MicroRNAs: Pleiotropic Regulators in the Tumor Microenvironment

Prediction of bladder cancer prognosis and immune microenvironment assessment using machine learning and deep learning models

Bladder cancer (BCa) is a heterogeneous malignancy characterized by distinct immune subtypes, primarily due to differences in tumor-infiltrating immune cells and their functional characteristics. Therefore, understanding the tumor immune microenvironment (TIME) landscape in BCa is crucial for prognostic prediction and guiding precision therapy. In this study, we integrated 10 machine learning algorithms to develop an immune-related machine learning signature (IRMLS) and subsequently created a deep learning model to detect the IRMLS subtype based on pathological images. The IRMLS proved to be an independent prognostic factor for overall survival (OS) and demonstrated robust and stable performance (p < 0.01). The high-risk group exhibited an immune-inflamed phenotype, associated with poorer prognosis and higher levels of immune cell infiltration. We further investigated the cancer immune cycle and mutation landscape within the IRMLS model, confirming that the high-risk group is more sensitive to immune checkpoint immunotherapy (ICI) and adjuvant chemotherapy with cisplatin (p = 2.8e-10), docetaxel (p = 8.8e-13), etoposide (p = 1.8e-07), and paclitaxel (p = 6.2e-13). In conclusion, we identified and validated a machine learning-based molecular characteristic, IRMLS, which reflects various aspects of the BCa biological process and offers new insights into personalized precision therapy for BCa patients.

In silico, in vitro, and ex vivo analysis reveals miR-27a-3p and miR-155-5p as key microRNAs for glioblastoma progression: Insights into Th1 differentiation and apoptosis induction

We explored key microRNAs (miRNAs) related to tumorigenesis and immune modulation in glioblastoma (GBM), employing in silico, in vitro, and ex vivo analysis along with an assessment of the cellular impacts resulting from miRNA inhibition. GBM and T cells miRNA expression profiles from public datasets were used to evaluate differentially expressed miRNAs (DEmiRNAs). Some DEmiRNAs were chosen for validation in GBM cell lines, primary cell cultures, and brain tumor patient samples, using RT-qPCR. Target genes and pathways were identified with bioinformatic analyses. In silico functional enrichment analysis revealed that miR-27a-3p and miR-155-5p modulate immune, metabolic, and GBM-related pathways. A172 cells were transfected with miRNA inhibitors and the effects on cellular processes and immunomodulation were analyzed by co-culture assays and flow cytometry. Upon validation, miR-27a-3p and miR-155-5p miRNAs expressions were consistently increased. Inhibiting these two miRNAs reduced cell viability, but only the inhibition of miR-27a-3p led to apoptosis. Co-culture assays showed an increase in Th1 cells along with elevated Th1/Treg and Th17/Treg ratios, and an increase in Th17 cells exclusively with miR-155-5p inhibition. Immune cells' gene expression modulation induced an antitumor profile, concomitant with an increase in the expression of apoptotic genes in cancer cells after co-culture. This study unveils potential targets for immune and tumor regulation, highlighting overexpressed miRNAs modulation as a novel therapeutic approach for GBM.

Clinical Significance of MicroRNA-299-3p in Coronary Artery Disease Based on Bioinformatics Analysis

The purpose of the research was to evaluate the diagnostic performance of microRNA-299-3p (miR-299-3p) in patients with coronary artery disease (CAD). The relative abundance of miR-299-3p in patients with CAD was verified by quantitative real time polymerase chain reaction (qRT-PCR) assay. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were used for analysis, and target genes were predicted and enriched by DAVID software. The protein-protein interaction (PPI) network was drawn by STRING database. Receiver operating characteristic (ROC) was adopted to appraise the diagnostic value of miR-299-3p in CAD. Bioinformatics analysis showed that the GO function of miR-299-3p target genes of miR-299-3p mainly focuses on specific granular membrane, regulation of apoptotic signaling pathway, growth factor binding and so on. KEGG analysis showed that the most abundant pathways involve fluid shear stress and atherosclerosis, as well as Notch signaling pathways. PPI network showed the seven predictive genes encoding the proteins play pivotal roles in maintaining the stability and interaction of the network, especially matrix metallopeptidase 2 (MMP2) and intercellular cell adhesion molecule-1 (ICAM1). Compared with the control group, serum miR-299-3p in the CAD group was distinctly up-regulated via qRT-PCR (p < 0.001). ROC analysis showed that miR-299-3p was an important index for detecting CAD patients and major adverse cardiovascular events (MACE) patients with an AUC of 0.931 and 0.758, respectively. MiR-299-3p is involved in the development of CAD, and might become a potential biomarker for monitoring CAD.

Noncoding RNAs in rheumatoid arthritis: modulators of the NF-κB signaling pathway and therapeutic implications

Rheumatoid arthritis (RA) is a chronic autoimmune disease that causes joint inflammation and gradual tissue destruction. New research has shown how important noncoding RNAs (ncRNAs) are for changing immune and inflammatory pathways, such as the WNT signaling pathway, which is important for activating synovial fibroblasts and osteoblasts to work. This article examines the current understanding of several ncRNAs, such as miRNAs, lncRNAs, and circRNAs, that influence NF-κB signaling in the pathogenesis of RA. We investigate how these ncRNAs impact NF-κB signaling components, altering cell proliferation, differentiation, and death in joint tissues. The paper also looks at how ncRNAs can be used as potential early detection markers and therapeutic targets in RA because they can change important pathogenic pathways. This study highlights the therapeutic potential of targeting ncRNAs in RA therapy techniques, with the goal of reducing inflammation and stopping disease progression. This thorough analysis opens up new possibilities for understanding the molecular foundations of RA and designing novel ncRNA-based treatments.

NAMPT enhances LOX expression and promotes metastasis in human chondrosarcoma cells by inhibiting miR-26b-5p synthesis

Chondrosarcoma is a malignant bone tumor that emerges from abnormalities in cartilaginous tissue and is related with lung metastases. Nicotinamide phosphoribosyltransferase (NAMPT) is an adipocytokine reported to enhance tumor metastasis. Our results from clinical samples and the Gene Expression Omnibus data set reveal that NAMPT levels are markedly higher in chondrosarcoma patients than in normal individuals. NAMPT stimulation significantly increased lysyl oxidase (LOX) production in chondrosarcoma cells. Additionally, NAMPT increased LOX-dependent cell migration and invasion in chondrosarcoma by suppressing miR-26b-5p generation through the c-Src and Akt signaling pathways. Overexpression of NAMPT promoted chondrosarcoma metastasis to the lung in vivo. Furthermore, knockdown of LOX counteracted NAMPT-facilitated metastasis. Thus, the NAMPT/LOX axis presents a novel target for treating the metastasis of chondrosarcoma.

Nerve growth factor promote VCAM-1-dependent monocyte adhesion and M2 polarization in osteosarcoma microenvironment: Implications for larotrectinib therapy

Osteosarcoma is the most prevalent form of primary malignant bone tumor, primarily affecting children and adolescents. The nerve growth factors (NGF) referred to as neurotrophins have been associated with cancer-induced bone pain; however, the role of NGF in osteosarcoma has yet to be elucidated. In osteosarcoma samples from the Genomic Data Commons data portal, we detected higher levels of NGF and M2 macrophage markers, but not M1 macrophage markers. In cellular experiments, NGF-stimulated osteosarcoma conditional medium was shown to facilitate macrophage polarization from the M0 to the M2 phenotype. NGF also enhanced VCAM-1-dependent monocyte adhesion within the osteosarcoma microenvironment by down-regulating miR-513c-5p levels through the FAK and c-Src cascades. In in vivo xenograft models, the overexpression of NGF was shown to enhance tumor growth, while the oral administration of the TrK inhibitor larotrectinib markedly antagonized NGF-promoted M2 macrophage expression and tumor progression. These results suggest that larotrectinib could potentially be used as a therapeutic agent aimed at mitigating NGF-mediated osteosarcoma progression.

Role of microRNA-363 during tumor progression and invasion

Recent progresses in diagnostic and therapeutic methods have significantly improved prognosis in cancer patients. However, cancer is still considered as one of the main causes of human deaths in the world. Late diagnosis in advanced tumor stages can reduce the effectiveness of treatment methods and increase mortality rate of cancer patients. Therefore, investigating the molecular mechanisms of tumor progression can help to introduce the early diagnostic markers in these patients. MicroRNA (miRNAs) has an important role in regulation of pathophysiological cellular processes. Due to their high stability in body fluids, they are always used as the non-invasive markers in cancer patients. Since, miR-363 deregulation has been reported in a wide range of cancers, we discussed the role of miR-363 during tumor progression and metastasis. It has been reported that miR-363 has mainly a tumor suppressor function through the regulation of transcription factors, apoptosis, cell cycle, and structural proteins. MiR-363 also affected the tumor progression via regulation of various signaling pathways such as WNT, MAPK, TGF-β, NOTCH, and PI3K/AKT. Therefore, miR-363 can be introduced as a probable therapeutic target as well as a non-invasive diagnostic marker in cancer patients.

