Clinical significance of serum miR-25 as a diagnostic and prognostic biomarker in human gastric cancer

Cell-free and extracellular vesicle microRNAs with clinical utility for solid tumors

As cutting-edge technologies applied for the study of body fluid molecular biomarkers are continuously evolving, clinical applications of these biomarkers improve. Diverse forms of circulating molecular biomarkers have been described, including cell-free DNA (cfDNA), circulating tumor cells (CTCs), and cell-free microRNAs (cfmiRs), although unresolved issues remain in their applicability, specificity, sensitivity, and reproducibility. Translational studies demonstrating the clinical utility and importance of cfmiRs in multiple cancers have significantly increased. This review aims to summarize the last 5 years of translational cancer research in the field of cfmiRs and their potential clinical applications to diagnosis, prognosis, and monitoring disease recurrence or treatment responses with a focus on solid tumors. PubMed was utilized for the literature search, following rigorous exclusion criteria for studies based on tumor types, patient sample size, and clinical applications. A total of 136 studies on cfmiRs in different solid tumors were identified and divided based on tumor types, organ sites, number of cfmiRs found, methodology, and types of biofluids analyzed. This comprehensive review emphasizes clinical applications of cfmiRs and summarizes underserved areas where more research and validations are needed.

Circulating miRNA and circulating tumor DNA application as liquid biopsy markers in gastric cancer

Liquid biopsy has been investigated as a novel method to overcome the numerous challenges in gastric cancer (GC) management. This non-invasive, feasible, and easy-to-repeat method has been shown to be cost-effective and capable of increasing diagnostic sensitivity and prognostic assessment. Additionally, it is potentially accurate to aid decision-making and personalized treatment planning. MicroRNA (miRNA) and circulating tumor DNA (ctDNA) markers can enhance GC management in various aspects, including diagnosis (mainly earlier diagnosis and the ability to perform population-based screening), prognosis (more precise stratification of prognosis), and treatment (including more accurate prediction of treatment response and earlier detection of resistance to the treatment). Concerning the treatment-related application, miRNAs' mimics and antagonists (by using two main strategies of restoring tumor suppressor miRNAs and inhibiting oncogene miRNAs) have been shown to be effective therapeutic agents. However, these need to be further validated in clinical trials. Furthermore, novel delivery systems, such as lipid-based vectors, polymeric-based vectors, and exosome-based delivery, have been developed to enhance the performance of these agents. Moreover, this paper explores the current detection and measuring methods for these markers. These approaches are categorized into direct methods (e.g., Chem-NAT, HTG EdgeSeq, and Multiplex Circulating Fireplex) and indirect methods (e.g., Reverse transcription-quantitative polymerase chain reaction (RT-qPCR), qPCR, microarray, and NGS) for miRNA detection. For ctDNA measurement, main core technologies like NGS, digital PCR, real-time PCR, and mass spectrometry are suggested.

Liquid Biopsy: An Emerging Diagnostic, Prognostic, and Predictive Tool in Gastric Cancer

Liquid biopsy, a minimally invasive procedure that causes minimal pain and complication risks to patients, has been extensively studied for cancer diagnosis and treatment. Moreover, it facilitates comprehensive quantification and serial assessment of the whole-body tumor burden. Several biosources obtained through liquid biopsy have been studied as important biomarkers for establishing early diagnosis, monitoring minimal residual disease, and predicting the prognosis and response to treatment in patients with cancer. Although the clinical application of liquid biopsy in gastric cancer is not as robust as that in other cancers, biomarker studies using liquid biopsy are being actively conducted in patients with gastric cancer. Herein, we aimed to review the role of various biosources that can be obtained from patients with gastric cancer through liquid biopsies, such as blood, saliva, gastric juice, urine, stool, peritoneal lavage fluid, and ascites, by dividing them into cellular and acellular components. In addition, we reviewed previous studies on the diagnostic, prognostic, and predictive biomarkers for gastric cancer using liquid biopsy and discussed the limitations of liquid biopsy and the challenges to overcome these limitations in patients with gastric cancer.

