MicroRNA-181a promotes tumor growth and liver metastasis in colorectal cancer by targeting the tumor suppressor WIF-1

miR-181a: regulatory roles, cancer-associated signaling pathway disruptions, and therapeutic potential

INTRODUCTION

microRNA-181a (miR-181a) is a crucial post-transcriptional regulator of many mRNA transcripts and noncoding-RNAs, influencing cell proliferation, cancer cell stemness, apoptosis, and immune responses. Its abnormal expression is well-characterized in numerous cancers, establishing it as a significant genomic vulnerability and biomarker in cancer research.

AREAS COVERED

Here, we summarize miR-181a's correlation with poor patient outcomes across numerous cancers and the mechanisms governing miR-181a's activity and processing. We comprehensively describe miR-181a's involvement in multiple regulatory cancer signaling pathways, cellular processes, and the tumor microenvironment. We also discuss current therapeutic approaches to targeting miR-181a, highlighting their limitations and future potential.

EXPERT OPINION

miR-181a is a clinically relevant pan-cancer biomarker with potential as a therapeutic target. Its regulatory control of tumorigenic signaling pathways and immune responses positions it as a promising candidate for personalized treatments. The success of miR-181a as a target relies on the development of specific therapeutics platforms. Future research on miR-181a's role in the tumor microenvironment and the RNA binding proteins that regulate its stability will help uncover new techniques to targeting miR-181a. Further research into miR-181a serum levels in patients undergoing therapy will help to better stratify patients and enhance therapeutic success.

Hepatic miR-363 promotes nonalcoholic fatty liver disease by suppressing INSIG1

Nonalcoholic fatty liver disease (NAFLD) constitutes one of major worldwide health problem which typically progressively results in nonalcoholic steatohepatitis (NASH) and eventually cirrhosis and liver cancer. Liver-specific deletion of INSIG1 promotes SREBP1 nuclear translocation to activate downstream lipogenic genes expression, leading to lipid accumulation. However, the underlying pathogenesis of NAFLD, and particularly involved in miRNA participation are still to be thoroughly explored. Here, we found that miR-363-3p was significantly overexpressed in high-fat, high-cholesterol (HFHC) diet mice liver tissue and fatty acid-induced steatosis cells. miR-363-3p directly targets INSIG1 to inhibit its expression, thereby facilitating the cleavage of SREBP and nuclear translocation to activate subsequent transcription of lipogenic genes in vitro and in vivo. In addition, we identified apigenin, a natural flavonoid compound, inhibited miR-363-3p expression to up-regulate INSIG1 and suppress nuclear translocation of SREBP1, thereby down-regulated lipogenic genes expression in steatosis cells and HFHC diet mice liver tissues. Taken together, our results demonstrated that miR-363-3p as a key regulator of hepatic lipid homeostasis targeted INSIG1, and apigenin alleviated NAFLD through the miR-363-3p/INSIG1/SREBP1 pathway. This indicates that reduction of miR-363-3p levels as a possible treatment of hepatic steatosis and provides a potential new therapeutic strategy for targeting miRNA to ameliorate NAFLD.

sChemNET: a deep learning framework for predicting small molecules targeting microRNA function

MicroRNAs (miRNAs) have been implicated in human disorders, from cancers to infectious diseases. Targeting miRNAs or their target genes with small molecules offers opportunities to modulate dysregulated cellular processes linked to diseases. Yet, predicting small molecules associated with miRNAs remains challenging due to the small size of small molecule-miRNA datasets. Herein, we develop a generalized deep learning framework, sChemNET, for predicting small molecules affecting miRNA bioactivity based on chemical structure and sequence information. sChemNET overcomes the limitation of sparse chemical information by an objective function that allows the neural network to learn chemical space from a large body of chemical structures yet unknown to affect miRNAs. We experimentally validated small molecules predicted to act on miR-451 or its targets and tested their role in erythrocyte maturation during zebrafish embryogenesis. We also tested small molecules targeting the miR-181 network and other miRNAs using in-vitro and in-vivo experiments. We demonstrate that our machine-learning framework can predict bioactive small molecules targeting miRNAs or their targets in humans and other mammalian organisms.

Rs12039395 Variant Influences the Expression of hsa-miR-181a-5p and PTEN Toward Colorectal Cancer Risk

BACKGROUND

Single nucleotide polymorphisms (SNPs) in microRNA (miRNA) genes could alter miRNA expression levels or processing and, thus, may contribute to colorectal cancer (CRC) development. Therefore, this study aimed to examine whether the MIR181A1 genomic sequence possesses SNPs that can affect the expression of hsa-miR-181a-5p and, subsequently, impact its targets and associate with CRC risk.

METHODS

The NCBI dbSNP database was searched for possible SNPs associated with MIR181A1. One SNP with a minor allele frequency > 5%, rs12039395 G > T was identified. In silico analyses determined the effect of the SNP on the secondary structure of the miRNA and predicted the hsa-miR-181a-5p target genes. The SNP was genotyped using allelic discrimination assay, the relative hsa-miR-181a-5p expression level was determined using quantitative real-time PCR, and immunohistochemical staining was used to detect target genes in 192 paraffin-embedded specimens collected from 160 CRC patients and 32 healthy subjects.

RESULTS

The rs6505162 SNP conferred protection against CRC, and the G-allele presence provides may provide accessibility for the transcriptional machinery. Hsa-miR-181a-5p was significantly over-expressed in the CRC group compared to controls and in samples carrying the G-allele compared to those with T-allele. PTEN, identified as the only hsa-miR-181a-5p target implicated in CRC, was significantly diminished in the CRC group compared to controls and showed an inverse relationship with hsa-miR-181a-5p expression level as well as negatively associated with the G-allele presence in CRC.

CONCLUSION

This study highlights that rs12039395 G > T may protect against CRC by influencing the expression of hsa-mir-181a-5p and its target gene, PTEN.

The Role of the MiR-181 Family in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fourth-leading cause of cancer-related death worldwide. Due to the high mortality rate in HCC patients, discovering and developing novel systemic treatment options for HCC is a vital unmet medical need. Among the numerous molecular alterations in HCCs, microRNAs (miRNAs) have been increasingly recognised to play critical roles in hepatocarcinogenesis. We and others have recently revealed that members of the microRNA-181 (miR-181) family were up-regulated in some, though not all, human cirrhotic and HCC tissues-this up-regulation induced epithelial-mesenchymal transition (EMT) in hepatocytes and tumour cells, promoting HCC progression. MiR-181s play crucial roles in governing the fate and function of various cells, such as endothelial cells, immune cells, and tumour cells. Previous reviews have extensively covered these aspects in detail. This review aims to give some insights into miR-181s, their targets and roles in modulating signal transduction pathways, factors regulating miR-181 expression and function, and their roles in HCC.

The underlying mechanism and targeted therapy strategy of miRNAs cross-regulating EMT process through multiple signaling pathways in hepatocellular carcinoma

The consistent notion holds that hepatocellular carcinoma (HCC) initiation, progression, and clinical treatment failure treatment failure are affected by the accumulation of various genetic and epigenetic alterations. MicroRNAs (miRNAs) play an irreplaceable role in a variety of physiological and pathological states. meanwhile, epithelial-mesenchymal transition (EMT) is a crucial biological process that controls the development of HCC. miRNAs regulate the intermediation state of EMTor mesenchymal-epithelial transition (MTE)thereby regulating HCC progression. Notably, miRNAs regulate key HCC-related molecular pathways, including the Wnt/β-catenin pathway, PTEN/PI3K/AKT pathway, TGF-β pathway, and RAS/MAPK pathway. Therefore, we comprehensively reviewed how miRNAs produce EMT effects by multiple signaling pathways and their potential significance in the pathogenesis and treatment response of HCC. emphasizing their molecular pathways and progression in HCC initiation. Additionally, we also pay attention to regulatory mechanisms that are partially independent of signaling pathways. Finally, we summarize and propose miRNA-targeted therapy and diagnosis and defense strategies forHCC. The identification of the mechanism leading to the activation of EMT programs during HCC disease processes also provides a new protocol for the plasticity of distinct cellular phenotypes and possible therapeutic interventions. Consequently, we summarize the latest progress in this direction, with a promising path for further insight into this fast-moving field.

