Downregulation of miR-484 is associated with poor prognosis and tumor progression of gastric cancer

miR-484 as an "OncomiR" in Breast Cancer Promotes Tumorigenesis by Suppressing Apoptosis Genes

PURPOSE

Breast cancer (BC) is one of the most common causes of death among females. Cancer cells escape from apoptosis, causing the cells to proliferate uncontrollably. MicroRNAs (miRNAs) are known to regulate apoptosis in cancer cells.

OBJECTIVE

This study aimed to determine the change in miR-484 in different BC cells and its relationship with the apoptosis pathway.

METHODS

In the study, tumor and healthy tissue samples adjacent to the tumor were collected from 42 patients (6 benign, 36 malignant). Tissue samples were classified according to tumor type, tumor histological grade, proliferation index, and molecular subtypes. Gene expression levels were determined by quantitative real-time polymerase chain reaction (qRT-PCR), and protein levels were determined using the Western Blot method. The results were analyzed using the delta-delta Ct method.

RESULTS

Findings showed that miR-484 expression levels were higher in malignant tumors than in benign tumors, and higher in tumor tissues than healthy tissues. Additionally, it was determined that as Ki-67 levels and histological grade and aggressiveness increased, miR-484 expression levels also increased. In tumor tissue compared with healthy adjacent tissue, there was an increase in BCL2 expression and a decrease in Casp3 and Casp9 expression. Therefore, a positive correlation was found between miR-484 expression and BCL2, and a negative correlation was found between CASP3 and CASP9 expression.

CONCLUSION

Our results show that miR-484 may play a roll as an onco-miR in BC. Increased miR-484 and BCL2, and decreased Casp3, in breast tumor tissues suggest that Casp9 expression may increase uncontrolled cell proliferation by suppressing apoptosis in BC cells and may contribute to tumor progression.

The role of microRNAs in the gastric cancer tumor microenvironment

BACKGROUND

Gastric cancer (GC) is one of the deadliest malignant tumors with unknown pathogenesis. Due to its treatment resistance, high recurrence rate, and lack of reliable early detection techniques, a majority of patients have a poor prognosis. Therefore, identifying new tumor biomarkers and therapeutic targets is essential. This review aims to provide fresh insights into enhancing the prognosis of patients with GC by summarizing the processes through which microRNAs (miRNAs) regulate the tumor microenvironment (TME) and highlighting their critical role in the TME.

MAIN TEXT

A comprehensive literature review was conducted by focusing on the interactions among tumor cells, extracellular matrix, blood vessels, cancer-associated fibroblasts, and immune cells within the GC TME. The role of noncoding RNAs, known as miRNAs, in modulating the TME through various signaling pathways, cytokines, growth factors, and exosomes was specifically examined. Tumor formation, metastasis, and therapy in GC are significantly influenced by interactions within the TME. miRNAs regulate tumor progression by modulating these interactions through multiple signaling pathways, cytokines, growth factors, and exosomes. Dysregulation of miRNAs affects critical cellular processes such as cell proliferation, differentiation, angiogenesis, metastasis, and treatment resistance, contributing to the pathogenesis of GC.

CONCLUSIONS

miRNAs play a crucial role in the regulation of the GC TME, influencing tumor progression and patient prognosis. By understanding the mechanisms through which miRNAs control the TME, potential biomarkers and therapeutic targets can be identified to improve the prognosis of patients with GC.

Implications of lncRNAs in Helicobacter pylori-associated gastrointestinal cancers: underlying mechanisms and future perspectives

Helicobacter pylori (H. pylori) is a harmful bacterium that is difficult to conveniently diagnose and effectively eradicate. Chronic H. pylori infection increases the risk of gastrointestinal diseases, even cancers. Despite the known findings, more underlying mechanisms are to be deeply explored to facilitate the development of novel prevention and treatment strategies of H. pylori infection. Long noncoding RNAs (lncRNAs) are RNAs with more than 200 nucleotides. They may be implicated in cell proliferation, inflammation and many other signaling pathways of gastrointestinal cancer progression. The dynamic expression of lncRNAs indicates their potential to be diagnostic or prognostic biomarkers. In this paper, we comprehensively summarize the processes of H. pylori infection and the treatment methods, review the known findings of lncRNA classification and functional mechanisms, elucidate the roles of lncRNAs in H. pylori-related gastrointestinal cancer, and discuss the clinical perspectives of lncRNAs.