Multi-omics Combined with Machine Learning Facilitating the Diagnosis of Gastric Cancer

Gastric cancer (GC) is a highly intricate gastrointestinal malignancy. Early detection of gastric cancer forms the cornerstone of precision medicine. Several studies have been conducted to investigate early biomarkers of gastric cancer using genomics, transcriptomics, proteomics, and metabolomics, respectively. However, endogenous substances associated with various omics are concurrently altered during gastric cancer development. Furthermore, environmental exposures and family history can also induce modifications in endogenous substances. Therefore, in this study, we primarily investigated alterations in DNA mutation, DNA methylation, mRNA, lncRNA, miRNA, circRNA, and protein, as well as glucose, amino acid, nucleotide, and lipid metabolism levels in the context of GC development, employing genomics, transcriptomics, proteomics, and metabolomics. Additionally, we elucidate the impact of exposure factors, including HP, EBV, nitrosamines, smoking, alcohol consumption, and family history, on diagnostic biomarkers of gastric cancer. Lastly, we provide a summary of the application of machine learning in integrating multi-omics data. Thus, this review aims to elucidate: i) the biomarkers of gastric cancer related to genomics, transcriptomics, proteomics, and metabolomics; ii) the influence of environmental exposure and family history on multiomics data; iii) the integrated analysis of multi-omics data using machine learning techniques.

Landscape of Innovative Methods for Early Diagnosis of Gastric Cancer: A Systematic Review

From a global perspective, gastric cancer (GC) persists as a significant healthcare issue. In the Western world, the majority of cases are discovered at late stages, when the treatment is generally unsuccessful. There are no organized screening programs outside of Asia (Japan and Republic of Korea). Traditional diagnosis techniques (such as upper endoscopy), conventional tumor markers (CEA, CA19-9, and CA72-4), radiographic imaging, and CT scanning all have drawbacks. The gold standard for the earliest detection of cancer and related premalignant lesions is still endoscopy with a proper biopsy follow-up. Since there are currently no clinically approved biomarkers for the early diagnosis of GC, the identification of non-invasive biomarkers is expected to help improve the prognosis and survival rate of these patients. The search for new screening biomarkers is currently underway. These include genetic biomarkers, such as circulating tumor cells, microRNAs, and exosomes, as well as metabolic biomarkers obtained from biofluids. Meanwhile, cutting-edge high-resolution endoscopic technologies are demonstrating promising outcomes in the visual diagnosis of mucosal lesions with the aid of linked color imaging and machine learning models. Following the PRISMA guidelines, this study examined the articles in databases such as PubMed, resulting in 167 included articles. This review discusses the currently available and emerging methods for diagnosing GC early on, as well as new developments in the endoscopic detection of early lesions of the stomach.

Novel biomarkers for early detection of gastric cancer

Gastric cancer (GC) remains a leading cause of cancer-related death worldwide. Less than half of GC cases are diagnosed at an advanced stage due to its lack of early symptoms. GC is a heterogeneous disease associated with a number of genetic and somatic mutations. Early detection and effective monitoring of tumor progression are essential for reducing GC disease burden and mortality. The current widespread use of semi-invasive endoscopic methods and radiologic approaches has increased the number of treatable cancers: However, these approaches are invasive, costly, and time-consuming. Thus, novel molecular noninvasive tests that detect GC alterations seem to be more sensitive and specific compared to the current methods. Recent technological advances have enabled the detection of blood-based biomarkers that could be used as diagnostic indicators and for monitoring postsurgical minimal residual disease. These biomarkers include circulating DNA, RNA, extracellular vesicles, and proteins, and their clinical applications are currently being investigated. The identification of ideal diagnostic markers for GC that have high sensitivity and specificity would improve survival rates and contribute to the advancement of precision medicine. This review provides an overview of current topics regarding the novel, recently developed diagnostic markers for GC.

