibitors induced squamous cell differentiation (defined as increased expression of involucrin and cytokeratin13) in epithelial-like but not mesenchymal-like cells. We found that EGFR inhibitors did not suppress the phosphorylation of EGFR in mesenchymal-like cells, while EGFR dephosphorylation was observed after treatment with EGFR inhibitors in epithelial-like cells. Furthermore, mesenchymal T-Epi cells showed resistance to EGFR inhibitors by circumventing the dephosphorylation of EGFR signaling. Cetuximab consistently showed antitumor effects, and increased involucrin expression in TE-11R (epithelial-like)-derived xenograft tumors but not TE-8 (mesenchymal-like)-derived xenograft tumors.

Conclusions

The factor determining the therapeutic effects of EGFR inhibitors in ESCC cells is the phenotype representing the epithelial-like or mesenchymal-like cells. Mesenchymal-like ESCC cells are resistant to EGFR inhibitors because EGFR signaling is not blocked. EGFR inhibitors show antitumor effects on epithelial-like ESCC cells accompanied by promotion of squamous cell differentiation.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-017-0572-7) contains supplementary material, which is available to authorized users.

Time trends of esophageal and gastric cancer mortality in China, 1991-2009: an age-period-cohort analysis

Esophageal and gastric cancers share some risk factors. This study aimed to compare the long-term trends in mortality rates of esophageal and gastric cancers in China to provide evidence for cancer prevention and control. Mortality data were derived from 103 continuous points of the Disease Surveillance Points system during 1991-2009, stratified by gender and urban-rural locations. Age-period-cohort models were used to disentangle the time trends of esophageal and gastric cancer mortality. The downward slope of the period effect for esophageal cancer was steeper than that for gastric cancer in rural areas. Cohort effect patterns were similar between esophageal and gastric cancers, with an inverse U-shape peaking around the late 1920s and early 1930s. A second peak, appearing around the 1950s, was weaker than the first but apparent in males, especially for esophageal cancer. The more marked changes in period effect for esophageal cancer in rural areas suggest esophageal cancer screening practices are effective in reducing mortality, and similar programs targeting gastric cancer should be implemented. The similarities of the cohort effects in these two cancers support the implication of nutrition deficiency in early childhood in the development of upper gastrointestinal cancer.

A three-gene signature from protein-protein interaction network of LOXL2- and actin-related proteins for esophageal squamous cell carcinoma prognosis

Current staging is inadequate for predicting clinical outcome of esophageal squamous cell carcinoma (ESCC). Aberrant expression of LOXL2 and actin-related proteins plays important roles in ESCC. Here, we aimed to develop a novel molecular signature that exceeds the power of the current staging system in predicting ESCC prognosis. We found that LOXL2 colocalized with filamentous actin in ESCC cells, and gene set enrichment analysis (GSEA) showed that LOXL2 is related to the actin cytoskeleton. An ESCC-specific protein-protein interaction (PPI) network involving LOXL2 and actin-related proteins was generated based on genome-wide RNA-seq in 15 paired ESCC samples, and the prognostic significance of 14 core genes was analyzed. Using risk score calculation, a three-gene signature comprising LOXL2, CDH1, and FN1 was derived from transcriptome data of patients with ESCC. The high-risk three-gene signature strongly correlated with poor prognosis in a training cohort of 60 patients (P = 0.003). In mRNA and protein levels, the prognostic values of this signature were further validated in 243 patients from a testing cohort (P = 0.001) and two validation cohorts (P = 0.021, P = 0.007). Furthermore, Cox regression analysis revealed that the signature was an independent prognostic factor. Compared with using the signature or TNM stage alone, the combined model significantly enhanced the accuracy in evaluating ESCC prognosis. In conclusion, our data reveal that the tumor-promoting role of LOXL2 in ESCC is mediated by perturbing the architecture of actin cytoskeleton through its PPIs. We generated a novel three-gene signature (PPI interfaces) that robustly predicts poor clinical outcome in ESCC patients.

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

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

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.

