MicroRNAs in Cancer: challenges and opportunities in early detection, disease monitoring, and therapeutic agents

Exosomes as carriers to stimulate an anti-cancer immune response in immunotherapy and as predictive markers

During this era of rapid advancements in cancer immunotherapy, the application of cell-released small vesicles that activate the immune system is of considerable interest. Exosomes are cell-derived nanovesicles that show great promise for the immunological treatment of cancer because of their immunogenicity and molecular transfer capacity. Recent technological advancements have enabled the identification of functional functions that exosome cargoes perform in controlling immune responses. Exosomes are originated specifically from immune cells and tumor cells and they show unique composition patterns directly related to the immunotherapy against cancer. Exosomes can also deliver their cargo to particular cells, which can affect the phenotypic and immune-regulatory functions of those cells. Exosomes can influence the course of cancer and have therapeutic benefits by taking part in several cellular processes; as a result, they have the dual properties of activating and restraining cancer. Exosomes have tremendous potential for cancer immunotherapy; they may develop into the most powerful cancer vaccines and carriers of targeted antigens and drugs. Comprehending the potential applications of exosomes in immune therapy is significant for regulating cancer progression. This review offers an analysis of the function of exosomes in immunotherapy, specifically as carriers that function as diagnostic indicators for immunological activation and trigger an anti-cancer immune response. Moreover, it summarizes the fundamental mechanism and possible therapeutic applications of exosome-based immunotherapy for human cancer.

MicroRNA 211-5p inhibits cancer cell proliferation and migration in pancreatic cancer by targeting BMP2

MicroRNAs (miRNAs) are essential to the tumour growth and metastasis of several cancers. However, the implied functions of miR-211-5p in pancreatic cancer (PC) remains poorly known. In the present study, we discovered that miR-211-5p was a significantly downregulated miRNA in PC tissues compared to adjacent non-tumour tissues. Moreover, we revealed that miR-211-5p overexpression suppressed the proliferation and metastasis of PC cells. Mechanistically, miR-211-5p directly bond to 3'UTR of bone morphogenetic protein-2 (BMP2) and negatively regulated its expression. Rescue experiments showed that the biological function of miR-211-5p was reversed by BMP-2 overexpression in PC cells. Clinical data indicated that BMP2 expression was negatively correlated with miR-211-5p levels in PC patients. Our study provided evidence that miR-211-5p served as a significant suppressor in PC, provided potential targets for prognosis and treatment of patients with PC.

MicroRNA as a Diagnostic Tool, Therapeutic Target and Potential Biomarker in Cutaneous Malignant Melanoma Detection—Narrative Review

Melanoma is the most serious type of skin cancer, causing a large majority of deaths but accounting for only ~1% of all skin cancer cases. The worldwide incidence of malignant melanoma is increasing, causing a serious socio-economic problem. Melanoma is diagnosed mainly in young and middle-aged people, which distinguishes it from other solid tumors detected mainly in mature people. The early detection of cutaneous malignant melanoma (CMM) remains a priority and it is a key factor limiting mortality. Doctors and scientists around the world want to improve the quality of diagnosis and treatment, and are constantly looking for new, promising opportunities, including the use of microRNAs (miRNAs), to fight melanoma cancer. This article reviews miRNA as a potential biomarker and diagnostics tool as a therapeutic drugs in CMM treatment. We also present a review of the current clinical trials being carried out worldwide, in which miRNAs are a target for melanoma treatment.

miRNA Profiles of Canine Intestinal Carcinomas, Lymphomas and Enteritis Analysed by Digital Droplet PCR from FFPE Material

