The intricate role of miR-155 in carcinogenesis: potential implications for esophageal cancer research

A new era of cancer immunotherapy: vaccines and miRNAs

Cancer immunotherapy has transformed the treatment landscape, introducing new strategies to fight various types of cancer. This review examines the important role of vaccines in cancer therapy, focusing on recent advancements such as dendritic cell vaccines, mRNA vaccines, and viral vector-based approaches. The relationship between cancer and the immune system highlights the importance of vaccines as therapeutic tools. The discussion covers tumor cell and dendritic cell vaccines, protein/peptide vaccines, and nucleic acid vaccines (including DNA, RNA, or viral vector-based), with a focus on their effectiveness and underlying mechanisms. Combination therapies that pair vaccines with immune checkpoint inhibitors, TIL therapy, and TCR/CAR-T cell therapy show promising potential, boosting antitumor responses. Additionally, the review explores the regulatory functions of microRNAs (miRNAs) in cancer development and suppression, featuring miR-21, miR-155, the let-7 family, and the miR-200 family, among others. These miRNAs influence various pathways, such as PI3K/AKT, NF-κB, and EMT regulation, providing insights into biomarker-driven therapeutic strategies. Overall, this work offers a thorough overview of vaccines in oncology and the integrative role of miRNAs, setting the stage for the next generation of cancer immunotherapies.

ENTPD8 overexpression enhances anti-PD-L1 therapy in hepatocellular carcinoma via miR-214-5p inhibition

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths globally, with poor prognosis due to late diagnosis and limited treatment options. In this study, we evaluated the expression of ectonucleoside triphosphate diphosphohydrolase 8 (ENTPD8) in HCC tissues and its clinical significance. Immunohistochemistry, The Cancer Genome Atlas (TCGA) data, and single-cell expression analysis revealed reduced ENTPD8 levels in liver cancer compared to adjacent tissues, with ENTPD8 primarily expressed in tumor cells within the tumor tissue. In vitro assays demonstrated that ENTPD8 inhibits HCC cell proliferation, invasion, and migration. Mechanistically, ENTPD8 regulates programmed death-ligand 1 (PD-L1) expression through miR-214-5p modulation. In vivo, ENTPD8 overexpression combined with anti-PD-L1 treatment enhanced therapeutic efficacy in HCC mouse models. These findings suggest that ENTPD8 may serve as a prognostic marker and therapeutic target for HCC, offering potential strategies for improving treatment outcomes.

From inflammation to metastasis: The central role of miR-155 in modulating NF-κB in cancer

Cancer is a multifaceted, complex disease characterized by unchecked cell growth, genetic mutations, and dysregulated signalling pathways. These factors eventually cause evasion of apoptosis, sustained angiogenesis, tissue invasion, and metastasis, which makes it difficult for targeted therapeutic interventions to be effective. MicroRNAs (miRNAs) are essential gene expression regulators linked to several biological processes, including cancer and inflammation. The NF-κB signalling pathway, a critical regulator of inflammatory reactions and oncogenesis, has identified miR-155 as a significant participant in its modulation. An intricate network of transcription factors known as the NF-κB pathway regulates the expression of genes related to inflammation, cell survival, and immunological responses. The NF-κB pathway's dysregulation contributes to many cancer types' development, progression, and therapeutic resistance. In numerous cancer models, the well-studied miRNA miR-155 has been identified as a crucial regulator of NF-κB signalling. The p65 subunit and regulatory molecules like IκB are among the primary targets that miR-155 directly targets to alter NF-κB activity. The molecular processes by which miR-155 affects the NF-κB pathway are discussed in this paper. It also emphasizes the miR-155's direct and indirect interactions with important NF-κB cascade elements to control the expression of NF-κB subunits. We also investigate how miR-155 affects NF-κB downstream effectors in cancer, including inflammatory cytokines and anti-apoptotic proteins.

miR-142: A Master Regulator in Hematological Malignancies and Therapeutic Opportunities

MicroRNAs (miRNAs) are a type of non-coding RNA whose dysregulation is frequently associated with the onset and progression of human cancers. miR-142, an ultra-conserved miRNA with both active -3p and -5p mature strands and wide-ranging physiological targets, has been the subject of countless studies over the years. Due to its preferential expression in hematopoietic cells, miR-142 has been found to be associated with numerous types of lymphomas and leukemias. This review elucidates the multifaceted role of miR-142 in human physiology, its influence on hematopoiesis and hematopoietic cells, and its intriguing involvement in exosome-mediated miR-142 transport. Moreover, we offer a comprehensive exploration of the genetic and molecular landscape of the miR-142 genomic locus, highlighting its mutations and dysregulation within hematological malignancies. Finally, we discuss potential avenues for harnessing the therapeutic potential of miR-142 in the context of hematological malignancies.