Diagnostic and Prognostic Value of Serum miR-296-5p and miR-28-3p in Human Gastric Cancer

Background: Previous studies reported the use of microRNAs (miRNAs) as diagnostic and/or prognostic biomarkers for various cancers, including gastric cancer (GC). This study evaluated the diagnostic and prognostic significance of serum miR-296-5p and miR-28-3p in GC. Materials and Methods: Serum samples of 90 patients with GC and 90 healthy individuals, and 20 pairs of tissue specimens from patients with GC were collected. The expression of miR-296-5p and miR-28-3p in both the serum and tissue samples were detected using quantitative real-time polymerase chain reaction analysis. The diagnostic and prognostic values of miR-296-5p and miR-28-3p were evaluated by using receiver operating characteristic curve and Kaplan-Meier analyses, respectively. Results: Compared with the healthy controls, the expression of miR-296-5p in the serum and tissues of patients with GC was significantly upregulated, whereas that of miR-28-3p was significantly downregulated. High miR-296-5p and low miR-28-3p levels in the serum significantly correlated with larger tumor size (>5 cm), lymph node metastasis, and TNM stage III+IV. The area under the curve values of miR-296-5p and miR-28-3p were 0.919 and 0.911, respectively, with high sensitivity and specificity. Kaplan-Meier survival curves showed that patients with GC with high level of miR-296-5p or low level of miR-1236-3p in the serum had the poorest overall survival. COX analysis showed that lymphatic metastasis, high miR-296-5p expression, and low miR-28-3p expression are independent parameters indicating poor prognosis in GC. Conclusion: Our findings indicate that serum miR-296-5p and miR-28-3p levels are potential biomarkers in the diagnosis and prognosis of GC.

MiR-223-3p attenuates the migration and invasion of NSCLC cells by regulating NLRP3

Lung cancer is the malignant tumor with high invasion and metastasis, which seriously threatens public health. Previous study showed that NLRP3 could promote the occurrence of lung tumors in B(a)P-induced mice. MicroRNAs are closely related to the progression and metastasis of lung cancer by regulating target genes. However, which miRNAs affect the migration and invasion of lung cancer cells through regulating NLRP3 remains poorly defined. In this study, the miRNAs targeting NLRP3 were selected from TargetScan and miRDB database and finally miR-223-3p was chosen due to the consistent expression in both A549 and H520 cells. Then, the migration and invasion of lung cancer cells were detected with miR-223-3p mimic and inhibitor using Transwell assay, at the same time the expression of NLRP3, cleaved caspase-1, IL-1β and IL-18 was determined using Western Blot and immunohistochemistry assay. Our data demonstrated that miR-223-3p was upregulated in both A549 and H520 cells. Furthermore, the migration and invasion of A549 and H520 cells were promoted after inhibiting miR-223-3p. Besides, the levels of NLRP3, cleaved caspase-1, IL-1β and IL-18 were increased in the two lung cancer cells. And the corresponding results were contrary in miR-223-3p mimic group. Taken together, miR-223-3p attenuates the migration and invasion of NSCLC cells by regulating NLRP3, which provides evidence for the prevention and targeted treatment of NSCLC.

Biomarkers of gastric cancer: current advancement

Gastric cancer (GC) is one of the most prevalent malignant types worldwide, especially in East Asia. Due to its frequently advanced stage at diagnosis, the mortality from GC is high and the prognosis is still unsatisfactory. Thus, early detection using effective screening approaches is vital to decrease the morbidity and mortality of GC. Interestingly, biomarkers can be used for diagnosis, prediction of sensitivity to treatment, and prognosis in GC. The potential biomarkers detectable in liquid biopsies such as circulating tumor cells (CTCs), long non-coding RNAs (lncRNAs), cell-free DNA (cfDNA), microRNAs, and exosomes reveal numerous information regarding the early prediction and the outcomes for GC patients. Additionally, using the novel serum biomarkers has opened up new opportunities for diagnosing and monitoring patients with GC. This review mainly summarizes the novel progress and approaches in GC biomarkers, which could be potentially used for early diagnosis and therapy monitoring. Meanwhile, we also discussed the advantages, disadvantages, and future perspectives of GC biomarkers.

