Distinctive microRNAs in esophageal tumor: early diagnosis, prognosis judgment, and tumor treatment

Pharmacoepigenetics and pharmacoepigenomics of gastrointestinal cancers

Our understanding of the epigenetic changes occurring in gastrointestinal cancers has gained tremendous advancements in recent years, and some epigenetic biomarkers are already translated into the clinics for cancer diagnostics. In parallel, pharmacoepigenetics and pharmacoepigenomics of solid tumors are relevant novel, but emerging and promising fields. Areas covered: A comprehensive review of the literature to summarize and update the emerging field of pharmacoepigenetics and pharmacoepigenomics of gastrointestinal cancers. Expert commentary: Several epigenetic modifications have been proposed to account for interindividual variations in drug response in gastrointestinal cancers. Similarly, single-agent or combined strategies with high doses of drugs that target epigenetic modifications (epi-drugs) were scarcely tolerated by the patients, and current research has moved to their combination with standard therapies to achieve chemosensitization, radiosensitization, and immune modulation of cancerous cells. In parallel, recent genome-wide technologies are revealing the pathways that are epigenetically deregulated during cancer-acquired resistance, including those targeted by non-coding RNAs. Indeed, novel, less toxic, and more specific molecules are under investigation to specifically target those pathways. The field is rapidly expanding and gathering together information coming from these investigations has the potential to lead to clinical applications in the coming new years.

Circulating miRNAs as novel potential biomarkers for esophageal squamous cell carcinoma diagnosis: a meta-analysis update

Early detection of esophageal squamous cell carcinoma (ESCC) is urgently needed to reduce the high morbidity and mortality of disease. Circulating microRNAs (miRNAs) are promising molecular biomarkers for ESCC prediction. We performed a comprehensive meta-analysis to systematically evaluate the diagnostic accuracy of circulating miRNAs in diagnosis of ESCC patients. Eligible studies were identified and assessed for quality employing multiple search strategies. Summary estimates for sensitivity, specificity, and other measures of accuracy of miRNAs in the diagnosis of ESCC were pooled using the bivariate random effects model. A total of 27 studies from 11 published articles were included in the meta-analysis. The overall sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio of circulating miRNAs for the diagnosis of ESCC were 79.9% (95% confidence intervals [CI]: 76.2%-83.1%), 81.3% (95% CI: 75.7-85.9), 4.27 (95%CI: 3.27-5.58), 0.25 (95% CI: 0.21-0.29), and 17.29 (95% CI: 12.01-24.86), respectively. The area under the summary receiver operating characteristic curve was 0.87 (95% CI: 0.84-0.90). The subgroup analyses based on research country (China vs. Japan), specimen type (plasma vs. serum), miRNAs profiling (single vs. multiple), and test method (screening vs. candidate; Taqman vs. SYBR) indicated no significant difference in the diagnostic accuracy of each subgroup. Collectively, our findings indicate that circulating miRNAs have significant potential to be used as noninvasive biomarkers for early detection of ESCC. Moreover, the subgroup analyses demonstrated the feasibility of using blood miRNAs as an ESCC diagnostic biomarker in Japanese and Chinese populations. Further, both plasma and serum are recommended as clinical specimens for miRNA detection. Further studies will be needed to validate these findings using larger numbers of patients.

Combined detection of serum Dickkopf-1 and its autoantibodies to diagnose esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) can be treated effectively if diagnosed at an early stage. We evaluated whether measurement of Dickkopf-1 (DKK-1) in combination of DKK-1 autoantibodies in serum may benefit early diagnosis of ESCC. Serum DKK-1 and DKK-1 autoantibodies were measured by enzyme-linked immunosorbent assay in a training cohort (185 ESCC samples vs. 97 normal controls) and validated in a validation cohort (104 ESCC samples vs. 53 normal controls). Receiver operating characteristic (ROC) was applied to calculate diagnostic accuracy. Testing of DKK-1 and DKK-1 autoantibodies together could differentiate ESCC from normal controls (area under the ROC curve [AUC] 0.769, 95% confidence interval (CI), 0.715-0.823, 50.3% sensitivity, and 90.7% specificity in the training cohort; AUC 0.752, 95% CI, 0.675-0.829, 50.0% sensitivity, and 84.9% specificity in the validation cohort). Importantly, the diagnostic performance of the combination of DKK-1 and DKK-1 autoantibodies persisted in early ESCC patients (AUC 0.780, 95% CI, 0.699-0.862, 50.0% sensitivity, and 90.7% specificity in the training cohort; AUC 0.745, 95% CI, 0.626-0.865, 53.8% sensitivity, and 84.9% specificity in the validation cohort). Furthermore, the levels of serum DKK-1 or DKK-1 autoantibody after surgical resection were lower, respectively, compared with the corresponding preoperative samples (P < 0.05). Our results suggest that measurement of DKK-1 combined with DKK-1 autoantibodies is a potentially valuable tool for the early detection of ESCC.

