Development of MicroRNAs as Potential Therapeutics against Cancer

Exploring cytokines dynamics: Uncovering therapeutic concepts for metabolic disorders in postmenopausal women- diabetes, metabolic bone diseases, and non-alcohol fatty liver disease

Menopause is an age-related change that persists for around one-third of a woman's life. Menopause increases the risk of metabolic illnesses such as diabetes, osteoporosis (OP), and nonalcoholic fatty liver disease (NAFLD). Immune mediators (pro-inflammatory cytokines), such as interleukin-1 (IL-1), IL-6, IL-17, transforming growth factor (TGF), and tumor necrosis factor (TNF), exacerbate the challenges of a woman undergoing menopause by causing inflammation and contributing to the development of these metabolic diseases in postmenopausal women. Furthermore, studies have shown that anti-inflammatory cytokines such as interleukin-1 receptor antagonists (IL-1Ra), IL-2, and IL-10 have a double-edged effect on diabetes and OP. Likewise, several interferon (IFN) members are double-edged swords in the OP. Therefore, addressing these immune mediators precisely may be an approach to improving the health of postmenopausal women. Hence, considering the significant changes in these cytokines, the present review focuses on the latest findings concerning the molecular mechanisms by which pro- and anti-inflammatory cytokines (interleukins) impact postmenopausal women with diabetes, OP, and NAFLD. Furthermore, we comprehensively discuss the therapeutic approaches that identify cytokines as therapeutic targets, such as hormonal therapy, physical activities, natural inhibitors (drugs), and others. Finally, this review aims to provide valuable insights into the role of cytokines in postmenopausal women's diabetes, OP, and NAFLD. Deeply investigating the mechanisms and therapeutic interventions involved will address the characteristics of immune mediators (cytokines) and improve the management of these illnesses, thereby enhancing the general quality of life and health of the corresponding populations of women.

Small molecules targeting microRNAs: new opportunities and challenges in precision cancer therapy

Noncoding RNAs, especially miRNAs, play a pivotal role in cancer initiation and metastasis, underscoring their susceptibility to precise modulation via small molecule inhibitors. This review examines the innovative strategy of targeting oncogenic miRNAs with small drug-like molecules, an approach that can reshape the cancer treatment landscape. We review the current understanding of the multifaceted roles of miRNAs in oncogenesis, highlighting emerging therapeutic paradigms that have the potential to expand cancer treatment options. As research on small molecule inhibitors of miRNA is still in its early stages, ongoing investigative efforts and the development of new technologies and chemical matter are essential to fulfill the significant potential of this innovative approach to cancer treatment.

A systematic review of non-coding RNA therapeutics in early clinical trials: a new perspective against cancer

Targeting non-coding RNAs (ncRNAs), including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), has recently emerged as a promising strategy for treating malignancies and other diseases. In recent years, the development of ncRNA-based therapeutics for targeting protein-coding and non-coding genes has also gained momentum. This review systematically examines ongoing and completed clinical trials to provide a comprehensive overview of the emerging landscape of ncRNA-based therapeutics. Significant efforts have been made to advance ncRNA therapeutics to early clinical studies. The most advanced trials have been conducted with small interfering RNAs (siRNAs), miRNA replacement using nanovector-entrapped miRNA mimics, or miRNA silencing by antisense oligonucleotides. While siRNA-based therapeutics have already received FDA approval, miRNA mimics, inhibitors, and lncRNA-based therapeutics are still under evaluation in preclinical and early clinical studies. We critically discuss the rationale and methodologies of ncRNA targeting strategies to illustrate this rapidly evolving field.

MicroRNA-425: A Pivotal Regulator Participating in Tumorigenesis of Human Cancers

MicroRNAs (miRNAs) are small single-stranded regulatory RNAs that are shown to be dysregulated in a wide array of human cancers. MiRNAs play critical roles in cancer progression and function as either oncogenes or tumor suppressors through modulating various target genes. Therefore, they possess great potential as diagnostic and therapeutic targets for cancer detection and treatment. In particular, recent studies have illustrated that miR-425 is also dysregulated in various human malignancies and plays a fundamental role in cancer initiation and progression. miR-425 has been reported to function as a dual-role miRNA participating in the regulation of cellular processes, including metastasis, invasion, and cell proliferation by modulating multiple signaling pathways, such as TGF-β, Wnt, and P13K/AKT pathways. Therefore, regarding recent researches showing the high therapeutic potential of miR-425, in this review, we have noted the impact of its dysregulation on signaling pathways and various aspects of tumorigenesis in a variety of human cancers.

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

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

Developing theragnostics for Alzheimer's disease: Insights from cancer treatment

The prevalence of Alzheimer's disease (AD) and its associated economic and societal burdens are on the rise, but there are no curative treatments for AD. Interestingly, this neurodegenerative disease shares several biological and pathophysiological features with cancer, including cell-cycle dysregulation, angiogenesis, mitochondrial dysfunction, protein misfolding, and DNA damage. However, the genetic factors contributing to the overlap in biological processes between cancer and AD have not been actively studied. In this review, we discuss the shared biological features of cancer and AD, the molecular targets of anticancer drugs, and therapeutic approaches. First, we outline the common biological features of cancer and AD. Second, we describe several anticancer drugs, their molecular targets, and their effects on AD pathology. Finally, we discuss how protein-protein interactions (PPIs), receptor inhibition, immunotherapy, and gene therapy can be exploited for the cure and management of both cancer and AD. Collectively, this review provides insights for the development of AD theragnostics based on cancer drugs and molecular targets.

microRNAs, oxidative stress, and genotoxicity as the main inducers in the pathobiology of cancer development

Cancer is one of the most serious leading causes of death in the world. Many eclectic factors are involved in cancer progression including genetic and epigenetic alongside environmental ones. In this account, the performance and fluctuations of microRNAs are significant in cancer diagnosis and treatment, particularly as diagnostic biomarkers in oncology. So, microRNAs manage and control the gene expression after transcription by mRNA degradation, or also they can inhibit their translation. Conspicuously, these molecular structures take part in controlling the cellular, physiological and pathological functions, which many of them can accomplish as tumor inhibitors or oncogenes. Relatively, Oxidative stress is defined as the inequality between the creation of reactive oxygen species (ROS) and the body's ability to detoxify the reactive mediators or repair the resulting injury. ROS and microRNAs have been recognized as main cancer promoters and possible treatment targets. Importantly, genotoxicity has been established as the primary reason for many diseases as well as several malignancies. The procedures have no obvious link with mutagenicity and influence the organization, accuracy of the information, or fragmentation of DNA. Conclusively, mutations in these patterns can lead to carcinogenesis. In this review article, we report the impressive and practical roles of microRNAs, oxidative stress, and genotoxicity in the pathobiology of cancer development in conjunction with their importance as reliable cancer biomarkers and their association with circulating miRNA, exosomes and exosomal miRNAs, RNA remodeling, DNA methylation, and other molecular elements in oncology.