Reactive oxygen species/glutathione dual sensitive nanoparticles with encapsulation of miR155 and curcumin for synergized cancer immunotherapy

Considerable attention has been directed towards exploring the potential efficacy of miR-155 in the realm of cancer immunotherapy. Elevated levels of miR-155 in dendritic cells (DCs) have been shown to enhance their maturation, migration, cytokine secretion, and their ability to promote T cell activation. In addition, overexpression of mir155 in M2 macrophages boost the polarization towards the M1 phenotype. Conversely, miR-155 has the propensity to induce the accumulation of immunosuppressive cells like regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs) in the tumor tissue. To account for this discrepancy, it is imperative to get help from a drug that could deal with immunosuppressive effect. Curcumin (CUR) exhibits the capacity to prompt Tregs converse into T helper 1 cells, fostering the polarization of M2 tumor-associated macrophage towards the M1 phenotype, and impeding the recruitment and aggregation of MDSCs within the tumor microenvironment. Nonetheless, CUR is known to exert an immunosuppressive impact on DCs by hindering the expression of maturation markers, cytokines, and chemokines, thereby prevent DCs response to immunostimulatory agents. Hence, a reactive oxygen species/glutathione dual responsive drug conveyance platform (CUR/miR155@DssD-Hb NPs) was devised to co-deliver CUR and miR155, with the aim of exploring their synergistic potential in bolstering a sustained and robust anti-tumor immune response. In vitro and in vivo results have suggested that CUR/miR155@DssD-Hb NPs can effectively inhibit the viability of 4T1 and B16F10 tumor cells, trigger the release of damage associated molecular patterns, stimulate DCs maturation, subsequent activation of CD8+ T cells, diminish immunosuppressive cell populations (MDSCs, Tregs, M2 TAMs and exhausted T cells), promote the formation of long-term immunity and lessen the formation of metastatic nodules in the lungs. In summary, the co-delivery system integrating CUR and miR155 (CUR/miR155@DssD-Hb NPs) demonstrates promise as a promising strategy for the immunotherapy of melanoma and triple negative breast cancer.

miR-497-5p Expression and Biological Activity in Gastric Cancer

Background: This research aims to investigate the expression and biological roles of miR-497-5p in gastric cancer (GC), and its possible mechanisms. Methods: Real Time Quantitative PCR (RT-qPCR) was performed to detect miR-497-5p in GC and normal tissues, as well as GC cell lines versus normal gastric mucosal cells (GES-1). The effects of miR-497-5p overexpression on proliferation were measured by the cell counting kit-8 (CCK8) assay and ethidium bromide (EdU) assay. Flow cytometry was used to assess the cell cycle. The migration and invasion were evaluated by scratch assay and Transwell assay, respectively. Gene targets of miR-497-5p were predicted using "multiMiR" R package combined with mirTarPathway database. And then luciferase reporter experiment was used to evaluate the activity of ERBB2 by miR-497-5p mimics in GC cell line. Besides, functional experiments were performed to verify the impact of miR-497-5p /ERBB2 on phenotypes of GC cells. Results: Compared with the normal tissues and mucosal cells, miR-497-5p was reduced in GC tissues and GC cell lines. miR-497-5p significantly decreased proliferation, migration, and invasion capacity, with an elevated apoptosis ratio of gastric cancer cells. Bioinformatics indicated that ERBB2 might be the potential target of miR-497-5p Dual-luciferase reporter experiments showed it adversely regulated ERBB2 3'UTR luciferase activity. The expression of ERBB2 in GC tissues and cells is significantly higher compared to normal tissues and cells. Over-expression of ERBB2 in gastric cancer cells significantly reduced miR-497-5p's inhibitory effect on the malignant behavior of GC cells. Conclusion: miR-497-5p was significantly down-regulated in GC tissues and cells, which inhibited the malignant features of GC cells by targeting ERBB2.

TUMOR MICROENVIRONMENT-ASSOCIATED miR-7-5p, miR-19a-3p, AND miR-23b-3p EXPRESSION IN PROSTATE CANCER WITH DIFFERENT PROGRESSION RISK

BACKGROUND

The tumor microenvironment (TME) plays an important role in the occurrence and progression of prostate cancer (PCa). At the same time, the mechanisms and features of the interaction between tumor cells and individual components of the TME in PCa remain not fully elucidated. The aim was to study the expression levels of tumor-associated miR-7-5p, miR-19a-3p, and miR-23b-3p in the PCa tissue and to analyze their relationship with the features of TME.

MATERIALS AND METHODS

The work is based on the analysis of the results of the examination and treatment of 50 patients with PCa of stages II-IV. The expression of miRNA in the PCa tissue was analyzed by the real-time polymerase chain reaction. The expression of alpha-smooth muscle actin (α-SMA), vimentin (VIM), and CD68 in PCa tissue was determined by the immunohistochemical method. The identification of mast cells in the PCa tissue was assessed by the histochemical method.

RESULTS

The analysis of the expression levels of tumor-associated miRNAs demonstrated that the tumor tissue of patients with a high risk of PCa progression was characterized by 4.93 (p < 0.01) and 8.97 (p < 0.05) times higher levels of miR-19a-3p and miR-23b-3p, respectively, compared to similar indicators in the group of patients with a low risk of PCa progression. The levels of miR-7-5p and miR-19a-3p expression in the PCa tissue correlated with the expression level of α-SMA (r = 0.49 and r = 0.45, respectively; p < 0.05) and VIM (r = 0.45 and r = 0.46; respectively, p < 0.05). A direct relationship (r = 0.44; p < 0.05) was established between the level of miR-7-5p expression and the degree of infiltration of the prostate gland tissue by tumor-associated macrophages.

CONCLUSIONS

The features of the expression of tumor-associated miR-7-5p, miR-19a-3p, and miR-23b-3p indicated the prospect of their use as markers of the aggressiveness of the PCa course.

Exploring signaling pathway crosstalk in glioma by mapping miRNA and WNT pathways: A review

Glioma is a significant healthcare burden; nevertheless, the particular genetic regulatory mechanism underpinning its onset and progression is still unknown. Recent research has focused in large part on trying to determine the underlying molecular pathways that contribute to the malignancy of this disease because of the difficulties in treating it. Many tumors have been linked to changes in the expression of microRNAs (miRNAs). miRNAs play a critical role in cancer development by controlling a wide variety of targets and signaling cascades. A rising body of evidence emphasizes WNT pathway dysregulation in glioma, despite the fact that it is dysregulated in many malignancies. Here, we give a detailed analysis of the roles played by miRNAs in the WNT pathway by glioma. We also demonstrate how the WNT pathway cooperates with miRNAs to control a variety of functions, including cell proliferation, invasion, migration, and epithelial-mesenchymal transition.

JAK1 Is a Novel Target of Tumor- and Invasion-Suppressive microRNA 494-5p in Colorectal Cancer

MiR-494-5p expression has been suggested to be associated with colorectal cancer (CRC) and its metastases in our previous studies. However, functional investigations on the molecule-mediating actions of this miR in CRC are lacking. In silico analysis in the present study revealed a putative binding sequence within the 3'UTR of JAK1. Overexpression of miR-494-5p in cultured CRC significantly reduced the luciferase activity of a reporter plasmid containing the wild-type JAK1-3'UTR, which was abolished by seed sequence mutation. Furthermore, the overexpression of miR-494-5p in CRC cell lines led to a significant reduction in JAK1 expression, proliferation, in vitro migration, and invasion. These effects were abolished by co-transfection with a specific double-stranded RNA that inhibits endogenous miR-494-5p. Moreover, IL-4-induced migration, invasion, and phosphorylation of JAK1, STAT6, and AKT proteins were reduced after an overexpression of this miR, suggesting that this miR affects one of the most essential pathways in CRC. A Kaplan-Meier plotter analysis revealed that patients with high JAK1 expression show reduced survival. Together, these data suggest that miR-494-5p physically inhibits the expression of JAK1 at the translational level as well as in migration and invasion, supporting the hypothesis of miR-494-5p as an early tumor suppressor and inhibitor of early steps of metastasis in CRC.

MiR-5195-3p functions as a tumor suppressor by targeting RHBDD1 in ovarian cancer

BACKGROUND

Recent studies have reported the tumor suppressive role of miR-5195-3p in the progression of several cancers, but the potential roles of miR-5195-3p in ovarian cancer (OC) remain largely unknown.

METHODS

We first analyzed the expression levels of miR-5195-3p in 83 pairs of human OC tissues and adjacent specimens by reverse transcription-quantitative PCR. The correlation of miR-5195-3p/rhomboid domain containing 1 (RHBDD1) and clinicopathological parameters was analyzed by chi-square test. The prognostic value of miR-5195-3p was evaluated by Kaplan-Meier method Cox proportional hazards models. The effects of miR-5195-3p on cell proliferation, cell cycle distribution, migration and invasion were examined by CCK-8 assay, colony formation assay, flow cytometry and transwell assay. Tumor forming was evaluated by nude mice model in vivo. The association between miR-5195-3p and RHBDD1 was verified by luciferase reporter assay.