Most canine intestinal tumours are B-cell or T-cell lymphomas or carcinomas. They have to be distinguished from cases of enteritis. Non-invasive biomarkers such as miRNAs would be a step towards faster diagnosis. The aim of this study was to investigate shifts in miRNA expression in tissue samples collected from cases of enteritis, carcinoma and lymphoma of the small and large intestine to better understand the potential of miRNA as biomarkers for tumour diagnosis and classification. We selected two oncogenic miRNAs (miR-18b and 20b), two tumour suppressive miRNAs (miR-192 and 194) and two potential biomarkers for neoplasms (miR-126 and 214). They were isolated from FFPE material, quantified by ddPCR, normalised with RNU6B and compared with normal tissue values. Our results confirmed that ddPCR is a suitable method for quantifying miRNA from FFPE material. Expression of miR-18b and miR-192 was higher in carcinomas of the small intestine than in those of the large intestine. Specific miRNA patterns were observed in cases of enteritis, B-cell and T-cell lymphoma and carcinoma. However, oncogenic miR-18b and 20b were not elevated in any group and miR-126 and 214 were down-regulated in T-cell and B-cell lymphoma, as well as in carcinomas and lymphoplasmacytic enteritis of the small intestine.

Potentiality of Exosomal Proteins as Novel Cancer Biomarkers for Liquid Biopsy

Liquid biopsy has been rapidly developed in recent years due to its advantages of non-invasiveness and real-time sampling in cancer prognosis and diagnosis. Exosomes are nanosized extracellular vesicles secreted by all types of cells and abundantly distributed in all types of body fluid, carrying diverse cargos including proteins, DNA, and RNA, which transmit regulatory signals to recipient cells. Among the cargos, exosomal proteins have always been used as immunoaffinity binding targets for exosome isolation. Increasing evidence about the function of tumor-derived exosomes and their proteins is found to be massively associated with tumor initiation, progression, and metastasis in recent years. Therefore, exosomal proteins and some nucleic acids, such as miRNA, can be used not only as targets for exosome isolation but also as potential diagnostic markers in cancer research, especially for liquid biopsy. This review will discuss the existing protein-based methods for exosome isolation and characterization that are more appropriate for clinical use based on current knowledge of the exosomal biogenesis and function. Additionally, the recent studies for the use of exosomal proteins as cancer biomarkers are also discussed and summarized, which might contribute to the development of exosomal proteins as novel diagnostic tools for liquid biopsy.

Mesenchymal stem cell-derived extracellular vesicles for cell-free therapy of ocular diseases

Mesenchymal stem cells-derived extracellular vesicles (MSC-EVs) have noticeably attracted clinicians' attention in treating ocular diseases. As the paracrine factor of MSCs and an alternative for cell-free therapies, MSC-EVs can be conveniently dropped over the ocular surface or diffused through the retina upon intravitreal injection, without increasing the risks of cellular rejection and tumor formation. For clinical translation, a standardized and scalable production, as well as reprogramming the MSC-EVs, are highly encouraged. This review aims to assess the potential approaches for EV production and functional modification, in addition to summarizing the worldwide clinical trials initiated for various physiological systems and the specific biochemical effects of MSC-EVs on the therapy of eye diseases. Recent advances in the therapy of ocular diseases based on MSC-EVs are reviewed, and the associated challenges and prospects are discussed as well.

Cervical cancer development, chemoresistance, and therapy: a snapshot of involvement of microRNA

Cervical cancer (CC) is one of the leading causes of death in women due to cancer and a major concern in the developing world. Persistent human papilloma virus (HPV) infection is the major causative agent for CC. Besides HPV infection, genetic and epigenetic factors including microRNA (miRNA) also contribute to the malignant transformation. Earlier studies have revealed that miRNAs participate in cell proliferation, invasion and metastasis, angiogenesis, and chemoresistance processes by binding and inversely regulating the target oncogenes or tumor suppressor genes. Based on functions and mechanistic insights, miRNAs have been identified as cellular modulators that have an enormous role in diagnosis, prognosis, and cancer therapy. Signatures of miRNA could be used as diagnostic markers which are necessary for early diagnosis and management of CC. The therapeutic potential of miRNAs has been shown in CC; however, more comprehensive clinical trials are required for the clinical translation of miRNA-based diagnostics and therapeutics. Understanding the molecular mechanism of miRNAs and their target genes has been useful to develop miRNA-based therapeutic strategies for CC and overcome chemoresistance. In this review, we summarize the role of miRNAs in the development, progression, and metastasis of CC as well as chemoresistance. Further, we discuss the diagnostic and therapeutic potential of miRNAs to overcome chemoresistance and treatment of CC.