Lau AT, Xu YM. The regulation of microRNAs on chemoresistance in triple-negative breast cancer: a recent update

Triple-negative breast cancer (TNBC) has negative expressions of ER, PR and HER2. Due to the insensitivity to both endocrine therapy and HER2-targeted therapy, the main treatment method for TNBC is cytotoxic chemotherapy. However, the curative effect of chemotherapy is limited because of the existence of acquired or intrinsic multidrug resistance. MicroRNAs (miRNAs) are frequently dysregulated in malignant tumors and involved in tumor occurrence and progression. Interestingly, growing studies show that miRNAs are involved in chemoresistance in TNBC. Thus, targeting dysregulated miRNAs could be a plausible way for better treatment of TNBC. Here, we present the updated knowledge of miRNAs associated with chemoresistance in TNBC, which may be helpful for the early diagnosis, prognosis and treatment of this life-threatening disease.

miR-185-5p May Modulate the Chemosensitivity of LUSC to Cisplatin via Targeting PCDHA11: Multi-omics Analysis and Experimental Validation

Drug resistance is the major difficulty in treatment of lung squamous cell carcinoma (LUSC). This study aims to explore drug response-related miRNAs (DRmiRNAs) based on multi-omics research. We identified DRmiRNAs of LUSC with a multi-omics integrated system that combines expression data of microRNA, lncRNA, mRNA, methylation levels, somatic mutations. After identifying DRmiRNAs, we screened and validated of the target mRNAs of DRmiRNAs through Targetscan and the miRDB database. Then, Real-time PCR and Western blot assays were used to estimate the expression of DRmiRNAs and target protein, and the dual-luciferase assays were used to confirm the interaction of DRmiRNAs and target mRNA. Furthermore, CCK-8 (Cell Counting Kit-8) assays were used to evaluate cell proliferation and drug sensitivity. After integrated analysis, hsa-miR-185-5p was identified as DRmiRNA based on multi-omics data. Through Targetscan and miRDB database, the possible target mRNAs were obtained and PCDHA11 was validated as a target mRNA of miR-185-5p by real-time PCR, Western blot assays and dual-luciferase assays. CCK-8 assays and clone formation assays showed that the proliferation of miR-185-5p mimics was significantly slower than that of miR-185-5p inhibitors, which means overexpression of miR-185-5p enhanced the anticancer effects of cisplatin, whereas the downregulation of miR-185-5p reduced the effects. Furthermore, the proliferation of silencing PCDHA11 was significantly slower than that of overexpression of PCDHA11, which means PCDHA11 overexpression weakened the anticancer effects of cisplatin, and silencing PCDHA11 enhanced the effects. This study demonstrated that miR-185-5p was involved in chemoresistance of LUSC cells to cisplatin partly via down-regulating PCDHA11, which may promote understanding the underlying molecular mechanisms of drug response.

Noncoding RNAs as an emerging resistance mechanism to immunotherapies in cancer: basic evidence and therapeutic implications

The increasing knowledge in the field of oncoimmunology has led to extensive research into tumor immune landscape and a plethora of clinical immunotherapy trials in cancer patients. Immunotherapy has become a clinically beneficial alternative to traditional treatments by enhancing the power of the host immune system against cancer. However, it only works for a minority of cancers. Drug resistance continues to be a major obstacle to the success of immunotherapy in cancer. A fundamental understanding of the detailed mechanisms underlying immunotherapy resistance in cancer patients will provide new potential directions for further investigations of cancer treatment. Noncoding RNAs (ncRNAs) are tightly linked with cancer initiation and development due to their critical roles in gene expression and epigenetic modulation. The clear appreciation of the role of ncRNAs in tumor immunity has opened new frontiers in cancer research and therapy. Furthermore, ncRNAs are increasingly acknowledged as a key factor influencing immunotherapeutic treatment outcomes. Here, we review the available evidence on the roles of ncRNAs in immunotherapy resistance, with an emphasis on the associated mechanisms behind ncRNA-mediated immune resistance. The clinical implications of immune-related ncRNAs are also discussed, shedding light on the potential ncRNA-based therapies to overcome the resistance to immunotherapy.

The various role of microRNAs in breast cancer angiogenesis, with a special focus on novel miRNA-based delivery strategies

After skin malignancy, breast cancer is the most widely recognized cancer detected in women in the United States. Breast cancer (BCa) can happen in all kinds of people, but it's much more common in women. One in four cases of cancer and one in six deaths due to cancer are related to breast cancer. Angiogenesis is an essential factor in the growth of tumors and metastases in various malignancies. An expanded level of angiogenesis is related to diminished endurance in BCa patients. This function assumes a fundamental part inside the human body, from the beginning phases of life to dangerous malignancy. Various factors, referred to as angiogenic factors, work to make a new capillary. Expanding proof demonstrates that angiogenesis is managed by microRNAs (miRNAs), which are small non-coding RNA with 19-25 nucleotides. MiRNA is a post-transcriptional regulator of gene expression that controls many critical biological processes. Endothelial miRNAs, referred to as angiomiRs, are probably concerned with tumor improvement and angiogenesis via regulation of pro-and anti-angiogenic factors. In this article, we reviewed therapeutic functions of miRNAs in BCa angiogenesis, several novel delivery carriers for miRNA-based therapeutics, as well as CRISPR/Cas9 as a targeted therapy in breast cancer.

MicroRNA-206 in human cancer: Mechanistic and clinical perspectives

MicroRNAs (miRNAs), small non-coding RNAs approximately 20-25 nt in length, play important roles via directly binding to the corresponding 3' UTR of target mRNAs. Recent research has shown that miRNAs cover a wide range of diseases, including several types of cancer. It is interesting to note that miR-206 operates as a tumor suppressor and is downregulated in abundant cancer types, such as breast cancer, lung cancer, colorectal cancer, and so forth. Interestingly, a growing number of studies have also reported that miR-206 could function as an oncogene and promote tumor cell proliferation. Thereby, miR-206 may act as either oncogenes or tumor suppressors under certain conditions. In addition, it was widely acknowledged that restoring tumor-suppressor miR-206 has emerged as an unconventional cancer therapy strategy. Therefore, miR-206 might be a newfangled procedure for achieving a more significant treatment outcome for cancer patients. This review summarizes the role of miR-206 in several cancer types and the contributions made between miR-206 and the diagnosis, treatment, and drug resistance of solid tumors.