LINC01133 regulates MARCKS expression via sponging miR-30d-5p to promote the development of lung squamous cell carcinoma

LncRNAs are vital regulators for lung squamous cell carcinoma (LUSC). However, the detailed role that LINC01133 plays in LUSC is unclear. This work sought to explore the potential function of LINC01133.Levels of LINC01133, miR-30d-5p, and MARCKS were separately tested in both tissues and cells using qRT-PCR. Proliferation was assessed through MTT experiment and apoptosis was detected upon flow cytometry. Transwell experiments were implemented to evaluate migratory and invasive abilities. The interaction between two genes was affirmed through luciferase reporter assay and RNA pull-down experiment. Western blotting measured the protein level of MARCKS. Animal models were established and tissues were taken for IHC analysis of MARCKS and Ki67.LINC01133 was elevated in LUSC and its downregulation could suppress proliferation, migration and invasion but induced apoptosis. LINC01133 interacted with and regulated the binding of miR-30d-5p to MARCKS. LINC01133/miR-30d-5p axis mediated proliferation, apoptosis, migration and invasion in LUSC cells, as well as modulated tumor growth in animal models. LINC01133 interacted with miR-30d-5p to modulate MARCKS expression, contributes to promoted cell proliferation, migration, invasion, and inhibited cell apoptosis in vitro, and promoted tumor growth in vivo. These findings could provide possible therapeutic targets in view of LUSC treatment in the future.

Exploring MiR-484 Regulation by Polyalthia longifolia: A Promising Biomarker and Therapeutic Target in Cervical Cancer through Integrated Bioinformatics and an In Vitro Analysis

BACKGROUND

MiR-484, implicated in various carcinomas, holds promise as a prognostic marker, yet its relevance to cervical cancer (CC) remains unclear. Our prior study demonstrated the Polyalthia longifolia downregulation of miR-484, inhibiting HeLa cells. This study investigates miR-484's potential as a biomarker and therapeutic target in CC through integrated bioinformatics and an in vitro analysis.

METHODS

MiR-484 levels were analyzed across cancers, including CC, from The Cancer Genome Atlas. The limma R package identified differentially expressed genes (DEGs) between high- and low-miR-484 CC cohorts. We assessed biological functions, tumor microenvironment (TME), immunotherapy, stemness, hypoxia, RNA methylation, and chemosensitivity differences. Prognostic genes relevant to miR-484 were identified through Cox regression and Kaplan-Meier analyses, and a prognostic model was captured via multivariate Cox regression. Single-cell RNA sequencing determined cell populations related to prognostic genes. qRT-PCR validated key genes, and the miR-484 effect on CC proliferation was assessed via an MTT assay.

RESULTS

MiR-484 was upregulated in most tumors, including CC, with DEGs enriched in skin development, PI3K signaling, and immune processes. High miR-484 expression correlated with specific immune cell infiltration, hypoxia, and drug sensitivity. Prognostic genes identified were predominantly epidermal and stratified patients with CC into risk groups, with the low-risk group showing enhanced survival and immunotherapeutic responses. qRT-PCR confirmed FGFR3 upregulation in CC cells, and an miR-484 mimic reversed the P. longifolia inhibitory effect on HeLa proliferation.

CONCLUSION

MiR-484 plays a crucial role in the CC progression and prognosis, suggesting its potential as a biomarker for targeted therapy.

Immune checkpoints signature-based risk stratification for prognosis of patients with gastric cancer

Until now, few researches have comprehensive explored the role of immune checkpoints (ICIs) and tumor microenvironment (TME) in gastric cancer (GC) patients based on the genomic data. RNA-sequence data and clinical information were obtained from The Cancer Genome Atlas Stomach Adenocarcinoma (TCGA-STAD) database, GSE84437 and GSE84433. Univariate Cox analysis identified 60 ICIs with prognostic values, and these genes were then subjected to NMF cluster analysis and the GC samples (n = 804) were classified into two distinct subtypes (Cluster 1: n = 583; Cluster 2: n = 221). The Kaplan-Meier curves for OS analysis indicated that C1 predicted a poorer prognosis. The C2 subtype illustrated a relatively better prognosis and characteristics of "hot tumors," including high immune score, overexpression of immune checkpoint molecules, and enriched tumor-infiltrated immune cells, indicating that the NMF clustering in GC was robust and stable. Regarding the patient's heterogeneity, an ICI-score was constructed to quantify the ICI patterns in individual patients. Moreover, the study found that the low ICI-score group contained mostly MSI-low events, and the high ICI-score group contained predominantly MSI-high events. In addition, the ICI-score groups had good responsiveness to CTLA4 and PD-1 based on The Cancer Immunome Atlas (TCIA) database. Our research firstly constructed ICIs signature, as well as identified some hub genes in GC patients.