RESULTS

We observed that miR-5195-3p level was remarkably reduced in OC tissues as compared to adjacent tissues. The expression of miR-5195-3p was associated with FIGO stage, depth of invasion and poor survival prognosis in OC patients. Overexpression of miR-5195-3p significantly suppressed cell proliferation, cell cycle G1/S transition, migration and invasion in OC cell lines (SKOV-3 and OVCAR3), while knockdown of miR-5195-3p obtained the opposite results. We further confirmed miR-5195-3p as a negative post-transcriptional modulator of RHBDD1. RHBDD1 expression was upregulated in OC tissues compared with adjacent tissues, which was inversely correlated with miR-5195-3p expression. The expression of RHBDD1 was associated with FIGO stage and distant metastasis. RHBDD1 overexpression reversed the suppressive role of miR-5195-3p on OC cell proliferation, migration and invasion. Consistent with the in vitro results, miR-5195-3p overexpression decreased the growth of subcutaneously inoculated tumors in nude mice.

CONCLUSIONS

Taken together, the present results indicated that miR-5195-3p acts a tumor suppressor by targeting RHBDD1 in OC.

MicroRNA‑27a‑3p regulates the proliferation and chemotaxis of pulmonary macrophages in non‑small cell lung carcinoma tissues through CXCL2

The present study aimed to investigate microRNA (miRNA)-27a-3p expression in the pulmonary macrophages and peripheral blood of patients with early non-small cell lung carcinoma (NSCLC) and its regulatory effect on the infiltration of pulmonary macrophages into cancer tissues and invasion of NSCLC cells. Blood specimens were withdrawn from 36 patients with NSCLC and 29 healthy subjects. NSCLC tissues and cancer-adjacent tissues were both obtained from patients with NSCLC; furthermore, certain tissue samples were used to extract macrophages. The levels of miRNA-27a-3p and C-X-C motif ligand chemokine 2 (CXCL2) mRNA were detected by reverse transcription-quantitative PCR and the levels of CXCL2 protein were measured by ELISA and western blot analysis. A dual-luciferase reporter assay was performed to determine the interactions between miRNA and mRNA. An MTT assay was employed to examine the viability of transfected cells and macrophages and a Transwell assay was performed to assess chemotaxis. The differential expression of miRNA-27a-3p in NSCLC tissues, pulmonary macrophages and peripheral blood indicated that miRNA-27a-3p exerted different roles in these specimens. CXCL2 was upregulated in NSCLC tissues at both transcriptional and translational levels. In addition, the untranslated region of CXCL2 was confirmed to be directly targeted by miRNA-27a-3p prior to its transcriptional activation. Furthermore, miRNA-27a-3p regulated CXCL2 expression, thereby affecting the proliferation of human pulmonary macrophages. The present study highlights that miRNA-27a-3p expression in the pulmonary macrophages and peripheral blood of patients with NSCLC is downregulated, while its target gene CXCL2 is upregulated. miRNA-27a-3p may regulate the viability and chemotaxis of macrophages in tumor tissues of patients with NSCLC through CXCL2 and is expected to become a genetic marker of this disease.

Circulating exosomal miRNAs as a promising diagnostic biomarker in cancer

Cancer belongs to multifactorial diseases characterized by uncontrolled growth and proliferation of abnormal cells. Breast cancer, non-small cell lung cancer, and colorectal cancer are the most frequently diagnosed malignancies with a high mortality rate. These carcinomas typically contain multiple genetically distinct subpopulations of tumor cells leading to tumor heterogeneity, which promotes the aggressiveness of the disease. Early diagnosis is necessary to increase patient progression-free survival. Particularly, miRNAs present in exosomes derived from tumors represent potential biomarkers suitable for early cancer diagnosis. Identification of miRNAs by liquid biopsy enables a personalized approach with the subsequent better clinical management of patients. This review article highlights the potential of circulating exosomal miRNAs in early breast, non-small cell lung, and colorectal cancer diagnosis.

Novel insights on perils and promises of miRNA in understanding colon cancer metastasis and progression

Colorectal cancer (CRC) is the third highest frequent malignancy and ultimate critical source of cancer-associated mortality around the world. Regardless of latest advances in molecular and surgical targeted medicines that have increased remedial effects in CRC patients, the 5-year mortality rate for CRC patients remains dismally low. Evidence suggests that microRNAs (miRNAs) execute an essential part in the development and spread of CRC. The miRNAs are a type of short non-coding RNA that exhibited to control the appearance of tumor suppressor genes and oncogenes. miRNA expression profiling is already being utilized in clinical practice as analytical and prognostic biomarkers to evaluate cancer patients' tumor genesis, advancement, and counteraction to drugs. By modulating their target genes, dysregulated miRNAs are linked to malignant characteristics (e.g., improved proliferative and invasive capabilities, cell cycle aberration, evasion of apoptosis, and promotion of angiogenesis). This review presents an updated summary of circulatory miRNAs, tumor-suppressive and oncogenic miRNAs, and the potential reasons for dysregulated miRNAs in CRC. Further we will explore the critical role of miRNAs in CRC drug resistance.

MicroRNA: trends in clinical trials of cancer diagnosis and therapy strategies

As a type of short noncoding RNAs, microRNA (miRNA) undoubtedly plays a crucial role in cancer development. Since the discovery of the identity and clinical functions of miRNAs, over the past few decades, the roles of miRNAs in cancer have been actively investigated. Numerous pieces of evidence indicate that miRNAs are pivotal factors in most types of cancer. Recent cancer research focused on miRNAs has identified and characterized a large cohort of miRNAs commonly dysregulated in cancer or exclusively dysregulated in specific types of cancer. These studies have suggested the potential of miRNAs as biomarkers in the diagnosis and prognostication of cancer. Moreover, many of these miRNAs have oncogenic or tumor-suppressive functions. MiRNAs have been the focus of research given their potential clinical applications as therapeutic targets. Currently, various oncology clinical trials using miRNAs in screening, diagnosis, and drug testing are underway. Although clinical trials studying miRNAs in various diseases have been reviewed before, there have been fewer clinical trials related to miRNAs in cancer. Furthermore, updated results of recent preclinical studies and clinical trials of miRNA biomarkers and drugs in cancer are needed. Therefore, this review aims to provide up-to-date information on miRNAs as biomarkers and cancer drugs in clinical trials.

A group of three miRNAs can act as candidate circulating biomarkers in liquid biopsies from melanoma patients

Background

Staging of melanoma and follow up after melanoma diagnosis aims at predicting risk and detecting progression or recurrence at early stage, respectively in order to timely start and/or change treatment. Tumor thickness according to Breslow, status of the sentinel node and value of the lactate dehydrogenase (LDH) are well-established prognostic markers for metastatic risk, but reliable biomarkers identifying early recurrence or candidates who may benefit best from medical treatment are still warranted. Liquid biopsy has emerged to be a suitable method for identifying biomarkers for early cancer diagnosis, prognosis, therapeutic response prediction, and patient follow-up. Liquid biopsy is a blood-based non-invasive procedure that allows analyzing circulating analytes, including extracellular vesicles.

Methods

In this study we have explored the use of 7 miRNAs, namely hsa-miR-149-3p, hsa-miR-150-5p, hsa-miR-21-5p, hsa-miR-200c-3p, hsa-miR-134-5p, hsa-miR-144-3p and hsa-miR-221-3p in plasma exosomes to discriminate melanoma patients from controls without melanoma in a cohort of 92 individuals.

Results and discussion

Our results showed that three out seven miRNAs, namely hsa-miR-200c-3p, hsa-miR-144-3p and hsa-miR-221-3p were differentially expressed in plasma-derived exosomes from melanoma patients and controls. Furthermore, the expression of the three miRNAs may be a promising ancillary tool as a melanoma biomarker, even for discriminating between nevi and melanoma.

MicroRNA analysis of Natural Killer cell-derived exosomes: the microRNA let-7b-5p is enriched in exosomes and participates in their anti-tumor effects against pancreatic cancer cells

Natural Killer (NK) cells are important components of the immune system in the defense against tumor growth and metastasis. They release exosomes containing proteins and nucleic acids, including microRNAs (miRNAs). NK-derived exosomes play a role in the anti-tumor NK cell function since they are able to recognize and kill cancer cells. However, the involvement of exosomal miRNAs in the function of NK exosomes is poorly understood. In this study, we explored the miRNA content of NK exosomes by microarray as compared to their cellular counterparts. The expression of selected miRNAs and lytic potential of NK exosomes against childhood B acute lymphoblastic leukemia cells after co-cultures with pancreatic cancer cells were also evaluated. We identified a small subset of miRNAs, including miR-16-5p, miR-342-3p, miR-24-3p, miR-92a-3p and let-7b-5p that is highly expressed in NK exosomes. Moreover, we provide evidence that NK exosomes efficiently increase let-7b-5p expression in pancreatic cancer cells and induce inhibition of cell proliferation by targeting the cell cycle regulator CDK6. Let-7b-5p transfer by NK exosomes could represent a novel mechanism by which NK cells counteract tumor growth. However, both cytolytic activity and miRNA content of NK exosomes were reduced upon co-culture with pancreatic cancer cells. Alteration in the miRNA cargo of NK exosomes, together with their reduced cytotoxic activity, could represent another strategy exerted by cancer to evade the immune response. Our study provides new information on the molecular mechanisms used by NK exosomes to exert anti-tumor-activity and offers new clues to integrate cancer treatments with NK exosomes.