Establishment of a Quick and Highly Accurate Breath Test for ALDH2 Genotyping

Objectives:

Acetaldehyde, the first metabolite of ethanol, is a definite carcinogen for the esophagus, head, and neck; and aldehyde dehydrogenase 2 (ALDH2) is a mitochondrial enzyme that catalyzes the metabolism of acetaldehyde. The ALDH2 genotype exists as ALDH2*1/*1 (active ALDH2), ALDH2*1/*2 (heterozygous inactive ALDH2), and ALDH2*2/*2 (homozygous inactive ALDH2). Many epidemiological studies have reported that ALDH2*2 carriers are at high risk for esophageal or head and neck squamous cell carcinomas by habitual drinking. Therefore, identification of ALDH2*2 carriers would be helpful for the prevention of those cancers, but there have been no methods suitable for mass screening to identify these individuals.

Methods:

One hundred and eleven healthy volunteers (ALDH2*1/*1 carriers: 53; ALDH2*1/*2 carriers: 48; and ALDH2*2/*2 carriers: 10) were recruited. Breath samples were collected after drinking 100 ml of 0.5% ethanol using specially designed gas bags, and breath ethanol and acetaldehyde levels were measured by semiconductor gas chromatography.

Results:

The median (range) breath acetaldehyde levels at 1 min after alcohol ingestion were 96.1 (18.1–399.0) parts per billion (p.p.b.) for the ALDH2*1/*1 genotype, 333.5 (78.4–1218.4) p.p.b. for the ALDH2*1/*2 genotype, and 537.1 (213.2–1353.8) p.p.b. for the ALDH2*2/*2 genotype. The breath acetaldehyde levels in ALDH2*2 carriers were significantly higher than for the ALDH2*1/*1 genotype. Notably, the ratio of breath acetaldehyde level-to-breath ethanol level could identify carriers of the ALDH2*2 allele very accurately (whole accuracy; 96.4%).

Conclusions:

Our novel breath test is a useful tool for identifying ALDH2*2 carriers, who are at high risk for esophageal and head and neck cancers.

Long noncoding RNA MALAT1 affects the efficacy of radiotherapy for esophageal squamous cell carcinoma by regulating Cks1 expression

OBJECTIVE

Long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been well studied in the progression of many malignancies. However, its association with the radioresistance of tumors has not been well understood yet. This study tried to explore the role of MALAT1 in regulating the radiosensitivity of esophageal cancer (EC), especially esophageal squamous cell carcinoma (ESCC), involving its regulation on Cks1 expression.

METHODS

KYSE150 cells were subcutaneously inoculated into nude mice to establish ESCC xenografts. Real-time PCR and Western blot analysis were performed to detect the expression of MALAT1 and Cks1 in irradiated xenografts and cells. Functional analysis was performed in both EC9706 and KYSE150 cells via the transfection of corresponding plasmids or small interfering RNAs (siRNAs). Irradiation-induced damage was examined by the detection of cell viability and apoptosis using MTT and TUNEL assays, respectively.

RESULTS

Both MALAT1 and Cks1 were downregulated in irradiated xenografts and cells. Cks1FER1L4 showed significant downregulation. Overexpression of MALAT1 inhibited irradiation-induced decrease in cell viability, increase in apoptosis, and downregulation of Cks1. Cks1 expression was also downregulated by MALAT1 siRNA, while Cks1 siRNA strongly recovered MALAT1-induced radioresistance in vitro. Moreover, better tumor growth, accompanied by Cks1 upregulation, was observed in KYSE150 xenografts with MALAT1 overexpression, especially under radiation treatment.

CONCLUSION

MALAT1 acted as one positive regulator of the radioresistance of ESCC, at least partly due to its promotion on Cks1 expression. Furthermore, MALAT1-targeted therapies showed great potential in enhancing the radiotherapeutic effect on ESCC.

Associations of carboxypeptidase 4 with ALDH1A1 expression and their prognostic value in esophageal squamous cell carcinoma

