Early miR-223 Upregulation in Gastroesophageal Carcinogenesis

Gastric Carcinoma in Autoimmune Gastritis: A Histopathologic and Molecular Study

Patients with autoimmune gastritis (AIG) have a 13-fold risk of developing type-1 neuroendocrine tumors, whereas the risk for gastric adenocarcinoma is still uncertain. Here we describe the clinicopathologic and molecular features of a series of gastric carcinomas (GC) arising in the context of AIG. A total of 26 AIG-associated GC specimens were collected from 4 Italian Institutions. Immunohistochemistry for MUC1, MUC2, MUC5AC, MUC6, CDX2, HER2, PD-L1, CLDN18, mismatch repair (MMR) proteins, and p53 and EBV-encoded RNA (EBER) in situ hybridization were performed. Histologic and immunohistochemical features were jointly reviewed by 5 expert gastrointestinal pathologists. Next-generation sequencing analysis (TrueSight Oncology 500, Illumina) of 523 cancer-related genes was performed on 19 cases. Most tumors were diagnosed as pT1 (52%) and they were located in the corpus/fundus (58%) and associated with operative link for gastritis assessment stage II gastritis (80.8%), absence of parietal cells, complete intestinal metaplasia, and enterochromaffin-like-cell micronodular hyperplasia. Only 4 (15.4%) GCs were diagnosed during follow-up for AIG. The following histotypes were identified: 20 (77%) adenocarcinomas; 3 (11%) mixed neuroendocrine-non-neuroendocrine neoplasms, and 2 (8%) high-grade solid adenocarcinomas with focal neuroendocrine component, 1 (4%) adenocarcinoma with an amphicrine component. Overall, 7 cases (27%) showed MMR deficiency, 3 (12%) were positive (score 3+) for HER2, 6 (23%) were CLDN18 positive, and 11 (42%) had PD-L1 combined positive score ≥ 10. EBER was negative in all cases. Molecular analysis revealed 5/19 (26%) microsatellite instability (MSI) cases and 7 (37%) tumor mutational burden (TMB) high. The most frequently altered genes were TP53 (8/19, 42%), RNF43 (7/19, 37%), ERBB2 (7/19, 37% [2 amplified and 5 mutated cases]), ARID1A (6/19, 32%), and PIK3CA (4/19, 21%). In summary, AIG-associated GCs are often diagnosed at low stage in patients with longstanding misrecognized severe AIG; they often display a neuroendocrine component or differentiation, have relatively higher rates of MMR deficiency, and TMB high.

[Epigenetic markers of choroidal melanoma]

MicroRNAs (miRNAs) are short non-coding RNAs (18-25 nucleotides in length) that are important participants in the regulation of gene expression. In 2003, their active role in oncogenesis was demonstrated. In 2008, the first report on the isolation of miRNAs from uveal melanoma (UM) tissue was published. Four years later (2012), the presence of miRNAs in the plasma of patients with this category was shown. To date, changes in the expression level of 100 miRNAs in the plasma of cancer patients (with cancer of various localizations) out of the 2654 miRNAs described in mirbase.org have been proven. In the plasma of patients with UM, changes in the expression of only 13 miRNAs have been confirmed. As a rule, studies were conducted in patients at the stage of hematogenous metastasis of UM.

PURPOSE

This study analyzed the expression pattern of miRNA-223 and miRNA-126 in patients with localized choroidal melanoma (CM) taking into account biometric parameters in the absence of metastases.

MATERIAL AND METHODS

Blood plasma of 84 patients with M0N0 CM aged 35-86 years (mean age 63.4±1.2 years) was investigated. The basis for the diagnosis of CM was the results of ophthalmological examination, optical coherence tomography, and ultrasound scanning. In all cases, the absence of metastases was proven (using computed tomography or magnetic resonance imaging). Control - plasma of 28 volunteers (mean age 62.9±1.42 years, age range 45-78 years), who did not have tumoral, autoimmune, or chronic inflammatory processes. The expression levels of miRNAs circulating in blood plasma were determined by real-time polymerase chain reaction.

RESULTS

An increase in the expression levels of miRNA-223 and miRNA-126 in the plasma of all 84 patients with CM was confirmed compared to the control group. Features of the miRNA expression pattern that emerged with changes in the tumor's quantitative parameters were identified.

CONCLUSION

Evaluation of the levels of miRNA-223 and miRNA-126 in the blood plasma of patients with CM can be used in clinical practice to clarify the diagnosis of CM, as well as to predict the development of hematogenous metastases.

