Prognostic markers in esophageal cancer: from basic research to clinical use

Prognostic Value of Systemic Inflammation Score for Esophageal Cancer Patients Undergoing Surgery: A Systematic Review and Meta-Analysis

OBJECTIVE

The link between inflammation and cancer survival has been the subject of substantial research. The goal of this review is to summarize the evidence on the prognostic value of systemic inflammation score (SIS) in esophageal cancer patients undergoing surgical intervention.

METHODS

PubMed, Scopus, Embase, and Web of Science were searched for relevant articles published until 30^th June 2022. We pooled adjusted data on overall survival (OS) and disease-free survival (DFS) using a random-effects meta-analysis model. The review was pre-registered on PROSPER (No. CRD42022340717).

RESULTS

Eight studies were included. All studies were conducted either in China or Japan. Six studies showed that patients with SIS of 1-2 had poor OS as compared to those with scores of 0 (HR:1.42 95% CI: 1.24, 1.62 I²=25%). SIS of 1 (HR:1.45 95% CI: 1.18, 1.78 I²=0%) and 2 (HR:1.94 95% CI: 1.49, 2.53 I²=0%) were also associated with poor OS. Two studies compared the SIS score of 2 vs 0-1. Meta-analysis indicated that poor OS was associated with SIS of 2 (HR:1.80 95% CI: 1.25, 2.58). Data from three studies showed that the SIS score did not predict DFS (HR:1.40 95% CI: 0.82, 2.39 I²=91%).

CONCLUSION

SIS can be a novel prognostic indicator for esophageal cancer patients undergoing surgical intervention. Higher SIS is associated with a poor OS, but it does not predict DFS. Future studies are needed to strengthen the current evidence.

A novel diagnostic signature of circulating tsRNAs and miRNAs in esophageal squamous cell carcinoma detected with a microfluidic platform

Small non-coding RNAs (sncRNAs) consisting of tRNA-derived small RNAs (tsRNAs) and miRNAs can be released by cancer cells and detected in blood, offering great potential for diagnosis of malignant tumors such as squamous cell carcinoma of the esophagus (ESCC). One of the major challenges for the clinical application of blood-based sncRNAs biomarkers is the difficulty of detection because of their small sncRNA size and low abundance. The deferentially expressed tsRNAs and miRNAs in plasma were studied with high-throughput sequencing and polymerase chain reaction in ESCC cohorts. A novel signature containing tRF-55:74-chrM.Phe-GAA, tRF-56:75-Ala-CGC-1-M4 and miR-4488 was identified with diagnostic potential. The signature was further confirmed by an attomolar-level ultrasensitive and rapid microfluidic biochip, which can achieve a multiplex, simple and low-cost detection. Our results indicated that a combination of tsRNAs and miRNAs has high diagnostic efficiency and tremendous potential to act as specific biomarkers through a reliable, highly sensitive, fast, and economic microfluidic biochip for ESCC diagnosis.

Co-Expression of Chromatin Assembly Factor 1 Subunit A and Proliferating Cell Nuclear Antigen Is a Prognostic Biomarker of Esophageal Cancer

(1) Background: Esophageal cancer (EC) is an important global health challenge. Due to the lack of necessary biomarkers and therapeutic targets, the survival of EC patients is poor. The EC proteomic data of 124 patients recently published by our group provides a database for research in this field. (2) Methods: Bioinformatics analysis was used to identify DNA replication and repair-related proteins in EC. Proximity ligation assay, colony formation assay, DNA fiber assay, and flow cytometry were used to study the effects of related proteins on EC cells. Kaplan-Meier survival analysis was used to evaluate the relationship between gene expression and the survival time of EC patients. (3) Results: Chromatin assembly factor 1 subunit A (CHAF1A) was highly correlated with proliferating cell nuclear antigen (PCNA) expression in EC. CHAF1A and PCNA colocalized in the nucleus of EC cells. Compared with the knockdown of CHAF1A or PCNA alone, the double knockdown of CHAF1A and PCNA could significantly inhibit EC cell proliferation. Mechanistically, CHAF1A and PCNA synergistically accelerated DNA replication and promoted S-phase progression. EC patients with high expression of both CHAF1A and PCNA had a worse survival rate. (4) Conclusion: we identify CHAF1A and PCNA as key cell cycle-related proteins leading to the malignant progression of EC, and these proteins could serve as important prognostic biomarkers and targets for EC.