Exploring the expression and clinical significance of the miR-140-3p-HOXA9 axis in colorectal cancer

PURPOSE

This study aims to investigate the expression patterns and clinical significance of miR-140-3p and homeobox A9 (HOXA9) in colorectal cancer (CRC) selected by bioinformatic study, while elucidating their potential interplay.

METHODS

The microRNA expression profiles of paired colorectal cancer and matched normal tissues were retrieved from the Gene Expression Omnibus Database. Differentially expressed microRNAs and microRNA candidates were filtered and subjected to further analysis. Clinicopathological data, along with paraffin-embedded samples of colorectal tumor tissues were collected to facilitate comprehensive analysis. Expression levels of miR-140-3p and HOXA9 were quantified using qRT-PCR and immunohistochemistry. Survival rates were determined using the Kaplan-Meier method, and the COX regression model was utilized to identify independent prognostic factors that impact the overall prognosis.

RESULTS

MiR-140-3p was significantly downregulated in colorectal tumors compared to normal tissue, and HOXA9 was identified as a previously unreported potential downstream target. HOXA9 expression was elevated in tumors compared to normal tissues. Reduced miR-140-3p expression was associated with lymph node metastasis, while high HOXA9 expression correlated with both lymph node metastasis and lympho-vascular invasion. Patients with low miR-140-3p and high HOXA9 expression had a poorer prognosis. HOXA9 was identified as an independent risk factor for CRC patient survival.

CONCLUSION

The miR-140-3p-HOXA9 signaling disruption is closely linked to lymph node metastasis and unfavorable prognosis in CRC. This axis shows promise as a clinical biomarker for predicting the CRC patient survival and a potential therapeutic target.

An in-silico approach to understand the potential role of Wnt inhibitory factor-1 (WIF-1) in the inhibition of the Wnt signalling pathway

WIF1 (Wnt inhibitory factor 1) is a potent tumour suppressor gene which is epigenetically silenced in numerous malignancies. The associations of WIF1 protein with the Wnt pathway molecules have not been fully explored, despite their involvement in the downregulation of several malignancies. In the present study, a computational approach encompassing the expression, gene ontology analysis and pathway analysis is employed to obtain an insight into the role of the WIF1 protein. Moreover, the interaction of the WIF1 domain with the Wnt pathway molecules was carried out to ascertain the tumour-suppressive role of the domain, along with the determination of their plausible interactions. Initially, the protein-protein interaction network analysis endowed us with the Wnt ligands (such as Wnt1, Wnt3a, Wnt4, Wnt5a, Wnt8a and Wnt9a), along with the Frizzled receptors (Fzd1 and Fzd2) and the low-density lipoprotein complex (Lrp5/6) as the foremost interactors of the protein. Further, the expression analysis of the aforementioned genes and proteins was determined using The Cancer Genome Atlas to comprehend the significance of the signalling molecules in the major cancer subtypes. Moreover, the associations of the aforementioned macromolecular entities with the WIF1 domain were explored using the molecular docking studies, whereas the dynamics and stability of the assemblage were investigated using 100 ns molecular dynamics simulations. Therefore, providing us insights into the plausible roles of WIF1 in inhibiting the Wnt pathways in various malignancies.Communicated by Ramaswamy H. Sarma.

Downregulation of Serum miR-133b and miR-206 Associate with Clinical Outcomes of Progression as Monitoring Biomarkers for Metastasis Colorectal Cancer Patients

BACKGROUND

Colorectal cancer (CRC) is the third most common cancer in the world. Noncoding RNAs or microRNAs (miRNAs; miRs) biomarkers can play a role in cancer carcinogenesis and progression. Specific KRAS and EGFR mutation are associated with CRC development playing a role in controlling the cellular process as epigenetic events. Circulating serum miRs can serve for early diagnosis, monitoring, and prognosis of CRC as biomarkers but it is still unclear, clinically.

OBJECTIVE

To determine potential biomarkers of circulating serum miR-133b and miR-206 in CRC patients Methods: Bioinformatic prediction of microRNA was screened followed by TargetScanHuman7.2, miRTar2GO, miRDB, MiRanda, and DIANA-microT-CDS. Forty-four CRC serum (19 locally advanced, 23 distant advanced CRC) and 12 normal serum samples were subsequently extracted for RNA isolation, cDNA synthesis, and miR validation. The candidate circulating serum miR-133b and miR-206 were validated resulting in a relative expression via quantitative RT-PCR. Relative expression was normalized to the spike-internal control and compared to normal samples as 1 using the -2ΔΔCt method in principle.

RESULTS

Our results represented 9 miRs of miR-206, miR-155-5p, miR-143-3p, miR-193a-3p, miR-30a- 5p, miR-30d-5p, miR-30e-5p, miR-543, miR-877-5p relate to KRAS-specific miRs, whereas, 9 miRs of miR-133b, miR-302a-3p, miR-302b-3p, miR-302d-3p, miR-302e, miR-520a-3p, miR-520b, miR-520c- 3p and miR-7-5p relevance to EGFR-specific miRs by using the bioinformatic prediction tools. Our results showed a decreased expression level of circulating serum miR-133b as well as miR-206 associating with CRC patients (local and advanced metastasis) when compared to normal (P < 0.05), significantly.

CONCLUSION

The circulating serum miR-133b and miR-206 can serve as significant biomarkers for monitoring the clinical outcome of progression with metastatic CRC patients. Increased drug-responsive CRC patients associated with crucial molecular intervention should be further explored, clinically.

Role of miR‑181a‑5p in cancer (Review)

MicroRNAs (miRNAs) are non‑coding RNAs (ncRNAs) that can post‑transcriptionally suppress targeted genes. Dysregulated miRNAs are associated with a variety of diseases. MiR‑181a‑5p is a conserved miRNA with the ability to regulate pathological processes, such as angiogenesis, inflammatory response and obesity. Numerous studies have demonstrated that miR‑181a‑5p exerts regulatory influence on cancer development and progression, acting as an oncomiR or tumor inhibitor in various cancer types by impacting multiple hallmarks of tumor. Generally, miR‑181a‑5p binds to target RNA sequences with partial complementarity, resulting in suppression of the targeted genes of miR‑181a‑5p. However, the precise role of miR‑181a‑5p in cancer remains incompletely understood. The present review aims to provide a comprehensive summary of recent research on miR‑181a‑5p, focusing on its involvement in different types of cancer and its potential as a diagnostic and prognostic biomarker, as well as its function in chemoresistance.

Mucosal-associated invariant T cells in digestive tract: Local guardians or destroyers?

Mucosa-associated invariant T cells (MAIT) are a class of innate-like T lymphocytes mainly presenting CD8+ phenotype with a semi-invariant αβ T-cell receptor, which specifically recognises MR1-presented biosynthetic derivatives of riboflavin synthesis produced by various types of microbiomes. As innate-like T lymphocytes, MAIT can be activated by a variety of cytokines, leading to immediate immune responses to infection and tumour cues. As an organ that communicates with the external environment, the digestive tract, especially the gastrointestinal tract, contains abundant microbial populations. Communication between MAIT and local microbiomes is important for the homeostasis of mucosal immunity. In addition, accumulating evidence suggests changes in the abundance and structure of the microbial community during inflammation and tumorigenesis plays a critical role in disease progress partly through their impact on MAIT development and function. Therefore, it is essential for the understanding of MAIT response and their interaction with microbiomes in the digestive tract. Here, we summarised MAIT characteristics in the digestive tract and its alteration facing inflammation and tumour, raising that targeting MAIT can be a candidate for treatment of gastrointestinal diseases.