The immunomodulatory role of exosomal microRNA networks in the crosstalk between tumor-associated myeloid-derived suppressor cells and tumor cells

Myeloid-derived suppressor cells (MDSCs) are considered a heterogeneous group of immature myeloid cells engaging in aggressive tumor progression and metastasis in the tumor microenvironment (TME) of patients diagnosed with cancer, through downregulation of anti-tumor immune responses. Exosomes are small vesicles carrying specific cargos, including proteins, lipids, and MicroRNA (miRNAs). Such exosomal miRNAs delivered by MDSCs and tumor cells are short noncoding RNAs mediating some of the immunosuppressive characteristics of MDSCs in the TME. However, when it comes to cancer diseases, how these miRNAs interact with MDSCs and encourage MDSCs differentiation and function need further investigations. In this review, we discuss MDSC-derived exosomal miRNAs and those derived from tumor cells (TDE) could modulate anti-tumor immunity and regulate the interaction between tumor cells and MDSCs in the TME. Afterward, we focus on dividing miRNAs, as an important substance interacting with MDSCs and tumor cells in the TME, into those have an immunosuppressive or stimulating effect not only on MDSCs expansion, differentiation, and suppressive function but also on tumor evasion.

miRNAs in Regulation of Tumor Microenvironment, Chemotherapy Resistance, Immunotherapy Modulation and miRNA Therapeutics in Cancer

miRNAs are 20-22 long nucleotide non-coding ribonucleic acid molecules critical to the modulation of molecular pathways. Immune evasion and the establishment of a suitable tumor microenvironment are two major contributors that support tumor invasion and metastasis. Tumorigenic miRNAs support these two hallmarks by desensitizing important tumor-sensitive regulatory cells such as dendritic cells, M1 macrophages, and T helper cells towards tumors while supporting infiltration and proliferation of immune cells like Treg cells, tumor-associated M2 macrophages that promote self-tolerance and chronic inflammation. miRNAs have a significant role in enhancing the efficacies of immunotherapy treatments like checkpoint blockade therapy, adoptive T cell therapy, and oncolytic virotherapy in cancer. A clear understanding of the role of miRNA can help scientists to formulate better-targeted treatment modalities. miRNA therapeutics have emerged as diverse class of nucleic acid-based molecules that can suppress oncogenic miRNAs and promote the expression of tumor suppressor miRNAs.

miR-aculous new avenues for cancer immunotherapy

The rising toll of cancer globally necessitates ingenuity in early detection and therapy. In the last decade, the utilization of immune signatures and immune-based therapies has made significant progress in the clinic; however, clinical standards leave many current and future patients without options. Non-coding RNAs, specifically microRNAs, have been explored in pre-clinical contexts with tremendous success. MicroRNAs play indispensable roles in programming the interactions between immune and cancer cells, many of which are current or potential immunotherapy targets. MicroRNAs mechanistically control a network of target genes that can alter immune and cancer cell biology. These insights provide us with opportunities and tools that may complement and improve immunotherapies. In this review, we discuss immune and cancer cell-derived miRNAs that regulate cancer immunity and examine miRNAs as an integral part of cancer diagnosis, classification, and therapy.

Solamargine Inhibits the Development of Hypopharyngeal Squamous Cell Carcinoma by Decreasing LncRNA HOXA11-As Expression

Hypopharyngeal squamous cell carcinoma (HSCC) is one of the high mortality cancers with a poor prognosis, which is driving the development of new chemotherapeutic agents. We identified the anticancer effects of a natural compound, solamargine (SM), on FaDU cells and explored its mechanism in terms of non-coding RNA. It was observed that SM inhibited the proliferation of FaDU cells with an IC₅₀ of 5.17 μM. High-throughput sequencing data revealed that lncRNA HOXA11-AS was significantly downregulated in cells co-incubated with SM. Further assays demonstrated that SM-induced downregulation of lncRNA HOXA11-AS showed important implications for apoptosis. Given the properties of HOXA11-AS as a miR-155 sponge, we further confirmed that SM upregulated the expression of miR-155 in FaDU cells. C-Myc is a transcription factor that regulates cell differentiation and apoptosis, whose mRNA is considered to be targeted by miR-155. We showed that c-Myc expression was downregulated by SM and accompanied by increased apoptosis, which was consistent with the findings of transcriptome sequencing. Furthermore, SM administration suppressed xenograft tumor growth in a xenograft mouse model in vivo. In the light of the aforementioned findings, our results suggested that SM downregulated the expression of HOXA11-AS, which in turn induces apoptosis by downregulating c-Myc in FaDU, providing evidence for the anticancer effect of SM on HSCC and uncovering the effect of SM on non-coding RNAs as, at least partly, a mechanism of action.

miRNAs as cornerstones in colorectal cancer pathogenesis and resistance to therapy: A spotlight on signaling pathways interplay - A review

Colorectal cancer (CRC) is the world's third most prevalent cancer and the main cause of cancer-related mortality. A lot of work has been put into improving CRC patients' clinical care, including the development of more effective methods and wide biomarkers variety for prognostic, and diagnostic purposes. MicroRNAs (miRNAs) regulate a variety of cellular processes and play a significant role in the CRC progression and spread via controlling their target gene expression by translation inhibition or mRNA degradation. Consequently, dysregulation and disruption in their function, miRNAs are linked to CRC malignant pathogenesis by controlling several cellular processes involved in the CRC. These cellular processes include increased proliferative and invasive capacity, cell cycle aberration, evasion of apoptosis, enhanced EMT, promotion of angiogenesis and metastasis, and decreased sensitivity to major treatments. The miRNAs control cellular processes in CRC via regulation of pathways such as Wnt/β-catenin signaling, PTEN/AKT/mTOR axis, KRAS, TGFb signaling, VEGFR, EGFR, and P53. Hence, the goal of this review was to review miRNA biogenesis and present an updated summary of oncogenic and tumor suppressor (TS) miRNAs and their potential implication in CRC pathogenesis and responses to chemotherapy and radiotherapy. We also summarise the biological importance and clinical applications of miRNAs in the CRC.

Leptin modulated microRNA-628-5p targets Jagged-1 and inhibits prostate cancer hallmarks

MicroRNAs (miRNAs) are single-stranded non-coding RNA molecules that play a regulatory role in gene expression and cancer cell signaling. We previously identified miR-628-5p (miR-628) as a potential biomarker in serum samples from men with prostate cancer (PCa) (Srivastava et al. in Tumour Biol 35:4867–4873, 10.1007/s13277-014-1638-1, 2014). This study examined the detailed cellular phenotypes and pathways regulated by miR-628 in PCa cells. Since obesity is a significant risk factor for PCa, and there is a correlation between levels of the obesity-associated hormone leptin and PCa development, here we investigated the functional relationship between leptin and miR-628 regulation in PCa. We demonstrated that exposure to leptin downregulated the expression of miR-628 and increased cell proliferation/migration in PCa cells. We next studied the effects on cancer-related phenotypes in PCa cells after altering miR-628 expression levels. Enforced expression of miR-628 in PCa cells inhibited cell proliferation, reduced PCa cell survival/migration/invasion/spheroid formation, and decreased markers of cell stemness. Mechanistically, miR-628 binds with the JAG1-3′UTR and inhibits the expression of Jagged-1 (JAG1). JAG1 inhibition by miR-628 downregulated Notch signaling, decreased the expression of Snail/Slug, and modulated epithelial-mesenchymal transition and invasiveness in PC3 cells. Furthermore, expression of miR-628 in PCa cells increased sensitivity towards the drugs enzalutamide and docetaxel by induction of cell apoptosis. Collectively our data suggest that miR-628 is a key regulator of PCa carcinogenesis and is modulated by leptin, offering a novel therapeutic opportunity to inhibit the growth of advanced PCa.