The Prognostic Role of miR-31 in Head and Neck Squamous Cell Carcinoma: Systematic Review and Meta-Analysis with Trial Sequential Analysis

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide with high recurrence, metastasis, and poor treatment outcome. Prognostic survival biomarkers can be a valid tool for assessing a patient's life expectancy and directing therapy toward specific targets. Recent studies have reported microRNA (miR) might play a critical role in regulating different types of cancer. The main miR used as a diagnostic and prognostic biomarker and reported in the scientific literature for HNSCC is miR-21. Other miRs have been investigated to a lesser extent (miR-99a, miR-99b, miR-100, miR-143, miR-155, miR-7, miR-424, miR-183), but among these, the one that has attracted major interest is the miR-31.

METHODS

The systematic review was conducted following the PRISMA guidelines using electronic databases, such as PubMed, Scopus, and the Cochrane Central Register of Controlled Trials, with the use of combinations of keywords, such as miR-31 AND HNSCC, microRNA AND HNSCC, and miR-31. The meta-analysis was performed using the RevMan 5.41 software (Cochrane Collaboration, Copenhagen, Denmark).

RESULTS

This search produced 721 records, which, after the elimination of duplicates and the application of the inclusion and exclusion criteria, led to 4 articles. The meta-analysis was conducted by applying fixed-effects models, given the low rate of heterogeneity (I2 = 40%). The results of the meta-analysis report an aggregate hazard ratio (HR) for the overall survival (OS), between the highest and lowest miR-31 expression, of 1.59, with the relative intervals of confidence (1.22 2.07). Heterogeneity was evaluated through Chi2 = 5.04 df = 3 (p = 0.17) and the Higgins index I2 = 40; testing for the overall effect was Z = 3.44 (p = 0.00006). The forest plot shows us a worsening HR value of OS, in relation to the elevated expression of miR-31.

CONCLUSIONS

In conclusion, the data resulting from the current meta-analysis suggest that miR-31 is associated with the prognosis of patients with HNSCC and that elevated miR-31 expression could predict a poor prognosis in patients with this type of neoplasm.

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.

Discovery of Novel Autophagy Inhibitors and Their Sensitization Abilities for Vincristine-Resistant Esophageal Cancer Cell Line Eca109/VCR

Resistance phenomena, especially acquired drug resistance, have been severely hampering the application of chemotherapeutics during cancer chemotherapy. Autophagy plays a role in maintaining the survival of cancer cells and might mediate resistance to chemotherapy drugs. Herein, a new series of 5-amino-2-ether-benzamide derivatives were synthesized and evaluated as autophagy inhibitors. Selected from 14 synthesized compounds as lead autophagy inhibitor, N-(cyclohexylmethyl)-5-(((cyclohexylmethyl)amino)methyl)-2-((4-(trifluoromethyl)benzyl)oxy)benzamide (4 d) showed the most obvious effect of LC3B protein conversion. Further, its autophagy inhibition, evaluated by using transmission electron microscopy and confocal microscopy, showed that the fusion of autophagosomes and lysosomes in the final stage of autophagic flux was suppressed. We also found that 4 d could enhance the chemosensitivity of vincristine in vincristine-resistant esophageal cancer cell line Eca109/VCR in a synergistic, associative manner. Moreover, a computational study showed that 4 d might bind with p62-zz to inhibit autophagy. We also found 4 d to be relatively less cytotoxic to normal cells versus cancer cells than the reported p62-zz inhibitor.

Characteristics Associated with Nodal and Distant Recurrence After Radical Esophagectomy for Squamous Cell Carcinoma of the Thoracic Esophagus

BACKGROUND

Recurrence after radical resection of esophageal squamous cell carcinoma (ESCC) is common. Limited evidence is available about the differences in clinical characteristics, risk factors, and prognostic significance between nodal and distant recurrence of thoracic ESCC.

PATIENTS AND METHODS

We retrospectively analyzed 341 patients who underwent radical resection of thoracic ESCC and experienced (1) initial recurrence only in lymph nodes (n = 39), (2) recurrence only at distant organs (n = 57), or (3) no recurrences (n = 245) after follow-up ≥ 24 months. Clinicopathological characteristics, survival times, and risk factors were compared between the nodal and distant recurrence groups.