MicroRNAs in Cancer and Cardiovascular Disease

Although cardiac tumor formation is rare, accumulating evidence suggests that the two leading causes of deaths, cancers, and cardiovascular diseases are similar in terms of pathogenesis, including angiogenesis, immune responses, and fibrosis. These similarities have led to the creation of new exciting field of study called cardio-oncology. Here, we review the similarities between cancer and cardiovascular disease from the perspective of microRNAs (miRNAs). As miRNAs are well-known regulators of translation by binding to the 3'-untranslated regions (UTRs) of messenger RNAs (mRNAs), we carefully dissect how a specific set of miRNAs are both oncomiRs (miRNAs in cancer) and myomiRs (muscle-related miRNAs). Furthermore, from the standpoint of similar pathogenesis, miRNAs categories related to the similar pathogenesis are discussed; namely, angiomiRs, Immune-miRs, and fibromiRs.

The Epitranscriptome in miRNAs: Crosstalk, Detection, and Function in Cancer

The epitranscriptome encompasses all post-transcriptional modifications that occur on RNAs. These modifications can alter the function and regulation of their RNA targets, which, if dysregulated, result in various diseases and cancers. As with other RNAs, miRNAs are highly modified by epitranscriptomic modifications such as m6A methylation, 2'-O-methylation, m5C methylation, m7G methylation, polyuridine, and A-to-I editing. miRNAs are a class of small non-coding RNAs that regulates gene expression at the post-transcriptional level. miRNAs have gathered high clinical interest due to their role in disease, development, and cancer progression. Epitranscriptomic modifications alter the targeting, regulation, and biogenesis of miRNAs, increasing the complexity of miRNA regulation. In addition, emerging studies have revealed crosstalk between these modifications. In this review, we will summarize the epitranscriptomic modifications-focusing on those relevant to miRNAs-examine the recent crosstalk between these modifications, and give a perspective on how this crosstalk expands the complexity of miRNA biology.

miR-155 regulates physiological angiogenesis but an miR-155-rich microenvironment disrupts the process by promoting unproductive endothelial sprouting

Angiogenesis involves cell specification orchestrated by regulatory interactions between the vascular endothelial growth factor and Notch signaling pathways. However, the role of microRNAs in these regulations remains poorly explored. Here we show that a controlled level of miR-155 is essential for proper angiogenesis. In the mouse retina angiogenesis model, antimiR-155 altered neovascularization. In vitro assays established that endogenous miR-155 is involved in podosome formation, activation of the proteolytic machinery and cell migration but not in morphogenesis. The role of miR-155 was explored using miR-155 mimics. In vivo, exposing the developing vasculature to miR-155 promoted hypersprouting, thus phenocopying defects associated with Notch deficiency. Mechanistically, miR-155 overexpression weakened Notch signaling by reducing Smad1/5 expression, leading to the formation of tip cell-like cells which did not reach full invasive capacity and became unable to undergo morphogenesis. These results identify miR-155 as a novel regulator of physiological angiogenesis and as a novel actor of pathological angiogenesis.

The Role of Mitochondrial miRNAs in the Development of Radon-Induced Lung Cancer

MicroRNAs are short, non-coding RNA molecules regulating gene expression by inhibiting the translation of messenger RNA (mRNA) or leading to degradation. The miRNAs are encoded in the nuclear genome and exported to the cytosol. However, miRNAs have been found in mitochondria and are probably derived from mitochondrial DNA. These miRNAs are able to directly regulate mitochondrial genes and mitochondrial activity. Mitochondrial dysfunction is the cause of many diseases, including cancer. In this review, we consider the role of mitochondrial miRNAs in the pathogenesis of lung cancer with particular reference to radon exposure.