Serum microRNA as a potential biomarker for the activity of thyroid eye disease

The aim of this study is to characterize the microRNA (miRNA) expression signatures in patients with thyroid eye disease (TED) and identify miRNA biomarkers of disease activity. Total RNA was isolated from the sera of patients with TED (n = 10) and healthy controls (HCs, n = 5) using the miRNeasy Serum/Plasma Kit. The NanoString assay was used for the comprehensive analysis of 798 miRNA expression profiles. Analysis of specific miRNA signatures, mRNA target pathway analysis, and network analysis were performed. Patients with TED were divided into two groups according to disease activity: active and inactive TED groups. Differentially expressed circulating miRNAs were identified and tested using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) tests in the validation cohort. Among the 798 miRNAs analyzed, 173 differentially downregulated miRNAs were identified in TED patients compared to those in the HCs. Ten circulating miRNAs were differentially expressed between the active and inactive TED groups and regarded as candidate biomarkers for TED activity (one upregulated miRNA: miR-29c-3p; nine downregulated miRNAs: miR-4286, miR-941, miR-571, miR-129-2-3p, miR-484, miR-192-5p, miR-502-3p, miR-597-5p, and miR-296-3p). In the validation cohort, miR-484 and miR-192-5p showed significantly lower expression in the active TED group than in the inactive TED group. In conclusion, the expression levels of miR-484 and miR-192-5p differed significantly between the active and inactive TED groups, suggesting that these miRNAs could serve as circulating biomarkers of TED activity, however, these findings need to be validated in further studies.

Ceramide Metabolism Regulated by Sphingomyelin Synthase 2 Is Associated with Acquisition of Chemoresistance via Exosomes in Human Leukemia Cells

Ceramide levels controlled by the sphingomyelin (SM) cycle have essential roles in cancer cell fate through the regulation of cell proliferation, death, metastasis, and drug resistance. Recent studies suggest that exosomes confer cancer malignancy. However, the relationship between ceramide metabolism and exosome-mediated cancer malignancy is unclear. In this study, we elucidated the role of ceramide metabolism via the SM cycle in exosomes and drug resistance in human leukemia HL-60 and adriamycin-resistant HL-60/ADR cells. HL-60/ADR cells showed significantly increased exosome production and release compared with parental chemosensitive HL-60 cells. In HL-60/ADR cells, increased SM synthase (SMS) activity reduced ceramide levels, although released exosomes exhibited a high ceramide ratio in both HL-60- and HL-60/ADR-derived exosomes. Overexpression of SMS2 but not SMS1 suppressed intracellular ceramide levels and accelerated exosome production and release in HL-60 cells. Notably, HL-60/ADR exosomes conferred cell proliferation and doxorubicin resistance properties to HL-60 cells. Finally, microRNA analysis in HL-60 and HL-60/ADR cells and exosomes showed that miR-484 elevation in HL-60/ADR cells and exosomes was associated with exosome-mediated cell proliferation. This suggests that intracellular ceramide metabolism by SMS2 regulates exosome production and release, leading to acquisition of drug resistance and enhanced cell proliferation in leukemia cells.

Total xanthone in mangosteen inhibits cell proliferation, migration, invasion, and inflammatory response in gastric cancer cells by regulating miR-338-3p

BACKGROUND

Total xanthone in mangosteen has antitumor effect, but its effect on the biological behavior of gastric cancer cells is still unknown. MicroRNAs (miRNAs) can play an important regulatory role in the occurrence and development of gastric cancer and may be a potential target for gastric cancer treatment, but whether they could be potential targets for total xanthone in mangosteen in the treatment of gastric cancer is unknown.

AIM

To explore the effect of total xanthone in mangosteen on the biological behavior of gastric cancer AGS cells and the possible mechanism involved.

