Molecular biomarkers in gastro-esophageal cancer: recent developments, current trends and future directions

Expression of Interleukin-8, Interleukin-12 and Interleukin-13 in Esophageal Squamous Cell Carcinoma: Biomarker Potentiality and Prognostic Significance

PURPOSE

Interleukin-8 (IL8), Interleukin-12 (IL12) and Interleukin-13 (IL13) are cytokines that play regulatory role in cancer pathogenesis. We analysed their expression profile to evaluate as molecular biomarkers of esophageal squamous cell carcinoma (ESCC) and their association with different parameters and patient survival.

METHODS

Expression analysis was performed by Real time quantitative polymerase chain reaction and receiver operating characteristic (ROC) curve analysis was done. The expression profiles were associated with different clinicopathological and dietary factors. Survival and hazard analysis were also performed.

RESULTS

IL8 expression showed upregulation in tissue (p = 0.000) and blood samples (p = 0.481), IL12 expression showed downregulation in tissue samples (p = 0.064) and upregulation in blood samples (p = 0.689) and IL13 expression showed upregulation in tissue (p = 0.000) and blood samples (p = 0.006). IL13 expression in tissue showed the highest area under the curve (AUC) value (0.773) for ESCC diagnosis, followed by IL8 expression in tissue (0.704) and IL13 expression in blood (0.643). This study also reveals the correlation of studied cytokines in tissue and blood level. Different clinicopathological and dietary factors showed significant association (p < 0.05) with IL8, IL12 and IL13 expression and with survival of ESCC patients. IL8 expression in blood and IL12 expression in tissue and blood showed significant association (p < 0.05) with patient survival.

CONCLUSION

Altered expression of IL8, IL12 and IL13 may be associated with ESCC progression. Overexpression of IL8 and IL13 in tissue samples may be potential biomarkers for ESCC screening. Additionally, both survival and hazard analysis data indicate the effects of different parameters on the prognosis of ESCC patients.

Management of Microsatellite Instability High (MSI-H) Gastroesophageal Adenocarcinoma

BACKGROUND

Gastroesophageal cancer is a major cause of cancer-related mortality worldwide. Treatment of both early stage and advanced disease remains highly reliant on cytotoxic chemotherapy. About 4-24% of gastroesophageal cancers are microsatellite instability high (MSI-H). The MSI-H subtype is associated with favorable prognosis, resistance to cytotoxic chemotherapy, and sensitivity to immune checkpoint inhibitors (ICI). Recent studies have demonstrated promising activity of ICIs in the MSI-H subtype, resulting in fundamental changes in the management of MSI-H gastroesophageal adenocarcinoma.

PURPOSE

In this review, we discuss the prevalence, characteristics, prognosis, and management of MSI-H gastroesophageal adenocarcinoma, with a focus on recent and ongoing studies that have changed the landscape of treatment for the MSI-H subtype. We also discuss current challenges in the management of resectable and advanced MSI-H gastroesophageal cancer, including the need for more accurate biomarkers of response to ICI therapy.

Genetic Impact of HOTAIR, LINC00951, POLR2E and HULC Polymorphisms in Histopathological and Laboratory Prognostic Factors in Esophageal Cancer in the West: A Case-Control Study

Long non-coding RNAs' HOTAIR rs920778, LINC00951 rs11752942, POLR2E rs3787016, and HULC rs7763881 are progressively reported having a close genetic affinity with esophageal carcinogenesis in the East. Nonetheless, their correlation with variables already endorsed as significant prognostic factors in terms of staging, guiding treatment and predicting recurrence, metastasis, and survival have yet to be explored. Herein, we investigated their prognostic value by correlating them with clinicopathological and laboratory prognostic markers in esophageal cancer in the West. Formalin-fixed paraffin-embedded tissue specimens from 95 consecutive patients operated on for esophageal cancer between 2014 and 2018 were compared with 121 healthy community controls. HULC was not detected differently in any of the cancer prognostic subgroups. LINC00951 was underrepresented in Ca19.9 elevated subgroup. HOTAIR was more frequent in both worse differentiation grade and positive Signet-Ring-Cell and Ca19.9 subgroups. POLR2E was identified less frequently in Adenocarcinoma, Signet-Ring-Cell, and Diffuse histologies, as well as in Perineural, Lymphovascular, and Perivascular Invasion positive, while it was overrepresented in CEA positive subgroup. These lncRNAs polymorphisms may hold great potential not only as future therapeutic agents but also as novel markers for predictive analysis of esophageal cancer risk, clinical outcome, and survival. Clinical implications of these findings need to be validated with prospective larger sample-size studies.

Long non coding RNA, C8orf49, a novel diagnostic and prognostic biomarker, enhances PTEN/FZD4-mediated cell growth and metastasis by sponging miR-1323 in endometriosis

Lack of sensitive biomarkers in the early stages of endometriosis (EMs) results in delayed diagnosis and intervention. Long non-coding RNAs (lncRNAs) have prognostic and diagnostic values in various diseases. However, the prognostic and diagnostic effects of lncRNAs on EMs have rarely been discussed in EMs. In this study, we found that lncRNA C8orf49 was stably overexpressed in EMs tissues/plasma, and its expression greatly influenced dysmenorrhea (p = 2.2605E-9) and the revised American Society for Reproductive Medicine stage (p = 0.040765) of EMs. Multivariate logistic regression results revealed that C8orf49 expression was an independent risk factor for EMs [p = 6.4997E-17, 95% confidence interval (CI) = 0.000559-0.023853]. In primary endometrial stromal cells (ESCs), inhibition of C8orf49 could impede the proliferation and metastasis of ESCs. C8orf49 influenced the expression of PTEN/FZD4 by absorbing miR-1323, thus controlling ESCs activity. The results of a subcutaneous endometriosis animal model showed that the inhibition of C8orf49 restrained endometrial growth. Overall, C8orf49 functioned as an activator of EMs pathogenesis via the C8orf49/miR-1323/PTEN/FZD4 axis.

Effects of Helicobacter pylori on the expression of the FTO gene and its biological role in gastric cancer

Helicobacter pylori (Hp) is a primary risk factor for gastric cancer. The fat mass and obesity-associated (FTO) gene is associated with the development and progression of various cancer types such as glioma, leukemia, breast cancer and colorectal cancer. The aim of the present study was to investigate the effect of Hp infection on the expression of FTO and its roles in gastric cancer. It was found that the expression levels of both FTO mRNA and protein were significantly increased in Hp-infected human gastric mucosal epithelial cells and Mongolian gerbil gastric tissues. The expression of FTO in gastric cancer tissues was higher than that in para-cancer tissues. Data from The Cancer Genome Atlas demonstrated that FTO expression in gastric cancer tissues was significantly higher than that in normal tissues. Patient survival rate was significantly decreased in patients with high expression levels of FTO. It was also demonstrated that FTO expression was associated with several pathological parameters, such as tumor stage, metastasis stage and the American Joint Committee on Cancer stage. The FTO gene was positively correlated with 16,601 genes in gastric cancer and negatively correlated with 3,623 genes. Gene Ontology enrichment analysis demonstrated that FTO was significantly enriched in the regulation of gene expression and oxidative RNA demethylase activity, and it was associated with components such as the RNA N6-methyladenosine methyltransferase complex and nuclear speckle. In addition, knockdown of the FTO gene inhibited the migration and invasion of Hp-infected cells. In conclusion, the data suggests that Hp infection leads to upregulation of the FTO gene, which may be related to patient survival rate, tumor staging and other pathological parameters of patients with gastric cancer. It also suggests that FTO promotes proliferation and migration of gastric cancer cells, which may be involved in the pathogenesis of Hp-induced gastric cancer.