Risk Factors to Predict Ocular Metastasis in Older Adult Patients With Gastric Cancer:LDL, ApoA1, and CA724

Objective: The purpose of this study was to explore the risk factors for Ocular metastasis (OM) of Gastric cancer (GC). Methods: This is a retrospective cohort study. A total of 1165 patients with GC were enrolled in this study and divided into OM and non-ocular metastasis (NOM) groups. Chi-square and independent samples t tests were used to determine whether differences in demographic characteristics and serological indicators (SI) between the two groups were significant. In addition, binary logistic regression was used to analyze the value of various SI as risk factors for OM in patients with GC. The statistical threshold was set as P < .05. Finally, receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic value of various SI in differentiating the occurrence of OM in patients with GC. Results: The incidence of OM in older adults with GC was 1.1%. Adenocarcinoma was the most common type of GC in both groups, and there was no significant difference in demographic characteristics between the groups. Low-density lipoprotein (LDL), carbohydrate antigen-724 (CA724), and carcinoembryonic antigen levels were significantly higher in the OM group than the NOM group, while those of apolipoprotein A1 (ApoA1) were significantly lower in the OM than the NOM group. Binary logistic analysis showed that LDL, ApoA1, and CA724 were independent risk factors for OM in patients with GC ( P < .001, P = .033, and P = .008, respectively). ROC curve analysis generated area under the curve (AUC) values of 0.881, 0.576, and 0.906 for LDL, ApoA1, and CA724, respectively. In addition, combined analysis of LDL, ApoA1, and CA724 generated the highest AUC value of 0.924 ( P < .001). Conclusion: Among SI, LDL, ApoA1, and CA724 have predictive value for the occurrence of OM in GC, with the three factors combined having the highest value.

microRNA-based diagnostic and therapeutic applications in cancer medicine

It has been almost two decades since the first link between microRNAs and cancer was established. In the ensuing years, this abundant class of short noncoding regulatory RNAs has been studied in virtually all cancer types. This tremendously large body of research has generated innovative technological advances for detection of microRNAs in tissue and bodily fluids, identified the diagnostic, prognostic, and/or predictive value of individual microRNAs or microRNA signatures as potential biomarkers for patient management, shed light on regulatory mechanisms of RNA-RNA interactions that modulate gene expression, uncovered cell-autonomous and cell-to-cell communication roles of specific microRNAs, and developed a battery of viral and nonviral delivery approaches for therapeutic intervention. Despite these intense and prolific research efforts in preclinical and clinical settings, there are a limited number of microRNA-based applications that have been incorporated into clinical practice. We review recent literature and ongoing clinical trials that highlight most promising approaches and standing challenges to translate these findings into viable microRNA-based clinical tools for cancer medicine. This article is categorized under: RNA in Disease and Development > RNA in Disease.

Aberrant expression of miR-483-5p in patients with asymptomatic carotid artery stenosis and its predictive value for cerebrovascular event occurrence

MicroRNAs (miRNAs/miRs) may be used as novel promising diagnostic and prognostic biomarkers for various diseases, including asymptomatic carotid artery stenosis (ACAS). The present study aimed to investigate the abnormal expression of microRNA-483-5p (miR-483-5p) in patients with ACAS and to evaluate its diagnostic value for ACAS screening and its predictive value for cerebrovascular events. A total of 128 patients with ACAS and 76 healthy controls were included in the present study. The expression of miR-483-5p in serum was measured by reverse transcription-quantitative PCR. Receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic value of miR-483-5p in patients with ACAS. Kaplan-Meier curves were drawn and Cox regression analysis was used to determine the predictive value of miR-483-5p for cerebrovascular events in patients with ACAS. Serum miR-483-5p levels were significantly increased in patients with ACAS as compared with those in healthy controls. The expression of miR-483-5p was significantly associated with diabetes (P=0.011), dyslipidemia (P=0.047) and the degree of carotid stenosis (P=0.006) in patients with ACAS. In addition, the area under the ROC curve was 0.910, with a sensitivity of 80.5% and a specificity of 89.5% at the cutoff value of 0.705, indicating that serum miR-483-5p expression has a certain diagnostic value in patients with ACAS. Furthermore, the patients with high miR-483-5p expression had a higher proportion of cerebrovascular events than patients with low miR-483-5p levels (log-rank P=0.011) and miR-483-5p was an independent prognostic marker for predicting the occurrence of cerebrovascular events in patients with ACAS. The results indicated that miR-483-5p expression is significantly increased in patients with ACAS and that abnormal miR-483-5p expression may be a candidate biomarker for ACAS diagnosis and the prediction of cerebrovascular event occurrence.