Optimization of Tumor Disease Monitoring in Medical Big Data Environment Based on High-Order Simulated Annealing Neural Network Algorithm

With the development of medical informatization, the data related to medical field are growing at an amazing speed, and medical big data appears. The mining and analysis of these data plays an important role in the prediction, monitoring, diagnosis, and treatment of tumor diseases. Therefore, this paper proposes a clustering algorithm of the high-order simulated annealing neural network algorithm and uses this algorithm to extract tumor disease-related big data, constructs training set according to the relevant information mined, designs a kind of dimension reduction model, aiming at the problem of excessive and wrong diagnosis and treatment in the diagnosis and treatment module of tumor disease monitoring mode, and establishes the corresponding control mechanism, so as to optimize the tumor disease monitoring mode. The results show that the clustering accuracy of the high-order simulated annealing neural network algorithm on different data sets (iris, wine, and Pima India diabetes) is 97.33%, 82.11%, and 70.56% and the execution time is 0.75 s, 0.562 s, and 1.092 s, which are better than those of the fast k-medoids algorithm and improved k-medoids clustering algorithm. To sum up, the high-order simulated annealing neural network algorithm can achieve good clustering effect in medical big data mining. The establishment of model M1 can reduce the probability of excessive and wrong medical treatment and improve the effectiveness of diagnosis and treatment module monitoring in tumor disease monitoring mode.

Bortezomib Sustains T Cell Function by Inducing miR-155-Mediated Downregulation of SOCS1 and SHIP1

Suppressive mechanisms operating within T cells are linked to immune dysfunction in the tumor microenvironment. We have previously reported using adoptive T cell immunotherapy models that tumor-bearing mice treated with a regimen of proteasome inhibitor, bortezomib - a dipeptidyl boronate, show increased antitumor lymphocyte effector function and survival. Here, we identify a mechanism for the improved antitumor CD8⁺ T cell function following bortezomib treatment. Intravenous administration of bortezomib at a low dose (1 mg/kg body weight) in wild-type or tumor-bearing mice altered the expression of a number of miRNAs in CD8⁺ T cells. Specifically, the effect of bortezomib was prominent on miR-155 - a key cellular miRNA involved in T cell function. Importantly, bortezomib-induced upregulation of miR-155 was associated with the downregulation of its targets, the suppressor of cytokine signaling 1 (SOCS1) and inositol polyphosphate-5-phosphatase (SHIP1). Genetic and biochemical analysis confirmed a functional link between miR-155 and these targets. Moreover, activated CD8⁺ T cells treated with bortezomib exhibited a significant reduction in programmed cell death-1 (PD-1) expressing SHIP1⁺ phenotype. These data underscore a mechanism of action by which bortezomib induces miR-155-dependent downregulation of SOCS1 and SHIP1 negative regulatory proteins, leading to a suppressed PD-1-mediated T cell exhaustion. Collectively, data provide novel molecular insights into bortezomib-mediated lymphocyte-stimulatory effects that could overcome immunosuppressive actions of tumor on antitumor T cell functions. The findings support the approach that bortezomib combined with other immunotherapies would lead to improved therapeutic outcomes by overcoming T cell exhaustion in the tumor microenvironment.

Circ_PSD3 promotes the progression of papillary thyroid carcinoma via the miR-637/HEMGN axis

AIMS

In the present study, we aimed to uncover the potential functions of circular RNA (circRNA) pleckstrin and Sec7 domain containing 3 (circ_PSD3) in papillary thyroid carcinoma (PTC) development.

MAIN METHODS

The abundance of circ_PSD3, PSD3 messenger RNA (mRNA), microRNA-637 (miR-637) and hemogen (HEMGN; EDAG-1) mRNA was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Flow cytometry was employed to measure cell cycle progression and cell apoptosis. Western blot assay was used to examine protein expression. The proliferation ability and motility of PTC cells were analyzed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and transwell assays, respectively. The interaction between miR-637 and circ_PSD3 or HEMGN was tested by dual-luciferase reporter assay. Animal experiments were used to explore the role of circ_PSD3 in PTC progression in vivo.