Effects of Citrus aurantium L. on Gastrointestinal Motility and Gastric Cancer Cell Proliferation

Background: To research the impact of a Chinese traditional medicine (Citrus aurantium L.) on gastric cancer proliferation and mice gastrointestinal motility. Materials and Methods: The intestinal transit rates (ITRs) and gastric emptying (GE) values in mice with experimentally induced gastrointestinal motility dysfunction (GMD) and in normal mice were calculated to research the in vivo influences of C. aurantium L. on gastrointestinal motility. CCK-8 was used to examined the effect of C. aurantium L. on gastric cancer proliferation. Results: The GE and ITR values were dose-dependently and notably added by C. aurantium L. in normal ICR mice (with 1 g/kg C. aurantium L., ITR values: 53.3% ± 0.8% versus 64.3% ± 0.9% and 53.3% ± 0.8% versus 79.8% ± 2.0%, p < 0.01; GE values: 59.3% ± 0.8% versus 70.1% ± 1.9% and 59.9% ± 0.8% versus 69.9% ± 2.1%, p < 0.01). Compared with the normal mice, the GMD mice's ITRs were notably declined; however, C. aurantium L. could dose-dependently and significantly reverse it. In addition, in the model of delayed GE induced by loperamide and cisplatin, C. aurantium L. administration reversed the GE deficit. Furthermore, C. aurantium L. significantly reduced gastric cancer proliferation. Conclusion: The results indicate that C. aurantium L. could become a new drug for gastrointestinal prokinetic and gastric cancer therapy.

Expression of Polyadenylate-binding Protein Cytoplasmic 1 (PABPC1) in Combination With RAD51 as Prognostic Biomarker in Patients Who Underwent Postoperative Chemotherapy for Esophageal Squamous Cell Carcinoma

Molecular markers in the prognosis of esophageal squamous cell carcinoma (ESCC) patients who received postoperative treatments are lacking. This research aims to evaluate the prognostic value of polyadenylate-binding protein cytoplasmic 1 (PABPC1) alone and in combination with RAD51 in ESCC patients who underwent postoperative chemotherapy (CT). A total of 103 ESCC patients who underwent postoperative CT and 103 matched ones who received surgery alone were analyzed in this study. PABPC1 and RAD51 expression was assessed in cancer samples by immunohistochemistry. PABPC1 high expression (PABPC1-HE) but not that of RAD51 was associated with poor patients' survival, regardless of the postoperative treatment or node status. Patients with PABPC1 low expression and RAD51 negative expression [RAD51- (PABPC1-LE/RAD51-)] tumor had good overall survival (OS) in both the CT treated and untreated groups. Patients with PABPC1-LE/RAD51+ and PABPC1-HE/RAD51+ tumors had longer OS in the CT treated group than in the untreated group. However, PABPC1-HE/RAD51- was associated with a poor outcome in both groups and the patients with PABPC1-HE/RAD51- tumor had hardly any benefit from CT in N+ status. PABPC1 alone and in combination with RAD51 was a prognostic biomarker for OS in ESCC patients who received postoperative CT.

Model construction and risk analysis of the lncRNA genes associated with the prognosis of esophageal adenocarcinoma with immune infiltration

Background

Our study analyzed the immune infiltration of esophageal adenocarcinoma (EAC) tumor cells and identified long non-coding ribonucleic acid (lncRNA) genes to construct a prognostic model of EAC to evaluate the survival prognosis of patients and explore potential therapeutic targets.

Methods

The data of 89 patients with EAC, including 11 normal tissue samples and 78 EAC of tumor tissue samples, were downloaded from The Cancer Genome Atlas public database. Perl script and R software were used to run the code, conduct the statistical analysis, calculate the risk coefficients of the patients, and conduct the Cox regression analysis, immune-related lncRNA survival analysis, risk analysis, principal component analysis (PCA), and receiver operating characteristic (ROC) curve analysis.

Results

We screened and identified 19 prognostic biomarkers, including LINC01612, AC008443.2, and LINC02582, allocated the patients into high- and low-risk groups, and found significant differences in the prognosis between the high- and low-risk groups using the Kaplan-Meier survival analysis (P<0.001). A ROC curve was used to evaluate the feasibility of the prognostic model for EAC, and we found that the model had high predictability (area under the curve =0.964). A PCA analysis was performed of the complex transcriptome sequencing data and other cubes to transform the data into a 3-dimensional space constructed by feature vectors.

Conclusions

Our study effectively screened and identified the lncRNA genes related to the immune infiltration of EAC and successfully constructed a prognostic model. In total, 19 potential diagnostic and therapeutic target genes, including LINC01612, AC008443.2, and LINC02582, were identified that have certain significance in guiding the clinical treatment of EAC patients.

Patient-Derived Xenograft: A More Standard "Avatar" Model in Preclinical Studies of Gastric Cancer

Despite advances in diagnosis and treatment, gastric cancer remains the third most common cause of cancer-related death in humans. The establishment of relevant animal models of gastric cancer is critical for further research. Due to the complexity of the tumor microenvironment and the genetic heterogeneity of gastric cancer, the commonly used preclinical animal models fail to adequately represent clinically relevant models of gastric cancer. However, patient-derived models are able to replicate as much of the original inter-tumoral and intra-tumoral heterogeneity of gastric cancer as possible, reflecting the cellular interactions of the tumor microenvironment. In addition to implanting patient tissues or primary cells into immunodeficient mouse hosts for culture, the advent of alternative hosts such as humanized mouse hosts, zebrafish hosts, and in vitro culture modalities has also facilitated the advancement of gastric cancer research. This review highlights the current status, characteristics, interfering factors, and applications of patient-derived models that have emerged as more valuable preclinical tools for studying the progression and metastasis of gastric cancer.

Combining gene expression analysis of gastric cancer cell lines and tumor specimens to identify biomarkers for anti-HER therapies-the role of HAS2, SHB and HBEGF

Background

The standard treatment for patients with advanced HER2-positive gastric cancer is a combination of the antibody trastuzumab and platin-fluoropyrimidine chemotherapy. As some patients do not respond to trastuzumab therapy or develop resistance during treatment, the search for alternative treatment options and biomarkers to predict therapy response is the focus of research. We compared the efficacy of trastuzumab and other HER-targeting drugs such as cetuximab and afatinib. We also hypothesized that treatment-dependent regulation of a gene indicates its importance in response and that it can therefore be used as a biomarker for patient stratification.

Methods

A selection of gastric cancer cell lines (Hs746T, MKN1, MKN7 and NCI-N87) was treated with EGF, cetuximab, trastuzumab or afatinib for a period of 4 or 24 h. The effects of treatment on gene expression were measured by RNA sequencing and the resulting biomarker candidates were tested in an available cohort of gastric cancer patients from the VARIANZ trial or functionally analyzed in vitro.