The role of extracellular vesicles and interleukin-8 in regulating and mediating neutrophil-dependent cancer drug resistance

Tumor drug resistance is a multifactorial and heterogenous condition that poses a serious burden in clinical oncology. Given the increasing incidence of resistant tumors, further understanding of the mechanisms that make tumor cells able to escape anticancer drug effects is pivotal for developing new effective treatments. Neutrophils constitute a considerable proportion of tumor infiltrated immune cells, and studies have linked elevated neutrophil counts with poor prognosis. Tumor-associated neutrophils (TANs) can acquire in fact immunoregulatory capabilities, thus regulating tumor progression and resistance, or response to therapy. In this review, we will describe TANs' actions in the tumor microenvironment, with emphasis on the analysis of the role of interleukin-8 (IL-8) and extracellular vesicles (EVs) as crucial modulators and mediators of TANs biology and function in tumors. We will then discuss the main mechanisms through which TANs can induce drug resistance, finally reporting emerging therapeutic approaches that target these mechanisms and can thus be potentially used to reduce or overcome neutrophil-mediated tumor drug resistance.

Autoimmune Atrophic Gastritis: The Role of miRNA in Relation to Helicobacter Pylori Infection

Introduction

MicroRNAs (miRNAs) have been proposed as diagnostic markers, biomarkers of neoplastic progression, and possible therapeutic targets in several immune-mediated diseases. We aimed to analyze the expression profile of selected miRNAs (miR21, miR142, miR223, miR155) in patients with autoimmune atrophic gastritis (AAG), patients with non-autoimmune multifocal atrophic gastritis (MAG), and healthy control subjects (HC).

Materials and methods

A total of 103 patients with AAG were consecutively recruited for this study among those attending our gastroenterology outpatient clinic. Participating patients were divided into two groups: primary, not Helicobacter pylori (HP)-associated related AAG (n=57, P-AAG) and HP-associated AAG (n=46, HP-AAG); this subgroup included HP-positive patients, patients with previously reported HP infection, and patients harboring antral atrophy, considered as a stigma of HP infection. We also included 20 sex-age-matched MAG patients and 10 HC. Upper endoscopy with gastric biopsies were performed on each AAG and MAG patient. Circulating levels of miR21-5p, miR142-3p, miR223-3p, and miR155-5p were measured by RT-PCR in all groups.

Results

MiR-21 was over-expressed in P-AAG (p=0.02), HP-AAG (p = 0.04), and MAG (p=0.03) compared with HC. By contrast, miR-142 was more expressed in HC than in HP-AAG (p=0.04) and MAG (p=0.03). MiR-155 showed no significant differences among the four subgroups, while, unexpectedly, miR-223 was overexpressed in HC compared to P-AAG (p=0.01), HP-AAG (p=0.003), and MAG (p<0.001), and was higher in P-AAG than in MAG (p=0.05).

Conclusions

MiR-21 was over-expressed in patients with gastric precancerous conditions irrespective of etiology, while in the same subgroups miR-142 and miR-223 were under-expressed compared to healthy controls. Controlling miRNAs up- or downregulation could lead to a breakthrough in treating chronic autoimmune diseases and potentially interfere with the progression to cancer.

Modulation of microRNAs and claudin-7 in Caco-2 cell line treated with Blastocystis sp., subtype 3 soluble total antigen

Background

Blastocystis sp., is a eukaryote of the large intestine, which is reported from almost all countries. The pathogenesis of this protist is not clear. The current study aimed to analyze the effects of Blastocystis sp., ST3 soluble total antigen (B3STA) on the microRNAs (miRNAs) involved in the gut permeability and also pro-inflammatory cytokines, occludin, and claudin-7.

Methods

Blastocystis sp., ST3 isolated from stool sample was purified, and its soluble total antigen was extracted using freeze and thawing. The Caco-2 cell line was treated with B3STA for 24 h and the expression levels of mir-16, mir-21, mir-29a, mir-223, and mir-874 were analyzed. In addition, the expression levels of il-8, il-15, occludin, and claudin-7 genes were assessed.

Results

B3STA significantly upregulated the expression of mir-223, and mir-874, and downregulated mir-29a. The expression of mir-16 and mir-21 was not significant. In addition, the expression of il-8 and il-15 was not significant. B3STA significantly decreased the expression level of claudin-7 (P-value < 0.0001), but the expression of occludin was not significant. Our results showed significant correlation between all studied miRNAs, except mir-29a, with downregulation of claudin-7.