RESULTS

The median follow-up time was 57.8 months. Metastasectomy as initial treatment for the recurrence was performed for six (15.4%) patients in the nodal recurrence group and one patient in the distant recurrence group. Compared with the nodal recurrence group, patients with distant recurrence had significantly shorter disease-free survival [hazard ratio (HR) 1.68, 95% confidence interval (CI) 1.10-2.57, P = 0.0169], postrecurrence survival (HR 1.77, 95% CI 1.01-3.10, P = 0.0476), and overall survival (HR 1.98, 95% CI 1.12-3.51, P = 0.0193). The distant recurrence group had significantly larger macroscopic tumor size and more advanced pathological T stage than the nodal recurrence group, whereas preoperative treatment, tumor location, number of fields dissected, tumor differentiation, lymphatic involvement, and vessel invasion were not significantly different between the two groups.

CONCLUSIONS

Survival times and recurrence risk factors differed between patients with nodal and distant recurrence after radical resection of thoracic ESCC.

Comprehensive Review of Web Servers and Bioinformatics Tools for Cancer Prognosis Analysis

Prognostic biomarkers are of great significance to predict the outcome of patients with cancer, to guide the clinical treatments, to elucidate tumorigenesis mechanisms, and offer the opportunity of identifying therapeutic targets. To screen and develop prognostic biomarkers, high throughput profiling methods including gene microarray and next-generation sequencing have been widely applied and shown great success. However, due to the lack of independent validation, only very few prognostic biomarkers have been applied for clinical practice. In order to cross-validate the reliability of potential prognostic biomarkers, some groups have collected the omics datasets (i.e., epigenetics/transcriptome/proteome) with relative follow-up data (such as OS/DSS/PFS) of clinical samples from different cohorts, and developed the easy-to-use online bioinformatics tools and web servers to assist the biomarker screening and validation. These tools and web servers provide great convenience for the development of prognostic biomarkers, for the study of molecular mechanisms of tumorigenesis and progression, and even for the discovery of important therapeutic targets. Aim to help researchers to get a quick learning and understand the function of these tools, the current review delves into the introduction of the usage, characteristics and algorithms of tools, and web servers, such as LOGpc, KM plotter, GEPIA, TCPA, OncoLnc, PrognoScan, MethSurv, SurvExpress, UALCAN, etc., and further help researchers to select more suitable tools for their own research. In addition, all the tools introduced in this review can be reached at http://bioinfo.henu.edu.cn/WebServiceList.html.

Optimized Cutoff Value of Serum Squamous Cell Carcinoma Antigen Concentration Accurately Predicts Recurrence After Curative Resection of Squamous Cell Carcinoma of the Esophagus

BACKGROUND

Squamous cell carcinoma antigen (SCC-Ag) and carcinoembryonic antigen (CEA) are widely used in clinical practice to predict the prognosis of patients with esophageal squamous cell carcinoma (ESCC). However, their predictive values for prognosis are controversial. This study determined optimal cutoff values of serum SCC-Ag and CEA concentrations for predicting postoperative recurrence of ESCC, which enabled selection of high-risk patients.

METHODS

The study retrospectively analyzed 427 patients who underwent curative resection for ESCC. The optimal cutoff values of preoperative SCC-Ag and CEA concentrations for predicting postoperative recurrence were determined using combined analysis of hazard ratios and sensitivities for recurrence. Using the optimal cutoff value, the study evaluated survival, recurrence patterns, and temporal changes in marker concentrations.

RESULTS

The preoperative SCC-Ag concentration of 1.1 ng/ml was the optimal cutoff value for predicting postoperative recurrence, whereas precise cutoff values could not be determined for preoperative CEA concentrations. High preoperative SCC-Ag concentrations (> 1.1 ng/ml), which were significantly associated with more aggressive tumor phenotypes and shorter disease-free survival, were identified as an independent prognostic factor in the multivariable analysis. High preoperative SCC-Ag concentrations were significantly associated with greater prevalence of lung/pleura and local recurrences. Normalization of serum SCC-Ag concentrations after neoadjuvant treatment or esophagectomy was not associated with a decreased risk of postoperative recurrence.

CONCLUSIONS

The optimal cutoff value of preoperative SCC-Ag concentrations that predicted recurrence of ESCC was 1.1 ng/ml, illuminating the utility of serum SCC-Ag concentrations as an easily measurable tool for selecting a perioperative management strategy.