miR-382 inhibits migration and invasion by targeting ROR1 through regulating EMT in ovarian cancer

Increasing evidence suggests that microRNAs (miRNAs) play a critical role in tumorigenesis. Decreased expression of miR‑382 has been observed in various types of cancers. However, the biological function of miRNA-382 in ovarian cancer is still largely unknown. Here, we found miR‑382 was downregulated in human ovarian cancer tissues and cell lines. miR‑382 inhibited ovarian cancer cell proliferation, migration, invasion and the epithelial-mesenchymal transition (EMT). Furthermore, we identified receptor tyrosine kinase orphan receptor 1 (ROR1) as a target of miR‑382, and miR‑382 rescued the promotion effect of ROR1 on migration, invasion and EMT process in SKOV3 and COV434 cells. Collectively, these findings revealed that miR‑382 inhibits migration and invision by targeting ROR1 through regulating EMT in ovarian cancer, and might serve as a tumor suppressor in ovarian cancer.

Early esophageal cancer screening in China

In China, the incidence of esophageal cancer (EC) and its related mortality are high. Screening strategies aiming at early diagnosis can improve the prognosis. Researches on detection of early EC, especially in China are reviewed. Compared to esophageal balloon cytology or routine endoscopy, chromoendoscopy with Lugol's staining and biopsy appears to be the gold standard for early EC diagnosis in China today. Narrow-band imaging endoscopy, Confocal Laser endomicroscopy and other novel diagnostic approaches are more and more widely used in developed urban areas, but cost and lack of essential training to the endoscopists have made their use limited in rural areas. No specific biomarkers or serum markers were strongly commended to be used in screening strategies currently, which need to be evaluated in future. Trials on organized screening have been proposed in some regions of china with high disease prevalence. Screening in these areas has been shown to be cost effective.

Comparison of long non‑coding RNAs, microRNAs and messenger RNAs involved in initiation and progression of esophageal squamous cell carcinoma

Traditionally, cancer research has focused on protein‑coding genes, which are considered the principal effectors and regulators of tumorigenesis. Non‑coding RNAs, in particular microRNAs (miRNAs) and long non‑coding RNAs (lncRNAs), have been widely reported to be important in the regulation of tumorigenesis and cancer development. However, to the best of our knowledge, investigation of the expression profiles of lncRNAs and a comparison of the involvement of lncRNAs, miRNAs and messenger RNAs (mRNAs) in esophageal tumorigenesis and development have not previously been performed. In the current study, intrinsic associations among the expression profiles of lncRNAs, miRNAs and mRNAs from normal esophageal tissues and those from cancer tissues were investigated. Oligonucleotide microarrays were used to detect the expression profiles of the three types of RNA in the canceration processes of human esophageal squamous cell carcinoma (ESCC) tissues. It was demonstrated that the different RNAs exhibit associated patterns of expression among normal esophageal epithelium, low‑grade intraepithelial neoplasia (LGIN), high‑grade intraepithelial neoplasia (HGIN), and carcinoma tissues, particularly in the critical period of canceration (HGIN to ESCC). Furthermore, the results indicated a high level of similarity in the potential function of lncRNAs, miRNAs and mRNAs in the processes of ESCC development. In the current study, a first generation atlas of lncRNA profiling and its association with miRNAs and mRNAs in the canceration processes of ESCC were presented.

MicroRNAs Involved in Anti-Tumour Immunity

MicroRNAs (miRNAs) are a category of small RNAs that constitute a new layer of complexity to gene regulation within the cell, which has provided new perspectives in understanding cancer biology. The deregulation of miRNAs contributes critically to the development and pathophysiology of a number of cancers. miRNAs have been found to participate in cell transformation and multiplication by acting as tumour oncogenes or suppressors; therefore, harnessing miRNAs may provide promising cancer therapeutics. Another major function of miRNAs is their activity as critical regulatory vehicles eliciting important regulatory processes in anti-tumour immunity through their influence on the development, differentiation and activation of various immune cells of both innate and adaptive immunity. This review aims to summarise recent findings focusing on the regulatory mechanisms of the development, differentiation, and proliferative aspects of the major immune populations by a diverse profile of miRNAs and may enrich our current understanding of the involvement of miRNAs in anti-tumour immunity.