Conclusions

This is the first study investigating the effects of Blastocystis sp., ST3 isolated from symptomatic subjects on the expression levels of miRNAs involved in the gut permeability. Our results demonstrated that B3STA may change miRNA expression, which are involved in the gut barrier integrity, and downregulates claudin-7, which is known as sealing factor.

MicroRNA in refined diagnosis of choroidal melanoma

Epigenetic studies of the level of microRNAs in human oncogenesis indicate their signifi cant role in the development and growth of malignant tumors of various origins. The fi rst works on the role of microRNAs in patients with uveal melanoma appeared in 2008.The aim: to analyze the expression level of miRNA-126 and miRNA-223 in the plasma blood of patients and to determine their signifi cance in the refi ned diagnosis of choroidal melanoma. Materials and methods. We examined 84 patients with choroidal melanoma (CM), mean age – 63.4 ± 1.2 (35–86 y.o.). Localization – a single CM node with a thickness of 0.77–17.19 mm. The control group consisted of 28 volunteers, age – 62.9 ± 1.42 (45–78 y.o.). Plasma miRNA expression levels were determined by real-time PCR.Results. An increase in the level of expression of miRNA-223 and miRNA-126 in blood plasma was confi rmed in all 84 patients with choroidal melanoma N0M0 compared with the control group. An increase in the expression of miRNA-223 and miRNA-126 was proved with an increase in tumor prominence.Conclusion. The obtained results of an increase in the expression of miRNA-223 indicate an increase in cell proliferation, and an increase in the expression of miRNA-126 on the activation of angiogenesis in a growing tumor, which makes it possible to recommend a study of the level of miRNA-223 and miRNA-126 for a more accurate diagnosis of small CM in cases of difficulty of differential diagnosis with other tumor-like diseases of the choroid.

MicroRNA profiling in a case-control study of African American women with uterine serous carcinoma

OBJECTIVE

Uterine serous carcinoma (USC) is an aggressive subtype of endometrial cancer associated with worse survival outcomes in African American (AA) patients. This study evaluated tumor miRNA expression by race, clinical and tumor characteristics, and survival outcomes.

METHODS

FFPE tumor tissue from hysterectomy specimens was identified for 29 AA cases. Case matching was performed by computer-based random assignment in a 1:1 ratio with Caucasian controls based on age, stage and histologic subtype (pure vs. mixed). RNA was extracted from 77 specimens (54 tumors and 23 matched normal endometrium). MicroRNA array profiling was performed by microRNA Hi-Power Labeling (Hy3/Hy5) and hybridization to miRCURY LNA microRNA Array 7th Gen.

RESULTS

Clinical and treatment characteristics were similar for cases and controls, although use of adjuvant radiation was less common in African Americans (p = 0.03). Of 968 miRNAs analyzed, 649 were differentially expressed in normal endometrium vs. tumor. When compared by race, histologic subtype, stage or presence of LVI, no differentially expressed miRNAs were identified. In patients with disease recurrence at 3 years, the three most upregulated miRNAs were miR-1, miR-21-5p and miR-223. Of these, increased miR-223 expression (>median) was associated with worse OS (p = 0.0496) in an independent dataset (TCGA dataset) comprising of 140 patients with USC (mixed or pure serous). After adjusting for age, ethnicity and BMI, upregulation of miR-223 remained risk factor for death (adjusted HR 2.87, 95% CI 1.00-8.27).

CONCLUSIONS

MiRNA profiling did not identify biological differences between AA and Caucasian patients with USC. Upregulation of miR-223 may be a prognostic factor in USC.

PDS5A and PDS5B in Cohesin Function and Human Disease

Precocious dissociation of sisters 5 (PDS5) is an associate protein of cohesin that is conserved from yeast to humans. It acts as a regulator of the cohesin complex and plays important roles in various cellular processes, such as sister chromatid cohesion, DNA damage repair, gene transcription, and DNA replication. Vertebrates have two paralogs of PDS5, PDS5A and PDS5B, which have redundant and unique roles in regulating cohesin functions. Herein, we discuss the molecular characteristics and functions of PDS5, as well as the effects of its mutations in the development of diseases and their relevance for novel therapeutic strategies.

Evaluation of the Diagnostic Properties of Serum hsa-miR-223-5p in the Detection of Gastric Cancer: A Case-Control Study

BACKGROUND

MicroRNAs (miRs) are a group of small non-coding and single-stranded RNAs of 18 to 25 nucleotides. The study of microRNAs is one of the new ways to detect cancer. In this study, the serum expression of miR-223 in patients with GC was measured and compared with the control group.