Esophageal cancer is an aggressive disease with poor prognosis because of early metastasis when diagnosed and recurrence after surgery. This study is aimed at investigating the expression of carboxypeptidaseA4 (CPA4) and aldehyde dehydrogenase 1A1 (ALDH1A1) in esophageal squamous cell carcinoma (ESCC) tumor tissues and analyzed their association and clinical significance. The expression of CPA4 and ALDH1A1 was determined by immunohistochemistry using the corresponding primary antibodies on two commercial tissue arrays. High level of CPA4 was observed in 87/150 (58%) ESCC samples and was significantly associated with histologic grade, lymph node metastasis, and TNM Classification of Esophageal cancer stage. The expression level of ALDH1A1 was much higher in ESCC than their corresponding normal epithelial tissues, with 66% positive rate. And, high levels of ALDH1A1 were significantly associated with lymph nodes metastasis (P < 0.05) and TNM stage (P < 0.05). Correlation analysis showed the expression level of CPA4 positively correlated with that of ALDH1A1 (r = 0.416, P < 0.01). In Kaplan-Meier survival analysis, either CPA4 or ALDH1A1 was significantly correlated with poor overall survival of ESCC patients. Multivariate Cox regression model showed that high expression of CPA4 was an independent prognostic factor for ESCC patients. In conclusion, our present study demonstrated for the first time that CPA4 might be used as an independent poor prognostic factor in ESCC. This study demonstrated for the first time that CPA4 was aberrantly expressed in ESCC tissues. Overexpression of CPA4 was closely associated with the putative cancer stem cell marker ALDH1A1 and might be used as an independent prognostic factor in ESCC.

Molecular subtypes in cancers of the gastrointestinal tract

Malignancies of the gastrointestinal tract are among the most common human cancers. The distinct tissues of origin give rise to a diverse set of diseases, such as colorectal cancer, pancreatic carcinoma and gastric cancers, with each associating with specific clinical features. Genomic and transcriptomic analyses have further defined the heterogeneity that occurs within these cancers by identifying so-called molecular subtypes. These subtypes are characterized by specific genetic aberrations and expression signatures that suggest important biological differences. Although at first sight this subdivision of organ-specific cancers might increase the complexity of classification, closer analysis suggests that the subtypes detected in the various malignancies are recurring. For example, nearly all gastrointestinal cancers appear to present with subtypes that are either characterized by a mesenchymal gene expression signatures, extensive immune infiltration or metabolic dysregulation. Additionally, in each of the gastrointestinal malignancies, a 'canonical' subtype is recognized that retains characteristic features of the epithelial tissue of origin. These common themes can enhance our collective understanding of these malignancies, and could perhaps be therapeutically exploited. In this Review, the identification of subtypes in the various gastrointestinal cancer types are discussed along with how they could be incorporated into clinical practice.

eEF2K promotes progression and radioresistance of esophageal squamous cell carcinoma

OBJECTIVES

To investigate the biological function of eEF2K in esophageal squamous cell carcinoma (ESCC).

MATERIALS AND METHODS

Tissue microarrays containing 100 pairs of ESCC tumor and adjacent normal tissues were completed. Overexpression and knockdown of eEF2K were constructed in ECA-109 and TE-13 ESCC cells. DNA damage, cell viability, migration and invasion, radioresistance, apoptosis and autophagy were determined by immunofluorescence, CCK-8, transwell assay, colony formation assay, flow cytometry and western blot, respectively. Tumor growth and radioresistance were also evaluated using xenograft models created in nude mice.

RESULTS

eEF2K expression was higher in ESCC tissues compared with matched non-tumor tissues (P<0.05). Proliferation was increased in eEF2K overexpressing cells compared with controls (P<0.05), while silencing eEF2K reduced cell proliferation (P<0.05). Furthermore, lower levels of eEF2K expression correlated with slower migration and invasion rates (P<0.05), while higher levels of eEF2K expression with faster migration and invasion rates (P<0.05). eEF2K overexpression resulted in radioresistance and radiation-induced autophagy, and reduced radiation-induced apoptosis compared with controls, but silencing eEF2K promoted radiosensitivity and apoptosis, and reduced autophagy. In addition, eEF2K overexpression promoted the tumor growth in vivo (P<0.01). Combined treatment of NH125 (a pharmacological inhibitor of eEF2K) and radiation was more effective at delaying xenograft tumor growth than NH125 and radiation alone (P<0.05).

CONCLUSION

eEF2K induced progression and radioresistance in ESCC, which may be a novel therapeutic target for ESCC to increase radiosensitivity.