MiR-155 Inhibitor-Laden Exosomes Reverse Resistance to Cisplatin in a 3D Tumor Spheroid and Xenograft Model of Oral Cancer

Cisplatin resistance is one of the major concerns in the treatment of oral squamous cell carcinoma (OSCC). Accumulating evidence suggests microRNA (miRNA) dysregulation as one of the mediators of chemoresistance. Toward this, our previous study revealed the role of exosomal microRNA-155 (miR-155) in cisplatin resistance via downregulation of FOXO3a, a direct target of miR-155, and induction of epithelial-to-mesenchymal transition in OSCC. In the present study, we demonstrate the therapeutic potential of miR-155 inhibitor-laden exosomes in the sensitization of a cisplatin-resistant (cis^Res) OSCC 3D tumor spheroid and xenograft mouse model. The cis^Res OSSC 3D tumor spheroid model recapitulated the hallmarks of solid tumors such as enhanced hypoxia, reactive oxygen species, and secretory vascular endothelial growth factor. Further treatment with miR-155 inhibitor-loaded exosomes showed the upregulation of FOXO3a and induction of the mesenchymal-to-epithelial transition with improved sensitization to cisplatin in cis^Res tumor spheroids and xenograft mouse model. Moreover, the exosomal miR-155 inhibitor suppressed the stem-cell-like property as well as drug efflux transporter protein expression in cisplatin-resistant tumors. Taken together, our findings, for the first time, established that the miR-155 inhibitor-loaded exosomes reverse chemoresistance in oral cancer, thereby providing an alternative therapeutic strategy for the management of refractory oral cancer patients.

The clinical significance and function of miR-146 in the promotion of epidural fibrosis

Epidural fibrosis is the main cause of failed back surgery syndrome. To investigate the role of miR-146 in the diagnosis and development of epidural fibrosis. Lumbar disc tissues were collected from 72 lumbar disc herniation patients (45 developed epidural fibrosis and 27 did not). The expression of miR-146 in collected tissues and isolated epidural fibroblasts was detected by RT-qPCR. The relative levels of pro-inflammatory cytokines were analyzed by ELISA. The effect of miR-146 on the proliferation of fibroblasts was evaluated by MTT assay. miR-146 was significantly upregulated in epidural fibrosis patients compared with control patients. The expression of miR-146 was closely associated with the location, lower limb symptom and duration of disease of epidural fibrosis patients, and was positively correlated with the relative levels of pro-inflammatory cytokines. Moreover, miR-146 could discriminate epidural fibrosis patients from control patients. In isolated epidural fibroblasts, the overexpression of miR-146 dramatically enhanced its proliferation and the inflammatory response. miR-146 serves as a diagnostic biomarker for the early detection of epidural fibrosis. The upregulation of miR-146 enhanced the fibroblasts proliferation and inflammatory response in epidural fibrosis. This study provides a novel potential therapeutic target for epidural fibrosis.

MicroRNAs Regulating Tumor and Immune Cell Interactions in the Prediction of Relapse in Early Stage Breast Cancer

MicroRNAs (miRNAs) are involved in the regulation of immune response and hold an important role in tumor immune escape. We investigated the differential expression of the immunomodulatory miR-10b, miR-19a, miR-20a, miR-126, and miR-155 in the plasma of healthy women and patients with early stage breast cancer and interrogated their role in the prediction of patients’ relapse. Blood samples were obtained from healthy women (n = 20) and patients with early stage breast cancer (n = 140) before adjuvant chemotherapy. Plasma miRNA expression levels were assessed by RT-qPCR. Relapse predicting models were developed using binary logistic regression and receiver operating curves (ROC) were constructed to determine miRNA sensitivity and specificity. Only miR-155 expression was lower in patients compared with healthy women (p = 0.023), whereas miR-155 and miR-10b were lower in patients who relapsed compared with healthy women (p = 0.039 and p = 0.002, respectively). MiR-155 expression combined with axillary lymph node infiltration and tumor grade demonstrated increased capability in distinguishing relapsed from non-relapsed patients [(area under the curve, (AUC = 0.861; p < 0.001)]. Combined miR-19a and miR-20a expression had the highest performance in discriminating patients with early relapse (AUC = 0.816; p < 0.001). Finally, miR-10b in combination with lymph node status and grade had the highest accuracy to discriminate patients with late relapse (AUC = 0.971; p < 0.001). The robustness of the relapse predicting models was further confirmed in a 10-fold cross validation. Deregulation of circulating miRNAs involved in tumor-immune interactions may predict relapse in early stage breast cancer. Their successful clinical integration could potentially address the significance challenge of treatment escalation or de-escalation according to the risk of recurrence.