METHODS

This case-control study was conducted on 39 patients with GC and 39 control subjects who visited the Reza Radiotherapy and Oncology Center, Mashhad, Iran, due to gastrointestinal complaints. The demographic information was collected, and the serum levels of miR-223 were measured using the real-time PCR technique in all study subjects. The association between the GC of miR-223 and tumor staging and cancer progression was assessed.

RESULTS

The miR-223 expression in GC patients was 3.10-fold higher than that of the control group (p<0.0001). The miR-223 expression was significantly higher in the GC stages and grades compared to the control group (p<0.0001 each). However, there was no significant effect for age, smoking, and gender on miR- 223 expression in GC and controls. At the optimal cutoff value of 0.7436, the maximal sensitivity of 89.74% and specificity of 84.62% were achieved for miR-223 (p<0.001). The sensitivity and specificity for miR-223 for differentiating low grades from high grade were 92.31% and 73.08% (p=0.0003), and for differentiating low stages from the high stage was 81.82% and 39.29% respectively (p=0.696).

CONCLUSION

This study revealed that miR-223 could be considered as a non-invasive diagnostic marker in the early diagnosis of GC.

Poorly Differentiated Neuroendocrine Larynx Carcinoma: Clinical Features and miRNAs Signature-A New Goal for Early Diagnosis and Therapy?

Laryngeal neuroendocrine carcinomas (LNECs) are rare and highly heterogeneous malignancies presenting a wide range of pathological and clinical manifestations. Herein, we retrospectively characterize ten patients diagnosticated with LNEC, five of which were defined as well-moderately differentiated neuroendocrine carcinomas, and five that were defined as poorly differentiated neuroendocrine carcinomas, according to the latest WHO classification. Clinical features were analyzed and compared between the two subgroups together with a microRNA study which evidenced a peculiar signature likely related to poorly differentiated larynx neuroendocrine carcinomas. These findings may offer new useful insights for clinicians to improve diagnosis efficiency, therapy response, and patients' outcome for this aggressive neoplasm.

The many facets of miR-223 in cancer: Oncosuppressor, oncogenic driver, therapeutic target, and biomarker of response

Given their intrinsic pleiotropism, microRNAs (miR) play complex biological roles, in both normal and pathological conditions. Often the same miR can act as oncogene or oncosuppressor, depending on the biological process dysregulated in each specific tissue. miR‐223 does not represent an exception to this rule and its functions greatly differ in different contexts. miR‐223 has been widely studied in the hematopoietic compartment, where it plays a central role in innate immune response, regulating myeloid differentiation and granulocytes function. Accordingly, dysregulated expression of miR‐223 has been associated to different inflammatory disorders and tumors arising from the immune compartment. Most carcinomas, breast cancer being the most studied, display loss of miR‐223. However, in gastro‐esophageal cancers miR‐223 is frequently overexpressed and correlates with worse prognosis. A link between miR‐223 and response to CDK4/6‐inhibitors has been recently proposed, suggesting a role as biomarker of therapeutic response. The notion that one of the most commonly mutated protein in cancer, mutant p53, binds the promoter of miR‐223 and suppresses its transcription, adds a further level of complexity to the full understanding of miR‐223 in cancer. In this review, we will summarize the current knowledge on the molecular networks that alter or are altered by miR‐223, in different cancer types. We will discuss if the times are ready for the exploitation of miR‐223 as predictive biomarker of treatment response or, even, as therapeutic target, in specific settings. Finally, we will suggest which could be the next steps to be taken for a realistic clinical application of miR‐223.

This article is categorized under:

RNA in Disease and Development > RNA in Disease

Inflammatory microRNAs in gastric mucosa are modulated by Helicobacter pylori infection and proton-pump inhibitors but not by aspirin or NSAIDs

