International cancer seminars: a focus on esophageal squamous cell carcinoma

Exosome-Encapsulated MicroRNA-21 from Esophageal Squamous Cell Carcinoma Cells Enhances Angiogenesis of Human Umbilical Venous Endothelial Cells by Targeting SPRY1

Objective

Esophageal squamous cell carcinoma (ESCC) persists among the most prevalent cancers worldwide. Angiogenesis represents a crucial element necessitated for tumor growth and metastasis in ESCC. In this study, we aimed to study the effect of microRNA (miR)-21 on angiogenesis in ESCC and its underlying mechanism.

Materials and Methods

Initially, the expression patterns of miR-21, SPRY1, and VEGF were determined in ESCC tissues and cells. The relationship between miR-21 and SPRY1 was identified using dual-luciferase reporter assay. Exosomes were subsequently isolated from the ESCC cells, followed by co-culture with the human umbilical venous endothelial cells (HUVECs). HUVEC proliferation and angiogenesis were determined by means of CCK-8, colony formation, and microtubule formation in vitro. Chicken chorioallantoic membrane (CAM) model and mouse xenograft model of ESCC cells were established to substantiate the function of miR-21 corresponding to the angiogenesis and tumor growth of ESCC, followed by microvascular density (MVD) evaluation.

Results

Expression patterns of miR-21 and VEGF were elevated, while the SPRY1 expression pattern was repressed in ESCC tissues and cells. The downregulation of miR-21 and exosome-derived miR-21 impeded the proliferation and angiogenesis in HUVECs. Our data revealed that miR-21 could negatively target SPRY1, and positively target VEGF. The downregulation of miR-21 could evidently encumber the angiogenesis and tumor growth of ESCC in vivo, as evidenced by the decrease in number of branches of the microvessels and MVD.

Conclusion

Collectively, ESCC cell-derived exosome containing miR-21 promotes the proliferation and angiogenesis of HUVECs via SPRY1 downregulation and VEGF upregulation.

The critical roles of somatic mutations and environmental tumor-promoting agents in cancer risk

Cancer is driven by genomic mutations in 'cancer driver' genes, which have essential roles in tumor development. These mutations may be caused by exposure to mutagens in the environment or by endogenous DNA-replication errors in tissue stem cells. Recent observations of abundant mutations, including cancer driver mutations, in histologically normal human tissues suggest that mutations alone are not sufficient for tumor development, thus prompting the question of how single mutant cells give rise to neoplasia. In a concept supported by decades-old data from mouse tumor models, non-mutagenic tumor-promoting agents have been posited to activate the proliferation of dormant mutated cells, thus generating actively growing lesions, with the promotion stage as the rate-limiting step in tumor formation. Non-mutagenic promoting agents, either endogenous or environmental, may therefore have a more important role in human cancer etiology than previously thought.

A multinational review: Oesophageal cancer in low to middle-income countries

Oesophageal cancer (OC) is an aggressive neoplasm that manifests in the gastrointestinal tract and is the result of numerous factors that can contribute to the development of the disease. These may include old age, nutritional deficiencies, oesophageal obstruction and food ingestion difficulties. Environmental factors serve a large role in increasing the risk of developing OC. Two factors that serve an increasing risk of developing OC are the use of tobacco and the consumption of alcohol. Genetic factors also exhibit a large effect on the risk of developing OC, for example, the causative genes in Black Africans differ from other races. OC is 3-4 times more common among men than women. OC has been previously reported in >450 000 individuals worldwide, and its incidence is increasing. The current review compares OC in low to middle-income countries with developed countries. The incidence of OC, particularly squamous cell carcinoma (SCC) is high in low and middle-income countries. In developed countries, the incidence of SCC is low compared with adenocarcinoma. The majority of OC cases are diagnosed in the late stages of the disease, leading to high mortality rates. The current review aimed to discuss factors that contribute to the development of this disease in different geographical areas and genetic mechanisms governing these findings. The current review also aims to discuss the preventative treatment options for the disease, and also discusses the diagnosis and surveillance in five LMICs, including South Africa, China, Tanzania, India and Brazil.

Gender Differences in Oesophageal Squamous Cell Carcinoma in a South African Tertiary Hospital

(1) Oesophageal squamous cell carcinoma is common in Africa and has a male preponderance. The gender-based differences in clinical presentation and risk factor exposure are poorly studied in the African context. Our aim was to compare males and females with this disease. We analyzed the differences in clinical features and risk factor exposure between males and females with oesophageal cancer. (2) Data from patients presenting to a tertiary hospital in South Africa with oesophageal squamous cell carcinoma were analyzed. Data collected included patient demographics, clinical presentation, pathology and risk factor exposure. (3) Three hundred and sixty three patients were included in the study. The male to female ratio was 1.4:1. The mean age was 66 years for females and 61 years for males (p < 0.0001). A significantly larger percentage of males were underweight compared to females (60% vs. 32%, p < 0.001). There were no differences between the genders with regards to performance status, dysphagia grade and duration and tumor length, location and degree of differentiation. There were significant differences between risk factor exposure between the two genders. Smoking and alcohol consumption was an association in more than 70% of males but in less than 10% of females There was no difference survival. (4) Female patients with oesophageal squamous cell carcinoma (OSCC) are older and have a higher body mass index (BMI) than their male counterparts. Traditionally purported risk factors of smoking and alcohol consumption are infrequent associations with OSCC in female patients and other environmental risk factors may be more relevant in this gender.

Thymine DNA glycosylase-regulated TAZ promotes radioresistance by targeting nonhomologous end joining and tumor progression in esophageal cancer

Radiation resistance is a major cause of esophageal cancer relapse or metastasis. Transcriptional coactivator with PDZ binding domain (TAZ) is a final effector of the Hippo signaling pathway and plays critical roles in several types of cancer, but how it participates in the progression and radiation resistance of esophageal cancer remains unclear. Here, we revealed that TAZ was the strongest prognostic factor among Hippo pathway members. Overexpression of TAZ predicted poor outcome and adverse pathological features. In cell and animal models, TAZ facilitated cell proliferation, motility, and radiation resistance. Additionally, TAZ promoted expression of nonhomologous end joining (NHEJ)‐related genes, which are the main contributors to repair irradiation‐induced DNA breaks and result in radiation resistance. Amplification of the TAZ gene occurred in 2.5%‐3.2% of esophageal cancers. In addition, the CpG islands of the TAZ gene were demethylated in esophageal cancer under thymine DNA glycosylase (TDG) regulation. Knockdown of TDG inhibited cell growth, motility, and radiation resistance, which were overridden by TAZ overexpression. Collectively, these findings suggest that the TDG/TAZ/NHEJ axis is a critical player in esophageal cancer progression and radiation resistance, as well as a potential target for radiotherapy.

miR-550a-3/NFIC plays a driving role in esophageal squamous cell cancer cells proliferation and metastasis partly through EMT process

In this study, the functional role of miR-550a-3 and its direct target nuclear factor IC (NFIC) in esophageal squamous cell cancer (ESCC) cells were explored. Differential expression of miR-550a-3 in ESCC tissues was acquired from TCGA database, and Kaplan-Meier method was used to determine the relationship between miR-550a-3 expression and survival time of ESCC patients. Expression level of miR-550a-3 in several ESCC cell lines was measured by qRT-PCR. Two cell lines including Eca109 and JAR were used to perform proliferation, cloning, invasion and migration experiments. Targeted relationship between miR-550a-3 and NFIC was speculated by predication software and confirmed by dual luciferase assay. Additionally, potential relationship between miR-550a-3 and NFIC was analyzed by Spearman rank correlation analysis and western blot. Rescue assays were performed to explore the function of miR-550a-3/NFIC in ESCC cells biological behaviors. Expression levels of key proteins involved in epithelial-to-mesenchymal transition (EMT) process were determined by western blot. By consulting TCGA database, we found that high expression of miR-550a-3 was positively connected with the poor prognosis of patients with ESCC. In addition, overexpression of miR-550a-3 promoted the proliferation, colony formation and metastasis of ESCC cells. Moreover, rescue assays revealed that overexpression of NFIC attenuated the promoting effects of miR-550a-3 on ESCC cells malignant behaviors. While the promoting effects of miR-550a-3 on EMT process were inhibited by NFIC. Our results illustrate the importance of miR-550a-3/NFIC in regulation of ESCC cells growth and metastasis, which could contribute to developing novel target for early diagnosis or neoteric therapeutic target for ESCC.