Lead (Pb) exposure is associated with changes in the expression levels of circulating miRNAS (miR-155, miR-126) in Mexican women

The environmental contamination with lead (Pb) is considered a critical issue worldwide. Therefore, this study aimed to evaluate the expression levels of circulating miRNAs (miR-155, miR-126, and miR-145) in Mexican women exposed to Pb. Blood lead levels (BLL) were assessed in enrolled women (n = 190) using an atomic absorption method. Also, serum miRNAs expression levels were quantified through a real-time PCR assay. A mean BLL of 10.5 ± 4.50 μg/dL was detected. Overexpression of miR-155 was detected in highly exposed women. Besides, a significant simple positive relationship (p < 0.05) was found between BLL and serum miR-155 expression levels. Additionally, a significant inverse correlation (p < 0.05) was determined between BLL and serum miR-126 expression levels, as downregulation of miR-126 expression levels was observed in highly exposed women. The findings in this study are the concern, as epigenetic changes detected may represent a connection between health illnesses and Pb exposure.

Demethylated miR-216a Regulates High Mobility Group Box 3 Promoting Growth of Esophageal Cancer Cells Through Wnt/β-Catenin Pathway

Background

Esophageal cancer (EC) is the eighth most common cause of cancer-associated mortality in humans. Recent studies have revealed the important roles of microRNAs (miRs) in mediating tumor initiation and progression. miR-216a has been found to be involved in the progression of EC, but the underlying mechanisms remain largely unknown. The aim of this study is to explore the mechanism of miR-216a and the downstream molecules in esophageal cancer.

Materials and Methods

The degree of methylation of miR-216a promoter in EC tissues and cell lines was determined with methylation specific polymerase chain reaction (MSP). The levels of miR-216a and HMGB3 in EC cells were quantified by quantitative PCR (qPCR) and Western blot (WB). EC cell lines were treated with DNA methylation inhibitor 5-aza-2’-deoxycytidine (5-AZ), miR-216a mimics, and HMGB3 siRNA to explore the effects of miR-216a and HMGB3 on the proliferation, migration, invasion, and apoptosis of cells. Dual-luciferase reporter assay was employed to verify the binding of miR-216a to the 3’UTR of HMGB2 mRNA.

Results

The promoter of MiR-216a was hypermethylated and the expression of miR-216a was down-regulated in EC, while HMGB3 was up-regulated. Dual luciferase reporter assay confirmed the binding of miR-216a to the 3’UTR of HMGB3 mRNA. Demethylated miR-216a and miR-216a mimics elevated miR-216a expression and down-regulated HMGB3, as well as inhibited cell proliferation, migration, and invasion. Inhibiting the expression of HMGB3 played an important role in inducing apoptosis, suppressing cell expansion, and down-regulating the activity of Wnt/β-catenin pathway.

Conclusions

Hypermethylation in the promoter of miR-216a upregulated HMGB3 and the Wnt/β-catenin pathway, resulting in enhanced EC progression.

Assessment of circulating miR-20b, miR-221, and miR-155 in occupationally lead-exposed workers of North-Western India

Lead (Pb), a toxic heavy metal, is capable of inducing several adverse health effects following its accumulation in the body. Lead is a potential carcinogen, capable of causing multisystem alterations. Recent reports identify small regulatory RNA molecules-miRNAs-which show differential expression in individuals exposed to similar levels of lead. These miRNAs can become potential molecular biomarkers of lead toxicity in the future and may unravel the possible molecular pathways through which this metal may exert its toxic manifestations. The present study aimed to assess the circulating levels of miRNA-20b, 221, and 155 in occupationally lead-exposed workers and correlate them with blood lead levels. One hundred ten participants working in various factories of Jodhpur and 97 participants not occupationally exposed to lead were recruited after obtaining due informed consent. Blood lead level (BLL) was estimated by graphite furnace atomic absorption spectrophotometry (GF-AAS). Circulating miRNAs were isolated from serum by Qiagen miRNA isolation kit and converted to cDNA by commercial kit. Expression profiles of miR-20b, miR-221, and miR-155 were performed in RT-PCR using Qiagen miRNA PCR assays. The blood lead level (mean ± SD) of occupationally lead-exposed subjects was 6.94 ± 11.96 μg/dL while that of non-exposed was 2.39 ± 4.66 μg/dL. Out of the three miRNAs, miR-155 and miR-221 were significantly upregulated, while miR-20b did not show significant difference among study groups. The fold change of miR-20b, miR-221 and miR-155 expression were 1.08, 2.71 and 2.07 respectively. Functional analysis revealed that these miRNAs have the potential to trigger various genes and cellular pathways. The findings of our study highlight the importance of miRNA dysregulation in lead-exposed individuals that may contribute to the systemic effects of lead toxicity.