Efficacy of circulating microRNA-130b and blood routine parameters in the early diagnosis of gastric cancer

Patients with gastric cancer (GC) have a poor prognosis, which is mainly due to the low rate of early diagnosis. The present study aimed to evaluate whether circulating microRNA-130b (miR-130b) and blood routine parameters [neutrophil count (N#), lymphocyte count (L#), monocyte count (M#), neutrophil percentage (N%), lymphocyte percentage (L%), monocyte percentage (M%), hemoglobin (Hb) level, hematocrit (Hct), red blood cell distribution width (RDW), platelet count, platelet distribution width (PDW), mean platelet volume (MPV), MPV to platelet count ratio (MPV/PC), monocyte to lymphocyte ratio (MLR), neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR)] are useful biomarkers for GC, early stage GC (EGC) and precancerous lesion (Pre) detection, and to identify more effective diagnostic models by combining circulating blood markers. Circulating levels of M#, M%, RDW-coefficient of variation (RDW-CV), MPV, PDW, MLR and NLR were significantly higher, and the levels of Hb and L% were significantly lower in patients with GC and Pre compared with those in healthy controls (NCs) (all P<0.05). The N#, N% and PLR in patients with GC were significantly higher and the Hct was significantly lower than those in the NCs (all P<0.05). The values of MPV/PC were significantly higher in the Pre cohort compared with those in the NCs. The area under the curve (AUC) of the receiver operating characteristic curve of potential biomarkers for GC was 0.634-0.887 individually, and this increased to 0.978 in the combination model of miR-130b-PDW-MLR-Hb. Additionally, the values for RDW-CV, PLR, NLR, N# and N% were positively correlated with cancer stage, while the values for MPV, L#, L%, Hb and Hct were negatively correlated with cancer stage. Furthermore, the circulating levels of miRNA-130b, and the values for NLR, RDW-CV, PDW, M%, red blood cell count, Hct, Hb and MLR differed between the EGC and NC groups. The AUC values of these biomarkers were 0.6491-0.911 individually in the diagnosis of EGC, and these increased to 0.960 in combination. In addition, the AUC values for miR-130b, RDW-CV, MPV/PC ratio, MLR, NLR, PDW, L%, M%, M# and Hb in the diagnosis of Pre were 0.638-0.811 individually. The dual-model of miR-130b-PDW manifested the largest AUC of 0.896 in the diagnosis of Pre, and the sensitivity and accuracy were increased when miR-130b and PDW were combined. All these results suggested that circulating miR-130b and blood routine parameters might be potential biomarkers, and combinations of measurements of these biomarkers may improve the GC, EGC and Pre diagnostic accuracy.

Risk Factors and Their Diagnostic Values for Ocular Metastases in Gastric Adenocarcinoma

Objective

Gastric adenocarcinoma originates from the glands in the superficial layer or mucosa of the stomach. It is prone to metastases, of which ocular metastasis (OM) is rare, but once it occurs the disease is considered more serious. The aim of this study was to investigate the risk factors for OM in gastric adenocarcinoma.