Serum exosomal microRNA-766-3p expression is associated with poor prognosis of esophageal squamous cell carcinoma

The aim was to analyze the association between exosomal microRNA (miR)‐766‐3p expression levels in serum and the prognosis of esophageal squamous cell carcinoma (ESCC). The serum global exosomal miRNA expression of ESCC patients was measured by microRNA microarray. Quantitative real‐time PCR was used to analyze the expression levels of candidate miRNAs in both serum and tissues from ESCC patients. Wilcoxon tests were applied to evaluate clinical characteristics and their association with serum levels of exosomal miR‐766‐3p. A Cox regression model was used to identify prognostic factors. The effects of miR‐766‐3p expression on cell migration and invasion were examined using Transwell assays, and CCK‐8 assays were carried out to measure cell proliferation. The TNM stage was associated with high serum exosomal miR‐766‐3p levels of ESCC patients (P = .030). Higher serum exosomal miR‐766‐3p expression levels were associated with poor prognosis (for overall survival, hazard ratio [HR] [95% confidence interval (CI)], 2.21 [1.00, 4.87]; for disease‐free survival, HR [95% CI], 2.15 [1.01, 4.59]). However, we found no association between the expression of miR‐766‐3p in tissue and ESCC prognosis. In vitro results showed that miR‐766‐3p promotes cell migration and invasion, but not cell proliferation. By using dual‐luciferase reporter assay, HOXA13 was confirmed as a direct target gene of miR‐766‐3p. The ESCC patients with highly expressed serum exosomal miR‐766‐3p had a significantly worse survival. Therefore, serum exosomal miR‐766‐3p could serve as a prognostic marker for the assessment of ESCC.

POLE2 knockdown reduce tumorigenesis in esophageal squamous cells

Background

Esophageal squamous cell carcinoma (ESCC) is one of the most frequent malignant tumors originated from digestive system around the world and the treatment was limited by the unclear mechanism. DNA polymerase epsilon 2, accessory subunit (POLE2) is involved in DNA replication, repair, and cell cycle control, whose association with ESCC is still not clear.

Methods

In this study, the expression level of POLE2 in ESCC tissues was detected by IHC. The POLE2 knockdown cell line was constructed, identified by qPCR and western blot and used for detecting cellular functions and constructing xenotransplantation mice model. MTT Assay, colony formation assay, flow cytometry, wound-healing assay and Transwell assay were used to detected cell proliferation, apoptosis and migration.

Results

We firstly identified that the expression of POLE2 was overexpressed in ESCC. Moreover, the high expression of POLE2 can predict the tumor deterioration and poor prognosis of ESCC patients. Additionally, downregulation of POLE2 was involved in ESCC progression by promoting proliferation, migration, and inhibiting apoptosis in vitro. In vivo studies proved that POLE2 was positively correlated with ESCC tumor formation, which was consistent with the results in vitro. We also illuminated that POLE2 knockdown upregulated pro-apoptotic proteins (Bax, Caspase3, CD40L, FasL, IGFBP-5 and P21) and downregulated anti-apoptotic proteins (CLAP-2, IGF-I and sTNF-R2). In addition, POLE2 was involved in ESCC via targeting PI3K/Akt, Cyclin D1 signaling pathway.

Conclusions

Therefore, POLE2 was proved to be involved in the development of ESCC, which may be a potential therapeutic target and bring new breakthroughs in the treatment of ESCC.

Surveillance of Esophageal Cancer in the Republic of Uzbekistan from 2000 to 2018

BACKGROUND

Differences in the geographical distributions of esophageal cancer (EC) are associated with environmental influences and genetic risk factors. The inhabitants of the Republic of Uzbekistan are at high-risk for EC; however, detailed epidemiological data regarding the dynamics of EC are not available.

METHODS

To address this gap in our knowledge, here we reviewed trends in the incidence of EC in Uzbekistan from 2000 through 2018. We acquired the epidemiological data for 17,144 patients with EC from the national epidemiological data base of Uzbekistan.

RESULTS

The mean incidence (per 100,000 persons) during the study period was 2.8, which peaked at 3.9 in 2007 and decreased below 2.5 in 2014 and thereafter. The incidence was highest for patients aged 61 years to 70 years (37.5%). Among patients with EC, 13,331 (80.0%) and 3,333 (20.0%) were diagnosed with squamous cell carcinoma or adenocarcinoma, respectively. The incidences of patients with EC with adenocarcinoma were 0.6 from 2010-2018 and 0.4 from 2000 to 2009. The majority of patients were diagnosed with stage III EC, which was associated with a 5-year survival rate that increased from approximately 15% (2000-2009) and plateaued at approximately 25% (2012-2018).

CONCLUSIONS

We conclude that preventing the progression of EC to stage III is required to improve the prognosis of patients with EC who reside in Uzbekistan.

Demographic Trends in Carcinoma Esophagus from India along with a Brief Comparative Review of the Global Trends

Background  Esophageal cancers (ECs) are more prevalent in the East Asian countries of the world, wherein squamous cell carcinomas (SCCs) are the predominant histological subtype. In contrast, the patterns in the West are a bit heterogeneous, with esophageal adenocarcinoma (AC) being the more frequent histological subtype. There is very sparse published Indian data pertaining to the demographic trends of ECs. Materials and Methods  Our study was a retrospective analysis of the demographic trends of 917 patients afflicted with ECs who were managed at our center over a 10-year period. Results and Discussion  EC accounted for nearly 4.1% of the total cancer burden managed at our center from January 2002 to December 2011. The mean age of our patient cohort was 54.2 years. The male:female ratio was nearly 1.7:1. Tobacco chewing was noted in 25.4%, smoking in 37%, while alcohol consumption was noted in approximately 20% of the patients. SCC was the most common histological subtype (78.3%), while ACs constituted only 9.9%. Eighty-nine percent of our patients presented with locally advanced staged tumors. Definitive chemoradiation was the most common modality of definitive management then; however, over the years, our preferred choice of the management of ECs has shifted to neoadjuvant chemoradiation, followed by surgery in the carefully selected patients of locally advanced resectable ECs. Conclusion  Our study clearly shows SCC to be the most common histological subtype among ECs, a trend that has been observed in the vast majority of the East Asian nations. The epidemic rise in the incidence of esophageal ACs as seen in the West is not seen in our study. Periodic monitoring of the demographic trends of ECs is of great importance both for clinicians and policymakers. We hope that our study will enlighten both policy holders and clinicians to better channelize the efforts toward prevention and more effective management of this deadly cancer.

β-elemene suppresses the malignant behavior of esophageal cancer cells by regulating the phosphorylation of AKT

BACKGROUND

Esophageal cancer is a digestive tract malignancy, ranking sixth among the world's deadliest tumor incidence. However, the pathogenesis of esophageal cancer is complex and the prognosis remains poor. Therefore, in-depth study of the pathogenesis and developing effective treatments are of great value for esophageal cancer. β-elemene is a natural monomeric compound derived from the Chinese herbal Curcuma wenyujin. β-elemene has been reported to have anti-tumor effects and used as an adjunct to clinical therapy for multiple cancers. This study aims to explore the effects of β-elemene on esophageal cancer and its related molecular mechanisms.

METHODS

TE-1 and KYSE-150 cells were used to evaluate the activity of β-elemene on esophageal cancerin vitro and in vivo. Western blot was performed for protein expression assessment. CCK8 assay and cell cycle analysis were used for proliferation testing. Flow cytometry was performed for apoptosis detection. Wound healing assay was subjected to assess the migration ability. Transwell chamber assay was applied to assess the invasion ability. HE staining, TUNEL staining and immunohistochemical staining were used to evaluate the changes in tumor tissues.