Gastric carcinogenesis is associated with alterations of microRNAs (miRNAs) and reversal of these alterations may be a crucial element in cancer prevention. Here we evaluate the influence of H. pylori eradication, low-dose aspirin (LDA), non-steroidal anti-inflammatory drugs (NSAIDs) and proton-pump inhibitors (PPI) on modification of inflammatory mucosal miRNAs miR-155 and miR-223 in Helicobacter pylori-infected and non-infected subjects. The study was performed in two parts: 1) interventional study in 20 healthy subjects with and without H. pylori infection or following eradication (each n = 10) where LDA (100 mg) was given daily for 7 days; 2) prospective case-control observational study (n = 188). MiR-155 and miR-223 expression was strongly linked to H. pylori-infection and in short-term view showed a trend for reversal after eradication. Daily LDA as well as regular NSAIDs showed no influence on miRNAs expression both in healthy subjects and patients, while regular PPI intake was associated with lower miR-155 expression in antrum of patients with chronic gastritis independent of density of neutrophils and mononuclear infiltrate. In summary, PPI but not LDA or NSAIDs were associated with modification of inflammatory miRNAs miR-155 and miR-223 in an H. pylori dependent manner. The functional role of inflammatory miR-155 and miR-223 in understanding of H. pylori-related diseases needs further evaluation.

miRNAs Involved in Esophageal Carcinogenesis and miRNA-Related Therapeutic Perspectives in Esophageal Carcinoma

MicroRNAs (miRNAs) are small non-coding RNAs that play a pivotal role in many aspects of cell biology, including cancer development. Within esophageal cancer, miRNAs have been proved to be involved in all phases of carcinogenesis, from initiation to metastatic spread. Several miRNAs have been found to be dysregulated in esophageal premalignant lesions, namely Barrett’s esophagus, Barrett’s dysplasia, and squamous dysplasia. Furthermore, numerous studies have investigated the alteration in the expression levels of many oncomiRNAs and tumor suppressor miRNAs in esophageal squamous cell carcinoma and esophageal adenocarcinoma, thus proving how miRNAs are able modulate crucial regulatory pathways of cancer development. Considering these findings, miRNAs may have a role not only as a diagnostic and prognostic tool, but also as predictive biomarker of response to anti-cancer therapies and as potential therapeutic targets. This review aims to summarize several studies on the matter, focusing on the possible diagnostic–therapeutic implications.

Extracellular miRNAs for the Management of Barrett's Esophagus and Esophageal Adenocarcinoma: A Systematic Review

Esophageal adenocarcinoma (EAC), the major histologic type of esophageal cancer (EC) in Western countries, is a disease with a poor prognosis, primarily due to usual diagnosis at an advanced stage. The prevalence of EAC has increased in recent years, both in Western countries and in Asia. Barrett's esophagus (BE) is a precursor lesion of EAC. Therefore, early detection and proper management of BE and EAC is important to improve prognosis. Here, we systematically summarize current knowledge about the potential utility of extracellular microRNAs (miRNAs), which are thought to be non-invasive biomarkers for many diseases, for these purposes. A search of the PubMed and Embase databases identified 22 papers about extracellular miRNAs that have potential utility for management of EAC. Among them, 19 were EAC-related and ten were BE-related; some of these dealt with both conditions. The articles included studies reporting diagnosis, prognosis, and treatment responses. Multiple papers report dysregulation of miR-194-5p in BE and miR-21-5p, -25-3p, and -93-5p in EAC. Although it will take time to utilize these miRNAs in clinical practice, they are likely to be useful non-invasive markers in the future.

MiR-223 regulates autophagy associated with cisplatin resistance by targeting FBXW7 in human non-small cell lung cancer

Background

Cisplatin is widely used as a first-line treatment for non-small cell lung cancer (NSCLC), but chemoresistance remains a major clinical obstacle for efficient use. As a microRNA, miR-223 was reported to promote the doxorubicin resistance of NSCLC. However, whether miR-223 is also involved in cisplatin resistance of NSCLC and the mechanism miR-223 involved in drug resistance is unclear. Accumulated evidence has shown that abnormal autophagy is associated with tumor chemoresistance. The study aimed to study the role of miR-223 on cisplatin sensitivity in NSCLC and uncover the potential mechanisms.

Methods

NSCLC cells transfected with mimic or inhibitor for miR-223 was assayed for chemoresistance in vitro. MiR-223 expression was assessed by quantitative real-time PCR (qRT-PCR). Western blot were used to study the expression level of F-box/WD repeat-containing protein 7 (FBXW7) and autophagy-related protein. The effect of miR-223 on cisplatin sensitivity was examined by using CCK-8, EdU assays and Autophagic flux assay. Luciferase assays, EdU assays and small interfering RNA were performed to identify the targets of miR-223 and the mechanism by which it promotes treatment resistance. Xenograft models were established to investigate the effect of mir-223 on cisplatin sensitivity.