Expression, prognosis and functional role of Thsd7a in esophageal squamous cell carcinoma of Kazakh patients, Xinjiang

Thsd7a (Thrombospondin type 1 domain containing 7a) is a critical transmembrane protein. Studies have indicated that Thsd7a was associated with cytoskeletal organization, cell migration and filopodia formation. However, the involvement of Thsd7a remains elusive in human Esophageal Squamous Cell Carcinoma (ESCC). Consequently, immunohistochemistry and reverse transcription-polymerase chain reaction were utilized to study the correlation between the expression of Thsd7a and clinical-pathological characteristics. The influence of Thsd7a on apoptosis, cell proliferating activity, cell cycle, migratory and invasive capacity was determined in Eca 109 and EC 9706 cell lines in vitro. And the influence on proliferating activity was testified using naked mice model in vivo. In addition, the potential molecular mechanism was tested by microarray. It was discovered that there is a certain correlation between Thsd7a and the Kazakh ESCC. By knocking out Thsd7a, the invasion, migration and proliferation could be decreased. And it could also arrest the cell cycle at G1 phase and increase the apoptosis rate. It was further verified that Thsd7a had obvious effect on proliferation in naked mice with xenograft of Eca109 cells. Finally, it was uncovered by microarray analysis that a variety of tumor genes and pathways related to Thsd7a. Together, it was demonstrated that Thsd7a might have a certain degree of carcinogenesis in ESCC.

Serum microRNA-15a level acts as a potential diagnostic and prognostic biomarker for human esophageal squamous cell carcinoma

BACKGROUND

Clinical significance of microRNA (miR)-15a in human esophageal squamous cell carcinoma (ESCC) remains unclear.

OBJECTIVE

To evaluate the expression level of miR-15a and to determine its potential for diagnosis and prognosis in ESCC.

METHODS

Quantitative reverse transcription polymerase chain reaction was performed to examine the expression levels of miR-15a in ESCC tissues and patients' sera. The diagnostic and prognostic implications of serum miR-15a level in human ESCC were further evaluated.

RESULTS

Expression levels of miR-15a in ESCC tissues and patients' sera were significantly decreased (both P< 0.001). Additionally, serum miR-15a had an optimal diagnostic cut-off point (2.29) for ESCC with sensitivity of 86.36% and specificity of 100.00%. Moreover, low serum miR-15a level more frequently occurred in ESCC patients with advanced tumor-node-metastasis, T and N stages (all P= 0.01) and poor tumor differentiation (P= 0.03). The Kaplan-Meier curve showed that low miR-15a expression was significantly associated with shorter overall survival (OS) and disease-free survival (DFS) of ESCC patients (both P< 0.001). Further multivariate analysis identified miR-15a as an independent prognostic factor for both OS and DFS (both P= 0.01).

CONCLUSION

Decreased expression of miR-15a may play a crucial role in ESCC development and progression. Serum miR-15a level could be used as a potential diagnostic and prognostic marker in clinics.

FOXF2 promoter methylation is associated with prognosis in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma is a commonly malignant tumor of digestive tract with poor prognosis. Previous studies suggested that forkhead box F2 ( FOXF2) could be a candidate gene for assessing and predicting the prognosis of human cancers. However, the relationship between FOXF2 promoter methylation and the prognosis of esophageal squamous cell carcinoma remained unclear. Formalin-fixed, paraffin-embedded esophageal squamous cell carcinoma tissues of 135 esophageal squamous cell carcinoma patients were detected for FOXF2 promoter methylation status by methylation-specific polymerase chain reaction approach. DNA methylation results were evaluated with regard to clinicopathological features and overall survival. Our study confirmed that FOXF2 promoter hypermethylation could independently predict a poorer overall survival of esophageal squamous cell carcinoma patients ( p = 0.002), which was consistent with the data mining results of the data from 82 esophageal squamous cell carcinoma patients in The Cancer Genome Atlas datasets ( p = 0.036). In addition, no correlation was found between FOXF2 promoter methylation and other clinic pathological parameters (age, gender, differentiation, lymph node metastasis, stage, cutting edge, vascular invasion, smoking behavior, and drinking history). In conclusion, FOXF2 methylation might be a useful prognostic biomarker for esophageal squamous cell carcinoma patients.