RESULTS

We found that β-elemene treatment suppressed proliferation, as well as induced apoptosis of esophageal cancer cells. In addition, β-elemene inhibited the migration and invasion ability of esophageal cancer cells. Furthermore, β-elemene exerted its effects against esophageal cancer by specifically regulating AKT signaling, thereby controlling the expression of PD-L1.

CONCLUSION

β-elemene inhibits proliferation and metastasis of esophageal cancer cells by regulating the phosphorylation of AKT.

Prdx1 promotes the loss of primary cilia in esophageal squamous cell carcinoma

Background

Loss of primary cilia is frequently observed in tumor cells, suggesting that the absence of this organelle may promote tumorigenesis through aberrant signal transduction, the inability to exit the cell cycle, and promotion of tumor cell invasion. Primary cilia loss also occurs in esophageal squamous cell carcinoma (ESCC) cells, but the molecular mechanisms that explain how ESCC cells lose primary cilia remain poorly understood.

Methods

Inhibiting the expression of Prdx1 in the ESCC cells to detect the up-regulated genes related to cilium regeneration and down-regulated genes related to cilium disassembly by Gene chip. And, mice and cell experiments were carried to confirm the role of the HEF1-Aurora A-HDAC6 signaling axis in ESCC.

Results

In this study, we found that silencing Peroxiredoxin 1 (Prdx1) restores primary cilia formation, and over-expressing Prdx1 induces primary cilia loss in ESCC cells. We also showed that the expression of Prdx1 regulates the action of the HEF1-Aurora A-HDAC6 signaling axis to promote the disassembly of primary cilia, and suppression of Prdx1 results in decreased tumor formation and tumor mass volume in vivo.

Conclusions

These results suggest that Prdx1 is a novel regulator of primary cilia formation in ESCC cells.

Starvation-induced suppression of DAZAP1 by miR-10b integrates splicing control into TSC2-regulated oncogenic autophagy in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) accounts for about 90% of all incident esophageal cancers, with a 5-year survival rate of < 20%. Autophagy is of particular importance in cancers; however, the detailed regulatory mechanisms of oncogenic autophagy in ESCC have not been fully elucidated. In the present study, we address how splicing control of TSC2 is involved in mTOR-regulated oncogenic autophagy. Methods: Alternative splicing events controlled by DAZAP1 in ESCC cells were identified via RNAseq. Differential phosphorylation of short or long TSC2 splicing variants by AKT and their impacts on mTOR signaling were also examined. Results: We found that starvation-induced miR-10b could enhance autophagy via silencing DAZAP1, a key regulator of pre-mRNA alternative splicing. Intriguingly, we observed a large number of significantly changed alternative splicing events, especially exon skipping, upon RNAi of DAZAP1. TSC2 was verified as one of the crucial target genes of DAZAP1. Silencing of DAZAP1 led to the exclusion of TSC2 exon 26 (from Leu947 to Arg988), producing a short TSC2 isoform. The short TSC2 isoform cannot be phosphorylated at Ser981 by AKT, which resulted in continuous activation of TSC2 in ESCC. The active TSC2 inhibited mTOR via RHEB, leading to continually stimulated oncogenic autophagy of ESCC cells. Conclusions: Our data revealed an important physiological function of tumor suppressor DAZAP1 in autophagy regulation and highlighted the potential of controlling mRNA alternative splicing as an effective therapeutic application for cancers.

Landscape of copy number aberrations in esophageal squamous cell carcinoma from a high endemic region of South Africa

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is an aggressive cancer with one of the highest world incidences in the Eastern Cape region of South Africa. Several genome wide studies have been performed on ESCC cohorts from Asian countries, North America, Malawi and other parts of the world but none have been conducted on ESCC tumors from South Africa to date, where the molecular pathology and etiology of this disease remains unclear. We report here tumor associated copy number changes observed in 51 ESCC patients' samples from the Eastern Cape province of South Africa.

METHODS

We extracted tumor DNA from 51 archived ESCC specimens and interrogated tumor associated DNA copy number changes using Affymetrix® 500 K SNP array technology. The Genomic Identification of Significant Targets in Cancer (GISTIC 2.0) algorithm was applied to identify significant focal regions of gains and losses. Gains of the top recurrent cancer genes were validated by fluorescence in situ hybridization and their protein expression assessed by immunohistochemistry.

RESULTS

Twenty-three significant focal gains were identified across samples. Gains involving the CCND1, MYC, EGFR and JAG1 loci recapitulated those described in studies on Asian and Malawian cohorts. The two most significant gains involved the chromosomal sub-bands 3q28, encompassing the TPRG1 gene and 11q13.3 including the CTTN, PPFIA1and SHANK2 genes. There was no significant homozygous loss and the most recurrent hemizygous deletion involved the B3GAT1 gene on chromosome 11q25. Focal gains on 11q13.3 in 37% of cases (19/51), consistently involved CTTN and SHANK2 genes. Twelve of these cases (23,5%), had a broader region of gain that also included the CCND1, FGF19, FGF4 and FGF3 genes. SHANK2 and CTTN are co-amplified in several cancers, these proteins interact functionally together and are involved in cell motility. Immunohistochemistry confirmed both Shank2 (79%) and cortactin (69%) protein overexpression in samples with gains of these genes. In contrast, cyclin D1 (65%) was moderately expressed in samples with CCND1 DNA gain.

CONCLUSIONS

This study reports copy number changes in a South African ESCC cohort and highlights similarities and differences with cohorts from Asia and Malawi. Our results strongly suggest a role for CTTN and SHANK2 in the pathogenesis of ESCC in South Africa.

Ivermectin suppresses tumour growth and metastasis through degradation of PAK1 in oesophageal squamous cell carcinoma

Oesophageal squamous cell carcinoma (ESCC), the most common form of oesophageal malignancies in the Asia‐Pacific region, remains a major clinical challenge. In this study, we found that ivermectin, an effective antiparasitic drug that has been approved for patients to orally treat onchocerciasis for over 30 years, displayed potent antitumour activity against ESCC cells in vitro and in nude mice. We demonstrated that ivermectin significantly inhibited cell viability and colony formation, and induced apoptosis through a mitochondrial‐dependent manner in ESCC cells. Ivermectin also abrogated ESCC cell migration, invasion, as well as the protein levels of MMP‐2 and MMP‐9. Mechanistically, ivermectin strongly inhibited the expression of PAK1; by further gain‐ and loss‐of‐function experiments, we confirmed that PAK1 played a crucial role in ivermectin‐mediated inhibitory effects on ESCC cells. In addition, the data indicated that ivermectin promoted PAK1 degradation through the proteasome‐dependent pathway. Additionally, ivermectin synergized with chemotherapeutic drugs including cisplatin and 5‐fluorouracil to induce apoptosis of ESCC cells. Interestingly, the in vivo experiments also confirmed that ivermectin effectively suppressed tumour growth and lung metastasis of ESCC. Collectively, these results indicate that ivermectin exerts a potent antitumour activity against ESCC and is a promising therapeutic candidate drug for ESCC patients, even those carrying metastasis.

Tumor-Derived EV-Encapsulated miR-181b-5p Induces Angiogenesis to Foster Tumorigenesis and Metastasis of ESCC

Pathological angiogenesis is necessary for tumor development and metastasis. Tumor-derived extracellular vesicles (EVs) play an important role in mediating the crosstalk between cancer cells and vascular endothelial cells. To date, whether and how microRNAs (miRNAs) encapsulated in tumor-derived EVs affect angiogenesis in esophageal squamous cell carcinoma (ESCC) remains unclear. Here, we showed that miR-181b-5p, an angiogenesis-promoting miRNA of ESCC, can be transferred from ESCC cells to vascular endothelial cells via EVs. In addition, ESCC-derived EVs-miR-181b-5p dramatically induced angiogenesis by targeting PTEN and PHLPP2, and thereby facilitated tumor growth and metastasis. Moreover, miR-181b-5p was highly expressed in ESCC tissues and serum EVs. High miR-181b-5p expression level in ESCC patients was well predicted for poor overall survival. Our work suggests that intercellular crosstalk between tumor cells and vascular endothelial cells is mediated by tumor-derived EVs. miR-181b-5p-enriched EVs secreted from ESCC cells are involved in angiogenesis that control metastasis of ESCC, providing a potential diagnostic biomarker or drug target for ESCC patients.