Double-edged sword role of miRNA-633 and miRNA-181 in human cancers

Understanding the function and mode of operation of microRNAs (miRNAs) in cancer is of growing interest. The short non-coding RNAs known as miRNAs, which target mRNA in multicellular organisms, are described as controlling essential cellular processes. The miR-181 family and miR-633 are well-known miRNAs that play a key role in the development and metastasis of tumor cells. They may facilitate either tumor-suppressive or oncogenic function in malignant cells, according to mounting evidence. Metastatic cells that are closely linked to cancer cell migration, invasion, and angiogenesis can be identified by abnormal levels of miR-181 and miR-633. Numerous studies have demonstrated their capacity to control drug resistance, cell growth, apoptosis, and the epithelial-mesenchymal transition (EMT) and metastasis process. Interestingly, the levels of miR-181 and miR-633 and their potential target genes in the basic cellular process can vary depending on the type of cancer cells and their gene expression profile. Such miRNAs' interactions with other non-coding RNAs such as long non-coding RNAs and circular RNAs can influence tumor behaviors. Herein, we concentrated on the multifaceted roles of miR-181 and miR-633 and potential targets in human tumorigenesis, ranging from cell growth and metastasis to drug resistance.

Cancer cell-derived extracellular vesicles activate hepatic stellate cells in colorectal cancer

Colorectal cancer (CRC) is the 2nd leading cause of cancer-related deaths worldwide, primarily due to the development of metastatic disease. The liver is the most frequently affected site. The metastatic cascade relies on a complex interaction between the immune system, tumor, and distant organs. Communication between the tumor and the metastatic site can be mediated by tumor-derived extracellular vesicles (EVs) and their cargo. The mechanisms underlying this process are starting to be understood through research that has rapidly expanded over the past 15 years. One crucial aspect is the remodeling of the microenvironment at the site of metastasis, which is essential for the formation of a premetastatic niche and the subsequent establishment of metastatic deposits. In the evaluated study, the authors use cellular experiments and a mouse model to investigate how tumour derived extracellular vesicles and their microRNA contents interact with hepatic stellate cells (HSCs). They demonstrate how this may lead to remodelling of the microenvironment and the formation of colorectal liver metastasis using their experimental model. In this mini review, we examine the current evidence surrounding tumour derived EVs and their effect on the tumour microenvironment to highlight potential areas for future research in CRC and other malignancies.

Expression Analysis of hsa-miR-181a-5p, hsa-miR-143-3p, hsa-miR-132-3p and hsa-miR-23a-3p as Biomarkers in Colorectal Cancer-Relationship to the Body Mass Index

This work aims to investigate the expression levels of four preselected miRNAs previously linked to cancer and/or obesity, with the purpose of finding potential biomarkers in the clinical management of CRC developed by patients showing different BMI values. We analyzed samples from a total of 65 subjects: 43 affected by CRC and 22 without cancer. Serum and both subcutaneous and omental adipose tissues (SAT and OAT) were investigated, as well as tumor and non-tumor colorectal tissues in the case of the CRC patients. The relative expression (2^-∆∆Ct) levels of 4 miRNAs (hsa-miR-181a-5p, hsa-miR-143-3p, has-miR-132-3p and hsa-miR-23a-3p) were measured by RT-qPCR. Serum, SAT and OAT expression levels of these miRNAs showed significant differences between subjects with and without CRC, especially in the group of overweight/obese subjects. In CRC, serum levels of hsa-miR-143-3p clearly correlated with their levels in both SAT and OAT, independently of the BMI group. Moreover, hsa-miR-181a-5p could be considered as a biomarker in CRC patients with BMI ≥ 25 Kg/m² and emerges as a tumor location marker. We conclude that both adiposity and CRC induce changes in the expression of the miRNAs investigated, and hsa-miR-143-3p and hsa-miR-181a-5p expression analysis could be useful in the clinical management of CRC.

Pinostrobin, a fingerroot compound, regulates miR-181b-5p and induces acute leukemic cell apoptosis

Pinostrobin (PN) is the most abundant flavonoid found in fingerroot. Although the anti-leukemic properties of PN have been reported, its mechanisms are still unclear. MicroRNAs (miRNAs) are small RNA molecules that function in posttranscriptional silencing and are increasingly being used in cancer therapy. The aims of this study were to investigate the effects of PN on proliferation inhibition and induction of apoptosis, as well as the involvement of miRNAs in PN-mediated apoptosis in acute leukemia. The results showed that PN reduced cell viability and induced apoptosis in acute leukemia cells via both intrinsic and extrinsic pathways. A bioinformatics approach and Protein-Protein Interaction (PPI) network analysis revealed that ataxia-telangiectasia mutated kinase (ATM), one of the p53 activators that responds to DNA damage-induced apoptosis, is a crucial target of PN. Four prediction tools were used to predict ATM-regulated miRNAs; miR-181b-5p was the most likely candidate. The reduction in miR-181b-5 after PN treatment was found to trigger ATM, resulting in cellular apoptosis. Therefore, PN could be developed as a drug for acute leukemia; in addition, miR-181b-5p and ATM may be promising therapeutic targets.

Epigenetic reader MeCP2 repressed WIF1 boosts lung fibroblast proliferation, migration and pulmonary fibrosis

Epigenetic has been implicated in pulmonary fibrosis. However, there is limited information regarding the biological role of the epigenetic reader MeCP2 in pulmonary fibrosis. The aim of this study was to investigate the role of MeCP2 and its target WIF1 in pulmonary fibrosis. The pathological changes and collagen depositions was analyzed by H&E, Masson's Trichrome Staining and Sirius Red staining. MeCP2, WIF1, α-SMA, Wnt1, β-catenin, and collagen I expression were analyzed by western blotting, RT-qPCR, immunohistochemistry, immunofluorescence, respectively. The effects of MeCP2 on pulmonary fibrosis involve epigenetic mechanisms, using cultured cells, animal models, and clinical samples. Herein, our results indicated that MeCP2 level was up-regulated, while WIF1 was decreased in Bleomycin (BLM)-induced mice pulmonary fibrosis tissues, patients pulmonary fibrosis tissues and TGF-β1-induced lung fibroblast. Knockdown of MeCP2 by siRNA can rescue WIF1 downregulation in TGF-β1-induced lung fibroblast, inhibited lung fibroblast activation. The DNA methylation inhibitor 5-azadC-treated lung fibroblasts have increased WIF1 expression with reduced MeCP2 association. In addition, we found that reduced expression of WIF1 caused by TGF-β1 is associated with the promoter methylation status of WIF1. Moreover, in vivo studies revealed that knockdown of MeCP2 mice exhibited significantly ameliorated pulmonary fibrosis, decreased interstitial collagen deposition, and increased WIF1 expression. Taken together, our study showed that epigenetic reader MeCP2 repressed WIF1 facilitates lung fibroblast proliferation, migration and pulmonary fibrosis.

Role of non-coding RNAs and exosomal non-coding RNAs in retinoblastoma progression

Retinoblastoma (RB) is a rare aggressive intraocular malignancy of childhood that has the potential to affect vision, and can even be fatal in some children. While the tumor can be controlled efficiently at early stages, metastatic tumors lead to high mortality. Non-coding RNAs (ncRNAs) are implicated in a number of physiological cellular process, including differentiation, proliferation, migration, and invasion, The deregulation of ncRNAs is correlated with several diseases, particularly cancer. ncRNAs are categorized into two main groups based on their length, i.e. short and long ncRNAs. Moreover, ncRNA deregulation has been demonstrated to play a role in the pathogenesis and development of RB. Several ncRNAs, such as miR-491-3p, miR-613,and SUSD2 have been found to act as tumor suppressor genes in RB, but other ncRNAs, such as circ-E2F3, NEAT1, and TUG1 act as tumor promoter genes. Understanding the regulatory mechanisms of ncRNAs can provide new opportunities for RB therapy. In the present review, we discuss the functional roles of the most important ncRNAs in RB, their interaction with the genes responsible for RB initiation and progression, and possible future clinical applications as diagnostic and prognostic tools or as therapeutic targets.