Innovative approaches in transforming microRNAs into therapeutic tools

MicroRNA (miRNA) is regarded as a prominent genetic regulator, as it can fine-tune an entire biological pathway by targeting multiple target genes. This characteristic makes miRNAs promising therapeutic tools to reinstate cell functions that are disrupted as a consequence of diseases. Currently, miRNA replacement by miRNA mimics and miRNA inhibition by anti-miRNA oligonucleotides are the main approaches to utilizing miRNA molecules for therapeutic purposes. Nevertheless, miRNA-based therapeutics are hampered by major issues such as off-target effects, immunogenicity, and uncertain delivery platforms. Over the past few decades, several innovative approaches have been established to minimize off-target effects, reduce immunostimulation, and provide efficient transfer to the target cells in which these molecules exert their function. Recent achievements have led to the testing of miRNA-based drugs in clinical trials, and these molecules may become next-generation therapeutics for medical intervention. Despite the achievement of exciting milestones, the dosage of miRNA administration remains unclear, and ways to address this issue are proposed. Elucidating the current status of the main factors of therapeutic miRNA would allow further developments and innovations to achieve safe therapeutic tools. This article is categorized under: RNA in Disease and Development > RNA in Disease Regulatory RNAs/RNAi/Riboswitches > RNAi: Mechanisms of Action.

RNA interference: Promising approach for breast cancer diagnosis and treatment

Today, cancer is one of the main health-related challenges, and in the meantime, breast cancer (BC) is one of the most common cancers among women, with an alarming number of incidences and deaths every year. For this reason, the discovery of novel and more effective approaches for the diagnosis, treatment, and monitoring of the disease are very important. In this regard, scientists are looking for diagnostic molecules to achieve the above-mentioned goals with higher accuracy and specificity. RNA interference (RNAi) is a posttranslational regulatory process mediated by microRNA intervention and small interfering RNAs. After transcription and edition, these two noncoding RNAs are integrated and activated with the RNA-induced silencing complex (RISC) and AGO2 to connect the target mRNA by their complementary sequence and suppress their translation, thus reducing the expression of their target genes. These two RNAi categories show different patterns in different BC types and stages compared to healthy cells, and hence, these molecules have high diagnostic, monitoring, and therapeutic potentials. This article aims to review the RNAi pathway and diagnostic and therapeutic potentials with a special focus on BC.

The role of miRNA-128 in the development and progression of gastrointestinal and urogenital cancer

Increasing data have shown the significance of various miRNAs in malignancy. In this regard, parallel to its biological role in normal tissues, miRNA-128 (miR-128) has been found to play an essential immunomodulatory function in the process of cancer initiation and development. The occurrence of the aberrant expression of miR-128 in tumors and the unique properties of miRNAs raise the prospect of their use as biomarkers and the next generation of molecular anticancer therapies. The function of miR-128 in malignancies such as breast, prostate, colorectal, gastric, pancreatic, esophageal, cervical, ovarian and bladder cancers and hepatocellular carcinoma is discussed in this review. Finally, the effect of exosomal miR-128 on cancer resistance to therapeutics and cancer immunotherapy in certain malignancies is highlighted.

Simultaneous Targeting of Multiple oncomiRs with Phosphorothioate or PNA-Based Anti-miRs in Lymphoma Cell Lines

PURPOSE

MicroRNAs (miRNAs) are short (~ 22 nts) RNAs that regulate gene expression via binding to mRNA. MiRNAs promoting cancer are known as oncomiRs. Targeting oncomiRs is an emerging area of cancer therapy. OncomiR-21 and oncomiR-155 are highly upregulated in lymphoma cells, which are dependent on these oncomiRs for survival. Targeting specific miRNAs and determining their effect on cancer cell progression and metastasis have been the focus of various studies. Inhibiting a single miRNA can have a limited effect, as there may be other overexpressed miRNAs present that may promote tumor proliferation. Herein, we target miR-21 and miR-155 simultaneously using nanoparticles delivered two different classes of antimiRs: phosphorothioates (PS) and peptide nucleic acids (PNAs) and compared their efficacy in lymphoma cell lines.

METHODS

Poly-Lactic-co-Glycolic acid (PLGA) nanoparticles (NPs) containing PS and PNA-based antimiR-21 and -155 were formulated, and comprehensive NP characterizations: morphology (scanning electron microscopy), size (differential light scattering), and surface charge (zeta potential) were performed. Cellular uptake analysis was performed using a confocal microscope and flow cytometry analysis. The oncomiR knockdown and the effect on downstream targets were confirmed by gene expression (real time-polymerase chain reaction) assay.

RESULTS

We demonstrated that simultaneous targeting with NP delivered PS and PNA-based antimiRs resulted in significant knockdown of miR-21 and miR-155, as well as their downstream target genes followed by reduced cell viability ex vivo.

CONCLUSIONS

This project demonstrated that targeting miRNA-155 and miR-21 simultaneously using nanotechnology and a diverse class of antisense oligomers can be used as an effective approach for lymphoma therapy.

miRacle of microRNA-Driven Cancer Nanotherapeutics

MicroRNAs (miRNAs) are non-protein-coding RNA molecules 20-25 nucleotides in length that can suppress the expression of genes involved in numerous physiological processes in cells. Accumulating evidence has shown that dysregulation of miRNA expression is related to the pathogenesis of various human diseases and cancers. Thus, stragegies involving either restoring the expression of tumor suppressor miRNAs or inhibiting overexpressed oncogenic miRNAs hold potential for targeted cancer therapies. However, delivery of miRNAs to tumor tissues is a challenging task. Recent advances in nanotechnology have enabled successful tumor-targeted delivery of miRNA therapeutics through newly designed nanoparticle-based carrier systems. As a result, miRNA therapeutics have entered human clinical trials with promising results, and they are expected to accelerate the transition of miRNAs from the bench to the bedside in the next decade. Here, we present recent perspectives and the newest developments, describing several engineered natural and synthetic novel miRNA nanocarrier formulations and their key in vivo applications and clinical trials.

Oncogenic Role of miR-217 During Clear Cell Renal Carcinoma Progression

Clear cell renal carcinoma (ccRC) comprises a set of heterogeneous, fast-progressing pathologies with poor prognosis. Analyzing ccRC progression in terms of modifications at the molecular level may provide us with a broader understanding of the disease, paving the way for improved diagnostics and therapeutics. The role of micro-RNAs (miRs) in cancer by targeting both oncogenes and tumor suppressor genes is widely known. Despite this knowledge, the role of specific miRs and their targets in the progression of ccRC is still unknown. To evaluate the action of miRs and their target genes during ccRC progression, here we implemented a three-step method for constructing miR–gene co-expression networks for each progression stage of ccRC as well as for adjacent-normal renal tissue (NT). In the first step, we inferred all miR–gene co-expression interactions for each progression stage of ccRC and for NT. Afterwards, we filtered the whole miR–gene networks by differential gene and miR expression between successive stages: stage I with non-tumor, stage II with stage I, and so on. Finally, all miR–gene interactions whose relationships were inversely proportional (overexpressed miR and underexpressed genes and vice versa) were kept and removed otherwise. We found that miR-217 is differentially expressed in all contrasts; however, its targets were different depending on the ccRC stage. Furthermore, the target genes of miR-217 have a known role in cancer progression—for instance, in stage II network, GALNTL6 is overexpressed, and it is related to cell signaling, survival, and proliferation. In the stage III network, WNK2, a widely known tumor suppressor, is underexpressed. For the stage IV network, IGF2BP2, a post-transcriptional regulator of MYC and PTEN, is overexpressed. This data-driven network approach has allowed us to discover miRs that have different targets through ccRC progression, thus providing a method for searching possible stage-dependent therapeutic targets in this and other types of cancer.