A novel positive feedback loop of linc02042 and c-Myc mediated by YBX1 promotes tumorigenesis and metastasis in esophageal squamous cell carcinoma

BACKGROUND

Long non-coding RNA (lncRNA) is a class of endogenous RNA with a length of more than 200 nucleotides, which is emerging as a pivotal player in cancer development and progression. However, the functional roles of many members in this class remain largely uncharacterized. In the present study, we explored the biological relevance of linc02042 in esophageal squamous cell carcinoma (ESCC).

METHODS

qRT-PCR was used to detect the levels of linc02042 and c-Myc. Western blot was used to assess protein expression level. CCK-8 and Transwell assays were employed to test ESCC cell proliferation and invasion, respectively. The mice study including xenograft tumor and lung metastasis models was used to determine the role of linc02042 in vivo. RNA pull-down, ChIP and luciferase reporter assays were employed to test the relationship between linc02042, YBX1 and c-Myc.

RESULTS

Linc02042 was found to be markedly upregulated in ESCC cell lines, tissues and plasma, and was closely correlated with malignant clinical features. Knockdown of linc02042 significantly inhibited ESCC cell viability and invasion in vitro as well as tumor growth and lung metastasis in vivo, whereas overexpression of linc02042 resulted in the opposite results. Mechanistically, linc02042 acted as a scaffold for YBX-1 binding to the 3'-UTR of c-Myc mRNA, leading to enhanced c-Myc mRNA stability, thereby facilitating ESCC growth and metastasis. Moreover, in turn, c-Myc was able to transcriptionally elevate linc02042 by directly binding to the E-box motif proximal to the transcription start site (TSS) of linc02042 promoter. Clinically, linc02042 was identified as an effective diagnostic and prognostic biomarker for ESCC patients, and its expression was strongly positively correlated with c-Myc expression in ESCC tissues.

CONCLUSION

Our data suggest that linc02042 plays an important tumor-promoting role in ESCC, which lays a foundation for considering it as a potential target for ESCC patients.

Garcinol inhibits esophageal cancer metastasis by suppressing the p300 and TGF-β1 signaling pathways

Metastasis causes the main lethality in esophageal cancer patient. Garcinol, a natural compound extracted from Gambogic genera, is a histone acetyltransferase (HAT) inhibitor that has shown anticancer activities such as cell cycle arrest and apoptosis induction. In this study, we investigated the effects of garcinol on the metastasis of esophageal cancer in vitro and in vivo. We found that garcinol (5-15 μM) dose-dependently inhibited the migration and invasion of human esophageal cancer cell lines KYSE150 and KYSE450 in wound healing, transwell migration, and Matrigel invasion assays. Furthermore, garcinol treatment dose-dependently decreased the protein levels of p300/CBP (transcriptional cofactors and HATs) and p-Smad2/3 expression in the nucleus, thus impeding tumor cell proliferation and metastasis. Knockdown of p300 could inhibit cell metastasis, but CBP knockdown did not affect the cell mobility. It has been reported that TGF-β1 stimulated the phosphorylation of Smad2/3, which directly interact with p300/CBP in the nucleus, and upregulating HAT activity of p300. We showed that garcinol treatment dose-dependently suppressed TGF-β1-activated Smad and non-Smad pathway, inhibiting esophageal cancer cell metastasis. In a tail vein injection pulmonary metastasis mouse model, intraperitoneal administration of garcinol (20 mg/kg) or 5-FU (20 mg/kg) significantly decreased the number of lung tumor nodules and the expression levels of Ki-67, p300, and p-Smad2/3 in lung tissues. In conclusion, our study demonstrates that garcinol inhibits esophageal cancer metastasis in vitro and in vivo, which might be related to the suppression of p300 and TGF-β1 signaling pathways, suggesting the therapeutic potential of Garcinol for metastatic tumors.

Role of TFF3 as an adjunct in the diagnosis of Barrett's esophagus using a minimally invasive esophageal sampling device-The CytospongeTM

The incidence of esophageal carcinoma continues to increase whilst its prognosis remains poor. The most dramatic reduction in mortality is likely to follow early diagnosis of the preinvasive precursor lesion, Barrett's esophagus (BE), coupled with treatment of dysplastic lesions. The major risk factor for BE is gastroesophageal reflux disease, however this is highly prevalent and only a small proportion of individuals have BE, therefore an endoscopy-based screening strategy to detect BE is unfeasible. Minimally invasive esophageal sampling devices offer an alternative, cost-effective strategy which can be deployed within an at-risk population in a primary care setting to identify individuals with probable BE who can then be referred for endoscopic confirmation. The device that has currently progressed furthest in clinical trials is the Cytosponge^TM which collects cells from the gastric cardia, gastroesophageal junction and along the whole esophageal length. The cell sample is processed into a formalin-fixed paraffin-embedded block and sections assessed for the presence of intestinal metaplasia. TFF3 immunohistochemistry has consistently been shown to be a valuable adjunct that increases the accuracy of the Cytosponge^TM test by highlighting early goblet cells which may be missed on morphological assessment and by allowing pseudogoblet cells to be differentiated from true goblet cells.

The state of cancer in Meru, Kenya: a retrospective study

Background: It is projected that by 2030, 70% of all cancer related deaths will occur in low-middle income countries. However, data on the state of cancer in most African countries is scanty. Cancer estimates for Kenya are based on the Nairobi and Eldoret cancer registries, leaving most parts of the country unrepresented. Lacking national coverage, these data do not accurately reflect Kenya’s cancer burden. The paucity of reliable data impedes formulation of effective cancer control strategies and cancer research prioritization. Here, we report the findings of a retrospective study of the cancer state in Meru County, Kenya. Methods: A retrospective analysis of patient files at Meru hospice was carried out. 2349 cancer cases seen at the Meru hospice between 2003 and 2018 were analyzed. Data abstracted from the records included patient age, gender and cancer type. The abstracted data was analyzed by descriptive statistics. Results: Our results indicate that cancer is almost evenly distributed across genders, with men accounting for 49% and women 51%. Stomach cancer rates are strikingly elevated and equal to those in countries with the highest stomach cancer rates globally – making it the commonest cancer in this region (14%). Among men, the most common cancers affect the prostate (18%), stomach (17%), esophagus (14%), head & neck (12%), liver (8%) and colorectum (5%). Among women, the commonest are cancers of the breast (22%), cervix (20%), stomach (11%), esophagus (8%), head & neck (6%) and liver (5%). Breast cancer occurs at a notably early age, with 20% of those affected aged below 40. Lung cancer rates are notably low in this region (1.3%) relative to world estimates. Conclusion: Cancer distribution in Meru is nearly even between sexes. Our analysis suggests that the Meru region is a stomach cancer hotspot and that it also experiences elevated esophageal cancer levels.

Epidemiologic trends and geographic distribution of esophageal cancer in Canada: A national population-based study

Background

Esophageal cancer can be subdivided into two main histological subtypes with significant variability in their etiology and epidemiology. The incidence of esophageal adenocarcinoma (AC) is increasing across the developed countries, whereas the incidence of esophageal squamous cell carcinoma (SCC) is declining. Several risk factors have been identified in the pathogenesis of each subtype, however, their epidemiologic characteristics and distribution throughout Canada remain poorly understood.

Methods

We performed a retrospective analysis of demographic data across Canada from 1992 to 2010 using two independent population‐based cancer registries. The incidence of esophageal cancer, for each subtype, was examined at the levels of provinces/territories, cities, and postal codes.