Results

In the present study, we found that the level of miR-223 was significantly positively correlated with cisplatin resistance. MiR-223 overexpression made NSCLC cells resistant to cisplatin treatment. We further found that autophagy mediated miR-223-mediated cisplatin resistance in NSCLC cells. Further mechanistic research demonstrated that miR-223 directly targeted FBXW7. The overexpression of miR-223 could inhibit the level of FBXW7 protein expression, thus promoting autophagy and making NSCLC cells resistant to cisplatin. Finally, we confirmed the increased effect of cisplatin sensitivity by miR-223 Antagomir in xenograft models of NSCLC.

Conclusions

Our results demonstrate that miR-223 could enhance autophagy by targeting FBXW7 in NSCLC cells. Inhibition of autophagy by miR-223 knockdown provides a novel treatment strategy to alleviate cisplatin resistance in NSCLC.

Circulating exosomal miRNAs as potential biomarkers for Barrett's esophagus and esophageal adenocarcinoma

Exosomes, a class of extracellular vesicles, are small membrane-bound vesicles derived from almost all cell types that can play important roles in intercellular communication. Exosomes contain proteins, lipids, and nucleic acids that are obtained from the parental cells and participate in various pathophysiological processes, including cell growth, migration, inflammation, immune regulation, and tumor pathogenesis. Moreover, exosomes might be applied in clinical settings, such as diagnosis, treatment, and outcome prediction of diseases, including various cancers. The incidence rates of Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC) have increased in recent decades, and studies have proposed specific factors that may contribute to the development and progression of these diseases. However, how exosomes play a role in this pathological process needs to be clarified. Studies have identified candidate microRNAs (miRNAs) that might be related to BE/EAC. Further studies are needed to ascertain whether circulating exosomal miRNAs are altered before or after disease onset, which could also help understand the pathophysiology of and find potential targets for prevention, diagnosis, and therapy in BE/EAC. This review summarizes recent findings on the features of circulating exosomal miRNAs in BE/EAC, which could be valuable for the early diagnosis, therapeutic approaches, and outcome prediction of BE/EAC.

Circulating microRNA expression profiling revealed miR-92a-3p as a novel biomarker of Barrett's carcinogenesis

The main intent of secondary prevention strategies for Barrett's esophagus (BE) patients relies in the prompt identification of patients with dysplasia (or intra-epithelial neoplasia; IEN) and early-stage adenocarcinoma (Barrett's adenocarcinoma; BAc). Despite the adequate characterization of the molecular landscape characterizing Barrett's carcinogenesis, no tissue and/or circulating biomarker has been approved for clinical use. A series of 25 serum samples (12 BE, 5 HG-IEN and 8 BAc) were analyzed for comprehensive miRNA profiling and ten miRNAs were found to be significantly dysregulated. In particular seven were upregulated (i.e. miR-92a-3p, miR-151a-5p, miR-362-3p, miR-345-3p, miR-619-3p, miR-1260b, and miR-1276) and three downregulated (i.e. miR-381-3p, miR-502-3p, and miR-3615) in HG-IEN/BAc samples in comparison to non-dysplastic BE. All the identified miRNAs showed significant ROC curves in discriminating among groups with AUC values range of 0.75-0.83. Validation of the results were performed by droplet digital PCR in two out of three tested miRNAs. To understand the cellular source of circulating miR-92a-3p, we analyzed its expression in endoscopy biopsy samples by both qRT-PCR and ISH analyses. As observed in serum samples, miR-92a-3p was over-expressed in HG-IEN/BAc samples in comparison to naïve esophageal squamous mucosa and BE and was mainly localized within the epithelial cells, supporting neoplastic cells as the main source of the circulating miRNA. Our data further demonstrated that circulating miRNAs are a promising mini-invasive diagnostic tool in the secondary follow-up and management of BE patients. Larger multi-Institutional studies should validate and investigate the most adequate miRNAs profile in discriminating BE patients in specific risk classes.

Downregulation of miR-223 Expression Is an Early Event during Mammary Transformation and Confers Resistance to CDK4/6 Inhibitors in Luminal Breast Cancer