KEY FINDINGS

Circ_PSD3 was aberrantly up-regulated in PTC tumor tissues compared with adjacent normal tissues. Circ_PSD3 and HEMGN promoted the cell cycle progression, proliferation and metastasis and impeded the apoptosis of PTC cells. MiR-637 was a direct target of circ_PSD3, and miR-637 directly interacted with HEMGN mRNA in PTC cells. Circ_PSD3 silencing-induced effects in PTC cells were partly attenuated by the addition of anti-miR-637 or HEMGN overexpression plasmid. Circ_PSD3/miR-637/HEMGN regulated the activity of PI3K/Akt signal pathway in PTC cells. Circ_PSD3 silencing inhibited the tumor growth in vivo.

SIGNIFICANCE

Circ_PSD3 promoted the progression of PTC through regulating miR-637/HEMGN axis and activating PI3K/Akt signaling. Circ_PSD3/miR-637/HEMGN signaling axis might be a potential target for PTC therapy.

MicroRNA Expression Profiling on Paired Primary and Lymph Node Metastatic Breast Cancer Revealed Distinct microRNA Profile Associated With LNM

Breast cancer (BC) is the foremost cause of cancer-related deaths in women. BC patients are oftentimes presented with lymph node metastasis (LNM), which increases their risk of recurrence. Compelling data have recently implicated microRNAs in promoting BC metastasis. Therefore, the identification of microRNA (miRNA)-based molecular signature associated with LNM could provide an opportunity for a more personalized treatment for BC patients with high risk of LNM. In current study, we performed comprehensive miRNA profiling in matched primary breast and LNM and identified 40 miRNAs, which were differentially expressed in LNM compared to primary tumors. The expression of 14 miRNAs (Up: hsa-miR-155-5p, hsa-miR-150-5p, hsa-miR-146a-5p, hsa-miR-142-5p and down: hsa-miR-200a-3p, hsa-miR-200b-3p, hsa-miR-200c-3p, hsa-miR-205-5p, hsa-miR-210-3p, hsa-miR-214-3p, hsa-miR-141-3p, hsa-miR-127-3p, hsa-miR-125a-5p, and hsa-let-7c-5p) was subsequently validated in a second cohort of 32 breast and 32 matched LNM tumor tissues. Mechanistically, forced expression of hsa-miR-205-5p, or hsa-miR-214-3p epigenetically inhibited MDA-MB-231 cell proliferation, colony formation, and cell migration. Global gene expression profiling on MDA-MB-231 cells overexpressing hsa-miR-205-5p, or hsa-miR-214-3p in combination with in silico target prediction and ingenuity pathway analyses identified multiple bona fide targets for hsa-miR-205-5p, hsa-miR-214-3p affecting cellular proliferation and migration. Interestingly, interrogation of the expression levels of hsa-miR-205 and hsa-miR-214 in the METABRIC breast cancer dataset revealed significantly poor overall survival in patients with downregulated expression of miR-205 [HR = 0.75 (0.61–0.91)], p = 0.003 and hsa-miR-214 [HR = 0.74 (0.59–0.93) p = 0.008]. Our data unraveled the miRNA-transcriptional landscape associated with LNM and provide novel insight on the role of several miRNAs in promoting BC LNM, and suggest their potential utilization in the clinical management of BC patients.

MicroRNA Expression Profiling on Paired Primary and Lymph Node Metastatic Breast Cancer Revealed Distinct microRNA Profile Associated With LNM