Functional high-throughput screen identifies microRNAs that promote butyrate-induced death in colorectal cancer cells

The gut fermentation product butyrate displays anti-cancer properties in the human proximal colon, including the ability to inhibit proliferation and induce apoptosis in colorectal cancer (CRC) cells. A natural histone deacetylase inhibitor (HDACi), butyrate can alter histone acetylation patterns in CRC cells, and thereby regulate global gene expression, including the non-coding transcriptome and microRNAs (miRNAs). Dysregulated miRNA expression affects CRC development and progression; however, the interplay between miRNA activity and butyrate response remains to be elucidated. A high-throughput functional screen was employed to identify miRNAs that can act as enhancers of the anti-cancer properties of butyrate. Validation studies confirmed that several miRNAs, including miR-125b, miR-181a, miR-593, and miR-1227, enhanced apoptosis, decreased proliferation, and promoted cell-cycle arrest in the presence of butyrate. Pathway analyses of predicted miRNA target genes highlighted their likely involvement in critical cancer-related growth pathways, including WNT and PI3K signaling. Several cancer-associated miRNA targets, including TRIM29, COX2, PIK3R3, CCND1, MET, EEF2K, DVL3, and NUP62 were synergistically regulated by the combination of cognate miRNAs and butyrate. Overall, this study has exposed the potential of miRNAs to act as enhancers of the anti-cancer effects of HDAC inhibition and identifies specific miRNAs that might be exploited for therapeutic benefit.

The imminent role of microRNAs in salivary adenoid cystic carcinoma

Unfortunately, despite the severe problem associated with salivary adenoid cystic carcinoma (SACC), it has not been studied in detail yet. Therefore, the time has come to understand the oncogenic cause of SACC and find the correct molecular markers for diagnosis, prognosis, and therapeutic target to tame this disease. Recently, we and others have suggested that non-coding RNAs, specifically microRNAs and long non-coding RNAs, can be ideal biomarkers for cancer(s) diagnosis and progression. Herein, we have shown that various miRNAs, like miR-155, miR‑103a‑3p, miR-21, and miR-130a increase the oncogenesis process, whereas some miRNAs such as miR-140-5p, miR-150, miR-375, miR-181a, miR-98, miR-125a-5p, miR-582-5p, miR-144-3p, miR-320a, miR-187 and miR-101-3p, miR-143-3p inhibit the salivary adenoid cystic carcinoma progression. Furthermore, we have found that miRNAs also target many vital genes and pathways like mitogen-activated protein kinases-snail family transcriptional repressor 2 (MAPK-Snai2), p38/JNK/ERK, forkhead box C1 protein (FOXC1), mammalian target of rapamycin (mTOR), integrin subunit beta 3 (ITGB3), epidermal growth factor receptor (EGFR)/NF-κB, programmed cell death protein 4 (PDCD4), signal transducer and activator of transcription 3 (STAT3), neuroblastoma RAS (N-RAS), phosphatidylinositol-3-kinase (PI3K)/Akt, MEK/ERK, ubiquitin-like modifier activating enzyme 2 (UBA2), tumor protein D52 (TPD52) which play a crucial role in the regulation of salivary adenoid cystic carcinoma. Therefore, we believe that knowledge from this manuscript will help us find the pathogenesis process in salivary adenoid cystic carcinoma and could also give us better biomarkers of diagnosis and prognosis of the disease.

Promotion or remission: a role of noncoding RNAs in colorectal cancer resistance to anti-EGFR therapy

Anti-epidermal-growth-factor-receptor (EGFR) monoclonal antibodies (mAbs) are of great significance for RAS and BRAF wild-type metastatic colorectal cancer (mCRC) patients. However, the generation of primary and secondary resistance to anti-EGFR mAbs has become an important factor restricting its efficacy. Recent studies have revealed that non-coding RNAs (ncRNAs), especially long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs), are implicated in anti-EGFR antibodies resistance, affecting the sensitivity of CRC cells to Cetuximab and Panitumumab. This paper briefly reviewed the research advance of the expression, signaling network and functional mechanism of ncRNAs related to anti-EGFR mAbs resistance in CRC, as well as their relationship with clinical prognosis and the possibility of therapeutic targets. In addition, some ncRNAs that are involved in the regulation of signaling pathways or genes related to anti-EGFR resistance, but need to be further verified by resistance experiments were also included in this review, thereby providing more ideas and basis for ncRNAs as CRC prognostic markers and anti-EGFR therapy sensitizers. Video Abstract.

MicroRNA-621 functions as a metastasis suppressor in colorectal cancer by directly targeting LEF1 and suppressing Wnt/β-catenin signaling

AIMS

Colorectal liver metastasis (CRLM) is the leading death-causing among colorectal cancer (CRC) patients. Recently, a novel tumor-related microRNA, miR-621, has been identified as a tumor suppressor in diverse tumor types, but its role in CRLM remains unclear and requires further investigation.

MAIN METHODS

To elucidate novel regulators of CRLM progression, we used a well-established CRLM animal model. After serially transplanting human colon carcinoma cell lines Caco-2 into the liver, we obtained liver metastatic variants that exhibited a strong ability for invasion and metastasis. High-throughput sequencing was conducted on these newly established cell lines. After comparison and prediction between the two cell lines: parental Caco-2 (hereafter referred to as F0) and F3, miR-621 was identified as a candidate regulator for lymphoid enhancer-binding factor 1 (LEF1) expression. Further validation was achieved with dual-luciferase reporter assay.

KEY FINDINGS

The gain- and loss-of-function validation showed that miR-621 inhibits cell viability, cell cycle progression, colony formation, and proliferation in vitro. Meanwhile, miR-621 could reverse EMT malignant phenotype. LEF1, an important downstream mediator of activated Wnt/β-catenin signaling pathway, was validated as the direct functional target of miR-621. miR-621 interacts directly with the LEF1 3'-UTR and post-transcriptionally suppresses LEF1 expression. Moreover, LEF1 overexpression reversed the effect of miR-621. LEF1 silencing counteracted miR-621 down-regulation-induced effects. Further in vivo experiments revealed that miR-621 over-expression suppressed CRLM, but LEF1 abrogated the inhibitory effect of miR-621.

SIGNIFICANCE

MiR-621 is a vital tumor suppressor in CRC and could be a promising anti-cancer therapeutic target.

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.