Results

After treatment of the cell lines with afatinib, the highest number of regulated genes was observed, followed by cetuximab and trastuzumab. Although trastuzumab showed only relatively small effects on gene expression, BMF, HAS2 and SHB could be identified as candidate biomarkers for response to trastuzumab. Subsequent studies confirmed HAS2 and SHB as potential predictive markers for response to trastuzumab therapy in clinical samples from the VARIANZ trial. AREG, EREG and HBEGF were identified as candidate biomarkers for treatment with afatinib and cetuximab. Functional analysis confirmed that HBEGF is a resistance factor for cetuximab.

Conclusion

By confirming HAS2, SHB and HBEGF as biomarkers for anti-HER therapies, we provide evidence that the regulation of gene expression after treatment can be used for biomarker discovery.

Trial registration.

Clinical specimens of the VARIANZ study (NCT02305043) were used to test biomarker candidates.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09335-4.

Expression of Neighbor of Punc E11 (NOPE) in early stage esophageal adenocarcinoma is associated with reduced survival

Current recommendations suggest neoadjuvant treatment in node-positive esophageal cancer or tumors staged T3 and upwards but some T2 N0 patients might benefit from neoadjuvant therapy. It is of clinical relevance to identify this subgroup. Loss of epithelial apicobasal polarity is a key factor in the development of invasive capabilities of carcinoma. The oncofetal stem/progenitor cell marker NOPE is expressed in adult depolarized murine hepatocytes and in murine/human hepatocellular carcinoma. We analyzed NOPE expression in 363 patients with esophageal adenocarcinoma using an RNA Scope Assay on a tissue microarray and correlated results with clinical data. Median follow-up was 57.7 months with a 5-year survival rate of 26.6%. NOPE was detectable in 32 patients (8.8%). In pT1/2 stages, NOPE expression was associated with a significantly reduced median OS of 6.3 months (95% CI 1.2-19.4 months), the median OS is not reached in the NOPE-negative group (calculated mean OS 117.1 months) (P = 0.012). In advanced tumor stages, a NOPE dependent survival difference was not detected. This is the first report of NOPE expression demonstrating a prognostic value in esophageal cancer. Early stage, NOPE positive patients are at a high risk of tumor progression and may benefit from neoadjuvant treatment analogous to advanced stage cancer.

Proteomic Identification of a Gastric Tumor ECM Signature Associated With Cancer Progression

The extracellular matrix (ECM) plays an undisputable role in tissue homeostasis and its deregulation leads to altered mechanical and biochemical cues that impact cancer development and progression. Herein, we undertook a novel approach to address the role of gastric ECM in tumorigenesis, which remained largely unexplored. By combining decellularization techniques with a high-throughput quantitative proteomics approach, we have performed an extensive characterization of human gastric mucosa, uncovering its composition and distribution among tumor, normal adjacent and normal distant mucosa. Our results revealed a common ECM signature composed of 142 proteins and indicated that gastric carcinogenesis encompasses ECM remodeling through alterations in the abundance of 24 components, mainly basement membrane proteins. Indeed, we could only identify one de novo tumor-specific protein, the collagen alpha-1(X) chain (COL10A1). Functional analysis of the data demonstrated that gastric ECM remodeling favors tumor progression by activating ECM receptors and cellular processes involved in angiogenesis and cell-extrinsic metabolic regulation. By analyzing mRNA expression in an independent GC cohort available at the TGCA, we validated the expression profile of 12 differentially expressed ECM proteins. Importantly, the expression of COL1A2, LOX and LTBP2 significantly correlated with high tumor stage, with LOX and LTBP2 further impacting patient overall survival. These findings contribute for a better understanding of GC biology and highlight the role of core ECM components in gastric carcinogenesis and their clinical relevance as biomarkers of disease prognosis.

Clinical utility and applicability of circulating tumor DNA testing in esophageal cancer: a systematic review and meta-analysis

Esophageal cancer is an aggressive malignancy with a relatively poor prognosis even after multimodality therapy. Currently, patients undergo a series of investigations that can be invasive and costly or pose secondary risks to their health. In other malignancies, liquid biopsies of circulating tumor DNA (ctDNA) are used in clinical practice for diagnostic and surveillance purposes. This systematic review summarizes the latest evidence for the clinical applicability of ctDNA technology in esophageal cancer. A systematic review of the literature was performed using MEDLINE, EMBASE, the Cochrane Review and Scopus databases. Articles were evaluated for the use of ctDNA for diagnosis and monitoring of patients with esophageal cancer. Quality assessment of studies was performed using the QUADAS-2 tool. A meta-analysis was performed to assess the diagnostic accuracy of sequencing methodologies. We included 15 studies that described the use of ctDNA technology in the qualitative synthesis and eight studies involving 414 patients in the quantitative analysis. Of these, four studies assessed its utility in cancer diagnosis, while four studies evaluated its use for prognosis and monitoring. The pooled sensitivity and specificity for diagnostic studies were 71.0% (55.7-82.6%) and 98.6% (33.9-99.9%), while the pooled sensitivity and specificity for surveillance purposes were 48.9% (29.4-68.8%) and 95.5% (90.6-97.9%). ctDNA technology is an acceptable method for diagnosis and monitoring with a moderate sensitivity and high specificity that is enhanced in combination with current imaging methods. Further work should demonstrate the practical integration of ctDNA in the diagnostic and surveillance clinical pathway.

NF-Y subunits overexpression in gastric adenocarcinomas (STAD)

NF-Y is a pioneer transcription factor-TF-formed by the Histone-like NF-YB/NF-YC subunits and the regulatory NF-YA. It binds to the CCAAT box, an element enriched in promoters of genes overexpressed in many types of cancer. NF-YA is present in two major isoforms-NF-YAs and NF-YAl-due to alternative splicing, overexpressed in epithelial tumors. Here we analyzed NF-Y expression in stomach adenocarcinomas (STAD). We completed the partitioning of all TCGA tumor samples (450) according to molecular subtypes proposed by TCGA and ACRG, using the deep learning tool DeepCC. We analyzed differentially expressed genes-DEG-for enriched pathways and TFs binding sites in promoters. CCAAT is the predominant element only in the core group of genes upregulated in all subtypes, with cell-cycle gene signatures. NF-Y subunits are overexpressed, particularly NF-YA. NF-YAs is predominant in CIN, MSI and EBV TCGA subtypes, NF-YAl is higher in GS and in the ACRG EMT subtypes. Moreover, NF-YAlhigh tumors correlate with a discrete Claudinlow cohort. Elevated NF-YB levels are protective in MSS;TP53+ patients, whereas high NF-YAl/NF-YAs ratios correlate with worse prognosis. We conclude that NF-Y isoforms are associated to clinically relevant features of gastric cancer.