Results

A total of 19 790 patients were diagnosed with esophageal cancer in Canada between 1992 and 2010; 74% were males. The average national incidence rate was 33.5 cases per million individuals per year. Incidence of esophageal AC increased over time, with notable high‐incidence rates on the Vancouver Island, the coasts of the Great Lakes, and the coasts of the Northumberland Strait in the Maritimes. The overall incidence of esophageal SCC has decreased. However, high incidence of esophageal SCC was detected in the Vancouver city, rural eastern Québec, and in the Maritimes. We also report clustering for each subtype using postal codes, which sheds light onto new avenues of research for potential environmental etiologies.

Conclusions

This study, for the first time, provides a detailed analysis on the burden of esophageal cancer in Canada, revealing important geographic clustering trends.

Turmeric, Pepper, Cinnamon, and Saffron Consumption and Mortality

Background Previous studies have reported the beneficial effects of spice consumption on lipid profiles, fasting glucose, and blood pressure, which suggests that spice consumption could affect the risk of cardiovascular disease, diabetes mellitus, and consequently mortality. The objective of this study was to evaluate the relationship between consumption of turmeric, black or chili pepper, cinnamon, and saffron with overall and cause-specific mortality in an adult population in Iran. Methods and Results We used data from the Golestan Cohort Study, which has followed 50 045 participants aged 40 to 75 years from baseline (2004-2008). After establishing the exclusion criteria, 44 398 participants were included in the analyses. Spice consumption data were extracted from the baseline Food Frequency Questionnaire. Cox models were used to estimate hazard ratios (HR) and 95% CI for overall and cause-specific mortality, comparing the ever consumers to the never consumers as a reference group for each type of spice (adjusted for known and suspected confounders). During 11 years of follow-up, 5121 people died. Turmeric consumption was associated with significantly reduced risk of overall mortality (HR=0.90, 95% CI=0.85-0.96) and cardiovascular mortality (HR=0.91, 95% CI=0.82-0.99). Black or chili pepper consumption was associated with significantly reduced risk of overall mortality (HR=0.91, 95% CI=0.86-0.98). Saffron consumption was associated with significantly reduced risk of overall (HR=0.85, 95% CI=0.77-0.94) and cardiovascular mortality (HR=0.79, 95% CI=0.68-0.92). We found no associations with cinnamon consumption or between any of these spices and cancer mortality. Conclusions Consuming turmeric or saffron was associated with decreased risk of overall and cardiovascular mortality. The hypothesis of a protective effect of spice consumption on mortality should be tested in other prospective studies.

MicroRNA‑212 facilitates the motility and invasiveness of esophageal squamous carcinoma cells

As a tumor-associated microRNA (miR), miR-212 has dual functions; either as an oncogene or a tumor suppressor. A high expression level of miR-212 was reported to be associated with poor outcome in patients with esophageal squamous cell carcinoma (ESCC), however, its role in ESCC progression has not been explored. In the present study, an in vitro cell model of lentivirus-mediated gain-of-function demonstrated promotion of ESCC cell migration and invasion when miR-212 was overexpressed, and no effect on cell proliferation. miR-212 resulted in downregulation of the expression of E-cadherin, β-catenin, vimentin and Twist1. Moreover, it led to increased levels of extracellular matrix (ECM)-degrading enzymes, matrix metalloproteinase-9 and urokinase-type plasminogen activator. Furthermore, berberine inhibited miR-212-induced ESCC cell migration, unlike the PI3K inhibitor LY294002, rapamycin (mTOR inhibitor), 5-(Tetradecyloxy)-2-furoic acid (TOFA; an acetyl-CoA carboxylase 1 inhibitor), metformin and propranolol. These data suggest that miR-212 activates multiple signaling cascades and facilitates ESCC cell motility and invasion by promoting the epithelial-mesenchymal transition and degrading the ECM. Berberine may be a potential therapeutic agent against metastasis in patients with ESCC, who express high levels of miR-212.

Prevalence of human papillomavirus and Helicobacter pylori in esophageal and gastroesophageal junction cancer biopsies from a case-control study in Ethiopia

BACKGROUND

Ethiopia lies in the high-risk corridor of esophageal squamous cell carcinoma in East Africa, where individuals with this malignancy often do not report established risk factors, suggesting unidentified etiologies. Here, we report the prevalence of mucosal human papillomavirus (HPV) and of Helicobacter pylori (H. pylori) detection in endoscopy-obtained esophageal and gastroesophageal junction biopsies and in oral cell specimens taken at the time of esophageal cancer diagnosis in a case-control study in Addis Ababa, Ethiopia.

METHODS

DNA extraction was performed from fresh frozen tissue and oral cell pellets obtained with saline solution gargling subsequently fixed with ethanol. Mucosal HPV and H. pylori DNA was detected using highly sensitive assays that combine multiplex polymerase chain reaction and bead-based Luminex technology. The proportions of specimens testing positive were expressed as percentages, with binomial 95% confidence intervals. Agreement of results between tissue biopsy and oral cell specimens was estimated using the kappa statistic. Comparison of study participants' characteristics by test results was done using the Pearson chi-square test.

RESULTS

HPV DNA was detected in 1 of 62 tumor specimens (2, 95% confidence interval (CI): 0-9%), corresponding to HPV16 type. HPV DNA was detected in the oral cavity of 7 cases (11, 95% CI: 5-22%) and 4 of 56 matched healthy controls (7, 95% CI: 2-17%), with multiple HPV types detected. Detection of H. pylori DNA was 55% (95% CI: 42-68%), and 20 of 34 H. pylori-positive specimens (59, 95% CI: 41-75%) were positive for the cagA gene. Agreement of detection rates between tissue and oral cells in cases was poor for HPV and for H. pylori.

CONCLUSIONS

The prevalence of mucosal-type HPV was very low, whereas H. pylori was more commonly detected, with a high proportion testing positive for the pro-inflammatory gene cagA. These novel findings remain to be replicated in larger studies and with the addition of serological determinations to better understand their biological significance in the context of esophageal and gastroesophageal junction cancers.

Systematic Review of Genetic Factors in the Etiology of Esophageal Squamous Cell Carcinoma in African Populations

Background: Esophageal squamous cell carcinoma (ESCC), one of the most aggressive cancers, is endemic in Sub-Saharan Africa, constituting a major health burden. It has the most divergence in cancer incidence globally, with high prevalence reported in East Asia, Southern Europe, and in East and Southern Africa. Its etiology is multifactorial, with lifestyle, environmental, and genetic risk factors. Very little is known about the role of genetic factors in ESCC development and progression among African populations. The study aimed to systematically assess the evidence on genetic variants associated with ESCC in African populations.

Methods: We carried out a comprehensive search of all African published studies up to April 2019, using PubMed, Embase, Scopus, and African Index Medicus databases. Quality assessment and data extraction were carried out by two investigators. The strength of the associations was measured by odds ratios and 95% confidence intervals.

Results: Twenty-three genetic studies on ESCC in African populations were included in the systematic review. They were carried out on Black and admixed South African populations, as well as on Malawian, Sudanese, and Kenyan populations. Most studies were candidate gene studies and included DNA sequence variants in 58 different genes. Only one study carried out whole-exome sequencing of 59 ESCC patients. Sample sizes varied from 18 to 880 cases and 88 to 939 controls. Altogether, over 100 variants in 37 genes were part of 17 case-control genetic association studies to identify susceptibility loci for ESCC. In these studies, 25 variants in 20 genes were reported to have a statistically significant association. In addition, eight studies investigated changes in cancer tissues and identified somatic alterations in 17 genes and evidence of loss of heterozygosity, copy number variation, and microsatellite instability. Two genes were assessed for both genetic association and somatic mutation.

Conclusions: Comprehensive large-scale studies on the genetic basis of ESCC are still lacking in Africa. Sample sizes in existing studies are too small to draw definitive conclusions about ESCC etiology. Only a small number of African populations have been analyzed, and replication and validation studies are missing. The genetic etiology of ESCC in Africa is, therefore, still poorly defined.