Exosomal miR-146a-5p and miR-155-5p promote CXCL12/CXCR7-induced metastasis of colorectal cancer by crosstalk with cancer-associated fibroblasts

C-X-C motif chemokine receptor 7 (CXCR7) is a newly discovered atypical chemokine receptor that binds to C-X-C motif chemokine ligand 12 (CXCL12) with higher affinity than CXCR4 and is associated with the metastasis of colorectal cancer (CRC). Cancer-associated fibroblasts (CAFs) have been known to promote tumor progression. However, whether CAFs are involved in CXCR7-mediated metastasis of CRC remains elusive. We found a significant positive correlation between CXCR7 expression and CAF activation markers in colonic tissues from clinical specimens and in villin-CXCR7 transgenic mice. RNA sequencing revealed a coordinated increase in the levels of miR-146a-5p and miR-155-5p in CXCR7-overexpressing CRC cells and their exosomes. Importantly, these CRC cell-derived miR-146a-5p and miR-155-5p could be uptaken by CAFs via exosomes and promote the activation of CAFs through JAK2–STAT3/NF-κB signaling by targeting suppressor of cytokine signaling 1 (SOCS1) and zinc finger and BTB domain containing 2 (ZBTB2). Reciprocally, activated CAFs further potently enhanced the invasive capacity of CRC cells. Mechanistically, CAFs transfected with miR-146a-5p and miR-155-5p exhibited a robust increase in the levels of inflammatory cytokines interleukin-6, tumor necrosis factor-α, transforming growth factor-β, and CXCL12, which trigger the epithelial–mesenchymal transition and pro-metastatic switch of CRC cells. More importantly, the activation of CAFs by miR-146a-5p and miR-155-5p facilitated tumor formation and lung metastasis of CRC in vivo using tumor xenograft models. Our work provides novel insights into CXCR7-mediated CRC metastasis from tumor–stroma interaction and serum exosomal miR-146a-5p and miR-155-5p could serve as potential biomarkers and therapeutic targets for inhibiting CRC metastasis.

Immune Infiltration in Gastric Cancer Microenvironment and Its Clinical Significance

Immunotherapy has developed rapidly and has gradually become one of the important methods for treatment of gastric cancer (GC). The research on tumor infiltrating immune cells (TIICs) and immune-related genes in the tumor microenvironment (TME) greatly encourages the development of immunotherapy. The devolution algorithm (CIBERSORT) was applied to infer the proportion of 22 TIICs based on gene expression profiles of GC tissues, which were downloaded from TCGA and GEO. TCGA was utilized to analyze the differential expression of immune-related genes, and explore the potential molecular functions of these genes. We have observed the enrichment of multiple TIICs in microenvironment of GC. Some of these cells were closely related to tumor mutational burden (TMB), microsatellite instability (MSI), Fuhrman grade, and TNM staging. Survival analysis showed that the infiltration level of CD8+ T cells, activated CD4+ memory T cells and M2 macrophages were significantly related to the prognosis of GC patients. The functional enrichment analysis of immune-related genes revealed that these genes were mainly associated with cytokine activation and response. Four significant modules were screened by PPI network and 20 key genes were screened from the modules. The expression levels of CALCR and PTH1R are strikingly related to the expression of immune checkpoint and the prognosis of GC patients. The type and number of TIICs in microenvironment of GC, as well as immune-related genes are closely related to tumor progression, and can be used as important indicators for patient prognosis assessment.

A review of the biological role of miRNAs in prostate cancer suppression and progression

Prostate cancer (PC) is the third-leading cause of cancer-related deaths worldwide. Although the current treatment strategies are progressing rapidly, PC is still representing a substantial medical problem for affected patients. Several factors are involved in PC initiation, progression, and treatments failure including microRNAs (miRNAs). The miRNAs are endogenous short non-coding RNA sequence negatively regulating target mRNA expression via degradation or translation repression. miRNAs play a pivotal role in PC pathogenesis through its ability to initiate the induction of cancer stem cells (CSCs) and proliferation, as well as sustained cell cycle, evading apoptosis, invasion, angiogenesis, and metastasis. Furthermore, miRNAs regulate major molecular pathways affecting PC such as the androgen receptor (AR) pathway, p53 pathway, PTEN/PI3K/AKT pathway, and Wnt/β-catenin pathway. Furthermore, miRNAs alter PC therapeutic response towards the androgen deprivation therapy (ADT), chemotherapy and radiation therapy (RT). Thus, the understanding and profiling of the altered miRNAs expression in PC could be utilized as a non-invasive biomarker for the early diagnosis as well as for patient sub-grouping with different prognoses for individualized treatment. Accordingly, in the current review, we summarized in updated form the roles of various oncogenic and tumor suppressor (TS) miRNAs in PC, revealing their underlying molecular mechanisms in PC initiation and progression.

LncRNA ILF3-AS1 promotes cell migration, invasion and EMT process in hepatocellular carcinoma via the miR-628-5p/MEIS2 axis to activate the Notch pathway

BACKGROUND

Long non-coding RNAs (lncRNAs) are essential indicators for hepatocellular carcinoma. LncRNAs can exert the same functions as their antisense mRNAs. ILF3 is an oncogene in hepatocellular carcinoma. ILF3 divergent transcript (ILF3-AS1) is the antisense RNA of ILF3, and has been reported as an oncogene in various cancers.

AIMS

To explore the role of lncRNA ILF3-AS1 in malignant phenotypes of hepatocellular carcinoma cells.

METHODS AND RESULTS

RT-qPCR analysis revealed that ILF3-AS1 was significantly upregulated in hepatocellular carcinoma cells. The hepatocellular carcinoma cell viability was suppressed by silenced ILF3-AS1. Transwell and wound healing assays showed that ILF3-AS1 downregulation inhibited cell invasion and migration. The levels of proteins associated with epithelial-mesenchymal transition (EMT) process and the Notch pathway were detected by western blot analysis. Luciferase reporter, RNA pull down and RIP assays were used to investigate the relationship between ILF3-AS1 and downstream target genes. ILF3-AS1 competed with meis homeobox 2 (MEIS2) for miR-628-5p in hepatocellular carcinoma cells. ILF3-AS1 elevated the levels of key proteins on the Notch pathway. Rescue assays demonstrated that MEIS2 reversed the antitumor effects of silenced ILF3-AS1 on hepatocellular carcinoma. In vivo assays demonstrated that ILF3-AS1 silencing inhibited the hepatocellular carcinoma tumor growth.

CONCLUSIONS

ILF3-AS1 promoted hepatocellular carcinoma progression via the Notch pathway and miR-628-5p/MEIS2 axis.

miRNAs in the Regulation of Cancer Immune Response: Effect of miRNAs on Cancer Immunotherapy

In the last few decades, carcinogenesis has been extensively explored and substantial research has identified immunogenic involvement in various types of cancers. As a result, immune checkpoint blockers and other immune-based therapies were developed as novel immunotherapeutic strategies. However, despite being a promising therapeutic option, immunotherapy has significant constraints such as a high cost of treatment, unpredictable toxicity, and clinical outcomes. miRNAs are non-coding, small RNAs actively involved in modulating the immune system's multiple signalling pathways by binding to the 3'-UTR of target genes. miRNAs possess a unique advantage in modulating multiple targets of either the same or different signalling pathways. Therefore, miRNA follows a 'one drug multiple target' hypothesis. Attempts are made to explore the therapeutic promise of miRNAs in cancer so that it can be transported from bench to bedside for successful immunotherapeutic results. Therefore, in the current manuscript, we discussed, in detail, the mechanism and role of miRNAs in different types of cancers relating to the immune system, its diagnostic and therapeutic aspect, the effect on immune escape, immune-checkpoint molecules, and the tumour microenvironment. We have also discussed the existing limitations, clinical success and the prospective use of miRNAs in cancer.

Role and Mechanism of mir-5189-3p in Deep Vein Thrombosis of Lower Extremities

BACKGROUND

This study is to investigate the role and mechanism of mir-5189-3p in deep vein thrombosis (DVT) in lower extremity.

METHODS

The blood samples were collected from Kazakh patients with DVT in lower extremity and were subjected to microRNA sequencing. Bioinformatics were used to identify mir-5189-3p and its target genes. Dual luciferase reporter assay was used to determine the regulatory effect of mir-5189-3p on JAG1. SD rats were randomly divided into normal control, DVT model, hsa-miR-5189-3p mimics and hsa-miR-5189-3p negative control groups. HE staining was used to observe the pathological changes. TUNEL method was used to observe apoptosis. Western blot was used to detect Bax and Bcl-2 protein expression. Real-time quantitative PCR was used to detect JAG1, Notch1 and Hes1 mRNA.

RESULTS

The target of Has-miR-5189-3p was JAG1. Co-transfection of miR-5189-3p mimics and pmirGLO/JAG1 wild-type plasmid induced significantly decreased luciferase activity. In hsa-miR-5189-3p mimics and hsa-miR-5189-3p negative control groups, there were more nucleated cells in the thrombus tissues, and the organization degree obviously increased. Signs of blood flow recanalization were observed. The apoptosis of hsa-miR-5189-3p mimics and hsa-miR-5189-3p negative control groups was lower than that in DVT model group. Furthermore, mir-5189-3p mimics significantly increased the mRNA levels of JAG1, Notch1 and Hes1. Additionally, mir-5189-3p mimics significantly increased Bcl-2 while decreased Bax protein.