MIR133A regulates cell proliferation, migration, and apoptosis by targeting SOX9 in human colorectal cancer cells

The human microRNA 133A (MIR133A) was identified as a CRC-associated miRNA. It was down-regulated in human CRC tissues. We identified the putative MIR133A1 and A2 target genes by comparing the transcriptome analysis data of MIR133A1 and A2 knock-in cells with the candidate MIR133A target genes predicted by bioinformatics tools. We identified 29 and 33 putative MIR133A and A2 direct target genes, respectively. Among them, we focused on the master transcription regulator gene SRY-box transcription factor 9 (SOX9), which exhibits a pleiotropic role in cancer. We confirmed that SOX9 is a direct target gene of MIR133A by luciferase reporter assay, quantitative RT-PCR, and western blot analysis. Overexpression of MIR133A in CRC cell lines significantly decreased SOX9 and its downstream PIK3CA-AKT1-GSK3B-CTNNB1 and KRAS-BRAF-MAP2K1-MAPK1/3 pathways and increased apoptosis. Furthermore, functional studies reveal that cell proliferation, colony formation, and migration ability were significantly decreased by MIR133A-overexpressed CRC cell lines. Knockdown of SOX9 in CRC cell lines by SOX9 gene silencing showed similar results. We also used a xenograft model to show that MIR133A overexpression suppresses tumor growth and proliferation. Our results suggest that MIR133A regulates cell proliferation, migration, and apoptosis by targeting SOX9 in human colorectal cancer.

miRNAs and the Hippo pathway in cancer: Exploring the therapeutic potential (Review)

Cancer is recognized as the leading cause of death worldwide. The hippo signaling pathway regulates organ size by balancing cell proliferation and cell death; hence dysregulation of the hippo pathway promotes cancer‑like conditions. miRNAs are a type of non‑coding RNA that have been shown to regulate gene expression. miRNA levels are altered in various classes of cancer. Researchers have also uncovered a crosslinking between miRNAs and the hippo pathway, which has been linked to cancer. The components of the hippo pathway regulate miRNA synthesis, and various miRNAs regulate the components of the hippo pathway both positively and negatively, which can lead to cancer‑like conditions. In the present review article, the mechanism behind the hippo signaling pathway and miRNAs biogenesis and crosslinks between miRNAs and the hippo pathway, which result in cancer, shall be discussed. Furthermore, the article will cover miRNA‑related therapeutics and provide an overview of the development of resistance to anticancer drugs. Understanding the underlying processes would improve the chances of developing effective cancer treatment therapies.

miR-27 and miR-124 target AR coregulators in prostate cancer: Bioinformatics and in vitro analysis

The inadequate efficacy of the current treatments for metastatic prostate cancer has directed efforts to the discovery of novel therapies. MicroRNAs (miRNAs) have been considered potential therapeutic agents due to their ability to control gene expression and cellular pathways. The accurate identification of genes and pathways which are targeted by a miRNA is the first step in the therapeutic use of these molecules. In this regard, there are multiple experimental and computational methods to predict and confirm the miRNA-mRNA relationships. The targeting the androgen receptor (AR) indirectly as the most important mediator of prostate cancer has been posited to both control the disease and prevent resistance to treatment. This study aimed to identify miRNAs targeting AR coregulators. For this purpose, we examined target genes by combining miRNA-mRNA computational and experimental data from various databases. miR-27a-3p and miR-124 displayed the highest scores and were selected as miRNAs with the potential to target candidate genes. Next, three cell lines of prostate cancer including PC3, LNCAP, and DU145 were transfected with plasmids which were expressed these selected miRNAs. Then, the gene expression and cell cycle analysis were performed. A decrease was observed in cell viability in all three cell lines than the cells transfected with backbone plasmid. Furthermore, the findings indicated that miR-27a-3p and miR-124 led to a significant decrease in the expression of all genes that were studied in PC3 cell line. In addition, miR-124 caused significant the cellular arrest in the G0/G1 stage, while for miR-27a-3p, this arrest occurred was in the G2/M stage. Our results indicated that the function of a unique miRNA could be different in different cell lines with particular cancer phenotype based on the cell line stage. These findings offer the possibility of employing the miR-124 and miR-27a-3p as therapeutic agents for prostate cancer treatment.

miRNAs in Lymphocytic Leukaemias-The miRror of Drug Resistance

Refractory disease and relapse remain the main causes of cancer therapy failure. Refined risk stratification, treatment regimens and improved early diagnosis and detection of minimal residual disease have increased cure rates in malignancies like childhood acute lymphoblastic leukaemia (ALL) to 90%. Nevertheless, overall survival in the context of drug resistance remains poor. The regulatory role of micro RNAs (miRNAs) in cell differentiation, homeostasis and tumorigenesis has been under extensive investigation in different cancers. There is accumulating data demonstrating the significance of miRNAs for therapy outcomes in lymphoid malignancies and some direct demonstrations of the interplay between these small molecules and drug response. Here, we summarise miRNAs' impact on chemotherapy resistance in adult and paediatric ALL and chronic lymphocytic leukaemia (CLL). The main focus of this review is on the modulation of particular signaling pathways like PI3K-AKT, transcription factors such as NF-κB, and apoptotic mediators, all of which are bona fide and pivotal elements orchestrating the survival of malignant lymphocytic cells. Finally, we discuss the attractive strategy of using mimics, antimiRs and other molecular approaches pointing at miRNAs as promising therapeutic targets. Such novel strategies to circumvent ALL and CLL resistance networks may potentially improve patients' responses and survival rates.