Methylation-regulated ZNF545 inhibits growth of the p53-mutant KYSE150 cell line by inducing p21 and Bax

The Krüppel-associated box zinc-finger protein 545 (ZNF545) was recently identified as a tumor suppressor in esophageal squamous cell carcinoma (ESCC). However, the role of ZNF545 in the tumorigenesis of esophageal cancer cells expressing loss-of-function mutant p53 has not been elucidated. In the present study, the role of ZNF545 in esophageal tumors and the p53-mutant ESCC cell line, KYSE150, was investigated. ZNF545 mRNA was significantly downregulated in tumors when compared with adjacent normal tissues. Methylated ZNF545 was detected in 76.6% of tumor tissues compared with 28.1% of adjacent normal tissues. Combined pharmacological treatment of KYSE150 cells with a demethylating reagent and deacetylase inhibitor restored the expression of ZNF545. Ectopic expression of ZNF545 activated p53 transcription and upregulated the protein expression levels of pivotal effectors p21 and Bax, which are associated with cell proliferation and apoptosis, respectively, in p53-mutant KYSE150 cells; while suppressing colony formation and inducing apoptosis. ZNF545 was therefore proposed as a potential tumor suppressor responsible for inhibiting the growth of p53-mutant ESCC cell lines. In addition, tumor-specific methylation of ZNF545 may represent an epigenetic diagnostic biomarker and a therapeutic target in patients with esophageal cancer.

LSD1 regulates Notch and PI3K/Akt/mTOR pathways through binding the promoter regions of Notch target genes in esophageal squamous cell carcinoma

Background: The aberrant activation of Lysine-specific demethylase 1(LSD1), Notch and PI3K/Akt/mTOR signaling pathways were frequently happened in many cancers, including esophageal squamous cell carcinoma (ESCC). However, the regulatory relationship between LSD1 and Notch as well as PI3K/Akt/mTOR pathways is still unclear. Purpose: This study aimed to explore the regulatory effects and mechanisms of LSD1 on Notch and PI3K/Akt/mTOR pathway in ESCC. Results: Firstly, we demonstrated that LSD1 and proteins in Notch and PI3K/Akt/mTOR pathway were expressed in ESCC cells. Secondly, inhibition of LSD1 by tranylcypromine (TCP) or shRNA could decrease the expressions of related proteins in Notch and PI3K/Akt/mTOR signaling pathways in ESCC cells. Finally, we found that LSD1 could bind to the promoter regions of Notch3, Hes1 and CR2, and the combinations between them were reduced by TCP in ESCC. Conclusion: Summarily, this study indicated that LSD1 might positively regulate Notch and PI3K/Akt/mTOR pathways through binding the promoter regions of related genes in Notch pathway in ESCC.

p53-induced long non-coding RNA PGM5-AS1 inhibits the progression of esophageal squamous cell carcinoma through regulating miR-466/PTEN axis

A growing body of evidence suggests that long non-coding RNA (lncRNA) is aberrantly expressed in human cancer and linked to cancer initiation and development. We previously identified Homo sapiens PGM5 antisense RNA 1 (PGM5-AS1) as a novel esophageal squamous cell carcinoma (ESCC)-related lncRNA by performing high-throughput RNA sequencing. However, its clinical implication and biological function in ESCC are still uncharacterized. In the present study, we found that PGM5-AS1 was frequently downregulated in ESCC tissues, plasma, and cell lines, and low PGM5-AS1 expression was positively correlated with poor differentiation, advanced tumor node metastasis (TNM) stage, and lymph node metastasis. Importantly, PGM5-AS1 was identified to be an effective diagnostic and prognostic biomarker for ESCC patients. Functional experiments revealed that exogenous expression of PGM5-AS1 significantly suppressed the proliferation, migration, and invasion of ESCC cells in vitro as well as tumor growth in vivo. Mechanistically, PGM5-AS1 was transcriptionally activated by p53 and it could directly interact with and sequester miR-466 to elevate PTEN expression, thereby inhibiting ESCC progression. Overall, our data indicate that PGM5-AS1 is a novel tumor suppressor in ESCC and restoration of PGM5-AS1 may be a promising avenue for treatment of ESCC patient.

Association of genetic variants in CHEK2 with oesophageal squamous cell carcinoma in the South African Black population

Oesophageal squamous cell carcinoma (OSCC) has a high incidence in southern Africa and a poor prognosis. Limited information is available on the contribution of genetic variants in susceptibility to OSCC in this region. However, recent genome-wide association studies have identified multiple susceptibility loci in Asian and European populations. In this study, we investigated genetic variants from seven OSCC risk loci identified in non-African populations for association with OSCC in the South African Black population. We performed association studies in a total of 1471 cases and 1791 controls from two study sample groups, which included 591 cases and 852 controls from the Western Cape and 880 cases and 939 controls from the Johannesburg region in the Gauteng province. Thereafter, we performed a meta-analysis for 11 variants which had been genotyped in both studies. A single nucleotide polymorphism in the CHEK2 gene, rs1033667, was significantly associated with OSCC [P = 0.002; odds ratio (OR) = 1.176; 95% confidence interval (CI): 1.06-1.30]. However, single nucleotide polymorphisms in the CASP8/ALS2CR12, TMEM173, PLCE1, ALDH2, ATP1B2/TP53 and RUNX1 loci were not associated with the disease (P > 0.05). The lack of association of six of these loci with OSCC in South African populations may reflect different genetic risk factors in non-African and African populations or differences in the genetic architecture of African genomes. The association at CHEK2, a gene with key roles in cell cycle regulation and DNA repair, in an African population provides further support for the contribution of common genetic variants at this locus to the risk of oesophageal cancer.

PI3Kα inhibitors sensitize esophageal squamous cell carcinoma to radiation by abrogating survival signals in tumor cells and tumor microenvironment

Radiotherapy is one of the standard therapies for esophageal squamous cell carcinoma (ESCC), but the efficacy is far from desirable. Large scale genome sequencing reveals PI3Kα is frequently hyper-activated in ESCC. We found that ESCC cells harboring alterations in PI3K pathway were more resistant to radiation and combination of a clinical PI3Kα-selective inhibitor CYH33 and radiation synergistically inhibited cell proliferation in 14 ESCC cell lines. Radiation induced phosphorylation of FOXO1 and Akt, which sensitized ESCC cells to PI3Kα inhibitors. Both S1PR3 and DNA-PK contributed to radiation-induced Akt phosphorylation, which were revealed to be collectively dependent on PI3Kα. By contrast, constitutively active Akt abrogated the synergism between PI3Kα inhibitors and radiation. PI3Kα inhibition enhanced radiation-induced DNA damage, G2/M arrest and apoptosis. Combination of CYH33 and radiation significantly inhibited the growth of xenografts derived from ESCC patients, which was accompanied with abrogation of radiation-induced phosphorylation of Akt and filtration of M2-like macrophages. Taken together, combination of CYH33 and radiation possesses synergism in ESCC, which provides promising rationale to test this combinatorial regimen in ESCC patients.

Glypican-1 Promotes Tumorigenesis by Regulating the PTEN/Akt/β-Catenin Signaling Pathway in Esophageal Squamous Cell Carcinoma

BACKGROUND AND AIMS

Glypican-1 (GPC1), a cell-surface heparan sulfate proteoglycan, promotes the pathogenesis of many human cancers. This study focuses on the role of GPC1 in the promotion of cell proliferation and motility in esophageal squamous cell carcinoma (ESCC).

METHODS

The expression and distribution of GPC1 were measured in tumor tissues from 248 ESCC patients using immunohistochemical (IHC) assays. Cell counting (kit-8), flow cytometry, Transwell, wound healing, IHC, and Western blotting assays were performed to examine the molecular mechanisms that underlie how GPC1 enhances cell proliferation and motility.