METHODS

Human gastric cancer AGS cells were randomly divided into the following groups: NC group, low-dose xanthone group, medium-dose xanthone group, high-dose xanthone group, miR-NC group, miR-338-3p group, high-dose xanthone + anti-miR-NC group, and high-dose xanthone group + anti-miR-338-3p group. MTT and Transwell assays were used to detect cell proliferation, migration, and invasion. ELISA was used to detect the levels of TNF-α, IL-6, and IL-1β. qRT-PCR was used to detect the expression of miR-338-3p.

RESULTS

After treatment with total xanthone in mangosteen, cell viability and the levels of TNF-α, IL-6, and IL-1β were decreased (P < 0.05), the number of migrating and invasive cells was decreased (P < 0.05), and the expression of miR-338-3p was increased (P < 0.05). After transfection with miR-338-3p mimic, cell viability and the levels of TNF-α, IL-6, and IL-1β were decreased (P < 0.05), and the number of migrating and invasive cells was decreased (P < 0.05). Transfection with anti-miR-338-3p could reverse the effect of total xanthone in mangosteen on the biological behavior of AGS cells.

CONCLUSION

Total xanthone in mangosteen can inhibit the proliferation, migration, invasion, and inflammatory response of gastric cancer cells by promoting the expression of miR-338-3p.

miR-484: A Potential Biomarker in Health and Disease

Disorders of miR-484 expression are observed in cancer, different diseases or pathological states. There is accumulating evidence that miR-484 plays an essential role in the development as well as the regression of different diseases, and miR-484 has been reported as a key regulator of common cancer and non-cancer diseases. The miR-484 targets that have effects on inflammation, apoptosis and mitochondrial function include SMAD7, Fis1, YAP1 and BCL2L13. For cancer, identified targets include VEGFB, VEGFR2, MAP2, MMP14, HNF1A, TUSC5 and KLF12. The effects of miR-484 on these targets have been documented separately. Moreover, miR-484 is typically described as an oncosuppressor, but this claim is simplistic and one-sided. This review will combine relevant basic and clinical studies to find that miR-484 promotes tumorigenesis and metastasis in liver, prostate and lung tissues. It will provide a basis for the possible mechanisms of miR-484 in early tumor diagnosis, prognosis determination, disease assessment, and as a potential therapeutic target for tumors.

Characteristics of the Immune Cell Infiltration Landscape in Gastric Cancer to Assistant Immunotherapy

Background: Gastric cancer (GC) was usually associated with poor prognosis and invalid therapeutical response to immunotherapy due to biological heterogeneity. It is urgent to screen reliable indices especially immunotherapy-associated parameters that can predict the therapeutic responses to immunotherapy of GC patients.

Methods: Gene expression profile of 854 GC patients were collected from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets (GSE84433) with their corresponding clinical and somatic mutation data. Based on immune cell infiltration (ICI) levels, molecular clustering classification was performed to identify subtypes and ICI scores in GC patients. After functional enrichment analysis of subtypes, we further explored the correlation between ICI scores and Tumor Mutation Burden (TMB) and the significance in clinical immunotherapy response.

Results: Three subtypes were identified based on ICI scores with distinct immunological and prognostic characteristics. The ICI-cluster C, associated with better outcomes, was characterized by significantly higher stromal and immune scores, T lymphocytes infiltration and up-regulation of PD-L1. ICI scores were identified through using principal component analysis (PCA) and the low ICI scores were consistent with the increased TMB and the immune-activating signaling pathways. Contrarily, the high-ICI score cluster was involved in the immunosuppressive pathways, such as TGF-beta, MAPK and WNT signaling pathways, which might be responsible for poor prognosis of GC. External immunotherapy and chemotherapy cohorts validated the patients with lower ICI scores exhibited significant therapeutic responses and clinical benefits.

Conclusion: This study elucidated that ICI score could sever as an effective prognostic and predictive indicator for immunotherapy in GC. These findings indicated that the systematic assessment of tumor ICI landscapes and identification of ICI scores have crucial clinical implications and facilitate tailoring optimal immunotherapeutic strategies.