CONCLUSIONS

mir-5189-3p could inhibit apoptosis and promote thrombus organization in DVT possibly via Notch signaling pathway. Mir-5189-3p can be used as a potential target for DVT treatment.

Targeting of the tumor immune microenvironment by metformin

Stimulating antitumor immunity is an attractive idea for suppressing tumors. CD4 + and CD8 + T cells as well as natural killer cells (NK) are the primary antitumor immune cells in the tumor microenvironment (TME). In contrast to these cells, regulatory T cells (Tregs), myeloid-derived suppressor cells (MDSCs), cancer-associated fibroblasts (CAFs), and tumor-associated macrophages (TAMs) release several molecules to suppress antitumor immunity and stimulate cancer cell invasion and proliferation. Adjuvant treatment with certain nontoxic agents is interesting to boost antitumor immunity. Metformin, which is known as an antidiabetes drug, can modulate both antitumor and protumor immune cells within TME. It has the ability to induce the proliferation of CD8 + T lymphocytes and NK cells. On the other hand, metformin attenuates polarization toward TAMs, CAFs, and Tregs. Metformin also may stimulate the antitumor activity of immune system cells, while it interrupts the positive cross-talk and interactions between immunosuppressive cells and cancer cells. The purpose of this review is to explain the basic mechanisms for the interactions and communications between immunosuppressive, anti-tumoral, and cancer cells within TME. Next, we discuss the modulating effects of metformin on various cells and secretions in TME.

MiR-296-5p ameliorates deep venous thrombosis by inactivating S100A4

Deep venous thrombosis is one of the most common venous thromboembolic diseases and has a low cure rate and a high postoperative recurrence rate. Furthermore, emerging evidence indicates that microRNAs are involved in deep venous thrombosis. miR-296-5p is an important microRNA that plays a critical role in various cellular functions, and S100A4 is closely related to vascular function. miR-296-5p is downregulated in deep venous thrombosis patients, and its predicted target S100A4 is upregulated in deep venous thrombosis patients. Therefore, it was hypothesized that miR-296-5p may play a vital role in the development of deep venous thrombosis by targeting S100A4. An Ox-LDL-stimulated HUVEC and deep venous thrombosis mouse model was employed to detect the biological functions of miR-296-5p and S100A4. Dual luciferase reporter assays and pull-down assays were used to authenticate the interaction between miR-296-5p and S100A4. ELISA and Western blotting were employed to detect the protein levels of thrombosis-related factors and the endothelial-to-mesenchymal transition (EndMT)-related factors. The miR-296-5p levels were reduced, while the S100A4 levels were enhanced in deep venous thrombosis patients, and the miR-296-5p levels were negatively correlated with the S100A4 levels in deep venous thrombosis patients. miR-296-5p suppressed S100A4 expression by targeting the 3' UTR of S100A4. MiR-296-5p knockdown accelerated ox-LDL-induced HUVEC apoptosis, oxidative stress, thrombosis-related factor expression, and EndMT, while S100A4 knockdown antagonized these effects in ox-LDL-induced HUVECs. S100A4 knockdown reversed the effect induced by miR-296-5p knockdown. Moreover, the in vivo studies revealed that miR-296-5p knockdown in deep venous thrombosis mice exacerbated deep venous thrombosis formation, whereas S100A4 knockdown had the opposite effect. These results indicate that elevated miR-296-5p inhibits deep venous thrombosis formation by inhibiting S100A4 expression. Both miR-296-5p and S100A4 may be potential diagnostic markers and therapeutic targets for deep venous thrombosis.

The Immune Subtypes and Landscape of Gastric Cancer and to Predict Based on the Whole-Slide Images Using Deep Learning

Background

Gastric cancer (GC) is a highly heterogeneous tumor with different responses to immunotherapy. Identifying immune subtypes and landscape of GC could improve immunotherapeutic strategies.

Methods

Based on the abundance of tumor-infiltrating immune cells in GC patients from The Cancer Genome Atlas, we used unsupervised consensus clustering algorithm to identify robust clusters of patients, and assessed their reproducibility in an independent cohort from Gene Expression Omnibus. We further confirmed the feasibility of our immune subtypes in five independent pan-cancer cohorts. Finally, functional enrichment analyses were provided, and a deep learning model studying the pathological images was constructed to identify the immune subtypes.

Results

We identified and validated three reproducible immune subtypes presented with diverse components of tumor-infiltrating immune cells, molecular features, and clinical characteristics. An immune-inflamed subtype 3, with better prognosis and the highest immune score, had the highest abundance of CD8+ T cells, CD4+ T–activated cells, follicular helper T cells, M1 macrophages, and NK cells among three subtypes. By contrast, an immune-excluded subtype 1, with the worst prognosis and the highest stromal score, demonstrated the highest infiltration of CD4+ T resting cells, regulatory T cells, B cells, and dendritic cells, while an immune-desert subtype 2, with an intermediate prognosis and the lowest immune score, demonstrated the highest infiltration of M2 macrophages and mast cells, and the lowest infiltration of M1 macrophages. Besides, higher proportion of EVB and MSI of TCGA molecular subtyping, over expression of CTLA4, PD1, PDL1, and TP53, and low expression of JAK1 were observed in immune subtype 3, which consisted with the results from Gene Set Enrichment Analysis. These subtypes may suggest different immunotherapy strategies. Finally, deep learning can predict the immune subtypes well.

Conclusion

This study offers a conceptual frame to better understand the tumor immune microenvironment of GC. Future work is required to estimate its reference value for the design of immune-related studies and immunotherapy selection.

Effects of CAF-Derived MicroRNA on Tumor Biology and Clinical Applications

Cancer-associated fibroblasts (CAFs), prominent cell components of the tumor microenvironment (TME) in most types of solid tumor, play an essential role in tumor cell growth, proliferation, invasion, migration, and chemoresistance. MicroRNAs (miRNAs) are small, non-coding, single-strand RNAs that negatively regulate gene expression by post-transcription modification. Increasing evidence has suggested the dysregulation of miRNAs in CAFs, which facilitates the conversion of normal fibroblasts (NFs) into CAFs, then enhances the tumor-promoting capacity of CAFs. To understand the process of tumor progression, as well as the development of chemoresistance, it is important to explore the regulatory function of CAF-derived miRNAs and the associated molecular mechanisms, which may become potential diagnostic and prognostic biomarkers and targets of anti-tumor therapeutics. In this review, we describe miRNAs that are differentially expressed by NFs and CAFs, summarize the modulating role of CAF-derived miRNAs in fibroblast activation and tumor advance, and eventually identify a potential clinical application for CAF-derived miRNAs as diagnostic/prognostic biomarkers and therapeutic targets in several tumors.

MicroRNAs Regulating Tumor Immune Response in the Prediction of the Outcome in Patients With Breast Cancer

MicroRNAs (miRNAs) are key regulators in immune surveillance and immune escape as well as modulators in the metastatic process of breast cancer cells. We evaluated the differential expression of plasma miR-10b, miR-19a, miR-20a, miR-126 and miR-155, which regulate immune response in breast cancer progression and we investigated their clinical relevance in the outcomes of breast cancer patients. Plasma samples were obtained from early (eBC; n = 140) and metastatic (mBC; n = 64) breast cancer patients before adjuvant or first-line chemotherapy, respectively. Plasma miRNA expression levels were assessed by qRT-PCR. We revealed a 4-miRNA panel consisted of miR-19a, miR-20a, miR-126, and miR-155 able to discriminate eBC from mBC patients with an AUC of 0.802 (p < 0.001). Survival analysis in eBC patients revealed that low miR-10b and miR-155 expression was associated with shorter disease free survival (disease free survival; p = 0.012 and p = 0.04, respectively) compared to high expression. Furthermore, miR-126 expression was associated with shorter overall survival (overall survival; p = 0.045). In multivariate analysis the number of infiltrated axillary lymph nodes and low miR-10b expression independently predicted for shorter DFS (HR: 2.538; p = 0.002 and HR: 1.943; p = 0.033, respectively) and axillary lymph nodes and low miR-126 for shorter OS (HR: 3.537; p = 0.001 and HR: 2.558; p = 0.018). In the subgroup of triple negative breast cancer (TNBC) patients, low miR-155 expression independently predicted for shorter DFS (HR: 5.056; p = 0.037). Accordingly in mBC, patients with low miR-10b expression had shorter progression free survival and OS compared to patients with high expression (p = 0.0017 and p = 0.042, respectively). In multivariate analysis, recurrent disease and low miR-10b expression independently predicted for shorter PFS (HR: 2.657; p = 0.001 and HR: 1.920; p = 0.017, respectively), whereas performance status two independently predicted for shorter OS (HR: 2.031; p = 0.03). In summary, deregulated expression of circulating miRNAs involved in tumor and immune cell interactions evaluated before adjuvant and 1st-line chemotherapy can distinguish disease status and emerge as independent predictors for outcomes of breast cancer patients.