ncRNAs and polyphenols: new therapeutic strategies for hypertension

Polyphenols have gained significant attention in protecting several chronic diseases, such as cardiovascular diseases (CVDs). Accumulating evidence indicates that polyphenols have potential protective roles for various CVDs. Hypertension (HTN) is among the hazardous CVDs accounting for nearly 8.5 million deaths worldwide. HTN is a complex and multifactorial disease and a combination of genetic susceptibility and environmental factors play major roles in its development. However, the underlying regulatory mechanisms are still elusive. Polyphenols have shown to cause favourable and beneficial effects in the management of HTN. Noncoding RNAs (ncRNAs) as influential mediators in modulating the biological properties of polyphenols, have shown significant footprints in CVDs. ncRNAs control basic functions in virtually all cell types relevant to the cardiovascular system and, thus, a direct link with blood pressure (BP) regulation is highly probable. Recent evidence suggests that a number of ncRNAs, including main small ncRNAs, microRNAs (miRNAs) and long ncRNAs (lncRNAs), play crucial roles with respect to the antihypertensive effects of polyphenols. Indeed, targeting lncRNAs by polyphenols will be a novel and promising strategy in the management of HTN. Herein, we reviewed the effects of polyphenols in HTN. Additionally, we emphasized on the potential effects of polyphenols on regulations of main ncRNAs, which imply the role of polyphenols in regulating ncRNAs in order to exert protective effects and thus proposing them as new targets for HTN treatment.Abbreviations : CVD: cardiovascular disease; BP: blood pressure; HTN: hypertension, lncRNAs: long noncoding RNAs; p38-MAPK: p38-mitogenactivated protein kinase; OPCs: oligomeric procyanidins; GTP: guanosine triphosphate; ROS: reactive oxygen species; cGMP: cyclic guanosine monophosphate; SGC: soluble guanylate cyclase; PI3K: phosphatidylinositol 3-kinase; cGMP: Cyclic GMP; eNOS: endothelial NO synthase; ERK ½: extracellular signal-regulated kinase ½; L-Arg: L-Arginine; MAPK: mitogen-activated protein kinases; NO: Nitric oxide; P: Phosphorus; PDK1: Phosphoinositide-dependent kinase 1; PI3-K: Phosphatidylinositol 3-kinase; PIP2: Phosphatidylinositol diphosphate; ncRNAs: non-protein-coding RNA; miRNAs: microRNAs; OPCs: oligomeric procyanidins; RES: resveratrol; GE: grape extract; T2DM: type 2 diabetes mellitus; IL: interleukin; TNF-α: tumour necrosis factor-alpha; NF-κB: nuclear factor NF-kappa-B; ALP: alkaline phosphatase; PARP1: poly [ADP-ribose] polymerase 1; HIF1a: Hypoxia-inducible-factor 1A; NFATc2: nuclear factor of activated T cells 2; PAD: peripheral artery disease; SHR: spontaneously hypertensive rat; RAAS: renin-angiotensin-aldosterone system; AT₁R: angiotensin type-1 receptor; Nox: NADPH oxidase; HO-1: haem oxygenase-1; JAK/STAT: Janus kinase/signal transducers/activators of the transcription; PNS: panax notoginseng saponin; snoRNA: small nucleolar RNA; hnRNA: heterogeneous nuclear RNA; VSMCs: vascular smooth muscle cells; irf7: interferon regulatory factor 7; limo2: LIM only domain 2; GWAS: genome-wide association study; GAS5: Growth arrest-specific 5; Asb3, Ankyrin repeat and SPCS box containing 3; Chac2: cation transport regulator homolog 2; Pex11b: peroxisomal membrane 11B; Sp5: Sp5 transcription factor; EGCG: epigallocatechin gallate; ApoE: Apo lipoprotein E; ERK-MAP kinase: extracellular signal-regulated kinases-mitogen-activated protein kinase; PAH: pulmonary artery hypertension; PAP: pulmonary arterial pressure; HIF1a: hypoxia-inducible-factor 1A; NFATc2: nuclear factor of activated T cells 2; HMEC-1: Human microvascular endothelial cells; stat2: signal transducers and activators of transcription 2; JNK: c-Jun N-terminal kinase; iNOS: inducible NO synthase. SNP: single nucleotide polymorphism; CAD: coronary artery disease.

Effect of Combined Perftoran and Indocyanine Green-Photodynamic Therapy on HypoxamiRs and OncomiRs in Lung Cancer Cells

Indocyanine green (ICG) is a nontoxic registered photosensitizer used as a diagnostic tool and for photodynamic therapy (PDT). Hypoxia is one the main factors affecting PDT efficacy. Perfluorodecalin emulsion (Perftoran®) is a known oxygen carrier. This study investigated the effect of Perftoran® on ICG/PDT efficacy in presence and absence of Perftoran® via evaluation of phototoxicity by MTT; hypoxia estimation by pimonidazole, HIF-1α/β by ELISA, and 17 miRNAs (tumor suppressors, oncomiRs, and hypoxamiRs) were analyzed by qPCR. Compared to ICG/PDT, Perftoran®/ICG/PDT led to higher photocytotoxicity, inhibited pimonidazole hypoxia adducts, inhibited HIF-1α/β concentrations, induced the expression of tumor-suppressing miRNAs let-7b/d/f/g, and strongly inhibited the pro-hypoxia miRNA let-7i. Additionally, Perftoran®/ICG/PDT suppressed the expression of the oncomiRs miR-155, miR-30c, and miR-181a and the hypoxamiRs miR-210 and miR-21 compared to ICG/PDT. In conclusion, Perftoran® induced the phototoxicity of ICG/PDT and inhibited ICG/PDT-hypoxia via suppressing HIF-α/β, miR-210, miR-21, let-7i, miR-15a, miR-30c, and miR-181a and by inducing the expression of let-7d/f and miR-15b.

Cancer-Associated Fibroblasts: Mechanisms of Tumor Progression and Novel Therapeutic Targets

Simple Summary

The tumor microenvironment plays an important role in determining the biological behavior of several of the more aggressive malignancies. Among the various cell types evident in the tumor “field”, cancer-associated fibroblasts (CAFs) are a heterogenous collection of activated fibroblasts secreting a wide repertoire of factors that regulate tumor development and progression, inflammation, drug resistance, metastasis and recurrence. Insensitivity to chemotherapeutics and metastatic spread are the major contributors to cancer patient mortality. This review discusses the complex interactions between CAFs and the various populations of normal and neoplastic cells that interact within the dynamic confines of the tumor microenvironment with a focus on the involved pathways and genes.

Abstract

Cancer-associated fibroblasts (CAFs) are a heterogenous population of stromal cells found in solid malignancies that coexist with the growing tumor mass and other immune/nonimmune cellular elements. In certain neoplasms (e.g., desmoplastic tumors), CAFs are the prominent mesenchymal cell type in the tumor microenvironment, where their presence and abundance signal a poor prognosis in multiple cancers. CAFs play a major role in the progression of various malignancies by remodeling the supporting stromal matrix into a dense, fibrotic structure while secreting factors that lead to the acquisition of cancer stem-like characteristics and promoting tumor cell survival, reduced sensitivity to chemotherapeutics, aggressive growth and metastasis. Tumors with high stromal fibrotic signatures are more likely to be associated with drug resistance and eventual relapse. Clarifying the molecular basis for such multidirectional crosstalk among the various normal and neoplastic cell types present in the tumor microenvironment may yield novel targets and new opportunities for therapeutic intervention. This review highlights the most recent concepts regarding the complexity of CAF biology including CAF heterogeneity, functionality in drug resistance, contribution to a progressively fibrotic tumor stroma, the involved signaling pathways and the participating genes.