Characterization of microRNA expression in B cells derived from Japanese black cattle naturally infected with bovine leukemia virus by deep sequencing

Bovine leukemia virus (BLV) is the causative agent of enzootic bovine leukosis (EBL), a malignant B cell lymphoma. However, the mechanisms of BLV-associated lymphomagenesis remain poorly understood. Here, after deep sequencing, we performed comparative analyses of B cell microRNAs (miRNAs) in cattle infected with BLV and those without BLV. In BLV-infected cattle, BLV-derived miRNAs (blv-miRNAs) accounted for 38% of all miRNAs in B cells. Four of these blv-miRNAs (blv-miR-B1-5p, blv-miR-B2-5p, blv-miR-B4-3p, and blv-miR-B5-5p) had highly significant positive correlations with BLV proviral load (PVL). The read counts of 90 host-derived miRNAs (bta-miRNAs) were significantly down-regulated in BLV-infected cattle compared to those in uninfected cattle. Only bta-miR-375 had a positive correlation with PVL in BLV-infected cattle and was highly expressed in the B cell lymphoma tissue of EBL cattle. There were a few bta-miRNAs that correlated with BLV tax/rex gene expression; however, BLV AS1 expression had a significant negative correlation with many of the down-regulated bta-miRNAs that are important for tumor development and/or tumor suppression. These results suggest that BLV promotes lymphomagenesis via AS1 and blv-miRNAs, rather than tax/rex, by down-regulating the expression of bta-miRNAs that have a tumor-suppressing function, and this downregulation is linked to increased PVL.

Long Non-Coding RNA PCED1B-AS1 Promotes the Progression of Clear Cell Renal Cell Carcinoma Through miR-484/ZEB1 Axis

Background

Long non-coding RNA (lncRNA) has been recognized as the new regulator and biomarker for cancers. However, in clear cell renal cell carcinoma (ccRCC), the functions of lncRNAs are not well characterized. This research aimed to probe the function of lncRNA PCED1B-AS1 in the progression of ccRCC.

Materials and Methods

Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to detect the expression levels of PCED1B-AS1, microRNA-484 (miR-484), and zinc finger E-box binding homeobox 1 (ZEB1) in 40 pairs of human ccRCC tissues and corresponding adjacent kidney tissue samples. Chi-square test was employed to evaluate the association between PCED1B-AS1 expression level and clinicopathological characteristics. The effects of PCED1B-AS1, miR-484 and ZEB1 on the cell proliferation, migration and epithelial-mesenchymal transition (EMT) process of ccRCC cells were studied by CCK-8 assay, EdU cell proliferation assay, wound healing test and Western blotting. The regulatory relationships among PCED1B-AS1, miR-484, ZEB1 were examined by luciferase reporter gene assay and RNA immunoprecipitation assay.

Results

PCED1B-AS1 was remarkably up-regulated in ccRCC tissues and cell lines. High expression of PCED1B-AS1 was associated with poor prognosis of the patients. Loss-of-function experiments showed that PCED1B-AS1 could regulate the proliferation, migration and EMT of ccRCC cells. PCED1B-AS1 sponged miR-484 to suppress its expression, and miR-484 targeted the 3ʹ-UTR of ZEB1 to repress the expression of ZEB1. MiR-484 counteracted the functions of PCED1B-AS1 in promoting the proliferation, migration and EMT of ccRCC cells, and PCED1B-AS1 promotes the expression of ZEB1 via repressing miR-484.

Conclusion

PCED1B-AS1/miR-484/ZEB1 axis is involved in regulating the progression of ccRCC.

MicroRNA in Gastric Cancer Development: Mechanisms and Biomarkers

Gastric cancer (GC) is one of the most common and difficult diseases to treat. The study of signaling pathway regulation by microRNA provides information on the mechanisms of GC development and is the basis for biomarker creation. In this study, a circuit of microRNA interactions with signaling pathways was constructed. The microRNAs, associated with metastasis and chemoresistance, are described. In most cases, microRNAs in GC regulate the Wnt/β-catenin, PI3K/AKT/mTOR, RAS/RAF/ERK/MAPK, NF-kB, TGF-β, and JAK/STAT pathways. Part of the microRNA acts on several target genes that function in different pathways. This often leads to an intensification of the induced processes. MicroRNAs have also been described that have the opposite effect on different pathways, causing different functional consequences. By acting on several target genes, or genes associated with several pathways, microRNAs can function in a signaling network. MicroRNAs associated with metastasis most often interact with the Wnt/β-catenin pathway. MicroRNAs affecting chemoresistance, in most cases, affect the regulators of apoptosis and are associated with the PI3K/AKT/mTOR pathway. The characteristics of microRNAs proposed as candidates for GC biomarkers were analyzed. The currently developed diagnostic and prognostic panels of microRNAs are also considered.