Diagnostic Value of Autoantibodies against Ezrin in Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC), one of the most common malignancies worldwide, is a highly aggressive and homogeneous entity occurring in esophageal squamous epithelium, and a reliable noninvasive test for early detection is needed. A recent study showed that serum autoantibodies against Ezrin could be detected in patients with pancreatic cancer. Here, we assessed whether autoantibodies against Ezrin could have diagnostic relevance for early ESCC. We analyzed autoantibodies against Ezrin in sera of 98 normal controls and 149 patients with ESCC. Ezrin autoantibodies levels were evaluated by enzyme-linked immunosorbent assay (ELISA). Results showed that higher levels of autoantibodies against Ezrin were observed in serum samples from patients with ESCC than in serum from normal controls (P < 0.0001). Based on a cutoff value of 0.319, the sensitivity and specificity of autoantibodies against Ezrin for diagnosis of ESCC were 27.5% and 95.9%, respectively. Compared with normal controls, the positive rate of autoantibodies against Ezrin was significantly elevated in patients with early-stage ESCC (P < 0.0001). Moreover, there was no significant difference of positivity of autoantibodies against Ezrin in ESCC patients categorized according to age, gender, tumor size, tumor invasion depth, tumor site, histological grade, lymph node status, or tumor stage. Our study indicates that the presence of autoantibodies against Ezrin is significantly associated with ESCC.

MicroRNA-30d inhibits the migration and invasion of human esophageal squamous cell carcinoma cells via the post‑transcriptional regulation of enhancer of zeste homolog 2

The present study was carried out to investigate the expression pattern, clinical significance and biological functions of microRNA-30d (miR-30d) in esophageal carcinogenesis. Quantitative real-time PCR was performed to detect the expression levels of miR-30d in esophageal squamous cell carcinoma (ESCC) tissues and cell lines. Then, associations between miR-30d expression and various clinicopathological features of patients with ESCC were statistically evaluated. In addition, the effects of miR-30d on the migration and invasion of two human ESCC cell lines transfected with miRNA or co-transfected with miRNA mimics and the expression vector of its target gene were determined. The results revealed that the expression levels of miR-30d were markedly decreased in ESCC tissues and cell lines, comparing with the corresponding normal controls. Notably, reduced expression of miR-30d occurred more frequently in ESCC patients with positive lymph node metastasis, moderate-poor differentiation and advanced tumor-node-metastasis stage than those with negative features. Functionally, enforced expression of miR-30d was found to inhibit cell invasion and migration of the ESCC cell lines. Luciferase reporter assay identified enhancer of zeste homolog 2 (EZH2) as a direct target gene of miR-30d. The expression level of EZH2 mRNA was negatively correlated with the expression of miR-30d in the ESCC tissues. Moreover, the inhibitory effect of miR-30d on ESCC cell motility was reversed by EZH2 overexpression. Collectively, these findings provide convincing evidence that decreased expression of miR-30d may be implicated in esophageal carcinogenesis and progression. We also confirmed miR-30d as a tumor-suppressor which may inhibit cancer cell motility by targeting EZH2, a potential therapeutic target for ESCC.

The low IGFBP-3 level is associated with esophageal cancer patients: a meta-analysis

Background

Esophageal cancer was a vital cause of cancer-related mortality worldwide, and the insulin-like growth factor-binding proteins (IGFBPs) has been proved to be an important factor of multiple types of tumors. There is a controversy that whether the IGFBP-3 level is associated with the clinical pathological characteristics and overall survival of esophageal cancer patients. Herein, we aimed to comprehensively assess the association between the low IGFBP-3 level and the risk, overall survival and clinical pathological characteristics of esophageal cancer.

Method

We conducted a meta-analysis using seven eligible studies. The overall odds ratios (OR)/relative risk (RR) and their corresponding 95% confidence interval (CI) were calculated for each parameter.

Results

For the risk of esophageal cancer, the OR was 2.342 (p = 0.000), indicating that individuals with lower IGFBP-3 level were more likely to suffer from esophageal cancer, compared to those with relatively high IGFBP-3 level. With respect to the 3-year survival rate, the RR was 2.163 (p = 0.027), which demonstrated that esophageal cancer patients with low IGFBP-3 level had significantly lower 3-year survival rate; in terms of clinical pathological characteristics, significantly lower IGFBP-3 level was found for patients in all categories; for survival status, patients in low IGFBP-3 level are more likely to be in the dead survival status (OR = 4.480, p = 0.000).

Conclusion

Our meta-analysis suggests that for esophageal cancer, the low IGFBP-3 level is associated with high cancer risk, poor prognosis, and unfavorable tumor stage and metastasis.

Surveillance of patients at high-risk of squamous cell esophageal cancer

Currently curative treatment for esophageal squamous cell cancer (ESCC) is possible only in patients with early-stage, usually asymptomatic disease. In Western countries, where the incidence of ESCC is relatively low, a screening of asymptomatic, average-risk population is untenable. In order to detect early-stage ESCC or its precursor lesions it is important to identify high-risk patients and consider endoscopic surveillance in these groups. These high-risk groups include patients after curative treatment for head and neck cancer, previous endoscopic resection of ESCC, caustic injury, and patients with tylosis or achalasia. This paper discuss the evidence and proposed method of endoscopy surveillance of these high-risk patients.