Modified Systemic Inflammation Score is Useful for Risk Stratification After Radical Resection of Squamous Cell Carcinoma of the Esophagus

BACKGROUND

Inflammation plays a critical role in the development and progression of cancers. We evaluated the clinical significance of the preoperative modified systemic inflammation score (mSIS) to predict long-term outcomes of patients with esophageal squamous cell carcinoma (ESCC).

METHODS

We included 443 patients who underwent curative resection of ESCC. The mSIS was formulated according to the serum albumin level (ALB) and lymphocyte-to-monocyte ratio (LMR) as follows: mSIS 0 (ALB ≥ 4.0 g/dL and LMR ≥ 3.4), mSIS 1 (ALB < 4.0 g/dL or LMR < 3.4), and mSIS 2 (ALB < 4.0 g/dL and LMR < 3.4).

RESULTS

Patients were categorized into preoperative mSIS 0 (n = 165), mSIS 1 (n = 183), and mSIS 2 (n = 95) groups. Preoperative mSIS was significantly associated with age, preoperative body mass index, and pathological disease stage. The disease-specific survival times of patients in preoperative mSIS 0, 1, and 2 sequentially shortened (P = 0.009), and mSIS 2 was identified as an independent prognostic factor (hazard ratio 2.63, 95% confidence interval 1.33-5.27, P = 0.0053). In most patient subgroups, the mSIS was associated with greater risk of disease-specific death. A stepwise increase in the prevalence of hematogenous recurrences was directly proportion to the mSIS. When patients were subdivided by mSIS before neoadjuvant treatment, there were no significant differences in disease-specific survival.

CONCLUSIONS

Our findings demonstrate that the preoperative mSIS may serve as a powerful prognosticator of ESCC that definitively stratifies clinical outcomes as well as a tool for selecting treatment strategies.

ALC1 knockdown enhances cisplatin cytotoxicity of esophageal squamous cell carcinoma cells by inhibition of glycolysis through PI3K/Akt pathway

AIMS

Amplified in liver cancer 1 gene (ALC1), a recently identified oncogene, was reported to be overexpressed in esophageal cancer cell lines and identified as a target oncogene in esophageal cancer pathogenesis. However, little literature is available to illustrate its significance in cisplatin resistance of esophageal squamous cell carcinoma (ESCC) cells. The aim of the current study was to investigate the effect of ALC1 on cisplatin cytotoxicity of ESCC cells and to study the potential mechanisms.

MAIN METHODS

ALC1 at mRNA and protein levels were detected by qRT-PCR and western blot, respectively. Cell viability was evaluated using CCK-8 assay. Apoptosis was assessed using caspase-3/7 activity assay and flow cytometry analysis. Glycolysis level was evaluated by measuring glucose consumption and lactate production. The protein levels of p-protein kinase B (Akt) and Akt were determined by western blot.

KEY FINDINGS

ALC1 was highly expressed in ESCC cells compared with human normal esophageal epithelial Het-1A cells. ALC1 knockdown suppressed the viability, induced apoptosis and enhanced cisplatin cytotoxicity in ESCC cells. In addition, ALC1 knockdown inhibited glycolysis and inactivated the phosphatidylinositol 3-kinase (PI3K)/Akt pathway in ESCC cells. Mechanistically, activation of the PI3K/Akt pathway by 740Y-P blocked the effects of ALC1 knockdown on cisplatin cytotoxicity and glycolysis in ESCC cells. In contrast, inhibition of the PI3K/Akt pathway by LY294002 or glycolysis by 2-deoxyglucose resisted the effect of ALC1 overexpression on cisplatin cytotoxicity in ESCC cells.

SIGNIFICANCE

ALC1 knockdown enhanced cisplatin cytotoxicity of ESCC cells by inhibition of glycolysis through inactivation of the PI3K/Akt pathway.

HCRP1 inhibits cell proliferation and invasion and promotes chemosensitivity in esophageal squamous cell carcinoma

Hepatocellular carcinoma related protein 1 (HCRP1), which is essential for internalization and degradation of ubiquitinated membrane receptors, was reported to play crucial roles in cancer pathogenesis and progression. However, the functional roles of HCRP1 in esophageal squamous cell carcinoma (ESCC) remain unknown. In this study, we investigated the effects of HCRP1 on ESCC cells and the underlying mechanism. Our results demonstrated that HCRP1 was lowly expressed in ESCC tissues and cell lines. Overexpression of HCRP1 significantly suppressed ESCC cell proliferation and invasion as well as the epithelial-mesenchymal transition (EMT) process. Furthermore, HCRP1 increased the sensitivity of ESCC cells towards cisplatin/fluorouracil. Mechanistically, HCRP1 inhibited the activity of Wnt/β-catenin signaling pathway in ESCC cells. In conclusion, these findings indicated that HCRP1 suppressed ESCC cell proliferation and invasion through regulation of the Wnt/β-catenin pathway. Therefore, HCRP1 may function as a tumor suppressor in ESCC progression.