DNA methylation markers in esophageal cancer: an emerging tool for cancer surveillance and treatment

Esophageal carcinoma (EC) is one of the most pervasive cancers in the world, with upwards of 500,000 new diagnoses, annually. Despite its prominence, advancements in the detection and treatment of EC have been marginal over the past 30 years and the survival rate continues to stay below 20%. This is due to the uncommonly heterogeneous presentation of EC which presents unprecedented challenges in improving patient survival and quality of care. However, distinct epigenetic alterations to the DNA methylome may provide an avenue to drastically improve the detection and treatment of EC. Specifically, the creation of novel biomarker panels that consist of EC-specific methylation markers have shown promise as a potential alternative to the more invasive, contemporary diagnostic methods. Additionally, growing insight into the biological and clinical properties of EC-specific methylation patterns have opened a window of opportunity for enhanced treatment; of growing interest is the application of "DNMT inhibitors" - a class of drugs which inhibit excessive methylation and have been shown to re-sensitize chemoresistant tumors. Here we provide a comprehensive review of the current advancements in EC DNA methylation to underscore a potential approach to its detection and treatment.

Diagnostic Performance of Artificial Intelligence-Centred Systems in the Diagnosis and Postoperative Surveillance of Upper Gastrointestinal Malignancies Using Computed Tomography Imaging: A Systematic Review and Meta-Analysis of Diagnostic Accuracy

Background

Upper gastrointestinal cancers are aggressive malignancies with poor prognosis, even following multimodality therapy. As such, they require timely and accurate diagnostic and surveillance strategies; however, such radiological workflows necessitate considerable expertise and resource to maintain. In order to lessen the workload upon already stretched health systems, there has been increasing focus on the development and use of artificial intelligence (AI)-centred diagnostic systems. This systematic review summarizes the clinical applicability and diagnostic performance of AI-centred systems in the diagnosis and surveillance of esophagogastric cancers.

Methods

A systematic review was performed using the MEDLINE, EMBASE, Cochrane Review, and Scopus databases. Articles on the use of AI and radiomics for the diagnosis and surveillance of patients with esophageal cancer were evaluated, and quality assessment of studies was performed using the QUADAS-2 tool. A meta-analysis was performed to assess the diagnostic accuracy of sequencing methodologies.

Results

Thirty-six studies that described the use of AI were included in the qualitative synthesis and six studies involving 1352 patients were included in the quantitative analysis. Of these six studies, four studies assessed the utility of AI in gastric cancer diagnosis, one study assessed its utility for diagnosing esophageal cancer, and one study assessed its utility for surveillance. The pooled sensitivity and specificity were 73.4% (64.6–80.7) and 89.7% (82.7–94.1), respectively.

Conclusions

AI systems have shown promise in diagnosing and monitoring esophageal and gastric cancer, particularly when combined with existing diagnostic methods. Further work is needed to further develop systems of greater accuracy and greater consideration of the clinical workflows that they aim to integrate within.

Precision diagnostics: Integration of tissue pathology and genomics in cancer

Traditionally, cancer diagnosis and management has been reactionary in that symptoms lead to investigations, then a diagnosis is followed by clinical management. This process is heavily dependent on tissue diagnosis mainly by histopathology and to a lesser extent, cytopathology. However, in recent times there has been a shift towards precision medicine to enable prevention, prediction and personalisation in healthcare. The core of precision medicine is optimising therapeutic benefit for patients, by using genomic and molecular profiling, analogously termed precision pathology. This review explores (1) the evolution of pathology from a para-clinical discipline to a mainstream medical field integral to oncology tumour boards; (2) its critical role in preventative, diagnostic, therapeutic and follow-up cancer care; (3) the future of tissue pathology in the era of precision oncology; and (4) how pathologists may evolve to future-proof their profession.

Real-world association of HER2/ERBB2 concordance with trastuzumab clinical benefit in advanced esophagogastric cancer

Aim: To assess concordance between HER2 status measured by traditional methods and ERBB2 amplification measured by next-generation sequencing and its association with first-line trastuzumab clinical benefit in patients with advanced esophagogastric cancer. Methods: Retrospective analysis of HER2/ERBB2 concordance using a deidentified USA-based clinicogenomic database. Clinical outcomes were assessed for patients with HER2⁺ advanced esophagogastric cancer who received first-line trastuzumab. Results: Overall HER2/ERBB2 concordance was 87.5%. Among patients who received first-line trastuzumab, concordant HER2/ERBB2 was associated with longer time to treatment discontinuation (adjusted hazard ratio [aHR]: 0.63; 95% CI: 0.43-0.90) and overall survival (aHR: 0.51; 95% CI: 0.33-0.79). ERBB2 copy number ≥25 (median) was associated with longer time to treatment discontinuation (aHR: 0.56; 95% CI: 0.35-0.88) and overall survival (aHR: 0.52; 95% CI: 0.30-0.91). Conclusion: HER2/ERBB2 concordance and higher ERBB2 copy number predicted clinical benefit from trastuzumab.

Genetically engineered mouse models of esophageal cancer

BACKGROUND

Esophageal cancer is the most common cause of cancer-related death worldwide with a diverse geographical distribution, poor prognosis, and diagnosis in advanced stages of the disease. Identification of the mechanisms involved in esophageal cancer development is evaluative to improve outcomes for patients. Genetically engineered mouse models (GEMMs) of cancer provide the physiologic, molecular, and histologic features of the human tumors to determine the pathogenesis and treatments for cancer, hence exhibiting a source of tremendous potential for oncology research. The advancement of cancer modeling in mice has improved to the extent that researchers can observe and manipulate the disease process in a specific manner. Despite the significant differences between mice and humans, mice can be great models for human oncology researches due to similarities between them at the molecular and physiological levels. Due to most of the existing esophageal cancer GEMMs do not propose an ideal system for pathogenesis of the disease, genetic risks, and microenvironment exposure, so identification of challenges in GEM modeling and well-developed technologies are required to obtain the most value for patients. In this review, we describe the biology of human and mouse, followed by the exciting esophageal cancer mouse models with a discussion of applicability and challenges of these models for generating new GEMMs in future studies.

Metabolic and Immunological Subtypes of Esophageal Cancer Reveal Potential Therapeutic Opportunities

BACKGROUND

Esophageal cancer has the sixth highest rate of cancer-associated deaths worldwide, with many patients displaying metastases and chemotherapy resistance. We sought to find subtypes to see if precision medicine could play a role in finding new potential targets and predicting responses to therapy. Since metabolism not only drives cancers but also serves as a readout, metabolism was examined as a key reporter for differences.

METHODS

Unsupervised and supervised classification methods, including hierarchical clustering, partial least squares discriminant analysis, k-nearest neighbors, and machine learning techniques, were used to discover and display two major subgroups. Genes, pathways, gene ontologies, survival, and immune differences between the groups were further examined, along with biomarkers between the groups and against normal tissue.

RESULTS

Esophageal cancer had two major unique metabolic profiles observed between the histological subtypes esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC). The metabolic differences suggest that ESCC depends on glycolysis, whereas EAC relies more on oxidative metabolism, catabolism of glycolipids, the tricarboxylic acid (TCA) cycle, and the electron transport chain. We also noted a robust prognostic risk associated with COQ3 expression. In addition to the metabolic alterations, we noted significant alterations in key pathways regulating immunity, including alterations in cytokines and predicted immune infiltration. ESCC appears to have increased signature associated with dendritic cells, Th17, and CD8 T cells, the latter of which correlate with survival in ESCC. We bioinformatically observed that ESCC may be more responsive to checkpoint inhibitor therapy than EAC and postulate targets to enhance therapy further. Lastly, we highlight correlations between differentially expressed enzymes and the potential immune status.