Functional assessment of miR‑1291 in colon cancer cells

miR‑1291 exerts an anti‑tumor effect in a subset of human carcinomas, including pancreatic cancer. However, its role in colorectal cancer (CRC) is largely unknown. In the present study, the expression and effect of miR‑1291 in CRC cells was investigated. It was identified that miR‑1291 significantly suppressed the proliferation, invasion, cell mobility and colony formation of CRC cells. Additionally, miR‑1291 induced cell apoptosis. A luciferase reporter assay revealed that miR‑1291 directly bound the 3'‑untranslated region sequence of doublecortin‑like kinase 1 (DCLK1). miR‑1291 also suppressed DCLK1 mRNA and protein expression in HCT116 cells that expressed DCLK1. Furthermore, miR‑1291 suppressed cancer stem cell markers BMI1 and CD133, and inhibited sphere formation. The inhibitory effects on sphere formation, invasion and mobility in HCT116 cells were also explored and verified using DCLK1 siRNAs. Furthermore, miR‑1291 induced CDK inhibitors p21WAF1/CIP1 and p27KIP1 in three CRC cell lines, and the overexpression of DCLK1 in HCT116 cells led to a decrease of p21WAF1/CIP1 and p27KIP1. Intravenous administration of miR‑1291 loaded on the super carbonate apatite delivery system significantly inhibited tumor growth in the DLD‑1 xenograft mouse model. Additionally, the resultant tumors exhibited significant upregulation of the p21WAF1/CIP1 and p27KIP1 protein with treatment of miR‑1291. Taken together, the results indicated that miR‑1291 served an anti‑tumor effect by modulating multiple functions, including cancer stemness and cell cycle regulation. The current data suggested that miR‑1291 may be a promising nucleic acid medicine against CRC.

Mesenchymal stem cell (MSC)-derived exosomes as novel vehicles for delivery of miRNAs in cancer therapy

Mesenchymal stem cells (MSCs) are known as promising sources for cancer therapy and can be utilized as vehicles in cancer gene therapy. MSC-derived exosomes are central mediators in the therapeutic functions of MSCs, known as the novel cell-free alternatives to MSC-based cell therapy. MSC-derived exosomes show advantages including higher safety as well as more stability and convenience for storage, transport and administration compared to MSCs transplant therapy. Unmodified MSC-derived exosomes can promote or inhibit tumors while modified MSC-derived exosomes are involved in the suppression of cancer development and progression via the delivery of several therapeutics molecules including chemotherapeutic drugs, miRNAs, anti-miRNAs, specific siRNAs, and suicide gene mRNAs. In most malignancies, dysregulation of miRNAs not only occurs as a consequence of cancer progression but also is directly involved during tumor initiation and development due to their roles as oncogenes (oncomiRs) or tumor suppressors (TS-miRNAs). MiRNA restoration is usually achieved by overexpression of TS-miRNAs using synthetic miRNA mimics and viral vectors or even downregulation of oncomiRs using anti-miRNAs. Similar to other therapeutic molecules, the efficacy of miRNAs restoration in cancer therapy depends on the effectiveness of the delivery system. In the present review, we first provided an overview of the properties and potentials of MSCs in cancer therapy as well as the application of MSC-derived exosomes in cancer therapy. Finally, we specifically focused on harnessing the MSC-derived exosomes for the aim of miRNA delivery in cancer therapy.

Evaluating the influence of Human Umbilical Cord Mesenchymal Stem Cells-derived exosomes loaded with miR-3182 on metastatic performance of Triple Negative Breast Cancer cells

AIMS

Deregulation of microRNA (miRNA) function has been linked to numerous human cancers, such as Triple Negative Breast Cancer (TNBC). Exosomes, a subgroup of extracellular vehicles (EVs), can efficiently deliver many different cargo types to the target cell and have an extensive role in delivering therapeutic cargo for treatment. The present study intended to interrogate the effects of exosomal delivery of miR-3182 on TNBC cellular processes.

MAIN METHODS

Human Umbilical Cord Mesenchymal Stem Cells (HUCMSCs) were cultured and exosomes were isolated and characterized using TEM, SEM, DLS, and Western blot. Exosomes were transfected with miR-3182 and added to the treatment groups. The expression level of miR-3182 and their target genes including mTOR and S6KB1 were evaluated using RT-qPCR. The effects of miR-3182 loaded HUCMSC-exosomes treatment on the cellular aspect of MDA-MB-231 cells including their viability, migration potency, cell cycle status and apoptosis were investigated.

KEY FINDINGS

According to the results, exosomal miR-3182 significantly abolished cell proliferation and migration (P < 0.05). miR-3182 loaded exosomes also induced apoptosis in TNBC cells by down-regulating mTOR and S6KB1 genes (P < 0.05).

SIGNIFICANCE

In nutshell, miR-3182-loaded HUCMSC-exosomes can suppress TNBC invasion, suggesting that exosomes containing miR-3182 could be a reliable therapeutic paradigm in TNBC therapy.

Crosstalk between miRNA and PI3K/AKT/mTOR signaling pathway in cancer

Phosphoinositide-3 kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway is one of the most important proliferative signaling pathways with critical undeniable function in various aspects of cancer initiation/progression, including proliferation, apoptosis, metastasis, angiogenesis, and drug resistance. On the other hand, numerous genetic alterations in the key genes involved in the PI3K/AKT/mTOR signaling pathway have been identified in multiple solid and hematological tumors. In addition, accumulating recent evidences have demonstrated a reciprocal interaction between this signaling pathway and microRNAs, a large group of small non-coding RNAs. Therefore, in this review, it was attempted to discuss about the interaction between key components of PI3K/AKT/mTOR signaling pathway with various miRNAs and their importance in cancer biology.

Improved In Vivo Delivery of Small RNA Based on the Calcium Phosphate Method

In the past few years, we have demonstrated the efficacy of a nanoparticle system, super carbonate apatite (sCA), for the in vivo delivery of siRNA/miRNA. Intravenous injection of sCA loaded with small RNAs results in safe, high tumor delivery in mouse models. To further improve the efficiency of tumor delivery and avoid liver toxicity, we successfully developed an inorganic nanoparticle device (iNaD) via high-frequency ultrasonic pulverization combined with PEG blending during the production of sCA. Compared to sCA loaded with 24 μg of miRNA, systemic administration of iNaD loaded with 0.75 μg of miRNA demonstrated similar delivery efficiency to mouse tumors with little accumulation in the liver. In the mouse therapeutic model, iNaD loaded with 3 μg of the tumor suppressor small RNA MIRTX resulted in an improved anti-tumor effect compared to sCA loaded with 24 μg. Our findings on the bio-distribution and therapeutic effect of iNaD provide new perspectives for future nanomedicine engineering.