Breast cancer (BC) is the foremost cause of cancer-related deaths in women. BC patients are oftentimes presented with lymph node metastasis (LNM), which increases their risk of recurrence. Compelling data have recently implicated microRNAs in promoting BC metastasis. Therefore, the identification of microRNA (miRNA)-based molecular signature associated with LNM could provide an opportunity for a more personalized treatment for BC patients with high risk of LNM. In current study, we performed comprehensive miRNA profiling in matched primary breast and LNM and identified 40 miRNAs, which were differentially expressed in LNM compared to primary tumors. The expression of 14 miRNAs (Up: hsa-miR-155-5p, hsa-miR-150-5p, hsa-miR-146a-5p, hsa-miR-142-5p and down: hsa-miR-200a-3p, hsa-miR-200b-3p, hsa-miR-200c-3p, hsa-miR-205-5p, hsa-miR-210-3p, hsa-miR-214-3p, hsa-miR-141-3p, hsa-miR-127-3p, hsa-miR-125a-5p, and hsa-let-7c-5p) was subsequently validated in a second cohort of 32 breast and 32 matched LNM tumor tissues. Mechanistically, forced expression of hsa-miR-205-5p, or hsa-miR-214-3p epigenetically inhibited MDA-MB-231 cell proliferation, colony formation, and cell migration. Global gene expression profiling on MDA-MB-231 cells overexpressing hsa-miR-205-5p, or hsa-miR-214-3p in combination with in silico target prediction and ingenuity pathway analyses identified multiple bona fide targets for hsa-miR-205-5p, hsa-miR-214-3p affecting cellular proliferation and migration. Interestingly, interrogation of the expression levels of hsa-miR-205 and hsa-miR-214 in the METABRIC breast cancer dataset revealed significantly poor overall survival in patients with downregulated expression of miR-205 [HR = 0.75 (0.61-0.91)], p = 0.003 and hsa-miR-214 [HR = 0.74 (0.59-0.93) p = 0.008]. Our data unraveled the miRNA-transcriptional landscape associated with LNM and provide novel insight on the role of several miRNAs in promoting BC LNM, and suggest their potential utilization in the clinical management of BC patients.

Upregulated hsa_circ_0004458 Contributes to Progression of Papillary Thyroid Carcinoma by Inhibition of miR-885-5p and Activation of RAC1

BACKGROUND Circular RNAs (circRNAs), a class of noncoding RNAs, may act as biomarkers and therapeutic targets of various cancers. However, the effects of hsa_circ_0004458 in papillary thyroid carcinoma (PTC) are still very much unclear. We aimed to demonstrate the potential roles of hsa_circ_0004458 in the progression of PTC. MATERIAL AND METHODS In our study, qRT-PCR assay was performed to assess hsa_circ_0004458, miR-885-5p and RAC1 expressions. Dual-luciferase reporter assay was used to detect the regulatory effects of hsa_circ_0004458 on miR-885-5p, and miR-885-5p on RAC1. MTT and flow cytometry assays were used to measure the cell proliferation, cycle, and apoptosis abilities. Tumor formation assay in nude mice was performed to measure the tumor growth in vivo. RESULTS Our results indicated that hsa_circ_0004458 was upregulated in PTC tissues and cells, while silencing of hsa_circ_0004458 suppressed PTC cell proliferation and promoted PTC cell cycle arrest and apoptosis in vitro. Tumor formation assay in nude mice showed that knockdown of hsa_circ_0004458 by siRNAs inhibited the growth of PTC tumor in vivo. In addition, we found that miR-885-5p was a direct target of hsa_circ_0004458, and silencing of hsa_circ_0004458 inhibited PTC cell proliferation by miR-885-5p. We also demonstrated that RAC1 was a direct target of miR-885-5p and silencing of RAC1 suppressed PTC cell proliferation. CONCLUSIONS We found that hsa_circ_0004458 promoted the progression of PTC by inhibition of miR-885-5p and activation of RAC1, and hsa_circ_0004458 may serve as a potential therapeutic target and biomarker for PTC.

RegenDbase: a comparative database of noncoding RNA regulation of tissue regeneration circuits across multiple taxa

Regeneration is an endogenous process of tissue repair that culminates in complete restoration of tissue and organ function. While regenerative capacity in mammals is limited to select tissues, lower vertebrates like zebrafish and salamanders are endowed with the capacity to regenerate entire limbs and most adult tissues, including heart muscle. Numerous profiling studies have been conducted using these research models in an effort to identify the genetic circuits that accompany tissue regeneration. Most of these studies, however, are confined to an individual injury model and/or research organism and focused primarily on protein encoding transcripts. Here we describe RegenDbase, a new database with the functionality to compare and contrast gene regulatory pathways within and across tissues and research models. RegenDbase combines pipelines that integrate analysis of noncoding RNAs in combination with protein encoding transcripts. We created RegenDbase with a newly generated comprehensive dataset for adult zebrafish heart regeneration combined with existing microarray and RNA-sequencing studies on multiple injured tissues. In this current release, we detail microRNA-mRNA regulatory circuits and the biological processes these interactions control during the early stages of heart regeneration. Moreover, we identify known and putative novel lncRNAs and identify their potential target genes based on proximity searches. We postulate that these candidate factors underscore robust regenerative capacity in lower vertebrates. RegenDbase provides a systems-level analysis of tissue regeneration genetic circuits across injury and animal models and addresses the growing need to understand how noncoding RNAs influence these changes in gene expression.