CONCLUSION

Overall, these results highlight the extreme differences observed between the histological subtypes and may lead to novel biomarkers, therapeutic strategies, and differences in therapeutic response for targeting each esophageal cancer subtype.

MSI Analysis in Solid and Liquid Biopsies of Gastroesophageal Adenocarcinoma Patients: A Molecular Approach

Gastroesophageal adenocarcinoma (GEA) patients with the microsatellite instability (MSI) subtype emerged as optimal candidates for immunotherapy. To date, immunohistochemistry (IHC) is the gold standard for MSI assessment in formalin-fixed paraffin-embedded (FFPE) specimens. However, IHC, although useful for diagnostic typing, cannot be used to analyze cell-free DNA (cfDNA) in liquid biopsy, a tool that could overcome tumor heterogeneity and enable longitudinal monitoring. In order to find an alternative diagnostic method to IHC, we analyzed 86 retrospective GEAs FFPE samples with multiplex PCR. Moreover, to verify the feasibility of MSI detection in liquid biopsy, cfDNA samples of five patients that resulted in having MSI in a prospective cohort of 35 patients were evaluated by multiplex PCR, real-time PCR and droplet digital PCR (ddPCR). Analysis of FFPE showed 100% concordance between multiplex PCR and IHC (Cohen’s Kappa agreement = 1). On the contrary, only ddPCR was able to detect MSI in cfDNAs of T3/T4 GEA patients. In conclusion, data highlight the molecular analysis as an optimal alternative to IHC for the diagnostic typing and suggest that the ddPCR assay can be considered as the most reliable and promising molecular approach to detect MSI in the cfDNA of GEA patients.

Monoclonal Antibodies, Small Molecule Inhibitors and Antibody-drug Conjugates as HER2 Inhibitors

Overexpression of human epidermal growth factor receptor (HER)-2 is found in a variety of cancers, often portending poor clinical outcomes. Therefore, HER2 is an attractive target for treatment. This review describes the research progress of HER2 targeted inhibitors in recent years. Excellent reviews are available, so we focus on the development, mechanisms of action, and structure-activity relationships of different types of inhibitors, including monoclonal antibodies, small molecule inhibitors, and antibody-drug conjugates (ADCs). In addition, the differences among them are compared.

Tumor Epigenetic Signature and Survival in Resected Gastric Cancer Patients

BACKGROUND

Precision oncology can identify patient-specific molecular signatures to better inform the prognosis and management of surgical cancer patients. Specifically, microRNAs (miRs) hold promise as prognostic biomarkers because dysregulation of individual miRs is implicated in tumorigenesis, progression, and metastases of various malignancies, including gastric adenocarcinoma (GC).

STUDY DESIGN

To identify miRs prognostic of survival after radical gastrectomy, we studied GC patients within The Cancer Genome Atlas (TCGA) who had undergone R0 or R1 resection and had data on clinical characteristics, overall survival (OS), and tumor miR expression. The miRs expressed by at least 15% of tumors were eligible for study. From 10 replicate samples, each with 80% of patients, miRs were selected using age-adjusted proportional hazards regression with stepwise selection. Cross-validated miRs (selected by multiple replicates) were retained if they optimized an accelerated failure-time model of OS using all patients.

RESULTS

In this GC cohort (n = 270), half (916/1,870) of miRs screened met our criteria for evaluation. Cross-validation identified 20 miRs as prognostic, of which 14 (miR-129-1, miR-373, miR-490, miR-597, miR-1185-2, miR-3943, miR-4756, miR-5683, miR-6510, miR-6733, miR-6808, miR-6855, miR-6882, miR-8072) were independently informative. The age-adjusted 14-miRNA panel remained significantly associated with OS after adjustment for pathologic prognostic factors (number of lymph nodes examined, number of positive lymph nodes) and other clinical covariates (TNM stage, residual tumor, tumor microsatellite instability, targeted molecular therapy, sex, race, ethnicity). Panel-predicted survival estimates below the upper tertile cut-off were associated with worse outcome (30% vs 74% OS at 3 years, p < 0.0001).

CONCLUSIONS

In surgically resected GC patients, an epigenetic signature of miRs associated with survival has the potential to improve prognostication.

Incidence, Survival and Prognostic Factors of Oesophagogastric Cancer

INTRODUCTION

Oesophagogastric cancer is one of the leading causes of cancer death worldwide due to its aggressive nature. Despite the high mortality rate, there is limited information regarding this cancer in Brunei.

AIM

To estimate the incidence and survival duration of oesophagogastric cancer patients, to identify prognostic factors of oesophagogastric cancer and associated factors for late-stage oesophagogastric cancer detection.

METHODS

A retrospective study on all oesophagogastric cancer patients registered in the population-based national cancer registry in Brunei from January 2010 to December 2018. Kaplan-Meier and Cox proportional hazard regression survival analyses and multiple logistic regression were applied.

RESULTS

Sixty-eight oesophagogastric cancer patients' data were retrieved from the registry. The incidence was 2.75 cases per 100,000 adults per year. Median survival time was 1.18 years (95% CI: 0.77, 1.80) and the 3-year survival rate was 26.3%. Age (61-70 years) (adjusted HR = 0.38; 95% CI: 0.17, 0.89; p = 0.025) and those who have undergone chemotherapy (adj. HR = 0.40; 95% CI: 0.18, 0.90; p = 0.026) have a significantly lower mortality risk. Obesity (adj. HR = 11.94; 95% CI: 1.94, 73.36; p = 0.007), and stage 4 (advanced stage) cancer (adj. HR=4.11; 95% CI: 1.97, 8.58; p< 0.001) have a significantly higher mortality risk. Females have 3-time odds (adj. OR = 3.05; 95% CI: 1.09, 9.02; p = 0.038) of presenting with stage 4 cancer. Smokers have 13-time odds (Adj. OR=12.99; 95% CI: 1.92, 262.0; p = 0.025) of presenting with stage 4 cancer.

CONCLUSION

Prognosis of oesophagogastric cancer remains poor. Addressing late detection and improve endoscopic surveillance and awareness of symptoms may help improve prognosis and mortality.

Mutational Characterization and Potential Prognostic Biomarkers of Chinese Patients with Esophageal Squamous Cell Carcinoma

Purpose

Esophageal squamous cell carcinoma (ESCC) is the most common type of esophageal cancer in China and the 5-year mortality rate is up to 70%. Studies on the ESCC genetic landscape are needed to further explore clinical therapeutic strategies. In this study, we evaluated the genetic landscape of ESCC to aid the search for clinical therapeutic strategies.

Patients and Methods

A total of 225 ESCC patients were enrolled in this study. Deep sequencing of 450 cancer genes was performed on formalin-fixed paraffin-embedded tumor biopsies and matched blood samples from patients. Tumor mutational burden (TMB) was calculated using an algorithm developed in-house.