RESULTS

The level of GPC1 was higher in ESCC tumor samples than in para-tumor tissues (IHC score: 5.42 ± 2.15 vs. 0.86 ± 0.96). Ectopic overexpression of GPC1 in EC9706 cells promoted cell growth and the G1/S phase transition; conversely, GPC1 knockdown in Eca109 cells attenuated cell proliferation and induced G2/M phase arrest. In addition, GPC1 upregulation enhanced ESCC cell motility and induced epithelial mesenchymal transition (EMT), as demonstrated by the aberrant expression of EMT markers. Mechanistically, we demonstrated that GPC1 increased levels of p-Akt and β-catenin and reduced PTEN expression in ESCC.

CONCLUSIONS

Our study indicated that GPC1 promotes the aggressive proliferation of ESCC cells by regulating the PTEN/Akt/β-catenin pathway. GPC1 may be a promising target for ESCC treatment.

What have we learned from Linxian esophageal cancer etiological studies?

Esophageal cancer is the sixth leading cause of cancer death in the world. Esophageal squamous cell carcinoma (ESCC) accounts for 90% of esophageal cancer cases, over half of which occur in China. Linxian, a county located in the North Central Taihang Mountain range, has the highest ESCC mortality rate, which may be the leading cause of death in this area. In a decades-long research program in Linxian, Chinese and international scientists have exerted great efforts to describe the epidemiological characteristics and elucidate the etiology of ESCC. A systematic review and summary of the current knowledge gained from previous research is informative for future ESCC prevention and control in similar populations, and may be translated to other high-incidence countries, such as Brazil, Iran, Malawi, and South Africa. As ESCC is a major cause of cancer death, more research is required in China and in other high-incidence countries to deepen our understanding of the etiology of ESCC and develop preventative strategies.

Individual and Combined Effects of Environmental Risk Factors for Esophageal Cancer Based on Results From the Golestan Cohort Study

BACKGROUND & AIMS

Northeast Iran has one of the highest reported rates of esophageal squamous cell carcinoma (ESCC) worldwide. Decades of investigations in this region have identified some local habits and environmental exposures that increase risk. We analyzed data from the Golestan Cohort Study to determine the individual and combined effects of the major environmental risk factors of ESCC.

METHODS

We performed a population-based cohort of 50,045 individuals, 40 to 75 years old, from urban and rural areas across Northeast Iran. Detailed data on demographics, diet, lifestyle, socioeconomic status, temperature of drinking beverages, and different exposures were collected using validated methods, questionnaires, and physical examinations, from 2004 through 2008. Participants were followed from the date of enrollment to the date of first diagnosis of esophageal cancer, date of death from other causes, or date of last follow-up, through December 31, 2017. Proportional hazards regression models were used to estimate hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) for the association between different exposures and ESCC.

RESULTS

During an average 10 years of follow-up, 317 participants developed ESCC. Opium smoking (HR 1.85; 95% CI 1.18-2.90), drinking hot tea (≥60°C) (HR 1.60; 95% CI 1.15-2.22), low intake of fruits (HR 1.48; 95% CI 1.07-2.05) and vegetables (HR 1.62; 95% CI 1.03-2.56), excessive tooth loss (HR 1.66; 95% CI 1.04-2.64), drinking unpiped water (HR 2.04; 95% CI 1.09-3.81), and exposure to indoor air pollution (HR 1.57; 95% CI 1.08-2.29) were significantly associated with increased risk of ESCC, in a dose-dependent manner. Combined exposure to these risk factors was associated with a stepwise increase in the risk of developing ESCC, reaching a more than 7-fold increase in risk in the highest category. Approximately 75% of the ESCC cases in this region can be attributed to a combination of the identified exposures.

CONCLUSIONS

Analysis of data from the Golestan Cohort Study in Iran identified multiple risk factors for ESCC in this population. Our findings support the hypothesis that the high rates of ESCC are due to a combination of factors, including thermal injury (from hot tea), exposure to polycyclic aromatic hydrocarbons (from opium and indoor air pollution), and nutrient-deficient diets. We also associated ESCC risk with exposure to unpiped water and tooth loss.

Combined Modality Therapy for Management of Esophageal Cancer: Current Approach Based on Experiences from East and West

Human evolutionary genetic divergence and distinctive environmental exposures have contributed to the development of clinicopathologic variations of esophageal cancer in Eastern and Western countries. Different treatment strategies have derived from the disparate regional experiences. Treatment strategy is more standardized in the West. Trimodality treatment with neoadjuvant chemoradiation followed by surgery is widely accepted as the standard treatment of locally advanced esophageal adenocarcinoma and esophageal squamous cell carcinoma. Trimodality treatment has not been adopted in many Eastern countries, and standard treatment is neoadjuvant chemotherapy. Several randomized trials are ongoing that may alter the standard management of esophageal cancer worldwide.

Prognostic impact of family history of cancer in Southern Chinese patients with esophageal squamous cell cancer

Background: First degree family history of cancer is associated with developing esophageal cancer and sparse data is about the impact on poor survival among established esophageal squamous cell cancer (ESCC) patients. In this study, we investigated the prognoses of patients with ESCC with a family history.

Methods: A total of 479 ESCC patients were retrospectively enrolled from a Southern Chinese institution. A positive family history was defined as having malignant cancer among parents and siblings. Kaplan-Meier plots and Cox proportional hazards regressions were applied for overall survival (OS) and progression-free survival (PFS).

Results: Among 479 patients, 119 (24.8%) and 68 (14.2%) reported a first-degree family history of cancer and digestive tract cancer, respectively. Compared with patients without a family history of cancer, the adjusted hazard ratios (HR) among those with it were 1.40 (95% CI, 1.08-1.82, p=0.011) for death, 1.36 (95% CI, 1.05-1.76, p=0.018) for progression. Similar results were observed in those with a family history of digestive tract cancer (HR=1.69, 95%CI, 1.24-1.98, p=0.001 for death and HR=1.77, 95%CI, 1.30-2.37, p<0.001 for progression, respectively). Furthermore, there was a trend for increasing risk of overall mortality (p=0.021, p=0.004, respectively), and progression (p=0.022, p=0.001, respectively) with an increasing number of affected family members.

Conclusion: A first-degree family history of cancer, especially digestive tract cancer is associated with poor survival for established ESCC patients and plays an important role in prognosis. The patients with a family history of cancer might need a greater intensity of treatment and more frequent follow-up.

Evaluating the optimal radiation dose for definitive chemoradiotherapy for esophageal squamous cell carcinoma: A single institution experience

The optimal radiation dose for definitive chemoradiotherapy in inoperable esophageal squamous cell carcinoma (ESCC) has been long debated. In this study, we evaluated the effect of doses greater than the conventional radiation dose (50.4 Gy) on tumor control, tumor response, overall survival (OS), and disease-free survival (DFS).The database of patients diagnosed with inoperable ESCC from 2007 to 2015 was obtained from the cancer registry of Chi-Mei Medical Center. All categorical variables were compared using Chi-squared test. The risk of OS and DFS were estimated using Cox proportional hazards regression, and Kaplan-Meier plots presented the trend of OS and DFS with log-rank tests used to compare differences. All significance levels were set at P < .05.A total of 84 patients were retrospectively analyzed, with 42 (50%) receiving >50.4 Gy and 42 (50%) receiving ≤50.4 Gy (50%) concurrently with chemotherapy. Univariate and multivariate analysis revealed no significant differences between higher dose and conventional dose in OS (P = .21) and DFS (P = .26). Further dose analysis of <50, 50 to 50.4, 51 to 60, and >60 Gy showed no significant differences in OS or DFS. Higher doses conveyed no significant benefit on the failure pattern, either local regional failure or distant failure (P = .42). Major prognostic factors associated with better OS on multivariate analysis were stages I and II patients (P = .03) and radiation technique using arc therapy (P = .04). No acute toxicity of grade III or higher was recorded.The results of our study show that providing higher than conventional radiation doses concurrent with chemotherapy for inoperable ESCC does not impact OS or DSF, nor does it improve locoregional failure or distant failure. Although tumor response might be improved by radiation doses >50.4 Gy, the impact on OS and DFS remain to be studied.