Harnessing the epigenome to boost immunotherapy response in non-small cell lung cancer patients

The introduction of immune checkpoint inhibitor (ICI)-based therapy for non-oncogene addicted non-small cell lung cancer (NSCLC) has significantly transformed the treatment landscape of the disease. Inhibitors of the programmed cell death protein 1/programmed death-ligand 1 (PD-1/PD-L1) immune checkpoint axis, which were initially considered as a late-line treatment option, gradually became the standard of care as first-line treatment for subgroups of NSCLC patients. However, a significant fraction of patients either fails to respond or progresses after a partial response to ICI treatment. Thus, the identification of mechanisms responsible for innate and acquired resistance to immunotherapy within a rapidly evolving tumor microenvironment (TME) is urgently required, as is the identification of reliable predictive biomarkers beyond PD-L1 expression. The deregulation of the epigenome is a key driver of cancer initiation and progression, and it has also been shown to drive therapeutic resistance. Tumor education of infiltrating myeloid cells towards an immuno-suppressive phenotype as well as induction of T-cell dysfunction in the TME is also driven by epigenome reprogramming. As it stands and, given their dynamic nature, epigenetic changes in cancer and non-cancer cells represent an attractive target to increase immunotherapy activity in NSCLC. Accordingly, clinical trials of combinatorial immuno-epigenetic drug regimens have been associated with tumor response in previously immunotherapy-resistant NSCLC patients irrespective of their PD-L1 status. Moreover, epigenetic signatures might represent valuable theragnostic biomarkers as they can be assayed easily in liquid biopsy and provide multiple layers of information. In this review, we discuss the current knowledge regarding the dysregulated epigenetic mechanisms contributing to immunotherapy resistance in NSCLC. Although the clinical data are still maturing, we highlight the attractive perspective that the synergistic model of immuno-epigenetic strategies might overcome the current limitations of immunotherapy alone and will be translated into durable clinical benefit for a broader NSCLC population.

CircRNA_2646 functions as a ceRNA to promote progression of esophageal squamous cell carcinoma via inhibiting miR-124/PLP2 signaling pathway

MicroRNA-124 (miR-124) has been predicted as a tumor suppressor in esophageal squamous cell carcinoma (ESCC). However, factors contributing to miR-124 reduction remain unclear. Circular RNAs (circRNAs) are a new family of non-coding RNAs with gene regulatory potential via interacting with miRNAs. We predicted three circRNAs, including CircRNA_14359, CircRNA_2646, and CircRNA_129, that could interact with miR-124 by bioinformatics analysis and determined their expressions in ESCC tissues and adjacent normal tissues. We found that CircRNA_2646 was up-regulated in ESCC, negatively correlated with the expression of miR-124 and positively associated with TNM stage and lymph node metastasis of ESCC. Luciferase reporter assay showed that CircRNA_2646 interacted with miR-124 in ESCC Eca109 and TE-1 cells. Moreover, ectopical overexpression of CircRNA_2646 accelerated cell proliferation, migration, invasion, and epithelial-to-mesenchymal transition (EMT), but restoration of miR-124 abrogated these functions and promoted Bcl-2-dependent cell apoptosis. Furthermore, it was found that the oncogene Proteolipid Protein 2 (PLP2) was the target gene of miR-124. In Eca109 and TE-1 cells, restoration of miR-124 decreased the level of PLP2 and inhibited PLP2-induced cell proliferation, migration, invasion, and EMT, but enhanced cell apoptosis. The in vivo study confirmed that CircRNA_2646 promoted ESCC development by repressing miR-124 and activating PLP2. Taken together, we identified that CircRNA_2646 functioned as an inhibitor in miR-124 signaling pathway in ESCC for carcinogenesis and could be a promising target for ESCC therapy.

Role of p53-miRNAs circuitry in immune surveillance and cancer development: A potential avenue for therapeutic intervention

The genome's guardian, p53, is a master regulatory transcription factor that occupies sequence-specific response elements in many genes and modulates their expression. The target genes transcribe both coding RNA and non-coding RNA involved in regulating several biological processes such as cell division, differentiation, and cell death. Besides, p53 also regulates tumor immunology via regulating the molecules related to the immune response either directly or via regulating other molecules, including microRNAs (miRNAs). At the post-transcriptional level, the regulations of genes by miRNAs have been an emerging mechanism. Interestingly, p53 and various miRNAs cross-talk at different regulation levels. The cross-talk between p53 and miRNAs creates loops, turns, and networks that can influence cell metabolism, cell fate, cellular homeostasis, and tumor formation. Further, p53-miRNAs circuit has also been insinuated in the regulation of immune surveillance machinery. There are several examples of p53-miRNAs circuitry where p53 regulates immunomodulatory miRNA expression, such as miR-34a and miR-17-92. Similarly, a reverse process occurs in which miRNAs such as miR-125b and miR-let-7 regulate the expression of p53. Thus, the p53-miRNAs circuitry connects the immunomodulatory pathways and may shift the pro-inflammatory balance towards the pro-tumorigenic condition. In this review, we discuss the influence of p53-miRNAs circuitry in modulating the immune response in cancer development. We assume that thorough studies on the p53-miRNAs circuitry in various cancers may prove useful in developing effective new cancer therapeutics for successfully combating this disease.

CircPITX1 Regulates Proliferation, Angiogenesis, Migration, Invasion, and Cell Cycle of Human Glioblastoma Cells by Targeting miR-584-5p/KPNB1 Axis

Recent researches reported that several circular RNAs (circRNAs) were associated with the glioblastoma (GBM) progression, while the regulatory role of circPITX1 remains unknown in GBM. The real-time quantitative polymerase chain reaction (RT-qPCR) was used to quantify circPITX1, miR-584-5p, and karyopherin b1 (KPNB1) expression in GBM tissues and cells. The proliferation capability of cells was analyzed by Cell Counting Kit-8 (CCK-8) and colony-forming assays. The matrigel angiogenesis assay was used to assess tube formation in GBM cells. Flow cytometry assays were conducted to evaluate the cell cycle distribution of GBM cells. The migration and invasion assays were assessed by transwell assay. The Western blot assay was employed to quantify the protein expression level in GBM tissues and cells. The targets of circPITX1 and miR-584-5p were confirmed by dual-luciferase reporter and RNA pull-down assays. A xenograft experiment in nude mice was used to assess the functional role of circPITX1 in vivo. CircPITX1 was obviously overexpressed in GBM tissues and cells when compared with negative groups. The functional experiment implied that knockdown of circPITX1 suppressed proliferation, angiogenesis, migration, invasion, and tumor growth in vivo along with induced cell cycle arrest of GBM cells. Furthermore, miR-584-5p was a target gene of circPITX1, and knockdown of miR-584-5p could abolish circPITX1 silencing-induced effects on GBM cells. KPNB1 was a target gene of miR-584-5p, and functional experiments revealed that overexpression of miR-584-5p repressed proliferation, angiogenesis, migration, invasion, and cell cycle process in GBM cells by targeting KPNB1. Mechanistically, circPITX1/miR-584-5p/KPNB1 axis regulated GBM process via mediating proliferation, angiogenesis, migration, invasion, and cell cycle process of GBM cells.

Biological Implications and Clinical Potential of Metastasis-Related miRNA in Colorectal Cancer

Colorectal cancer (CRC), ranking as the third commonest cancer, leads to extremely high rates of mortality. Metastasis is the major cause of poor outcome in CRC. When metastasis occurs, 5-year survival rates of patients decrease sharply, and strategies to enhance a patient's lifetime seem limited. MicroRNAs (miRNAs) are evolutionarily conserved small non-coding RNAs that are significantly involved in manipulation of CRC malignant phenotypes, including proliferation, invasion, and metastasis. To date, accumulating studies have revealed the mechanisms and functions of certain miRNAs in CRC metastasis. However, there is no systematic discussion about the biological implications and clinical potential (diagnostic role, prognostic role, and targeted therapy potential) of metastasis-related miRNAs in CRC. This review mainly summarizes the recent advances of miRNA-mediated metastasis in CRC. We also discuss the clinical values of metastasis-related miRNAs as potential biomarkers or therapeutic targets in CRC. Moreover, we envisage the future orientation and challenges in translating these findings into clinical applications.

miRNAs as biomarkers for early cancer detection and their application in the development of new diagnostic tools

Over the last decades, microRNAs (miRNAs) have emerged as important molecules associated with the regulation of gene expression in humans and other organisms, expanding the strategies available to diagnose and handle several diseases. This paper presents a systematic review of literature of miRNAs related to cancer development and explores the main techniques used to quantify these molecules and their limitations as screening strategy. The bibliographic research was conducted using the online databases, PubMed, Google Scholar, Web of Science, and Science Direct searching the terms "microRNA detection", "miRNA detection", "miRNA and prostate cancer", "miRNA and cervical cancer", "miRNA and cervix cancer", "miRNA and breast cancer", and "miRNA and early cancer diagnosis". Along the systematic review over 26,000 published papers were reported, and 252 papers were returned after applying the inclusion and exclusion criteria, which were considered during this review. The aim of this study is to identify potential miRNAs related to cancer development that may be useful for early cancer diagnosis, notably in the breast, prostate, and cervical cancers. In addition, we suggest a preliminary top 20 miRNA panel according to their relevance during the respective cancer development. Considering the progressive number of new cancer cases every year worldwide, the development of new diagnostic tools is critical to refine the accuracy of screening tests, improving the life expectancy and allowing a better prognosis for the affected patients.