MicroRNA-125a-5p enhances the sensitivity of esophageal squamous cell carcinoma cells to cisplatin by suppressing the activation of the STAT3 signaling pathway

Increasing evidence has demonstrated that microRNAs (miRNAs or miRs) play a variety of roles in tumor development, progression and chemosensitivity in a wide range of tumors. In this study, we found that miR-125a-5p exhibited a low expression in esophageal squamous cell carcinoma (ESCC) tissues and cells, and that its low expression was associated with higher tumor staging and shorter a survival time of patients with ESCC. Moreover, miR-125a-5p overexpression contributed to the suppression of cell proliferation, cell cycle arrest, cell apoptosis and a decrease in cell migratory and invasive abilities, whereas the downregulation of miR-125a-5p promoted cell proliferation, accelerated cell cycle progression, suppressed apoptosis and enhanced the migratory and invasive abilities of ESCC EC1 and TE1 cells, which may be tightly associated with the epithelial-mesenchymal transition (EMT) process in ESCC. Importantly, miR-125a-5p enhanced the cytotoxic effects of cisplatin on EC1 and TE1 cells, and co-treatment with miR-125a-5p and cisplatin significantly induced cell apoptosis and reduced the cell migratory and invasive abilities of EC1 and TE1 cells, coupled with an increase in the E-cadherin level and a decrease in the N-cadherin and Vimentin levels. Most notably, signal transducer and activator of transcription-3 (STAT3) was found to be a direct target of miR-125a-5p in ESCC cells, and miR-125a-5p overexpression significantly reduced the protein levels of t-STAT3, p-STAT3 and vascular endothelial growth factor (VEGF) in EC1 and TE1 cells. Furthermore, the combination of miR-125a-5p and cisplatin markedly inactivated the STAT3 signaling pathway; however, interleukin (IL)-6, a widely reported activator of the STAT3 signaling pathway, reversed the suppressive effects of miR-125a-5p/cisplatin in ESCC cells on the activation of the STAT3 signaling pathway. Of note, we found that IL-6 markedly reversed the altered cell phenotype mediated by the combination of miR-125a-5p and cisplatin in ESCC cells. These findings suggest that miR-125a-5p may play a pivotal role in the development and progression of ESCC, which may be achieved via the manipulation of the STAT3 signaling pathway.

Esophageal cancer in patients under 50: a SEER analysis

Background

Concomitant with rising rates of esophageal adenocarcinoma, there has been a significant increase of diagnoses among relatively younger individuals. However, most studies that focus on esophageal cancer (EC) in younger patients have had small sample sizes of patients treated at a single institute. The aim of this study was to analyze the clinical characteristics, outcomes and independent prognostic factors for EC in patients under 50-year-old using a large, multi-center dataset.

Methods

The national Surveillance, Epidemiology, and End Results (SEER) database was analyzed for EC reported from 2004 to 2013. Patients were divided into two groups, those under 50-year-old and those 50 years or older, and comparisons were made regarding demographics, histology, stage distribution, treatment, overall survival (OS), and esophageal cancer-specific survival (ECSS). Multivariate Cox proportional hazard regression analyses were also used to identify independent prognostic factors.

Results

Among the 16,544 eligible patients, 1,385 (8.37%) were under 50 and 15,159 (91.63%) were over 50. Compared with the older group, patients under 50 were characterized by a higher frequency of males, lower esophagus involvement, adenocarcinoma histology, stage III/IV disease, and receiving esophagectomy or radiation therapy. The stage-wise OS and ECSS were significantly better in the younger group (P<0.001). The multivariate analysis indicated that African-American heritage, grade III or IV, later stage, and not undergoing surgical or radiation therapy were independent negative prognostic factors of ECSS for patients under 50.