Expression of Insulin-Like Growth Factor Binding Protein-5 (IGFBP5) Reverses Cisplatin-Resistance in Esophageal Carcinoma

Cisplatin (CDDP) is one of the front-line chemotherapeutic drugs used in the treatment of esophageal squamous cell carcinoma (ESCC). Occurrence of resistance to CDDP has become one of the main challenges in cancer therapy. In this study, the gene expression profile of CDDP-resistant ESCC cells was investigated and molecular approaches were explored in an attempt to reverse the CDDP resistance. A CDDP-resistant SLMT-1/CDDP1R cell line was established from SLMT-1 cells by subculturing in the medium containing an increasing concentration of CDDP (0.1⁻1μg/mL). Mitochondrial (MTS) cytotoxicity assay, cell proliferation assay and cell morphology were used to assess the acquisition of cisplatin-resistance. The most differentially expressed gene in SLMT-1/CDDP1R cells was identified by cDNA microarray analysis compared with the parental SLMT-1 cells and validated by quantitative real-time polymerase chain reaction (qPCR). Association between expression of the most differentially expressed target gene to cisplatin-resistance was verified by RNA interference. An attempt to reversecisplatin-resistance phenotypes was made by using the vector expressing the most downregulated target gene in the CDDP-resistant cells. A CDDP-resistant ESCC cell line, SLMT-1/CDDP1R, was established with 2.8-fold increase CDDP-resistance (MTS50 = 25.8 μg/mL) compared with the parental SLMT-1 cells. cDNA microarray analysis revealed that IGFBP5 showed the highest level of downregulation in SLMT-1/CDDP1R cells compared with the parental SLMT-1 cells. Suppression of IGFBP5 mediated by IGFBP5-targeting siRNA in parental SLMT-1 cells confirmed that IGFBP5 suppression in ESCC cells would induce CDDP-resistance. More importantly, upregulation of IGFBP5 using IGFBP5 expression vector reduced cisplatin-resistance in SLMT-1/CDDP1R cells by 41%. Thus, our results demonstrated that IGFBP5 suppression is one of the mechanisms for the acquisition of cisplatin-resistance in ESCC cells. Cisplatin-resistance phenotype can be reversed by increasing the expression level of IGFBP5. The overall findings of this study thus offered a new direction for reversing the CDDP resistance in ESCC and possibly in other cancer types with further investigations in future.

The African Esophageal Cancer Consortium: A Call to Action

Esophageal cancer is the eighth most common cancer worldwide and the sixth most common cause of cancer-related death; however, worldwide incidence and mortality rates do not reflect the geographic variations in the occurrence of this disease. In recent years, increased attention has been focused on the high incidence of esophageal squamous cell carcinoma (ESCC) throughout the eastern corridor of Africa, extending from Ethiopia to South Africa. Nascent investigations are underway at a number of sites throughout the region in an effort to improve our understanding of the etiology behind the high incidence of ESCC in this region. In 2017, these sites established the African Esophageal Cancer Consortium. Here, we summarize the priorities of this newly established consortium: to implement coordinated multisite investigations into etiology and identify targets for primary prevention; to address the impact of the clinical burden of ESCC via capacity building and shared resources in treatment and palliative care; and to heighten awareness of ESCC among physicians, at-risk populations, policy makers, and funding agencies.

Nut consumption and the risk of oesophageal squamous cell carcinoma in the Golestan Cohort Study

BACKGROUND

Nut consumption has been inversely associated with gastric cancer incidence in US-based studies, but not with oesophageal cancer. However, there is aetiologic heterogeneity, among oesophageal squamous cell carcinoma (ESCC) cases in low-risk vs. high-risk populations. The objective of this study was to evaluate the association between nut consumption and risk of ESCC in a high-risk population.

METHODS

The Golestan Cohort Study enroled 50,045 participants in Northeastern Iran, between 2004 and 2008. Intake of peanuts, walnuts and mixed nuts (including seeds) were assessed using a validated food frequency questionnaire at baseline. Cox proportional hazard models were used to estimate hazard ratios (HR) and 95% confidence intervals for subsequent ESCC adjusted for potential confounders. Non-consumers of nuts were used as the reference category and the consumers were categorised into tertiles.

RESULTS

We accrued 280 incident ESCC cases during 337,983 person-years of follow up. Individuals in the highest tertiles of total nut consumption, and mixed nut consumption were significantly associated with lower risk of developing ESCC compared to non-consumers (HR = 0.60, 95% CI = 0.39-0.93, p-trend = 0.02, and HR = 0.52, 95% CI = 0.32-0.84, p trend = 0.002, respectively).

CONCLUSIONS

We found a statistically significant inverse association between total nut consumption and the risk of ESCC in this high-risk population.

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.

Toenail mineral concentration and risk of esophageal squamous cell carcinoma, results from the Golestan Cohort Study

Studies conducted in China linked selenium deficiency to higher risk of esophageal squamous cell carcinoma (ESCC), but this has not been widely tested outside that selenium-deficient region. The aim of this study was to investigate the association between selenium and other mineral concentrations in toenails and risk of ESCC in a region with high incidence rates. In this nested case-control study, we identified 222 cases of ESCC from the Golestan Cohort Study, Iran, which has followed up 50,045 participants since enrollment (2004-2008). We randomly selected one control for each case matched by age and sex, using incidence density sampling. We used toenail samples collected at baseline to measure the concentration of selenium, zinc, chromium, mercury, and scandium using instrumental neutron activation analysis. Multivariate adjusted logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals. Median nail selenium, zinc, chromium, and mercury levels were 1.01, 74.59, 0.77, and 0.018 μg/g in cases and 1.02, 75.71, 0.71, and 0.023 μg/g in controls, respectively. The adjusted odds ratios comparing each fourth quartile of mineral status versus the first quartile were as follows: selenium = 0.78 (95% CI, 0.41-1.49); zinc=0.80 (95% CI, 0.42-1.53); chromium = 0.91 (95% CI, 0.46-1.80); and mercury=0.61 (95% CI, 0.27-1.38), and all trend tests were non-significant. The nail selenium concentration in our controls reflects relatively high selenium status. No evidence of association between selenium or chromium concentrations in toenails and the risk of ESCC was detected in this population.

Nut and peanut butter consumption and the risk of esophageal and gastric cancer subtypes

Background: Nut consumption has been associated with decreased risk of colorectal, endometrial, lung, and pancreatic cancers. Polyphenols, fiber, vitamins, and minerals in nuts may confer this observed protective effect. To our knowledge, no prospective study has evaluated the effect of nut consumption on esophageal and gastric cancers.Objective: The objective was to evaluate the associations between nut and peanut butter consumption and the risk of esophageal and gastric cancers and their different subtypes.Design: In this study we used data from the NIH-AARP Diet and Health Study, which enrolled 566,407 persons who were 50-71 y old at baseline (1995-1996). The median follow-up time was 15.5 y. Intakes of nuts and peanut butter were assessed through the use of a validated food-frequency questionnaire. We used Cox proportional hazard models to estimate HRs and 95% CIs for esophageal and gastric cancers and their subtypes.Results: We identified 966 incident cases of esophageal adenocarcinomas, 323 cases of esophageal squamous cell carcinoma, 698 cases of gastric cardia adenocarcinoma, and 732 cases of gastric noncardia adenocarcinoma. Compared with those who did not consume nuts or peanut butter [lowest category of consumption (C0)], participants in the highest category of nut consumption (C3) had a lower risk of developing gastric noncardia adenocarcinoma [C3 compared with C0, HR: 0.73 (95% CI: 0.57, 0.94)]. This inverse association was also seen for peanut butter consumption [C3 compared with C0, HR: 0.75 (95% CI: 0.60, 0.94)]. We observed no significant associations between the highest and lowest intakes of nuts or peanut butter and the risk of gastric cardia adenocarcinoma, esophageal adenocarcinoma, or esophageal squamous cell carcinoma.Conclusions: Among older American adults, both nut and peanut butter consumption were inversely associated with the risk of gastric noncardia adenocarcinoma. This trial was registered at clinicaltrials.gov as NCT00340015.