Results

Our results showed that the most commonly mutated genes in ESCC were TP53 (96%), CCND1 (46%), FGF4 (44%), FGF19 (44%), FGF3 (44%), CDKN2A (31%), PIK3CA (26%), NOTCH1 (24%), KMT2D (18%), FAT1 (16%), and LRP1B (16%). We found that TMB correlated with patient drinking status. We identified mutations associated with sex, early ESCC, high TMB, and metastasis lymph nodes. KMT2D mutations associated with sex (P = 0.035), tumor stage (P = 0.016), high TMB (P = 0.0072), and overall survival of patients (P = 0.0026). SPEN mutations associated with high TMB (P = 0.0016) and metastasis-positive lymph nodes (P = 0.027). These results suggested that SPEN and KMT2D could be potential prognosis biomarkers for Chinese patients with ESCC. We also found that the number of positive lymph nodes was associated with disease-free survival. Clinical target gene analysis indicated that nearly half of Chinese ESCC patients might benefit from treatment with gene-specific target drugs.

Conclusion

Our study revealed the ESCC mutational landscape in 225 Chinese patients and uncovered the potential prognosis biomarker for Chinese patients with ESCC.

Viruses and esophageal cancer

Esophageal adenocarcinoma (EAC) has had the fastest increasing incidence of any solid tumor in the United States in the last 30 years. Long standing gastroesophageal reflux disease is a well-established risk factor with strong associations with obesity, alcohol and tobacco. However, there are likely additional contributing factors. Viruses such as human papillomavirus, ebstein-barr virus and herpes simplex virus have been implicated in the pathogenesis of esophageal cancer. This review will discuss the known literature linking viruses to esophageal adenocarcinoma and consider future relationships such as identifying prognostic and predictive molecular biomarkers to guide therapies.

Transcriptomic biomarkers for predicting response to neoadjuvant treatment in oesophageal cancer

Oesophageal cancer is a devastating disease with poor outcomes and is the sixth leading cause of cancer death worldwide. In the setting of resectable disease, there is clear evidence that neoadjuvant chemotherapy and chemoradiotherapy result in improved survival. Disappointingly, only 15%-30% of patients obtain a histopathological response to neoadjuvant therapy, often at the expense of significant toxicity. There are no predictive biomarkers in routine clinical use in this setting and the ability to stratify patients for treatment could dramatically improve outcomes. In this review, we aim to outline current progress in evaluating predictive transcriptomic biomarkers for neoadjuvant therapy in oesophageal cancer and discuss the challenges facing biomarker development in this setting. We place these issues in the wider context of recommendations for biomarker development and reporting. The majority of studies focus on messenger RNA (mRNA) and microRNA (miRNA) biomarkers. These studies report a range of different genes involved in a wide variety of pathways and biological processes, and this is explained to a large extent by the different platforms and analysis methods used. Many studies are also vastly underpowered so are not suitable for identifying a candidate biomarker. Multiple molecular subtypes of oesophageal cancer have been proposed, although little is known about how these relate to clinical outcomes. We anticipate that the accumulating wealth of genomic and transcriptomic data and clinical trial collaborations in the coming years will provide unique opportunities to stratify patients in this poor-prognosis disease and recommend that future biomarker development incorporates well-designed retrospective and prospective analyses.

Circ_0110805 Knockdown Enhances Cisplatin Sensitivity and Inhibits Gastric Cancer Progression by miR-299-3p/ENDOPDI Axis

Background

Gastric cancer is a prevalent primary stomach tumor. Cisplatin is frequently used to treat gastric cancer. However, the resistance of cisplatin in gastric cancer often occurs, which brings a heavy burden to gastric cancer treatment.

Methods

In this study, we revealed a novel underlying mechanism about cisplatin-resistant effect in gastric cancer. A Cell Counting Kit-8 (CCK-8) cell viability assay and a xenograft model were performed to evaluate the function of circRNA in the cisplatin resistance of gastric cancer.

Results

Compared with control groups, we observed that circ_0110805 was highly expressed, the mRNA and protein expression levels of ENDOPDI were dramatically upregulated, and the expression of miR-299-3p was significantly downregulated in gastric cancer cells, cisplatin-resistant gastric cancer tissues or cells. Functionally, circ_0110805 knockdown improved cisplatin sensitivity, induced cell apoptosis, whereas repressed cell viability, migration and invasion in AGS/DDP and HGC-27/DDP cells, which was reversed by miR-299-3p inhibitor. Additionally, ENDOPDI overexpression hindered the effects of miR-299-3p on cisplatin sensitivity and gastric cancer progression. Circ_0110805 knockdown enhanced cisplatin sensitivity in vivo. Mechanistically, circ_0110805 acted as a sponge of miR-299-3p and its targeted ENDOPDI.

Conclusion

We showed that circ_0110805 knockdown increased the sensitivity of gastric cancer to cisplatin, which also repressed gastric cancer progression by sponging miR-299-3p to downregulate ENDOPDI expression. It might provide a new insight for future studying cisplatin-resistant gastric cancer.

Mismatch Repair System Genomic Scars in Gastroesophageal Cancers: Biology and Clinical Testing

Alterations in the mismatch repair (MMR) system result in genomic instability, neoantigen production, and immune response in cancer. There is evidence that gastroesophageal tumors with MMR deficiency may be susceptible to immune-checkpoint inhibitors treatment, especially in those presenting at advanced-stage disease. Although a number of biomarkers have been developed in histology-agnostic settings to assess MMR status, there is evidence that a tumor-specific testing approach would improve the selection of patients for immunotherapy. However, no testing methods have been developed specifically for gastroesophageal cancers so far. Here, we discuss the state of the art, current advances, and future perspectives of MMR-related biomarkers’ biologic and clinical role in gastroesophageal cancers.

Definitive chemoradiotherapy plus cetuximab for cancer in the oesophagus or gastro-oesophageal junction

BACKGROUND

Chemoradiotherapy is standard treatment for localized oesophageal cancer unsuitable for surgery. We aimed to evaluate the efficacy of cetuximab in combination with chemoradiotherapy.

METHODS

This non-randomised multicentre phase II trial recruited patients aged 18-75 with WHO performance status 0-2 having squamous cell carcinoma or adenocarcinoma in the oesophagus or gastro-oesophageal junction, T2-4, N0-3, M0 not suitable for surgery. Chemotherapy was three 21-day cycles of fluorouracil 750 mg/m2 D1-5 and oxaliplatin D1 (cycle 1:130mg/m 2, cycle 2-3:85 mg/m 2). Radiotherapy was 50Gy in 2Gy/fraction, 5 days a week, concurrent with cycle 2 and 3 and weekly cetuximab. The primary objective was loco-regional control at one year.

RESULTS

52 patients were included. 51 were eligible for toxicity and survival analysis and 46 for recurrence analysis. Full radiotherapy dose was delivered to 80%, 75% received all three cycles of chemotherapy and 75% received four or more doses of cetuximab. The most common related grade III-IV adverse events were gastro-intestinal(16), hypersensitivity(6) and infection(5). There were two drug-related deaths. Within six months from the end of treatment, six patients died from complications from fistulas. The loco-regional control rate at one year was 47.3%(95%CI 30.9%-62.1%). Overall survival at three years was 29.1%(95% CI 17.4-41.9%).

CONCLUSIONS

Oxaliplatin and fluorouracil given concurrent with radiotherapy and cetuximab had an acceptable safety profile and showed a clinical response in patients with locoregionally advanced oesophageal cancer unsuitable for surgery. However, the primary end-point was not met, and the addition of cetuximab to definitive chemoradiotherapy cannot be recommended.