miR-223 is an anti-inflammatory miRNA that in cancer acts either as an oncosuppressor or oncopromoter, in a context-dependent manner. In breast cancer, we demonstrated that it dampens the activation of the EGF pathway. However, little is known on the role of miR-223 during breast cancer onset and progression. miR-223 expression was decreased in breast cancer of luminal and HER2 subtypes and inversely correlated with patients' prognosis. In normal luminal mammary epithelial cells, miR-223 acted cell autonomously in the control of their growth and morphology in three-dimensional context. In the MMTV-Δ16HER2 transgenic mouse model, oncogene transformation resulted in a timely abrogation of miR-223 expression, likely due to activation of E2F1, a known repressor of miR-223 transcription. Accordingly, treatment with CDK4/6 inhibitors, which eventually results in restraining E2F1 activity, restored miR-223 expression and miR-223 ablation induced luminal breast cancer resistance to CDK4/6 inhibition, both in vitro and in vivo. Notably, miR-223 expression was lost in microdissected ductal carcinoma in situ (DCIS) from patients with luminal and HER2-positive breast cancer. Altogether, these results identify downmodulation of miR-223 as an early step in luminal breast cancer onset and suggest that it could be used to identify aggressive DCIS and predict the response to targeted therapy. SIGNIFICANCE: miR-223 may represent a predictive biomarker of response to CDK4/6 inhibitors and its loss could identify DCIS lesions that are likely to progress into invasive breast cancer.

miR-223 Regulates Cell Proliferation and Invasion via Targeting PDS5B in Pancreatic Cancer Cells

Emerging evidence has demonstrated that miR-223 is critically involved in the progression of pancreatic cancer (PC); however, the underlying mechanisms are not fully elucidated. In the present study, we explored the molecular basis of miR-223-mediated tumor progression in PC. We performed numerous approaches including MTT, FACS, transfection, RT-PCR, western blotting, Transwell, and animal studies to determine the physiological role of miR-223 in PC cells. We found that sister chromatid cohesion protein PDS5 homolog B (PDS5B) is a direct target of miR-223 in PC. Moreover, PDS5B exhibits tumor-suppressive function in PC cells. Consistently, ectopic overexpression of PDS5B reversed miR-223-mediated tumor progression in PC cells. These results suggest that the miR-223/PDS5B axis regulates cell proliferation and invasion in PC cells. Our findings indicated that downregulation of miR-223 could be a novel therapeutic approach for PC.

MicroRNAs as non-invasive diagnostic biomarkers for gastric cancer: Current insights and future perspectives

Non-invasive diagnostic biomarkers may contribute to an early identification of gastric cancer (GC) and improve the clinical management. Unfortunately, no sensitive and specific screening biomarkers are available yet and the currently available approaches are limited by the nature of the disease. GC is a heterogenic disease with various distinct genetic and epigenetic events that occur during the multifactorial cascade of carcinogenesis. MicroRNAs (miRNAs) are commonly deregulated in gastric mucosa during the Helicobacter pylori infection and in stepwise manner from chronic gastritis, through preneoplastic conditions such as atrophic gastritis and intestinal metaplasia, to early dysplasia and invasive cancer. Identification of miRNAs in blood in 2008 led to a great interest on miRNA-based diagnostic, prognostic biomarkers in GC. In this review, we provide the most recent systematic review on the existing studies related to miRNAs as diagnostic biomarkers for GC. Here, we systematically evaluate 75 studies related to differential expression of circulating miRNAs in GC patients and provide novel view on various heterogenic aspects of the existing data and summarize the methodological differences. Finally, we highlight several important aspects crucial to improve the future translational and clinical research in the field.

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

Gastro-esophageal adenocarcinomas (GEA) represent a severe global health burden and despite improvements in the multimodality treatment of these malignancies the prognosis of patients remains poor. HER2 overexpression/amplification has been the first predictive biomarker approved in clinical practice to guide patient selection for targeted treatment with trastuzumab in advanced gastric and gastro-esophageal junction cancers. More recently, immunotherapy has been approved for the treatment of GEA and PD-L1 expression is now a biomarker required for the administration of pembrolizumab in these diseases. Significant progress has been made in recent years in dissecting the genomic makeup of GEA in order to identify distinct molecular subtypes linked to distinct patterns of molecular alterations. GEA have been found to be highly heterogeneous malignances, representing a challenge for biomarkers discovery and targeted treatment development. The current review focuses on an overview of established and novel promising biomarkers in GEA, covering recent molecular classifications from TCGA and ACRG. Main elements of molecular heterogeneity are discussed, as well as emerging mechanisms of primary and secondary resistance to HER2 targeted treatment and recent biomarker-driven trials. Future perspectives on the role of epigenetics, miRNA/lncRNA and liquid biopsy, and patient-derived xenograft models as a new platform for molecular-targeted drug discovery in GEA are presented. Our knowledge on the genomic landscape of GEA continues to evolve, uncovering the high heterogeneity and deep complexity of these tumors. The availability of new technologies and the identification of promising novel biomarker will be critical to optimize targeted treatment development in a setting where therapeutic options are currently lacking. Nevertheless, clinical validation of novel biomarkers and treatment strategies still represents an issue.