Conclusions

EC patients under 50-year-old had distinctive clinicopathological characteristics compared with patients over 50-year-old. Despite more often presenting with stage III and IV disease, survival rates were better in the younger cohort. Prognostic factors for ECSS in patients under 50 differed from those in all age patients.

Molecular mechanisms and clinical implications of miRNAs in drug resistance of esophageal cancer

With the increasing incidence of esophageal cancer, drug resistance is becoming a major obstacle to successful cancer therapy since chemotherapy is regarded as a curative approach to inhibit cancer cell proliferation. Despite the great progress in anticancer treatment achieved during the last decades, the mechanisms of multidrug resistance have not been completely elucidated. Recently, accumulating studies and pre-clinical reports highlighted the role of miRNAs in the drug resistance of esophageal cancer. Areas covered: In this review, we mainly summarized the current advances of miRNAs in esophageal cancer and the mechanisms underlying drug resistance. We also reviewed the potential role of miRNAs as biomarkers for predicting drug response and prognosis. Finally, we envisaged the future orientation and challenges in translating the existing knowledge of drug resistance related miRNAs into clinical applications. Expert commentary: Based on the current knowledge of certain miRNAs, we believe that miRNAs would be helpful to overcome the drug resistance and provide personalized treatment for patients with esophageal cancer. The aims of this study were to provide a comprehensive summary on the emerging role of miRNAs in the drug resistance of esophageal cancer and attract broad attention of more researchers on this field.

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.

Molecular mechanisms and theranostic potential of miRNAs in drug resistance of gastric cancer

INTRODUCTION

Systemic chemotherapy is a curative approach to inhibit gastric cancer cells proliferation. Despite the great progress in anti-cancer treatment achieved during the last decades, drug resistance and treatment refractoriness still extensively persists. Recently, accumulating studies have highlighted the role of miRNAs in drug resistance of gastric cancers by modulating some drug resistance-related proteins and genes expression. Pre-clinical reports indicate that miRNAs might serve as ideal biomarkers and potential targets, thus holding great promise for developing targeted therapy and personalized treatment for the patients with gastric cancer. Areas covered: This review provide a comprehensive overview of the current advances of miRNAs and molecular mechanisms underlying miRNA-mediated drug resistance in gastric cancer. We particularly focus on the potential values of drug resistance-related miRNAs as biomarkers and novel targets in gastric cancer therapy and envisage the future research developments of these miRNAs and challenges in translating the new findings into clinical applications. Expert opinion: Although the concrete mechanisms of miRNAs in drug resistance of gastric cancer have not been fully clarified, miRNA may be a promising theranostic approach. Further studies are still needed to facilitate the clinical applications of miRNAs in drug resistant gastric cancer.

Identification of NCCRP1 as an epigenetically regulated tumor suppressor and biomarker for malignant phenotypes of squamous cell carcinoma of the esophagus

The poor prognosis and increasing incidence of esophageal squamous cell carcinoma (ESCC) highlight the need for identification of novel ESCC-associated molecular events to improve the diagnosis, and treatment of this disease. Non-specific cytotoxic cell receptor protein 1 (NCCRP1) was reported to be abundantly expressed in human squamous epithelium and to be involved in cell proliferation; however, the role of NCCRP1 in ESCC remains unclear. To elucidate the oncological roles of NCCRP1 in ESCC, NCCRP1 expression, DNA methylation, and copy numbers were analyzed in ESCC cell lines. Nine ESCC cell lines demonstrated different NCCRP1 mRNA expression levels and all exhibited hypermethylation of the NCCRP1 promoter, but no copy number loss. Additionally, NCCRP1 expression was determined in 213 surgically resected esophageal tissue samples. NCCRP1 mRNA expression levels were reduced in ESCC tissues compared with corresponding non-cancerous adjacent tissues in 204 (95.8%) patients. Patients in the low NCCRP1 expression group tended to have a higher recurrence rate and a shorter overall survival time compared with those in the high NCCRP1 expression group. Additionally, multivariate analysis revealed that low NCCRP1 expression was an independent prognostic factor (hazard ratio, 1.75; 95% confidence interval, 1.08-2.87; P=0.022). The findings of the current study indicate that NCCRP1 acts as a putative tumor suppressor that is inactivated through promoter hypermethylation, and serves as a promising biomarker to predict postoperative prognosis in ESCC.