Methods

Patients with gastric adenocarcinoma were recruited to this study between June 2003 and July 2019. Demographic data and serological indicators (SI) were compared between patients with and without OM, and binary logistic regression was used to explore whether the relevant SI may be risk factors for OM of gastric adenocarcinoma. Receiver operating characteristic (ROC) curves were used to analyze different SIs for OM in gastric cancer patients.

Results

Chi-square tests showed significant between-groups difference in gender composition (P < 0.05), but not in age or histological grade (P > 0.05). t-test results showed that low-density lipoprotein (LDL) and carbohydrate antigen-724 (CA724) were significantly higher in patients with than without OM (P < 0.05). Binary logistic regression analysis showed that LDL was an independent risk factor for OM (P < 0.001). ROC curve analysis showed that the areas under the curves (AUC) for LDL and CA724 were 0.903 and 0.913 respectively, with higher AUC for combined LDL and CA724 (0.934; P < 0.001).

Conclusion

LDL and CA724 have value as predictors for OM in patients with gastric adenocarcinoma, with higher predictive value when these factors are combined.

Recent advances of miRNAs in the development and clinical application of gastric cancer

Gastric cancer (GC) is one of the most common malignant tumors. The mechanism of how GC develops is vague, and therapies are inefficient. The function of microRNAs (miRNAs) in tumorigenesis has attracted the attention from many scientists. During the development of GC, miRNAs function in the regulation of different phenotypes, such as proliferation, apoptosis, invasion and metastasis, drug sensitivity and resistance, and stem-cell-like properties. MiRNAs were evaluated for use in diagnostic and prognostic predictions and exhibited considerable accuracy. Although many problems exist for the application of therapy, current studies showed the antitumor effects of miRNAs. This paper reviews recent advances in miRNA mechanisms in the development of GC and the potential use of miRNAs in the diagnosis and treatment of GC.

Upregulation of microRNA-1303 is a potential prognostic marker of non-small cell lung cancer

BACKGROUND

Non-small cell lung cancer (NSCLC) is the major subtype of lung cancer, imposing a huge disease burden worldwide. MicroRNA-1303 (miR-1303) has been demonstrated to be involved in several diseases, including cancers. In this study, we aimed to investigate the role of miR-1303 in NSCLC.

METHODS

We quantified the expression levels of miR-1303 in NSCLC tissues and cells using the qRT-PCR assay. Then the association between miR-1303 expression and clinical characteristics of patients was analyzed using the χ2 test. The Kaplan-Meier and multivariate Cox regression assays were used to investigate the prognostic value of miR-1303 in NSCLC. Furthermore, the functional proliferation, migration, and invasion assays were used to explore the miR-1303 functions in vitro.

RESULTS

The expression of miR-1303 was upregulated in NSCLC tissue samples and cells. The upregulation of miR-1303 was associated with TNM stage and lymph node metastasis. The survival time of NSCLC patients with high expression of miR-1303 was shorter than those with low expression. The functional analyses revealed that overexpression of miR-1303 in H1299 and A549 cells promoted cell proliferation, migration, and invasion.

CONCLUSION

These results suggest that miR-1303 may be a potential prognostic biomarker for NSCLC and be involved in the progression of NSCLC.

Relationship between miR-378c and YY1 expression in patients with gastric cancer and the clinicopathological features

Background

The purpose of this study was to explore the clinical value of miR-378c and its target gene YY1 in gastric cancer.

Methods

The TCGA database was employed to analyse miR-378c expression in gastric cancer. qRT-PCR was applied to identify miR-378c and YY1 in tissues and serum of patients suffering from gastric cancer. The association of miR-378c with the clinical data of patients with gastric cancer was analysed. Receiver operating characteristics (ROC) curve analysis was used to determine the diagnostic value of miR-378c and YY1 in gastric cancer, and analyse the relationship between miR-378c and YY1 and patients’ survival. Pearson’s test was applied to determine the association between miR-378c and YY1 in tissue and serum of patients. Dual-Luciferase Reporter assay was employed to examine the targeting association between miR-378c and YY1. Finally, independent prognostic factors was determined in patients with gastric cancer using Cox regression analysis.