ATP2B1-AS1 Promotes Cerebral Ischemia/Reperfusion Injury Through Regulating the miR-330-5p/TLR4-MyD88-NF-κB Signaling Pathway

We aim to explore the expression and function of long non-coding RNA (lncRNA) ATP2B1-AS1 in a cerebral ischemia/reperfusion (I/R) injury. In this study, we established a middle cerebral artery occlusion/reperfusion (MCAO/IR) rat model and an OGD/R PC12 cell model to evaluate the expression and role of ATP2B1-AS1 in the cerebral I/R injury. We found that the expression of ATP2B1-AS1 was upregulated in both in vitro and in vivo cerebral I/R injury models. Knockdown of ATP2B1-AS1 increased the cell viability, inhibited apoptosis, and decreased the expressions of inflammation cytokines. The target of ATP2B1-AS1 was predicted and validated to be miR-330-5p. MiR-330-5p abrogated the regulatory effect of ATP2B1-AS1 on cell viability, apoptosis, and cytokines of OGD/R PC12 cells. Furthermore, the results showed that miR-330-5p targeted TLR4, which was also upregulated in the infarcted area of MCAO/IR rats and OGD/R PC12 cells. Overexpression of ATP2B1-AS1 increased the expressions of TLR4, MyD88, and NF-κB p65 of OGD/R PC12 cells, while the effect of ATP2B1-AS1 was abrogated by miR-330-5p. In addition, knockdown of ATP2B1-AS1 decreased the latency time, increased the time of passing the platform position, reduced the cerebral infarct volume, decreased neurological deficit scores, and reduced the number of damaged neurons of MCAO/IR rats that were subjected to the Morris water maze test. Taken together, our study indicates that ATP2B1-AS1 may be an attractive therapeutic target for the treatment of cerebral ischemic injuries.

MicroRNA Expression Profiling of Lung Cancer with Differential Expression of the RON Receptor Tyrosine Kinase

Background

The Ron receptor tyrosine kinase (RON) can act as a protooncogene and may play a prominent role in the initiation and development of lung cancer. microRNAs (miRNA) are master regulators of gene expression through direct or indirect regulation, and impact all aspects of cell biology.

Methods

Nonsmall-cell lung cancer (NSCLC) samples and small-cell lung cancer (SCLC) were stratified based on RON expression to identify miRNA profiles associated with RON expression levels, differentially expressed miRNA regulated by RON were screened out, and their biological behavior was analyzed.

Results

miRNA expression was most significantly affected by cancer type, and we found 85 miRNAs that were significantly differentially expressed between NSCLC and SCLC. There were 46 miRNAs differentially expressed between high RON expressing NSCLC compared to low RON expressing NSCLC. Biological processes and pathways found to be significantly influenced by RON expression included epithelial-mesenchymal transition (EMT) and activation of the PI3K-Akt and MAPK signaling pathways.

Conclusions

These data may provide the basis for a novel strategy to characterize lung cancer by RON expression and microRNA genotyping.

Highlighting the interplay of microRNAs from Leishmania parasites and infected-host cells

Leishmania parasites, the causative agents of leishmaniasis, are protozoan parasites with the ability to modify the signalling pathway and cell responses of their infected host cells. These parasite strategies alter the host cell environment and conditions favouring their replication, survival and pathogenesis. Since microRNAs (miRNAs) are able to post-transcriptionally regulate gene expression processes, these biomolecules can exert critical roles in controlling Leishmania-host cell interplay. Therefore, the identification of relevant miRNAs differentially expressed in Leishmania parasites as well as in infected cells, which affect the host fitness, could be critical to understand the infection biology, pathogenicity and immune response against these parasites. Accordingly, the current review aims to address the differentially expressed miRNAs in both, the parasite and infected host cells and how these biomolecules change cell signalling and host immune responses during infection. A deep understanding of these processes could provide novel guidelines and therapeutic strategies for managing and treating leishmaniasis.

circRNA-miRNA-mRNA in breast cancer

Among cancers, breast cancer has the highest incidence rate among women and poses a tremendous threat to women's health. Messenger RNA (mRNA), microRNA (miRNA) and circular RNA (circRNA) play vital roles in the progression of breast cancer through a variety of biological effects and mechanisms. Recently, the regulatory network formed by circRNAs, miRNAs and mRNAs has piqued attention and garnered interest. CircRNAs bind to miRNAs through a regulatory mechanism in which endogenous RNAs compete to indirectly regulate the expression of mRNA corresponding to downstream target genes of miRNAs, contributing to the progression of breast cancer. The circRNA-miRNA-mRNA axis may be a marker for the early diagnosis and prognosis of breast cancer and a potential breast cancer treatment target, providing unlimited possibilities for the development of breast cancer biomarkers and therapeutic strategies. This article reviews recent research progress on the circRNA-miRNA-mRNA axis as a regulatory network of competing endogenous RNAs in breast cancer. Herein, we focus on the mechanism and function of the circRNA-miRNA-mRNA axis in the occurrence and metastasis of breast cancer, and resistance to chemotherapy.

MicroRNA miR-145-5p inhibits Phospholipase D 5 (PLD5) to downregulate cell proliferation and metastasis to mitigate prostate cancer

Prostate cancer (PCa), a frequently detected malignant tumor, is the fifth leading global cancer mortality cause in men. Although research has improved the PCa survival rate, significantly reduced survival occurs among patients at the metastatic stage. MiRNAs, which are short non-coding proteins, are crucial for several biological roles, essential for PCa proliferation, differentiation, multiplication, and migration. The investigation aimed to explore miR-145-5p and PLD5 association and clarify their function in regulating proliferation in PCa cell lines.The study used PC-3, LNCaP, DU-145 PCa, and RWPE-1 non-cancerous cell line, PCa, and BPH tissue specimens, and nude mice to validate results. MiR-145-5p and PLD5 manifestation were assessed through RT-qPCR. PLD5 and miR-145 binding was determined through dual-luciferase reporter gene assays. Validation of cell proliferation, migration, and invasion was assessed through MTT, scratch wound, and transwell assays, respectively.The results indicated a downregulation of miR-145-5p level in PCa cell lines and tissues in comparison to the non-cancerous controls. PLD5 overexpression exerted a cancerous effect while mimicking of miR-145-5p reversed the PLD5-oncogenic effects and significantly inhibited PCa cells proliferation, migration, invasion, and metastasis.In conclusion, the study revealed that miR-145-5p upregulated apoptosis and repressed migration, invasion, and metastasis of PCa via direct PLD5 modulation.

Breast Cancer Response to Therapy: Can microRNAs Lead the Way?