Impact of pretreatment plasma D-dimer levels and its perioperative change on prognosis in operable esophageal squamous cell carcinoma

The aim of this study was to investigate the relationship between plasma D-dimer levels and its perioperative change and clinicopathological parameters in patients with operable esophageal squamous cell carcinoma (ESCC). We also analyzed their prognostic significance in ESCC patients. The data of 294 ESCC patients between December 2007 and December 2012 in Mingzhou hospital, Ningbo, China were analyzed retrospectively. Plasma D-dimer levels were measured one week before surgery and on the thirtieth postoperative day. The association between plasma D-dimer levels and clinicopathological parameters was evaluated. Kaplan-Meier survival analysis and Cox proportional hazards models were used to estimate the effect of plasma D-dimer levels and its perioperative change on disease-free survival (DFS) and overall survival (OS). Plasma D-dimer levels were above 0.5 µg/mL in 148 patients (50.3%). Plasma D-dimer levels were significantly related with DFS (P < 0.001) and OS (P < 0.001) in univariate analysis. There was significant relationship between plasma D-dimer levels and DFS in patients with N₀ (P < 0.001) or N₊ (P = 0.003). Multivariate analysis revealed that plasma D-dimer levels (P < 0.001), sex (P = 0.012), and T stage (P = 0.033) were independent prognostic factors for DFS. Tumor length (P = 0.018), T stage (P = 0.008) and plasma D-dimer levels (P = 0.001) qualified as independent prognostic factors for OS. Our study suggests that pretreatment plasma D-dimer levels is a powerful independent prognostic factor for operable ESCC. Further studies are needed to prospectively validate this prognostic model and investigate the mechanisms underlying the correlation between elevated plasma D-dimer levels and poor prognosis in operable ESCC.

Low expression of miR-1469 predicts disease progression and unfavorable post-surgical clinical outcomes in patients with esophageal squamous cell cancer

Recent studies have demonstrated that deregulated microRNA (miRNA/miR) expression has a profound impact on biological and pathological processes; abnormal miR-1469 expression was detected in several human malignancies. In the present study, the clinicopathological and prognostic significance of miR-1469 was assessed in 129 patients with esophageal squamous cell cancer (ESCC) who successfully underwent esophagectomy and esophagogastrostomy. Low miR-1469 expression was identified to be significantly associated with tumor invasion depth (P=0.026), lymph node metastasis status (P<0.001) and pathological tumor stage (P<0.001). Survival analysis demonstrated that patients with low miR-1469 expression had significantly poorer disease-free survival (DFS) (18.2 vs. 43.2%; P=0.004) and overall survival (29.1 vs. 47.3%; P=0.029) 5 years following surgery compared with patients with high miR-1469 expression. Univariate survival analysis demonstrated that low miR-1469 expression significantly predicted unfavorable 5-year DFS among patients with N1-3 disease (7.1 vs. 31.8%; P=0.043). The results from the present study indicate that miR-1469 expression could be used in the clinic to predict ESCC progression and prognosis. This will aid in the identification of high-risk patients with ESCC that require more aggressive therapeutic interventions.

miR-200c: a versatile watchdog in cancer progression, EMT, and drug resistance

MicroRNAs (miRNAs) are 20-22-nucleotide small endogenous non-coding RNAs which regulate gene expression at post-transcriptional level. In the last two decades, identification of almost 2600 miRNAs in human and their potential to be modulated opened a new avenue to target almost all hallmarks of cancer. miRNAs have been classified as tumor suppressors or oncogenes depending on the phenotype they induce, the targets they modulate, and the tissue where they function. miR-200c, an illustrious tumor suppressor, is one of the highly studied miRNAs in terms of development, stemness, proliferation, epithelial-mesenchymal transition (EMT), therapy resistance, and metastasis. In this review, we first focus on the regulation of miR-200c expression and its role in regulating EMT in a ZEB1/E-cadherin axis-dependent and ZEB1/E-cadherin axis-independent manner. We then describe the role of miR-200c in therapy resistance in terms of multidrug resistance, chemoresistance, targeted therapy resistance, and radiotherapy resistance in various cancer types. We highlight the importance of miR-200c at the intersection of EMT and chemoresistance. Furthermore, we show how miR-200c coordinates several important signaling cascades such as TGF-β signaling, PI3K/Akt signaling, Notch signaling, VEGF signaling, and NF-κB signaling. Finally, we discuss miR-200c as a potential prognostic/diagnostic biomarker in several diseases, but mainly focusing on cancer and its potential application in future therapeutics.