Results

In the TCGA database, miR-378c was weakly expressed in gastric cancer. Overall, patients with low expression had a lower survival rate. The expression of miR-378c decreased and the expression of YY1 increased in cancer tissues and serum of tumour patients. In patients with low expression of miR-378c the tumour size was ≥ 5 cm. Low differentiation, high TNM staging and lymph node invasion rate increased significantly, but the 5-year survival rate decreased in the patients. miR-378c and YY1 had better diagnostic value in gastric cancer. TargetScan, miRDB, starBase and miRTarBase predicted that YY1 was a potential gene of miR-378c, and the Dual-Luciferase Reporter assay revealed that there was a targeting relationship between the two, which was proved by correlation analysis. Multivariate Cox analysis revealed that differentiation, TNM staging and miR-378c were independent prognostic factors for patients.

Conclusions

MiR-378c is weakly expressed in gastric cancer patients and may be considered as a promising diagnostic and prognostic indicator for gastric cancer.

A systematic review of microRNAs as potential biomarkers for diagnosis and prognosis of gastric cancer

Gastric cancer (GC) is the third leading cause of global cancer morbidity and mortality. One of the significant challenges in GC treatment is that most GC patients are diagnosed with advanced-stage disease due to the lack of suitable biomarkers. Recent studies have shown that microRNAs (miRNAs) can acts as a potential biomarker in GC diagnosis and prognosis. I performed a systematic review of published miRNA studies in GC, which includes the miRNA expression profiles between GC tissues and normal tissues and also miRNA studies to evaluate their potential value in the diagnosis and prognosis of GC. Among the studies, upregulation of miR-21, miR-106b, miR-25, miR-214, miR-18a, miR-191, and miR-93 and downregulation of miR-375, miR-148a, miR-92, miR-155, and miR-564 were observed in GC tissues. In evaluating of diagnosis value of miRNAs, the study was performed on a combined miRNA include miR-21, miR-93, miR-106a, and miR-106b indicated the panel of these miRNAs have the highest AUC 0.887 to discriminate GC patients from healthy. Also, miR-940 with a sensitivity of 81.25% and specificity of 98.57% may be used for diagnostic biomarkers for GC. Finally, the pooled prognostic result of miR-21 for hazard ratios (HR) was 1.260 (95% CI 0.370-4.330, P < 0.001), showing that miR-21 could predict poor survival in GC patients. This systematic review can confirm that we need to find a miRNA or a panel of miRNAs with high sensitivity and specificity for further exploration to investigate a better diagnostic or therapeutic tool for personalized management of GC patients.

miR-3196 acts as a Tumor Suppressor and Predicts Survival Outcomes in Patients With Gastric Cancer

BACKGROUND

Gastric cancer is one of the most common malignancies worldwide with high mortality. Therefore, identifying cancer-related biomarkers for predicting prognosis and progression of gastric cancer is essential. This study aimed to investigate the clinical value and functional role of microRNA-3196 in gastric cancer.

METHODS

The relative expression levels of microRNA-3196 in gastric cancer tissues and adjacent normal tissues were detected by quantitative reverse transcription-polymerase chain reaction. In this study, quantitative reverse transcription-polymerase chain reaction, cell proliferation assay, and Transwell migration and invasion assays were performed to explore microRNA-3196 expression level and its effects on cell proliferation, migration, and invasion in gastric cancer cells. The Kaplan-Meier method and multivariate Cox regression analyses were used to explore the prognostic significance of microRNA-3196 in gastric cancer. Dual-luciferase report assay was performed to validate the potential target gene regulated by microRNA-3196 in gastric cancer.

RESULTS

The expression of microRNA-3196 was downregulated in gastric cancer tissues and cell lines. Downregulation of microRNA-3196 was associated with lymph node metastasis and Tumor Node Metastasis (TNM) stage. The Kaplan-Meier curve analysis indicated that patients with low expression of microRNA-3196 had a poor prognosis, and the Cox regression analysis results showed microRNA-3196 expression was an independent prognostic factor of gastric cancer. Moreover, overexpression of microRNA-3196 inhibited cell proliferation, migration, and invasion, while knockdown of microRNA-3196 promoted these cellular behaviors in AGS and MKN45 cells. OTX1 may be a potential target gene regulated by microRNA-3196 in gastric cancer.