Laboratory animal models for esophageal cancer

The incidence of esophageal cancer is rapidly increasing especially in developing countries. The major risk factors include unhealthy lifestyle practices such as alcohol consumption, smoking, and chewing tobacco to name a few. Diagnosis at an advanced stage and poor prognosis make esophageal cancer one of the most lethal diseases. These factors have urged further research in understanding the pathophysiology of the disease. Animal models not only aid in understanding the molecular pathogenesis of esophageal cancer but also help in developing therapeutic interventions for the disease. This review throws light on the various recent laboratory animal models for esophageal cancer.

ZNF750 is a lineage-specific tumour suppressor in squamous cell carcinoma

ZNF750 controls epithelial homeostasis by regulating epidermal-differentiation genes, a role underscored by its pathogenic mutations in esophageal squamous cell cancers (SCCs). However, the precise role of ZNF750 in SCC cell biology remains unclear. In this study, we report that ZNF750 is exclusively deleted, mutated and underexpressed in human SCCs, and low ZNF750 expression is associated with poor survival. Restoration of wildtype, but not mutant ZNF750 protein uniquely inhibited the malignant phenotypes of SCC cells both in vitro and in vivo. Notably, ZNF750 promoted the expression of a long non-coding RNA (TINCR), which mediated both cancer-inhibition and differentiation-induction effects of ZNF750. In addition, ZNF750 potently suppressed cell migration by directly inhibiting the transactivation of LAMC2. Together, our findings characterize ZNF750 as a crucial SCC-specific suppressor and uncover its novel anticancer-associated functions.

Extranodal extension of lymph node metastasis is a marker of poor prognosis in oesophageal cancer: a systematic review with meta-analysis

The extranodal extension (ENE) of nodal metastasis is the extension of neoplastic cells through the nodal capsule into the perinodal adipose tissue. This histological feature has recently been indicated as an important prognostic factor in different types of malignancies; in this manuscript, we aim at defining its role in the prognosis of oesophageal cancer with the tool of meta-analysis. Two independent authors searched SCOPUS and PubMed until 31 August 2015 without language restrictions. The studies with available data about prognostic parameters in subjects with oesophageal cancer, comparing patients with the presence of ENE (ENE+) versus only intranodal extension (ENE-), were considered as eligible. Data were summarised using risk ratios (RRs) for number of deaths/recurrences and HRs together with 95% CIs for time-dependent risk related to ENE+, adjusted for potential confounders. Fourteen studies were selected; they followed-up 1437 patients with oesophageal cancer for a median follow-up of 39.4 months. The presence of ENE was associated with a significantly increased risk of all-cause mortality (RR=1.33; 95% CI 1.18 to 1.50, p<0.0001, I2=49%; HR=2.72, 95% CI 2.03 to 3.64, p<0.0001, I2=0%), cancer-specific mortality (RR=1.35; 95% CI 1.14 to 1.59, p=0.001, I2=57%; HR=1.97, 95% CI 1.41 to 2.75, p<0.0001, I2=41%) and of risk of recurrence (RR=1.50, 95% CI 1.20 to 1.88, p<0.0001, I2=9%; HR=2.27, 95% CI 1.72 to 2.90, p<0.0001, I2=0%). On the basis of these results, in oesophageal cancer, ENE should be considered from the gross sampling to the pathology report, and in future oncological staging system.

Melatonin enhances sensitivity to fluorouracil in oesophageal squamous cell carcinoma through inhibition of Erk and Akt pathway

Oesophageal squamous cell carcinoma (ESCC) is the sixth most common cause of cancer-associated death in the world and novel therapeutic alternatives are urgently warranted. In this study, we investigated the anti-tumour activity and underlying mechanisms of melatonin, an indoleamine compound secreted by the pineal gland as well as naturally occurring plant products, in ESCC cells and revealed that melatonin inhibited proliferation, migration, invasion and induced mitochondria-dependent apoptosis of ESCC cells in vitro and suppressed tumour growth in the subcutaneous mice model in vivo. Furthermore, after treatment with melatonin, the expressions of pMEK, pErk, pGSK3β and pAkt were significantly suppressed. In contrast, treatment of the conventional chemotherapeutic drug fluorouracil (5-Fu) resulted in activation of Erk and Akt, which could be reversed by co-treatment with melatonin. Importantly, melatonin effectively enhanced cytotoxicity of 5-Fu to ESCC in vitro and in vivo. Together, these results suggested that inhibition of Erk and Akt pathway by melatonin have an important role in sensitization of ESCC cells to 5-Fu. Combined 5-Fu and melatonin treatment may be appreciated as a useful approach for ESCC therapy that warrants further investigation.