Circular RNA hsa_circ_0001829 promotes gastric cancer progression through miR-155-5p/SMAD2 axis

Background

Accumulating evidences have shown that circular RNAs (circRNAs) play important roles in regulating the pathogenesis of cancer. However, the role of circRNAs in gastric cancer (GC) remains largely unclear.

Methods

In this study, we identified a novel upregulated circRNA, hsa_circ_0001829, in chemically induced malignant transformed human gastric epithelial cells using RNA-seq. Subsequent qRT-PCR and ISH assays were performed to detect the expression level of hsa_circ_0001829 in GC cell lines and tissues. Functional roles of hsa_circ_0001829 in GC were then explored by loss- and gain-of- function assays. Bioinformatic prediction and luciferase assay were used to investigate potential mechanisms of hsa_circ_0001829. Finally, the mice xenograft and metastasis models were constructed to assess the function of hsa_circ_0001829 in vivo.

Results

We found that hsa_circ_0001829 was significantly upregulated in GC tissues and cell lines. Loss- and gain-of- function assays showed that hsa_circ_0001829 promotes GC cells proliferation, migration and invasion, and the affected cell cycle progression and apoptosis rates may account for the effect of hsa_circ_0001829 on GC proliferation. In addition, bioinformatic prediction and luciferase assay showed that hsa_circ_0001829 acts as a molecular sponge for miR-155-5p and that SMAD2 was a target gene of miR-155-5p; moreover, hsa_circ_0001829 sponges miR-155-5p to regulate SMAD2 expression and hsa_circ_0001829 promotes GC progression through the miR-155-5p–SMAD2 pathway. Finally, suppression of hsa_circ_0001829 expression inhibited tumor growth and aggressiveness in vivo.

Conclusion

Taken together, our findings firstly demonstrated a novel oncogenic role of hsa_circ_0001829 in GC progression through miR-155-5p–SMAD2 axis, and our study may offer novel biomarkers and therapeutic targets for GC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-020-01790-w.

Integrative analyses of triple negative dysregulated transcripts compared with non-triple negative tumors and their functional and molecular interactions

Triple-negative (TN) tumors are a subtype of breast cancer with aggressive behaviors and limited targeted therapies. Microarray studies were not concerned with interactions and functional relations of dysregulated transcripts. Here, we aimed to conduct integrative strategy to analyze gene and miRNA available microarray data as well as bioinformatic analyses to catch a more inclusive picture of pivotal dysregulated transcripts and their interactions in TN tumors. Several online datasets and offline bioinformatic tools were used to detect differentially expressed (DE) transcripts, both protein and nonprotein coding, in TN compared with non-TN tumors and their functional and molecular interactions. Sixteen upregulated and 58 downregulated genes with a log fold change higher or equal to | 2 | were identified, including nine transcription factors. Coexpression network revealed EN1 as a hub gene, moreover Kaplan-Meier plotter survival analysis indicated that it was an appropriate prognostic marker for TN patients with breast cancer. Functional annotation analysis of protein-protein interaction network showed FOXM1 as an upexpressed and ESR1 as a downexpressed hub genes are suitable targets as far as antitumor protein therapy is concerned in TN breast cancers. The consensus analysis of two microRNA datasets revealed seven DE miRNAs. The gene-transcriptional factor (TF)-miRNA network revealed mir-135b and mir-29b are the hub nodes and involved in feedback loops with GATA3. This study suggests that dysregulated TFs and miRNAs have pivotal roles in regulation of TN oncotranscriptomic profile and might become both biomarkers and therapeutic targets.