MicroRNAs in the Tumor Microenvironment

The tumor microenvironment (TME) is decisive for the eradication or survival of any tumor mass. Moreover, it plays a pivotal role for metastasis and for providing the metastatic niche. The TME offers special physiological conditions and is composed of, for example, surrounding blood vessels, the extracellular matrix (ECM), diverse signaling molecules, exosomes and several cell types including, but not being limited to, infiltrated immune cells, cancer-associated endothelial cells (CAEs), and cancer-associated fibroblasts (CAFs). These cells can additionally and significantly contribute to tumor and metastasis progression, especially also by acting via their own deregulated micro (mi) RNA expression or activity. Thus, miRNAs are essential players in the crosstalk between cancer cells and the TME. MiRNAs are small non-coding (nc) RNAs that typically inhibit translation and stability of messenger (m) RNAs, thus being able to regulate several cell functions including proliferation, migration, differentiation, survival, invasion, and several steps of the metastatic cascade. The dynamic interplay between miRNAs in different cell types or organelles such as exosomes, ECM macromolecules, and the TME plays critical roles in many aspects of cancer development. This chapter aims to give an overview on the multiple contributions of miRNAs as players within the TME, to summarize the role of miRNAs in the crosstalk between different cell populations found within the TME, and to illustrate how they act on tumorigenesis and the behavior of cells in the TME context. Lastly, the potential clinical utility of miRNAs for cancer therapy is discussed.

Cytokine-chemokine network driven metastasis in esophageal cancer; promising avenue for targeted therapy

Esophageal cancer (EC) is a disease often marked by aggressive growth and poor prognosis. Lack of targeted therapies, resistance to chemoradiation therapy, and distant metastases among patients with advanced disease account for the high mortality rate. The tumor microenvironment (TME) contains several cell types, including fibroblasts, immune cells, adipocytes, stromal proteins, and growth factors, which play a significant role in supporting the growth and aggressive behavior of cancer cells. The complex and dynamic interactions of the secreted cytokines, chemokines, growth factors, and their receptors mediate chronic inflammation and immunosuppressive TME favoring tumor progression, metastasis, and decreased response to therapy. The molecular changes in the TME are used as biological markers for diagnosis, prognosis, and response to treatment in patients. This review highlighted the novel insights into the understanding and functional impact of deregulated cytokines and chemokines in imparting aggressive EC, stressing the nature and therapeutic consequences of the cytokine-chemokine network. We also discuss cytokine-chemokine oncogenic potential by contributing to the Epithelial-Mesenchymal Transition (EMT), angiogenesis, immunosuppression, metastatic niche, and therapeutic resistance development. In addition, it discusses the wide range of changes and intracellular signaling pathways that occur in the TME. Overall, this is a relatively unexplored field that could provide crucial insights into tumor immunology and encourage the effective application of modulatory cytokine-chemokine therapy to EC.

T Lymphocytes and Testicular Immunity: A New Insight into Immune Regulation in Testes

The immune privilege of the testes is necessary to prevent immune attacks to gamete-specific antigens and paternal major histocompatibility complex (MHC) antigens, allowing for normal spermatogenesis. However, infection and inflammation of the male genital tract can break the immune tolerance and represent a significant cause of male infertility. Different T cell subsets have been identified in mammalian testes, which may be involved in the maintenance of immune tolerance and pathogenic immune responses in testicular infection and inflammation. We reviewed the evidence in the published literature on different T subtypes (regulatory T cells, helper T cells, cytotoxic T cells, γδ T cells, and natural killer T cells) in human and animal testes that support their regulatory roles in infertility and the orchitis pathology. While many in vitro studies have indicated the regulation potential of functional T cell subsets and their possible interaction with Sertoli cells, Leydig cells, and spermatogenesis, both under physiological and pathological processes, there have been no in situ studies to date. Nevertheless, the normal distribution and function of T cell subsets are essential for the immune privilege of the testes and intact spermatogenesis, and T cell-mediated immune response drives testicular inflammation. The distinct function of different T cell subsets in testicular homeostasis and the orchitis pathology suggests a considerable potential of targeting specific T cell subsets for therapies targeting chronic orchitis and immune infertility.

SLC16A1-AS1 enhances radiosensitivity and represses cell proliferation and invasion by regulating the miR-301b-3p/CHD5 axis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC), a common type of human malignancies, leads to increasing incidence and fairly high mortality. An increasing number of studies have verified that long noncoding RNAs (lncRNAs) played key roles in the development of multiple human cancers. As a biomarker, SLC16A1-AS1 has been reported in non-small cell lung cancer (NSCLC) and oral squamous cell carcinoma (OSCC). Thus, we decided to investigate whether SLC16A1-AS1 exerts its biological function in HCC. In this study, we discovered that SLC16A1-AS1 was obviously downregulated in HCC tissues and cells. Overexpression of SLC16A1-AS1 inhibited HCC cell proliferation, invasion, and epithelial-mesenchymal transition (EMT) process as well as promoted cell apoptosis. Moreover, SLC16A1-AS1 was confirmed to enhance the radiosensitivity of HCC cells. Molecular mechanism exploration suggested that SLC16A1-AS1 served as a sponge for miR-301b-3p and CHD5 was the downstream target gene of miR-301b-3p in HCC cells. Rescue assays implied that CHD5 knockdown could recover the effects of SLC16A1-AS1 overexpression on HCC cellular processes. In brief, our study clarified that SLC16A1-AS1 acted as a tumor suppressor in HCC by targeting the miR-301b-3p/CHD5 axis, which may be a promising diagnostic biomarker and provide promising treatment for HCC patients.

MicroRNAs: As Critical Regulators of Tumor- Associated Macrophages

Emerging shreds of evidence suggest that tumor-associated macrophages (TAMs) modulate various hallmarks of cancer during tumor progression. Tumor microenvironment (TME) prime TAMs to execute important roles in cancer development and progression, including angiogenesis, matrix metalloproteinases (MMPs) secretion, and extracellular matrix (ECM) disruption. MicroRNAs (miRNAs) are critical epigenetic regulators, which modulate various functions in diverse types of cells, including macrophages associated with TME. In this review article, we provide an update on miRNAs regulating differentiation, maturation, activation, polarization, and recruitment of macrophages in the TME. Furthermore, extracellular miRNAs are secreted from cancerous cells, which control macrophages phenotypic plasticity to support tumor growth. In return, TAMs also secrete various miRNAs that regulate tumor growth. Herein, we also describe the recent updates on the molecular connection between tumor cells and macrophages. A better understanding of the interaction between miRNAs and TAMs will provide new pharmacological targets to combat cancer.

A novel miR-1291-ERRα-CPT1C axis modulates tumor cell proliferation, metabolism and tumorigenesis

Rationale: MicroRNAs are known to influence the development of a variety of cancers. Previous studies revealed that miR-1291 has antiproliferative functions in cancer cells. Carnitine palmitoyltransferase 1C (CPT1C) has a vital role in mitochondrial energy metabolism and modulation of cancer cell proliferation. Since both miR-1291 and CPT1C regulate tumor cell metabolism and cancer progression, we hypothesized that they might be regulated synergistically. Methods: A series of cell phenotype indicators, such as BrdU, colony formation, cell cycle, ATP production, ROS accumulation and cell ability to resist metabolic stress, were performed to clarify the effects of miR-1291 and ERRα expression on tumor cell proliferation and metabolism. A xenograft tumor model was used to evaluate cell tumorigenesis. Meta-analysis and bioinformatic prediction were applied in the search for the bridge-link between miR-1291 and CPT1C. RT-qPCR, western-blot and IHC analysis were used for the detection of mRNA and protein expression. Luciferase assays and ChIP assays were conducted for in-depth mechanism studies. Results: The expression of miR-1291 inhibited growth and tumorigenesis as a result of modulation of metabolism. CPT1C expression was indirectly and negatively correlated with miR-1291 levels. ESRRA was identified as a prominent differentially expressed gene in both breast and pancreatic cancer samples, and estrogen-related receptor α (ERRα) was found to link miR-1291 and CPT1C. MiR-1291 targeted ERRα and CPT1C was identified as a newly described ERRα target gene. Moreover, ERRα was found to influence cancer cell metabolism and proliferation, consistent with the cellular changes caused by miR-1291. Conclusion: This study demonstrated the existence and mechanism of action of a novel miR-1291-ERRα-CPT1C cancer metabolism axis that may provide new insights and strategies for the development of miRNA-based therapies for malignant cancers.