MicroRNA-181a-5p prevents the progression of esophageal squamous cell carcinoma in vivo and in vitro via the MEK1-mediated ERK-MMP signaling pathway

MicroRNAs (miRNAs) have been revealed to play a crucial role in oncogenesis of esophageal squamous cell carcinoma (ESCC). However, the biological role of miR-181a-5p in ESCC is currently less explored. The current study was designed to assess whether miR-181a-5p affects ESCC progression and further investigate relevant underlying mechanisms. Based on the data of GSE161533, GSE17351, GSE75241 and GSE67269 downloaded from GEO database, MAP2K1 (MEK1) was revealed to be one overlapping gene of the top 300 DGEs. Additionally, using the predicting software, miR-181a-5p was projected as the presumed target miRNA. Immunohistochemical staining and RT-qPCR research revealed that miR-181a-5p expression was decreased in human tumor tissues relative to surrounding peri-cancerous tissues. In an in vivo experiment, miR-181a-5p mimics could inhibit tumor growth and metastasis of ESCC. Gene expression profiles in combination with gene ontology (GO) and KEGG pathway analysis revealed that MAP2K1 (MEK1) gene and ERK-MMP pathway were implicated in ESCC progression. MiR-181a-5p mimics inhibited the activity of p-ERK1/2, MMP2 and MMP9 in vivo, as shown by Western blotting and immunohistochemistry labeling. There were no variations in the expression of p-P38 and p-JNK proteins. Additionally, miR-181a-5p mimics lowered p-ERK1/2, MMP2 and MMP9 levels in ECA109 cells, which were restored by MEK1-OE lentivirus. MEK1-OE Lentivirus significantly reversed the function induced by miR-181a-5p mimics in ECA109 cells. Moreover, further investigation indicated that the capability of migration, invasion and proliferation was repressed by miR-181a-5p mimics in ECA109 cells. In short, repressed ERK-MMP pathway mediated by miR-181a-5p can inhibit cell migration, invasion and proliferation by targeting MAP2K1 (MEK1) in ESCC.

The lncRNA MIAT/miR-181a-5p axis regulates osteopontin (OPN)-mediated proliferation and apoptosis of human chondrocytes in osteoarthritis

Osteoarthritis (OA) is a slow-progressing degenerative joint disease mainly characterized by progressive cartilage loss and subchondral bone remodeling. Osteopontin (OPN) is a matrix extracellular glyco-phosphoprotein capable of regulating the expression levels of multiple factors linked with OA pathogenesis. This study explores the upstream regulatory molecular mechanism of OPN on proliferation and apoptosis of human chondrocytes in OA. Chondrocytes were isolated from OA cartilage and identified by toluidine blue staining and immunofluorescent staining of type II collagen. An MTT assay was used for cell viability, and a BrdU assay was applied for DNA synthesis. Cell apoptosis was detected by a flow cytometry assay. A lncRNA MIAT/miR-181a-5p/OPN axis regulating OA chondrocyte proliferation and apoptosis were identified. miR-181a-5p directly targeted OPN and inhibited OPN expression in OA chondrocytes. miR-181a-5p overexpression inhibited OA chondrocyte viability, suppressed DNA synthesis, and promoted apoptosis. OPN overexpression exerted opposite effects on OA chondrocytes and significantly attenuated the roles of miR-181a-5p overexpression in OA chondrocytes. A total of six long non-coding RNAs (lncRNAs) were predicted to target miR-181a-5p, and MIAT was the most up-regulated in OA cartilage tissues among the six lncRNAs. Through direct targeting, MIAT inhibited miR-181a-5p expression. MIAT silencing inhibited cell viability, suppressed DNA synthesis, and promoted cell apoptosis. Moreover, miR-181a-5p inhibition partially reversed the effects of MIAT silencing on OA chondrocytes. The lncRNA MIAT/miR-181a-5p/OPN axis could modulate OA chondrocyte proliferation and apoptosis. The comprehensive function of this axis on OA requires further in vivo and clinical investigations.

Colorectal liver metastasis: molecular mechanism and interventional therapy

Colorectal cancer (CRC) is one of the most frequently occurring malignancy tumors with a high morbidity additionally, CRC patients may develop liver metastasis, which is the major cause of death. Despite significant advances in diagnostic and therapeutic techniques, the survival rate of colorectal liver metastasis (CRLM) patients remains very low. CRLM, as a complex cascade reaction process involving multiple factors and procedures, has complex and diverse molecular mechanisms. In this review, we summarize the mechanisms/pathophysiology, diagnosis, treatment of CRLM. We also focus on an overview of the recent advances in understanding the molecular basis of CRLM with a special emphasis on tumor microenvironment and promise of newer targeted therapies for CRLM, further improving the prognosis of CRLM patients.

Oxyresveratrol inhibits human colon cancer cell migration through regulating epithelial-mesenchymal transition and microRNA

The major cause of death in colorectal cancer (CRC) patients is metastasis. Moreover, lots of studies have emphasized that the epithelial-mesenchymal transition (EMT) is a pivotal step in metastasis. Both transforming growth factor beta (TGF-β) and dysregulation of microRNAs (miRNAs) can induce or regulate EMT, promoting the loss of intercellular adhesion and increased motility of cancer cells. Therefore, it is necessary to prevent or inhibit the metastasis of colorectal cancer. Relatively little is known about the anti-metastatic effect of oxyresveratrol (OXY), a natural derivative of resveratrol (RES), compared to RES. Accordingly, RES was used as the positive control to investigate the effects of OXY on colon cancer cell migration. The results showed that OXY could significantly inhibit cell migration (67.17% ± 0.04, 64.89% ± 0.04) compared to RES (84.6% ± 0.07, 76.34% ± 0.08) in HCT116 cells and TGF-β-induced HT-29 cells, respectively, via Snail/E-cadherin expression. In addition, OXY improved EMT-related miRNA expression through, for example, lowering the levels of miR-3687 and miR-301a-3p while upregulating miR-3612 in TGF-β-induced HT-29 cells. In conclusion, OXY inhibits human colon cancer cell migration by regulating EMT and miRNAs. Based on these findings, it can be stated that OXY promotes anti-metastatic properties in CRC.

microRNAs: Small molecules with a large impact on colorectal cancer

Colorectal cancer (CRC) accounts for one of the main cancer-related mortality and morbidity worldwide. The molecular mechanisms of CRC development have been broadly investigated and, over the last decade, it has become evident that aberrant transcription of microRNAs (miRNAs), a class of small, noncoding RNA molecules, has a significant role in the inception and promotion of CRC. In the involved tissues of CRC, the transcription profile of miRNAs is modulated, and their expression templates are related with prognosis, diagnosis, and treatment outcomes. Here, in the current review, we attempted to discuss the latest information regarding the aberrantly expressed miRNAs in CRC and the advantages of utilizing miRNAs as biomarkers for early diagnosis and prognosis of CRC as well as potential therapeutic application. The effect of miRNAs involved in various signaling pathways, primarily p53, EGFR, Wnt, and TGF-β pathways, was clarified.

MiRNA-Wnt signaling regulatory network in colorectal cancer

Colorectal cancer (CRC) is one of the common malignancies worldwide and the Wnt signaling pathway is recognized as the main disrupted pathway in this malignancy. MicroRNAs (miRNAs) are recognized to contribute to the pathogenesis of CRC by triggering or impeding the Wnt signaling pathway. In addition, transcriptional regulation of miRNAs by canonical Wnt signaling also participates in CRC cell progression. In this review, we present comprehensive literature of the existing data on the interaction of miRNAs and Wnt signaling that could be useful in future studies in the field of CRC management.

MiR-181a promotes cell proliferation and migration through targeting KLF15 in papillary thyroid cancer

INTRODUCTION

Papillary thyroid cancer (PTC) is the predominant histological type of thyroid cancer, accounting for 80% of thyroid cancers. MiR-181a is a novel microRNA that is usually upregulated in multiple cancers. This study aims to explore the role and underlying mechanism of miR-181a in PTC.

METHODS

CCK8 and Transwell assays were performed to evaluate cell viability and migration. The mRNA level of miR-181a and KLF15 was calculated by qRT-PCR. The protein level of E-Cadherin, N-Cadherin and GAPDH was evaluated by western blot. Dual luciferase assay was conducted to validate that miR-181a directly targeting the 3'-UTR of KLF15 mRNA in TPC-1 cells.

RESULTS

We observed that miR-181a was overexpressed and KLF15 was low expressed in PTC tissues and cell lines. Upregulation of miR-181a or downregulation of KLF15 predicted poor outcomes in PTC patients. MiR-181a improved cell growth of PTC, migration and epithelial-mesenchymal transition (EMT) in TPC-1 cells. KLF15 was a target gene of miR-181a and its expression was mediated by miR-181a. KLF15 partially reversed the facilitating effect of miR-181a on cell proliferation and migration in TPC-1 cells.