Melatonin enhances sensitivity to fluorouracil in oesophageal squamous cell carcinoma through inhibition of Erk and Akt pathway

Oesophageal squamous cell carcinoma (ESCC) is the sixth most common cause of cancer-associated death in the world and novel therapeutic alternatives are urgently warranted. In this study, we investigated the anti-tumour activity and underlying mechanisms of melatonin, an indoleamine compound secreted by the pineal gland as well as naturally occurring plant products, in ESCC cells and revealed that melatonin inhibited proliferation, migration, invasion and induced mitochondria-dependent apoptosis of ESCC cells in vitro and suppressed tumour growth in the subcutaneous mice model in vivo. Furthermore, after treatment with melatonin, the expressions of pMEK, pErk, pGSK3β and pAkt were significantly suppressed. In contrast, treatment of the conventional chemotherapeutic drug fluorouracil (5-Fu) resulted in activation of Erk and Akt, which could be reversed by co-treatment with melatonin. Importantly, melatonin effectively enhanced cytotoxicity of 5-Fu to ESCC in vitro and in vivo. Together, these results suggested that inhibition of Erk and Akt pathway by melatonin have an important role in sensitization of ESCC cells to 5-Fu. Combined 5-Fu and melatonin treatment may be appreciated as a useful approach for ESCC therapy that warrants further investigation.

Regulation of MMP13 by antitumor microRNA-375 markedly inhibits cancer cell migration and invasion in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive malignancies. Recently developed molecular targeted therapies are not available for patients with ESCC. After curative surgical resection, patients frequently suffer distant metastasis and recurrence. Exploration of novel ESCC metastatic pathways may lead to the development of new treatment protocols for this disease. Accordingly, we have sequentially identified microRNA (miRNA)-mediated metastatic pathways in several cancers. Our past studies of miRNA expression signatures have shown that microRNA-375 (miR-375) is frequently reduced in several types of cancers, including ESCC. In the present study, we aimed to investigate novel miR-375-mediated metastatic pathways in ESCC cells. The expression of miR-375 was downregulated in ESCC tissues, and ectopic expression of this miRNA markedly inhibited cancer cell migration and invasion, suggesting that miR-375 acted as an antimetastatic miRNA in ESCC cells. Our strategies for miRNA target searching demonstrated that matrix metalloproteinase 13 (MMP13) was directly regulated by miR-375 in ESCC cells. Overexpression of MMP13 was observed in ESCC clinical tissues, and the expression of MMP13 promoted cancer cell aggressiveness. Moreover, oncogenic genes, including CENPF, KIF14 and TOP2A, were shown to be regulated downstream of MMP13. Taken together, these findings demonstrated that the antitumor miR-375/oncogenic MMP13 axis had a pivotal role in ESCC aggressiveness. These results provide novel insights into the potential mechanisms of ESCC pathogenesis.

Current status of proteomics of esophageal carcinoma

INTRODUCTION

Esophageal cancer (EC) is one of the most common causes of cancer-related death worldwide. Identifying suitable biomarkers for early diagnosis as well as predicting lymph node metastasis, prognosis and the therapeutic response of EC is essential for the effective and efficient management for EC. There is an urgent need to develop effective, novel approaches for patients who do not respond to conventional treatment. Areas covered: EC is characterized by the presence of two main histological types such as squamous cell carcinoma and adenocarcinoma, which differ in their response to treatments and prognosis. Thus, this review describes the latest research into biomarkers and novel treatment targets generated by cancer proteomics for the two main histological types. Finally, the main difficulties facing the translation of biomarkers and novel treatment targets into the clinical settings are discussed. Expert commentary: EC proteomics have provided useful results and, after their validation, novel clinical tools should be developed to improve the clinical outcomes for EC patients.