Breast cancer (BC) is a leading cause of death among women with malignant diseases. The selection of adequate therapies for highly invasive and metastatic BCs still represents a major challenge. Novel combinatorial therapeutic approaches are urgently required to enhance the efficiency of BC treatment. Recently, microRNAs (miRNAs) emerged as key regulators of the complex mechanisms that govern BC therapeutic resistance and susceptibility. In the present review we aim to critically examine how miRNAs influence BC response to therapies, or how to use miRNAs as a basis for new therapeutic approaches. We summarized recent findings in this rapidly evolving field, emphasizing the challenges still ahead for the successful implementation of miRNAs into BC treatment while providing insights for future BC management.The goal of this review was to propose miRNAs, that might simultaneously improve the efficacy of all four therapies that are the backbone of current BC management (radio-, chemo-, targeted, and hormone therapy). Among the described miRNAs, miR-21 and miR-16 emerged as the most promising, closely followed by miR-205, miR-451, miR-182, and miRNAs from the let-7 family. miR-21 inhibition might be the best choice for future improvement of invasive BC treatment.New therapeutic strategies of miRNA-based agents alongside current standard treatment modalities could greatly benefit BC patients. This review represents a guideline on how to navigate this elaborate puzzle.

Interplay between MAPK/ERK signaling pathway and MicroRNAs: A crucial mechanism regulating cancer cell metabolism and tumor progression

Mitogen-activated protein kinase (MAPK) signal transduction, as a highly conserved signaling pathway, is reported to be involved in various biological events, including metabolic reprogramming, cell proliferation, survival, and differentiation. Mutations in key molecules involved in MAPK/ERK signaling and dysregulation of this pathway are very common events in various human malignancies, which make the MAPK signaling a crucial signaling pathway participating in the regulation of glucose uptake by malignant cells and tumorigenesis. MicroRNAs (miRNAs), as small non-coding RNAs, are critical regulators of gene expression that play key roles in cancer initiation and progression. On the other hand, these small RNAs mutually regulate the MAPK signaling which is often overexpressed in the case of cancer progression; suggesting that crosstalk between miRNAs and this signaling pathway plays a pivotal role in the development of human cancers. Some miRNAs such as miR-20b, miR-34c-3p, miR-152, miR-181a, and miR-302b through inhibiting MAPK signaling, and miR-193a-3p, miR-330-3p, and miR-592 by activating this signaling pathway, play imperative roles in tumorigenesis. Therefore, in this review, we aimed to focus on the interplay between miRNAs and MAPK signaling in the various steps of tumorigenesis, including metabolic regulation, cell proliferation, apoptosis, metastasis, angiogenesis, and drug resistance.

The emerging role of miRNA in the perturbation of tumor immune microenvironment in chemoresistance: Therapeutic implications

Chemoresistance is a major hindrance in cancer chemotherapies, a leading cause of tumor recurrence and cancer-related deaths. Cancer cells develop numerous strategies to elude immune attacks and are regulated by immunological factors. Cancer cells can alter the expression of several immune modulators to upregulate the activities of immune checkpoint pathways. Targeting the immune checkpoint inhibitors is a part of the cancer immunotherapy altered during carcinogenesis. These immune modulators have the capability to reprogram the tumor microenvironment, thereby change the efficacy of chemotherapeutics. In general, the sensitivity of drugs is reduced in the immunosuppressive tumor microenvironment, resulting in chemoresistance and tumor relapse. The regulation of microRNAs (miRNAs) is well established in cancer initiation, progression, and therapy. Intriguingly, miRNA affects cancer immune surveillance and immune response by targeting immune checkpoint inhibitors in the tumor microenvironment. miRNAs alter the gene expression at the post-transcriptional level, which modulates both innate and adaptive immune systems. Alteration of tumor immune microenvironment influences drug sensitivity towards cancer cells. Besides, the expression profile of immune-modulatory miRNAs can be used as a potential biomarker to predict the response and clinical outcomes in cancer immunotherapy and chemotherapy. Recent evidences have revealed that cancer-derived immune-modulatory miRNAs might be promising targets to counteract cancer immune escape, thereby increasing drug efficacy. In this review, we have compiled the role of miRNAs in overcoming the chemoresistance by modulating tumor microenvironment and discussed their preclinical and clinical implications.

Expression of miR-18a-5p, miR-144-3p, and miR-663b in colorectal cancer and their association with cholesterol homeostasis

OBJECTIVE

Though cholesterol accumulation is an established hallmark of a tumor cell, the relationship between the two is still not clear. Previously, we identified 3-Hydroxy-3-Methylglutaryl-CoA Reductase (HMGCR), Sterol Regulatory Element BindingTranscription Factor 2 (SREBF2), Nuclear Receptor Subfamily 1 Group H Member 3 (NR1H3), and Nuclear Receptor Subfamily 1 Group H Member 2 (NR1H2) as the key cholesterol homeostasis genes involved in colorectal cancer (CRC). In the present study, we aimed to identify microRNAs regulating these key genes in CRC.

METHODS

miR-18a-5p, miR-144-3p, and miR-663b were selected as the miRNAs targeting NR1H2, HMGCR, and SREBF2, respectively, based on the bioinformatic prediction tools and literature review. Their expression was evaluated in the local and The Cancer Genome Atlas (TCGA) cohorts. Receiver Operating Characteristic Curves and Kaplan Meier analysis were performed to elucidate their diagnostic and prognostic potential. Pearson or Spearman's correlations were used to evaluate the relationship between miRNAs and their target genes. Protein-protein interaction networks and Gene Ontology analyses were performed to investigate the potential molecular mechanism of these miRNAs.

RESULTS

Deregulated expression of miR-18a-5p, miR-144-3p, and miR-663b was associated with various clinicopathological features. miR-18a-5p exhibited an inverse correlation with NR1H2. miR-18a-5p and miR-144-3p also had a significant direct correlation with miR-33a-5p, an important modulator of cholesterol homeostasis. These miRNAs also exhibited high centrality in the mirna-protein interaction network. miR-144-3p and miR-663b exhibited the potential to be used as diagnostic biomarkers.

CONCLUSIONS

miR-18a-5p and miR-144-3p exhibited the potential to modulate cholesterol homeostasis in CRC. miR-663b is an interesting candidate in CRC pathophysiology.

Therapeutic Targeting of MicroRNAs in the Tumor Microenvironment

The tumor-microenvironment (TME) is an amalgamation of various factors derived from malignant cells and infiltrating host cells, including cells of the immune system. One of the important factors of the TME is microRNAs (miRs) that regulate target gene expression at a post transcriptional level. MiRs have been found to be dysregulated in tumor as well as in stromal cells and they emerged as important regulators of tumorigenesis. In fact, miRs regulate almost all hallmarks of cancer, thus making them attractive tools and targets for novel anti-tumoral treatment strategies. Tumor to stroma cell cross-propagation of miRs to regulate protumoral functions has been a salient feature of the TME. MiRs can either act as tumor suppressors or oncogenes (oncomiRs) and both miR mimics as well as miR inhibitors (antimiRs) have been used in preclinical trials to alter cancer and stromal cell phenotypes. Owing to their cascading ability to regulate upstream target genes and their chemical nature, which allows specific pharmacological targeting, miRs are attractive targets for anti-tumor therapy. In this review, we cover a recent update on our understanding of dysregulated miRs in the TME and provide an overview of how these miRs are involved in current cancer-therapeutic approaches from bench to bedside.