CONCLUSION

We discovered that miR-181a served as an oncogene downregulating KLF15, thereby inhibiting cell proliferation, migration and the EMT. These findings demonstrate that miR-181a plays a significant role in PTC progression and could be a therapeutic target for PTC.

miRNA Clusters with Up-Regulated Expression in Colorectal Cancer

Simple Summary

As miRNAs show the capacity to be used as CRC biomarkers, we analysed experimentally validated data about frequently up-regulated miRNA clusters in CRC tissue. We identified 15 clusters that showed increased expression in CRC: miR-106a/363, miR-106b/93/25, miR-17/92a-1, miR-181a-1/181b-1, miR-181a-2/181b-2, miR-181c/181d, miR-183/96/182, miR-191/425, miR-200c/141, miR-203a/203b, miR-222/221, mir-23a/27a/24-2, mir-29b-1/29a, mir-301b/130b and mir-452/224. Cluster positions in the genome are intronic or intergenic. Most clusters are regulated by several transcription factors, and by long non-coding RNAs. In some cases, co-expression of miRNA with other cluster members or host gene has been proven. miRNA expression patterns in cancer tissue, blood and faeces were compared. The members of the selected clusters target 181 genes. Their functions and corresponding pathways were revealed with the use of Panther analysis. Clusters miR-17/92a-1, miR-106a/363, miR-106b/93/25 and miR-183/96/182 showed the strongest association with metastasis occurrence and poor patient survival, implicating them as the most promising targets of translational research.

Abstract

Colorectal cancer (CRC) is one of the most common malignancies in Europe and North America. Early diagnosis is a key feature of efficient CRC treatment. As miRNAs can be used as CRC biomarkers, the aim of the present study was to analyse experimentally validated data on frequently up-regulated miRNA clusters in CRC tissue and investigate their members with respect to clinicopathological characteristics of patients. Based on available data, 15 up-regulated clusters, miR-106a/363, miR-106b/93/25, miR-17/92a-1, miR-181a-1/181b-1, miR-181a-2/181b-2, miR-181c/181d, miR-183/96/182, miR-191/425, miR-200c/141, miR-203a/203b, miR-222/221, mir-23a/27a/24-2, mir-29b-1/29a, mir-301b/130b and mir-452/224, were selected. The positions of such clusters in the genome can be intronic or intergenic. Most clusters are regulated by several transcription factors, and miRNAs are also sponged by specific long non-coding RNAs. In some cases, co-expression of miRNA with other cluster members or host gene has been proven. miRNA expression patterns in cancer tissue, blood and faeces were compared. Based on experimental evidence, 181 target genes of selected clusters were identified. Panther analysis was used to reveal the functions of the target genes and their corresponding pathways. Clusters miR-17/92a-1, miR-106a/363, miR-106b/93/25 and miR-183/96/182 showed the strongest association with metastasis occurrence and poor patient survival, implicating them as the most promising targets of translational research.

The Clinical Assessment of MicroRNA Diagnostic, Prognostic, and Theranostic Value in Colorectal Cancer

Simple Summary

MiRNAs are of great interest within colorectal cancers in diagnosis, prognosis, and within the field of personalized treatments; they are present within different biological fluids such as blood and can lead to specific information for daily clinical use. Herein, we review the current literature focusing on miRNAs as potential diagnostic and prognostic biomarkers in patients treated for colorectal cancers. Detection and analysis of miRNA expression are cost-effective and lead to high sensitivity and specificity rates. However, it is now necessary to highlight the most sensitive and specific miRNAs for each goal, either diagnostic, prognostic, or theranostic, thanks to multicentric prospective studies.

Abstract

MiRNAs have recently become a subject of great interest within cancers and especially colorectal cancers in diagnosis, prognosis, and therapy decisions; herein we review the current literature focusing on miRNAs in colorectal cancers, and we discuss future challenges to use this tool on a daily clinical basis. In liquid biopsies, miRNAs seem easily accessible and can give important information toward each step of the management of colorectal cancers. However, it is now necessary to highlight the most sensitive and specific miRNAs for each goal thanks to multicentric prospective studies. Conclusions: by their diversity and the feasibility of their use, miRNAs are getting part of the armamentarium of healthcare management of colorectal cancers.

miR-340 Promotes Retinoblastoma Cell Proliferation, Migration and Invasion Through Targeting WIF1

Background

MicroRNAs (miRNAs) function as important regulators of gene expression involved in tumor pathogenesis, including retinoblastoma. However, the expression profiles and potential roles in retinoblastoma are still largely unclear.

Material and Methods

Differentially expressed miRNAs (DEmiRs) and genes (DEGs) in retinoblastoma were extracted from Gene Expression Omnibus (GEO) repository. Expression levels of miR-340 and WIF1 were detected in retinoblastoma tissues and cell lines by qRT-PCR. Both gain-of-function and loss-of-function experiments were performed to explore the effects of miR-340 on cell proliferation, migration and invasion. Bioinformatics analysis and luciferase reporter assay were used to explore the interaction between miR-340 and WIF1.

Results

A total of 11 DEmiRs were identified in retinoblastoma tissue and blood samples. Among them, we validated that miR-340 was the most highly expressed miRNA and correlated with tumor size, ICRB stage and optic nerve invasion. miR-340 was observed to enhance the proliferation, migration and invasion capacity of retinoblastoma cells. We then identified 26 DEGs from 3 retinoblastoma GEO datasets and subsequently constructed a miRNA–mRNA regulatory network. Further analysis revealed that WIF1 was a direct target of miR-340. Moreover, overexpression of WIF1 could repress retinoblastoma progression induced by miR-340 in vitro and in vivo.

Conclusion

Collectively, miR-340 functioned as an oncomiRNA to promote retinoblastoma cell proliferation, migration and invasion via regulating WIF1. Our data also provided multiple miRNAs and genes that may contribute to a better understanding of retinoblastoma pathogenesis.

Emerging Mechanisms and Treatment Progress on Liver Metastasis of Colorectal Cancer

Colorectal cancer is currently the third largest malignant tumor in the world, with high new cases and high mortality. Metastasis is one of the most common causes of death of colorectal cancer, of which liver metastasis is the most fatal. Since the beginning of the Human Genome Project in 2001, people have gradually recognized the 3 billion base pairs that make up the human genome, of which only about 1.5% of the nucleic acid sequences are used for protein coding, including proto-oncogenes and tumor suppressor genes. A large number of differences in the expression of proto-oncogenes and tumor suppressor genes have also been found in the study of colorectal cancer, which proves that they are also actively involved in the progression of colorectal cancer and promote the occurrence of liver metastasis. Except for 1.5% of the coding sequence, the rest of the nucleic acid sequence does not encode any protein, which is called non-coding RNA. With the deepening of research, genome sequences without protein coding potential that were originally considered “junk sequences” may have important biological functions. Many years of studies have found that a large number of abnormal expression of ncRNA in colorectal cancer liver metastasis, indicating that ncRNA plays an important role in it. To explore the role and mechanism of these coding sequences and non-coding RNA in liver metastasis of colorectal cancer is very important for the early diagnosis and treatment of liver metastasis of colorectal cancer. This article reviews the coding genes and ncRNA that have been found in the study of liver metastasis of colorectal cancer in recent years, as well as the mechanisms that have been identified or are still under study, as well as the clinical treatment of liver metastasis of colorectal cancer.

microRNAs and Corresponding Targets Involved in Metastasis of Colorectal Cancer in Preclinical In Vivo Models

The high death toll of colorectal cancer patients is due to metastatic disease which is difficult to treat. The liver is the preferred site of metastasis, followed by the lungs and peritoneum. In order to identify new targets and new modalities of intervention we surveyed the literature for microRNAs (miRs) which modulate metastasis of colorectal cancer in preclinical in vivo models. We identified 12 up-regulated and 19 down-regulated miRs corresponding to the latter criterium. The vast majority (n=16) of identified miRs are involved in modulation of epithelial-mesenchymal transition (EMT). Other categories of metastasis-related miRs exhibit tumor- and metastasis-suppressing functions, modulation of signaling pathways, transmembrane receptors and a class of miRs, which interfere with targets which do not fit into these categories. Finally, we discuss the principles of miR inhibition and reconstitution of function, prospective clinical evaluation of with miR-related agents in the context of clinical evaluation in metastasis relevant settings.