Messenger RNA Life-Cycle in Cancer Cells: Emerging Role of Conventional and Non-Conventional RNA-Binding Proteins?

Functional specialization of cells and tissues in metazoans require specific gene expression patterns. Biological processes, thus, need precise temporal and spatial coordination of gene activity. Regulation of the fate of messenger RNA plays a crucial role in this context. In the present review, the current knowledge related to the role of RNA-binding proteins in the whole mRNA life-cycle is summarized. This field opens up a new angle for understanding the importance of the post-transcriptional control of gene expression in cancer cells. The emerging role of non-classic RNA-binding proteins is highlighted. The goal of this review is to encourage readers to view, through the mRNA life-cycle, novel aspects of the molecular basis of cancer and the potential to develop RNA-based therapies.

Proliferation-associated miRNAs-494, -205, -21 and -126 detected by in situ hybridization: expression and prognostic potential in breast carcinoma patients

PURPOSE

To visualize by in situ hybridization (ISH) the levels of a set of proliferation-associated miRNAs and to evaluate their impact and clinical applicability in prognostication of invasive breast carcinoma.

METHODS

Tissue specimen from breast carcinoma patients were investigated for miRNAs-494, -205, -21 and -126. Prognostic associations for levels of miRNAs were analyzed based on complete clinical data and up to 22.5-year follow-up of the patient material (n = 285). For detection of the miRNAs, an automated sensitive protocol applying in situ hybridization was developed.

RESULTS

MiRNA-494 indicated prognostic value for patients with invasive breast carcinoma. Among node-negative disease reduced level of miRNA-494 predicted 8.5-fold risk of breast cancer death (p = 0.04). Altered levels and expression patterns of the studied miRNAs were observed in breast carcinomas as compared to benign breast tissue.

CONCLUSIONS

The present paper reports for the first time on the prognostic value of miRNA-494 in invasive breast cancer. Particularly, detection of miRNA-494 could benefit patients with node-negative breast cancer in identifying subgroups with aggressive disease. Based on our experience, the developed automatic ISH method to visualize altered levels of miRNAs-494, -205, -21 and -126 could be applied to routine pathology diagnostics providing that conditions of tissue treatment, especially fixation delays, are managed.

miR-135b-5p Promotes migration, invasion and EMT of pancreatic cancer cells by targeting NR3C2

The exact mechanisms of metastasis for pancreatic cancer remain to be uncovered. This study aimed to elucidate the potential functional mechanism of miR-135b-5p in migration, invasion and epithelial-to-mesenchymal transition (EMT) of pancreatic cancer cells. By real-time PCR and analysis of GEO database, we determined the up-regulated expression of miR-135b-5p in pancreatic cancer tissues and cell lines. Clinically, highly expressed miR-135b-5p was closely related to advanced TNM stage, more lymph node metastasis, more distant metastasis and worse overall survival (OS) and disease-free survival (DFS). Functionally, Transwell assays indicated that miR-135b-5p was a promoter for migration and invasion of pancreatic cancer cells. Additionally, immunohistochemistry staining and Western blot showed that highly expressed miR-135b-5p accelerated EMT process of pancreatic cancer cells. Furthermore, a series of experiments and rescue experiments revealed that Nuclear Receptor Subfamily 3 Group C Member 2 (NR3C2) was the target of miR-135b-5p in pancreatic cancer cells, mediating the promotion effects of miR-135b-5p on the tumor cells migration, invasion and EMT. In conclusion, miR-135b-5p, maybe a novel therapeutic target for pancreatic cancer, promoted migration, invasion and EMT of pancreatic cancer cells by targeting NR3C2.