miR-223-RhoB signaling pathway regulates the proliferation and apoptosis of colon adenocarcinoma

MicroRNAs (miRNAs) can function as tumor suppressor or oncogenic genes. The putative targets of miR-223 include tumor suppressor gene, RhoB. Here we sought to investigate the role of miR-223-RhoB signaling pathway in proliferation of colon cancer. We used Western blot, immunofluorescence staining, or RT-PCR to detect expression levels of miR-223 and RhoB in colon adenocarcinoma and adjacent non-cancerous tissue samples, or in human colon adenocarcinoma cell lines. MTT assay was used to determine proliferation and apoptosis in cell lines. We further used Western blot to determine levels of cell cycle regulators CDK1 and Cyclin B1 with anti-miR-223 or apoptosis with overexpression of RhoB. The expression level of miR-223 was significantly upregulated in clinical samples and cell lines of colon adenocarcinoma, in contrast to down-regulation of RhoB. In addition, we showed that inhibition of miR-223 led to upregulation of RhoB and in turn suppression of proliferation of colon adenocarcinoma. Moreover, inhibition of miR-223 or overexpression of RhoB induced cell arrest or apoptosis in colon adenocarcinoma. These results suggest that miR-223-RhoB signaling pathway plays an important role in modulation of proliferation, cell arrest, and apoptosis in colon cancer.

MiR-223-3p targets ECT2 to regulate cell cycle and apoptosis in gastric cancer cells

AIM

To explore the role of miRNA-223-3p and epithelial cell transforming sequence 2 oncogene (ECT2) in cell cycle and apoptosis of gastric cancer (GC) cells and to analyze their correlation with clinicopathological characteristics.

METHODS

The expression of ECT2 and miR-223-3p in normal gastric mucosa cells (GSE-1) and GC cells (SGC-7901 and BGC-823) was detected by real-time fluorescent quantitative PCR and Western blot. Immunohistochemistry and RT-PCR were used to examine the expression of ECT2 and miR-223-3p in GC tissues and paired adjacent normal tissues, respectively. The correlation between ECT2 and miR-223-3p expression and clinicopathological characteristics was then analyzed. After miRNA-223-3p inhibitor and mimic were used to transfect SGC-7901 cells with LipofectamineTM2000, the expression of miRNA-223-3p and ECT2 was assessed by RT-PCR and Western blot in SGC-7901 cells. After another 24 h culture, the apoptosis rate and cell cycle progression were examined by flow cytometry.

RESULTS

The expression levels of ECT2 and miR-223-3p in GC cells were significantly increased as compared with those in normal gastric mucosa cells (P < 0.05 for both). In comparison with tumor adjacent normal tissues, the expression of ECT2 and miR-223-3p in GC tissues was significantly higher (P < 0.05). The expression of ECT2 and miR-223-3p was related to histologic differentiation (P < 0.05), Lauren type (P < 0.05), and TNM stage (P < 0.01), but not with gender, age, Bormann type, or tumor size (P > 0.05). Transfection with miR-223-3p mimic up-regulated ECT2 expression, whereas transfection of miR-223-3p inhibitor downregulated the expression of ECT2. Compared with negative control cells, the apoptosis rate of SGC-7901 cells transfected with miR-223-3p inhibitor significantly increased (P < 0.05), and the percentage of G₁ phase cells also significantly increased in miR-223-3p inhibitor transfected cells (P < 0.05).

CONCLUSION

MiR-223-3p is closely related with cell cycle and apoptosis of gastric cancer cells, and it can regulate the occurrence and development of GC by influencing the expression of ECT2. ECT2 and miR-223-3p may serve as good factors to indicate the biologic behavior of GC.

Research progress on the relationship between zinc deficiency, related microRNAs, and esophageal carcinoma

Esophageal cancer (EC) is a common malignant tumor of the gastrointestinal tract with a high incidence in China. Zinc (Zn) deficiency is a key risk factor for the occurrence and development of EC and affects progression by regulating microRNA (miRNA, miR) expression. In addition, the dysregulation of miRNAs is accompanied by the dysregulation of their target genes in EC. In this paper, we review the potential molecular mechanisms between Zn deficiency and EC with the aim of providing new strategies and methods for early diagnosis, targeted therapy, and prognostic evaluation.