Differential Expression Profiles of Mitogenome Associated MicroRNAs Among Colorectal Adenomatous Polyps

Colorectal tumors are mostly of epithelial origin and represent a wide spectrum of neoplasms. About 97% of colorectal cancer originating from benign lesions of adenomatous polyps are adenocarcinomas. Reactive oxygen species (ROS) generating from mitochondrial DNA (mtDNA) mutations and microRNAs (miRNAs) are associated with oncogene and tumor suppressor genes regulation which are known to parallel the tissue abnormalities involved with tumorigenesis such as colorectal adenoma to adenocarcinoma. However, the differential expression patterns of mitochondrial associated microRNAs (referred as MitomiRs) among colorectal adenomatous polyps progression is yet to be determined. Thus, the aim of this study was to determine the differential expressions profiles of MitomiRs (miR-24, miR-181, miR-210, miR-21 and miR378) in patients with colorectal adenomatous polyps tissues in correlation with clinicopathological tumor architectures of tubular, tubulovillous, villous adenomas and adenocarcinomas. Isolation of mitochondria RNA from colorectal adenomatous polyps, adenocarcinomas, and normal adjacent tissue samples was performed and assessed for mitochondrial associated miRNAs expression differences using quantitative reverse transcription PCR. Data from this study demonstrates that mitochondria genome expression of mitomiRNAs; miR-24, miR-181, miR-210, miR-21 and miR-378 in colorectal tissue samples varies among the adenomatous polyps. Expression of mitomiRNAs 24, 181, 210 and 378 progressively increased from the precancerous of adenomatous polyps to adenocarcinoma. In addition, miR-210 and miR-181 expression increased 3 folds in villous adenomas and greater than 3 folds increased in miR378 in adenocarcinoma (p < 0.005) when compared to tubular adenoma. Meanwhile, miR-21 increased progressively in adenoma tissues but decreased almost 2.5 folds in adenocarcinomas when compared to villous adenoma tissues (p < 0.001). These results suggest mitomiRs may regulate important mitochondrial functional pathways leading to a more favorable environment for transformation or progression of colorectal adenomatous polyps into adenocarcinomas.

Tissue micro-RNAs associated with colorectal cancer prognosis: a systematic review

Colorectal cancer (CRC) is a multifactorial disease commonly diagnosed worldwide, with high mortality rates. Several studies demonstrate important associations between differential expression of micro-RNAs (miRs) and the prognosis of CRC. The present study aimed to identify differentially expressed tissue miRs associated with prognostic factors in CRC patients, through a systematic review of the Literature. Using the PubMed database, Cochrane Library and Web of Science, studies published in English evaluating miRs differentially expressed in tumor tissue and significantly associated with the prognostic aspects of CRC were selected. All the included studies used RT-PCR (Taqman or SYBR Green) for miR expression analysis and the period of publication was from 2009 to 2018. A total of 115 articles accomplished the inclusion criteria and were included in the review. The studies investigated the expression of 100 different miRs associated with prognostic aspects in colorectal cancer patients. The most frequent oncogenic miRs investigated were miR-21, miR-181a, miR-182, miR-183, miR-210 and miR-224 and the hyperexpression of these miRs was associated with distant metastasis, lymph node metastasis and worse survival in patients with CRC. The most frequent tumor suppressor miRs were miR-126, miR-199b and miR-22 and the hypoexpression of these miRs was associated with distant metastasis, worse prognosis and a higher risk of disease relapse (worse disease-free survival). Specific tissue miRs are shown to be promising prognostic biomarkers in patients with CRC, given their strong association with the prognostic aspects of these tumors, however, new studies are necessary to establish the sensibility and specificity of the individual miRs in order to use them in clinical practice.

The tumorigenic and therapeutic functions of exosomes in colorectal cancer: Opportunity and challenges

Most cells release extracellular vesicles (EVs) mediating intercellular communication via transferring various biomolecules including proteins, nucleic acids, and lipids. A subset of EVs is exosomes that promote tumorigenesis. Different tumour cells such as colorectal cancer (CRC) cells produce exosomes that participate in the progression of CRC. Exosomes cargo including proteins and miRNAs not only support proliferation and metastasis of tumour cells but also mediate chemoresistance, immunomodulation and angiogenesis. In addition, as exosomes are present in most body fluids, they can hold the great capacity for clinical usage in early diagnosis and prognosis of CRC. Exosomes from CRC (CRC-Exo) differentially contain proteins and miRNAs that make them a promising candidate for CRC diagnosis by a simple liquid-biopsy. Despite hopeful results, some challanges about exosomes terminology and definition remains to be clarified in further experiments. In addition, there are little clinical trials regarding the application of exosomes in CRC treatment, therefore additional studies are essential focusing on exosome biology and translation of preclinical findings into the clinic. The present study discusses the key role of exosomes in CRC progression and diagnosis. Furthermore, it describes the opportunity and challenges associated with using exosomes as tumour markers.

Discovery of extracellular vesicles derived miR-181a-5p in patient's serum as an indicator for bone-metastatic prostate cancer

Purpose: To identify extracellular vesicle (EV)-delivered microRNAs in the patient's serum as indicators for bone-metastatic prostate cancer.

Methods: First, the profiling change of serum EV-delivered miRNAs in patients with either benign prostatic hyperplasia (BPH), non-bone metastatic prostate cancer or bone-metastatic prostate cancer was detected by microRNA deep sequencing assay and microRNA-chip array assay, respectively. Second, the candidates were further confirmed using TaqMan microRNA assay in two independent validation cohorts of total 176 patients with either BPH, non-bone metastatic prostate cancer or bone metastatic prostate cancer to seek the most valuable microRNA(s).

Results: Through microRNA deep sequencing and microRNA-chip array, we found 4 prospective EV-delivered miRNAs including miR-181a-5p with significantly upregulated expression in bone metastatic groups than in non-bone metastatic prostate cancer groups (p < 0.05). In the validation cohorts, logistic regression analysis was performed to evaluate the diagnostic association of candidates with bone metastasis, which indicated that miR-181a-5p was significantly associated with bone metastatic prostate cancer. Furthermore, accuracy estimate of each candidate for the diagnosis of bone metastatic prostate cancer was quantified using the area under the receiver-operating characteristic curve (AUC), which identified miR-181a-5p as the best biomarker with the AUCs of 85.6% for diagnosis of prostate cancer and 73.8% for diagnosis of bone metastatic prostate cancer.

Conclusion: EV-delivered miR-181a-5p from patient's serum is a promising diagnostic biomarker for bone metastatic prostate cancer.