High plasma levels of COL10A1 are associated with advanced tumor stage in gastric cancer patients

BACKGROUND

Gastric cancer (GC) remains an aggressive malignancy with a high rate of mortality, being the third leading cause of cancer-related death. More than one million newly diagnosed cases and 782685 deaths due to GC were reported in 2018. GC is characterized by limited effective treatment options and the lack of consistent biomarkers for the diagnosis and prognosis of these patients. The discovery of new biomarkers useful in the early diagnosis of GC is mandatory.

AIM

To evaluate the potential of COL10A1 as a circulating biomarker for the diagnosis and prognosis of gastric adenocarcinoma patients.

METHODS

Plasma and tissue obtained from 49 patients with gastric adenocarcinoma have been used in exploring the expression of COL10A1. Real-time PCR and western blot techniques were used to evaluate COL10A1 level in gastric tumor tissue compared to normal adjacent tissue. The circulating level of COL10A1 was also evaluated by ELISA in plasma of gastric adenocarcinoma patients. Survival analysis was made in order to evaluate the potential of COL10A1 as a biomarker for the diagnosis and prognosis of gastric adenocarcinoma patients.

RESULTS

Our results showed a significant increase in COL10A1 gene expression and protein levels in gastric tumor tissue compared to adjacent normal tissue (P < 0.05). COL10A1 seems to show an elevated expression from the beginning of carcinogenesis, in the early stages, and its increased level remains elevated during cancer progression. A significant increase of COL10A1 plasma level in gastric adenocarcinoma patients was also identified. Moreover, increased COL10A1 plasma level was associated with poor survival of the patients. Plasma COL10A1 performed a diagnostic value in GC with area under the receiver operating characteristic curve (AUC) of 0.9171 (P = 0.0002), sensitivity of 87.76%, and specificity of 100.0%. Furthermore, this study demonstrated the potential role of plasma COL10A1 in the early detection of GC, as in the early stage, we obtained an AUC of 0.8789 (P = 0.0030), sensitivity of 81.25%, and specificity of 100.0%.

CONCLUSION

Circulating expression level of COL10A1 is significantly increased in gastric adenocarcinoma patients being associated with poor survival and is a potential biomarker for early detection of GC.

Quantitative Analysis of Differential Expression of HOX Genes in Multiple Cancers

Transcription factors encoded by Homeobox (HOX) genes play numerous key functions during early embryonic development and differentiation. Multiple reports have shown that mis-regulation of HOX gene expression plays key roles in the development of cancers. Their expression levels in cancers tend to differ based on tissue and tumor type. Here, we performed a comprehensive analysis comparing HOX gene expression in different cancer types, obtained from The Cancer Genome Atlas (TCGA), with matched healthy tissues, obtained from Genotype-Tissue Expression (GTEx). We identified and quantified differential expression patterns that confirmed previously identified expression changes and highlighted new differential expression signatures. We discovered differential expression patterns that are in line with patient survival data. This comprehensive and quantitative analysis provides a global picture of HOX genes' differential expression patterns in different cancer types.

Overcoming resistance to anti-PD1 and anti-PD-L1 treatment in gastrointestinal malignancies

In the last few years, the unprecedented results of immune checkpoint inhibitors have led to a paradigm shift in clinical practice for the treatment of several cancer types. However, the vast majority of patients with gastrointestinal cancer do not benefit from immunotherapy. To date, microsatellite instability high and DNA mismatch repair deficiency are the only robust predictive biomarkers of response to immune checkpoint inhibitors. Unfortunately, these patients comprise only 5%-10% of all gastrointestinal cancers. Several mechanisms of both innate and adaptive resistance to immunotherapy have been recognized that may be at least in part responsible for the failure of immune checkpoint inhibitors in this population of patients. In the first part of this review article, we provide an overview of the main clinical trials with immune checkpoint inhibitors in patients with gastrointestinal cancer and the role of predictive biomarkers. In the second part, we discuss the actual body of knowledge in terms of mechanisms of resistance to immunotherapy and the most promising approach that are currently under investigation in order to expand the population of patients with gastrointestinal cancer who could benefit from immune checkpoint inhibitors.

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.

HER2 Heterogeneity in Personalized Therapy of Gastro-Oesophageal Malignancies: An Overview by Different Methodologies

Human epidermal growth factor receptor-2 (HER2)-expression gastro-oesophageal adenocarcinomas (GEA) gained interest as an important target for therapy with trastuzumab. In the current review, we focused the current knowledge on HER2 status in dysplastic and neoplastic gastric conditions, analyzing the methodological procedures to identify HER2 expression/amplification, as well as the proposed scoring recommendations. One of the most relevant questions to evaluate the useful impact of HER2 status on therapeutic choice in GEAs is represented by the significant heterogeneity of HER2 protein and gene expression that may affect the targeted treatment selection. Future development of biotechnology will continue to evolve in order to offer more powerful detection systems for the assessment of HER2 status. Finally, liquid biopsy as well as mutation/amplification of several additional genes may furnish an early detection of secondary HER2 resistance mechanisms in GEAs with a better monitoring of the treatment response.

Circulating lncRNA SNHG11 as a novel biomarker for early diagnosis and prognosis of colorectal cancer

Colorectal cancer (CRC) is the third most common cancer and the second leading cause of cancer mortality worldwide. Emerging evidence indicates that tumour cells release substantial amounts of RNA into the bloodstream, in which RNA strongly resists RNases and is present at sufficient levels for quantitative analyses. Our study aimed to discover blood-based markers for the early detection of CRC and to ascertain their efficiency in discriminating healthy controls, patients with polyps and adenomas and cancer patients. We first analysed and screened ZFAS1, SNHG11, LINC00909 and LINC00654 in a bioinformatics database and then collected clinical plasma samples for preliminary small-scale analysis and further large-scale verification. We then explored the mechanism of dominant lncRNA SNHG11 expression in CRC by in vitro and in vivo assays. The combination of ZFAS1, SNHG11, LINC00909 and LINC00654 showed high diagnostic performance for CRC (AUC: 0.937), especially early-stage disease (AUC: 0.935). Plasma levels of the four candidate lncRNAs were significantly reduced in postoperative samples compared to preoperative samples. A panel including these four lncRNAs performed well in distinguishing patient groups with different stages of colon disease, and SNHG11 exhibited the greatest diagnostic ability to identify precancerous lesions and early-stage tumour formation. Mechanistically, high SNHG11 expression promotes proliferation and metastasis by targeting the Hippo pathway. Taken together, the data indicate that SNHG11 may be a novel therapeutic target for the treatment of CRC and a potential biomarker for the early detection of CRC.