CONCLUSIONS

These results suggested that microRNA-3196 might not only a tumor suppressor in gastric cancer cells by modulating OTX1 but also might be an independent prognostic biomarker and therapeutic target of gastric cancer.

miR-25-3p inhibition impairs tumorigenesis and invasion in gastric cancer cells in vitro and in vivo

Deregulated expression of microRNAs (miRNAs) plays a role in the pathogenesis and progression of gastric cancer (GC). Among upregulated miRNAs, miR-25-3p has oncogenic potential and therefore represents an attractive target for the treatment of GC. Here, we investigated the role of miR-25-3p on GC cells in vitro and in vivo. We found that miR-25-3p overexpression significantly promoted growth and invasion of gastric cancer cells in vitro. Conversely, targeting miR-25-3p triggered significant inhibition of growth, invasion and migration in GC cells in vitro. In vivo delivery of miR-25-3p inhibitors induced significant anti-tumor activity in SCID mice bearing human GC xenografts. Our findings showed the evidence that in vivo antagonism of miR-25-3p impaired tumorigenesis, providing the rationale for clinical development of miR-25-3p inhibitors in GC.

The current state of MiRNAs as biomarkers and therapeutic tools

MicroRNAs (miRNAs) are non-coding RNAs with a length of 18-22 nucleotides that regulate about a third of the human genome at the post-transcriptional level. MiRNAs are involved in almost all biological processes, including cell proliferation, apoptosis, and cell differentiation, but also play a key role in the pathogenesis of many diseases. Most miRNAs are expressed within the cells themselves. Due to various forms of transport from cells like exosomes, circulating miRNAs are stable and can be found in human body fluids, such as blood, saliva, cerebrospinal fluid, and urine. Circulating miRNAs are of great interest as potential noninvasive biomarkers for tumors, lipid disorders, diabetes mellitus, and cardiovascular diseases. However, the possibility of their use in the clinic is limited, and this is associated with a number of problems since currently there are significant differences between the procedures for processing samples, methods of analysis, and especially strategies for standardizing results. Moreover, miRNAs can represent not only potential biomarkers but also become new therapeutic agents and be used in modern clinical practice, which again confirms the need for their study.

miR-183-5p acts as a potential prognostic biomarker in gastric cancer and regulates cell functions by modulating EEF2

BACKGROUND

Gastric cancer (GC) is the fourth most prevalent malignant tumor and the second leading cause of cancer-related death around the world. Aberrant proliferation and metastasis are the mainspring of death in patients with GC. However, the specific mechanism of gastric cancer is far from being fully elucidated. Accumulating evidence revealed that miRNA played a significant role in the tumorigenesis and development.

METHODS

The level of miR-183-5p was detected in 102 GC patients by using qRT-PCR. The prognostic value of miR-183-5p in GC was evaluated. Cell function assays (CCK-8 and transwell assays) were conducted to assess the role of miR-183-5p in proliferation and metastasis in GC. Dual luciferase report assay and western blot were performed to validate this potential target regulated by miR-183-5p in GC.

RESULTS

miR-183-5p was down-regulated in GC tissues and cell lines. Remarkable pertinence was obtained between miR-183-5p level and TNM stage, tumor size, invasion depth, and lymph node metastasis. TNM stage, differentiation and miR-183-5p level were independent causes impacting on the overall survival in GC in multivariate analysis. GC individuals with high miR-183-5p level would experience a relatively better survival prognosis. Upregulation of miR-183-5p restrained GC cell proliferation and migration. EEF2 may be a potential target gene regulated by miR-183-5p in GC.

CONCLUSION

miR-183-5p acts as a potential prognostic biomarker in gastric cancer and regulates cell functions by modulating EEF2.