MALAT1 promotes gastric adenocarcinoma through the MALAT1/miR-181a-5p/AKT3 axis

Gastric adenocarcinoma, which originates from the gastric mucosal epithelium, has the highest incidence among various malignant tumours in China. As a crucial long non-coding RNA, metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been suggested to play an important role in many tumours. Here, we aimed to investigate the role and underlying mechanism of MALAT1 in gastric adenocarcinoma. Quantitative reverse transcription polymerase chain reaction was applied to determine the expression levels of MALAT1 in serum and cell lines. A CCK-8 assay and a clonogenic survival assay were used to examine cell proliferation and apoptosis. The protein level of RAC-γ serine/threonine-specific protein kinase (AKT3) was determined by western blot. Our results showed that MALAT1 was highly expressed in the serum of patients with gastric adenocarcinoma and in cell lines. Downregulating MALAT1 inhibited proliferation and promoted apoptosis of MGC-803 cells. In addition, MALAT1 directly targeted and decreased the expression of miR-181a-5p, which in turn upregulated the expression of AKT3. Further, overexpressing miR-181a-5p or directly inhibiting the AKT pathway with the inhibitor ipatasertib exhibited similar effects to MALAT1 knockdown. Our research proposes a novel mechanism where the role of MALAT1 is dependent on the MALAT1/miR-181a-5p/AKT3 axis. MALAT1 competes with AKT3 for miR-181a-5p binding, thereby upregulating the AKT3 protein level and ultimately promoting the growth of gastric adenocarcinoma.

Down-regulation of lncRNA XIST inhibits cell proliferation via regulating miR-744/RING1 axis in non-small cell lung cancer

Long non-coding RNAs (lncRNAs) are known to be potential factors in promoting tumor progression. However, the function and mechanism of lncRNA XIST in non-small cell lung cancer (NSCLC) remains poorly understood. The expression levels of lncRNA XIST in NSCLC tissues and cell lines were detected with real-time PCR, and the correlation of the expression level of XIST with histopathological characteristics and prognosis was analyzed. The biological function of lncRNA XIST was validated through assays in vivo and in vitro. The expression of lncRNA XIST was significantly up-regulated in NSCLC tissues. In addition, overexpression of XIST was positively correlated with the advanced clinical status of tumors, as well as poor overall survival and DFS. A tumor suppressive effect was presented via functional knockdown of lncRNA XIST. Up-regulation of XIST enhanced the proliferation, migration, and invasion ability of NSCLC cells both in vivo and in vitro. Mechanically, it was indicated that XIST could serve as an endogenous competitive RNA modulating miR-744, leading to the miR-744/RING1 signaling pathway inhibition and Wnt/β-catenin signaling pathway activation. Taken together, it was confirmed here that XIST overexpression is associated with tumor progression phenotype and the newly discovered XIST/miR-744/RING1 axis, which could serve as a potential biomarker and therapeutic target for NSCLC.

Towards precision medicine: advances in 5-hydroxymethylcytosine cancer biomarker discovery in liquid biopsy

Robust and clinically convenient biomarkers for cancer diagnosis, early detection, and prognosis have great potential to improve patient survival and are the key to precision medicine. The advent of next-generation sequencing technologies enables a more sensitive and comprehensive profiling of genetic and epigenetic information in tumor-derived materials. Researchers are now able to monitor the dynamics of tumorigenesis in new dimensions, such as using circulating cell-free DNA (cfDNA) and tumor DNA (ctDNA). Mutation-based assays in liquid biopsy cannot always provide consistent results across studies due partly to intra- and inter-tumoral heterogeneity as well as technical limitations. In contrast, epigenetic analysis of patient-derived cfDNA is a promising alternative, especially for early detection and disease surveillance, because epigenetic modifications are tissue-specific and reflect the dynamic process of cancer progression. Therefore, cfDNA-based epigenetic assays are emerging to be a highly sensitive, minimally invasive tool for cancer diagnosis and prognosis with great potential in future precise care of cancer patients. The major obstacle for applying epigenetic analysis of cfDNA, however, has been the lack of enabling techniques with high sensitivity and technical robustness. In this review, we summarized the advances in epigenome-wide profiling of 5-hydroxymethylcytosine (5hmC) in cfDNA, focusing on the detection approaches and potential role as biomarkers in different cancer types.

WISP2 exhibits its potential antitumor activity via targeting ERK and E-cadherin pathways in esophageal cancer cells

Backgrounds

Emerging evidence has demonstrated that WISP2 is critically involved in cell proliferation, migration, invasion and metastasis in cancers. However, the function of WISP2 in esophageal squamous cell carcinoma (ESCC) is largely unclear. Therefore, we aim to explore the effects and the potential mechanism of WISP2 on proliferation and motility and invasion of ESCC cells.

Methods

Cell proliferation was detected by MTT assay and apoptosis was measured by FACS in ESCC cells after WISP2 downregulation and overexpression. Cell migration and invasion were analyzed by wound healing assay and transwell migration assay, respectively. The expression of ERK-1/2, Slug and E-cadherin was measured by Western blot respectively. IHC was performed to measure the expression of WISP2 in ESCC tissues.

Results

WISP2 overexpression is associated with survival in ESCC patients. WISP2 overexpression inhibited cell growth and induced cell apoptosis, suppressed cell migration and invasion in ESCC cells. Moreover, WISP overexpression retarded tumor growth in mouse model. WISP2 downregulation enhanced cell growth, inhibited apoptosis, promoted cell migration and invasion in ESCC cells. Mechanistically, WISP2 exerts its tumor suppressive functions via regulation of ERK1/2, Slug, and E-cadherin in ESCC cells.

Conclusions

Our findings suggest that activation of WISP2 could be a useful therapeutic strategy for the treatment of ESCC.

Long noncoding RNA PXN-AS1-L promotes non-small cell lung cancer progression via regulating PXN

Background

Increasingly evidences suggest that long noncoding RNAs (lncRNAs) play important roles in various cancers. LncRNA PXN-AS1-L is recently revealed to act as on oncogene in liver cancer. However, the expression, functions, and mechanisms of action of PXN-AS-L in non-small cell lung cancer (NSCLC) remain unclear.

Methods

The expression of PXN-AS1-L in primary NSCLC tissues, NSCLC bone metastasis tissues, and cell lines was measured by quantitative real-time PCR. The correlations between PXN-AS1-L expression and clinicopathological characteristics of NSCLC patients were analyzed by Pearson Chi square test and log-rank test. The roles of PXN-AS1-L in cell viability, proliferation, apoptosis, and migration of NSCLC cells, and in vivo NSCLC tumor growth were investigated by a series of gain-of-function and loss-of-function assays. The regulatory roles of PXN-AS1-L on PXN were determined by quantitative real-time PCR and western blot.

Results

PXN-AS1-L was up-regulated in NSCLC tissues compared with noncancerous lung tissues, and PXN-AS1-L was further up-regulated in NSCLC bone metastasis tissues. Increased expression of PXN-AS1-L was positively associated with advanced TNM stages and poor prognosis. Gain-of-function and loss-of-function assays showed that PXN-AS1-L increased cell viability, promoted cell proliferation, inhibited cell apoptosis, and promoted cell migration of NSCLC cells. Xenograft assays showed that PXN-AS1-L also promoted NSCLC tumor growth in vivo. Mechanistically, we found that PXN-AS1-L, as an antisense transcript of PXN, up-regulated the expression of PXN. PXN was also up-regulated in NSCLC tissues. The expression of PXN and PXN-AS1-L was positively correlated in NSCLC tissues. Furthermore, PXN knockdown attenuated the roles of PXN-AS1-L in increasing cell viability, promoting cell proliferation, inhibiting cell apoptosis, and promoting cell migration of NSCLC cells.

Conclusions

Our data revealed that PXN-AS1-L is up-regulated and acts as an oncogene in NSCLC via up-regulating PXN. Our data suggested that PXN-AS1-L might serve as a potential prognostic biomarker and therapeutic target for NSCLC.