The significance of microRNA deregulation in colorectal cancer development and the clinical uses as a diagnostic and prognostic biomarker and therapeutic agent

Colorectal cancer (CRC) is one of the most widely recognized and deadly malignancies worldwide. Although death rates have declined over the previous decade, mainly because of enhanced screening or potential treatment alternatives, CRC remains the third leading cause of cancer-related mortality globally, with an estimated incidence of over 1 million new cases and approximately 600 000 deaths estimated yearly. Therefore, many scientific efforts are put into the development of new diagnostic biomarkers for CRC. MicroRNAs (miRNAs), one of the epigenetics categories, have demonstrated significant roles in carcinogenesis and progression through regulating epithelial-mesenchymal transition (EMT), oncogenic signaling pathways, and metastasis. Dysregulation of miRNAs expression has been reported in many cancers, including CRC. The expression profile of miRNAs is reproducibly altered in CRC, and their expression patterns are associated with diagnosis, prognosis, and therapeutic outcomes in CRC. Recently, many studies were conducted on the dysregulation of miRNAs as a diagnostic and prognostic biomarker in CRC. Among them, some miRNAs, which include miR-21, miR-34 family, miR-155, miR-224, and miR-378, have been more studied in CRC with more prominent roles in diagnosis, prognosis, and therapy. In the present review, we summarized the latest information regarding the dysregulated miRNAs in CRC and the advantages of using miRNAs as a biomarker for CRC diagnosis, treatment, and their function in different signaling pathways involved in CRC progression. Moreover, we described the translation of miRNA research to potential therapeutic applications in the management of CRC in clinical settings.

Insights into the Role of microRNAs in Colorectal Cancer (CRC) Metabolism

Colorectal cancer (CRC) is one of the most frequently diagnosed cancers, with a high mortality rate globally. The pathophysiology of CRC is mainly initiated by alteration in gene expression, leading to dysregulation in multiple signalling pathways and cellular processes. Metabolic reprogramming is one of the important cancer hallmarks in CRC, which involves the adaptive changes in tumour cell metabolism to sustain the high energy requirements for rapid cell proliferation. There are several mechanisms in the metabolic reprogramming of cancer cells, such as aerobic glycolysis, oxidative phosphorylation, lactate and fatty acids metabolism. MicroRNAs (miRNAs) are a class of non-coding RNAs that are responsible for post-transcriptional regulation of gene expression. Differential expression of miRNAs has been shown to play an important role in different aspects of tumorigenesis, such as proliferation, apoptosis, and drug resistance, as well as metabolic reprogramming. Increasing evidence also reports that miRNAs could function as potential regulators of metabolic reprogramming in CRC cells. This review provides an insight into the role of different miRNAs in regulating the metabolism of CRC cells as well as to discuss the potential role of miRNAs as biomarkers or therapeutic targets in CRC tumour metabolism.

Colorectal Cancer Stem Cells in the Progression to Liver Metastasis

Colorectal carcinoma (CRC) is a leading cause of cancer mortality. Tumorigenesis is a dynamic process wherein cancer stem cells (CSCs) and their microenvironment promote initiation, progression, and metastasis. Metastatic colonization is an inefficient process that is very complex and is poorly understood; however, in most cases, metastatic disease is not curable, and resistance mechanisms tend to develop against conventional treatments. An understanding of the underlying mechanisms and factors that contribute to the development of metastasis in CRC can aid in the search for specific therapeutic targets for improving standard treatments. In this review, we summarize current knowledge regarding tumor biology and the use of stroma cells as prognostic factors and inflammatory inducers associated with the use of tumor microenvironments as a promoter of cancer metastasis. Moreover, we look into the importance of CSC, pericytes, and circulating tumor cells as mechanisms that lead to liver metastasis, and we also focus on the cellular and molecular pathways that modulate and regulate epithelial–mesenchymal transition. Finally, we discuss a novel therapeutic target that can potentially eliminate CSCs as a CRC treatment.

Non-coding RNAS and colorectal cancer liver metastasis

More than 50% of colorectal cancer (CRC) deaths are attributed to metastasis, and the liver is the most common distant metastatic site of CRC. The molecular mechanisms underlying CRC liver metastasis are very complicated and remain largely unknown. Accumulated evidence has shown that non-coding RNAs (NcRNAs) play critical roles in tumor development and progression. Here we reviewed the roles and underlying mechanisms of NcRNAs in CRC liver metastasis.

Long non-coding RNA CCAT1 promotes colorectal cancer progression by regulating miR-181a-5p expression

The vital roles of long noncoding RNAs (lncRNAs) have been implicated in growing number of studies in tumor development. LncRNA CCAT1 has been recognized as associated with tumor development, yet its relation with colorectal cancer (CRC) remains elusive. Our study aimed at elucidating the function and mechanisms of long non-coding RNA CCAT1 in CRC. From a lncRNA profile dataset of 38 pairs of matched tumor-control colon tissues from colorectal patients housed in The Cancer Genome Atlas (TCGA), we detected 10 upregulated and 10 down-regulated lncRNAs in CRC. Fifty cases of CRC patients were enrolled to analyze the correlation between the expression of CCAT1 and clinical pathology. The inverse correlation of expression and target relationship between CCAT1 and miR-181a-5p were verified using qRT-PCR and dual-luciferase reporter gene assay. Cell viability, colony formation ability, aggression and apoptosis were determined by MTT assay, colony formation assay, Transwell and wound healing assays and flow cytometry analysis. Furthermore, Xenograft model was used to show that knockdown of CCAT1 inhibits tumor growth in vivo. The expression of lncRNA CCAT1 was significantly upregulated in CRC tissues. The CCAT1 expression was positively associated with cancer stage (American Joint Committee on Cancer stage, P<0.05). CCAT1 promoted cell proliferation, growth and mobility by targeting miR-181a-5p and the silence of CCAT1 increased the cell apoptosis. Same effect was observed in an in vivo xenograft model, which the tumor size and pro-tumor proteins were significantly diminished by knocking down of CCAT1.

The Pervasive Role of the miR-181 Family in Development, Neurodegeneration, and Cancer

MicroRNAs (miRNAs) are small noncoding RNAs playing a fundamental role in the regulation of gene expression. Evidence accumulating in the past decades indicate that they are capable of simultaneously modulating diverse signaling pathways involved in a variety of pathophysiological processes. In the present review, we provide a comprehensive overview of the function of a highly conserved group of miRNAs, the miR-181 family, both in physiological as well as in pathological conditions. We summarize a large body of studies highlighting a role for this miRNA family in the regulation of key biological processes such as embryonic development, cell proliferation, apoptosis, autophagy, mitochondrial function, and immune response. Importantly, members of this family have been involved in many pathological processes underlying the most common neurodegenerative disorders as well as different solid tumors and hematological malignancies. The relevance of this miRNA family in the pathogenesis of these disorders and their possible influence on the severity of their manifestations will be discussed. A better understanding of the miR-181 family in pathological conditions may open new therapeutic avenues for devasting disorders such as neurodegenerative diseases and cancer.

Exosome-mediated miRNA delivery promotes liver cancer EMT and metastasis

The deregulation of exosomal microRNAs (miRNAs) plays an important role in the progression of hepatocarcinogenesis. In this study, we highlight exosomes as mediators involved in modulating miRNA profiles in liver cancer cells after induction of the epithelial-mesenchymal transition (EMT) and metastasis. Initially, we induced EMT in a hepatocellular carcinoma cell (HCC) line (Hep3B) by stimulation with transforming growth factor-β (TGF-β) and confirmed by western blot detection of EMT markers such as vimentin and E-cadherin. Exosomes were then isolated from the cells and identified by nanoparticle tracking analysis (NTA). The isolated exosomal particles from unstimulated Hep3B cells (Hep3B exo) or TGF-β-stimulated EMT Hep3B cells (EMT-Hep3B exo) contained higher levels of exosome marker proteins, CD63 and TSG101. After incubation with EMT-Hep3B exo, Hep3B cell proliferation increased. EMT-Hep3B exo promoted the migration and invasion of Hep3B and 7721 cells. High-throughput sequencing of miRNAs and mRNA within the exosomes showed 119 upregulated and 186 downregulated miRNAs and 156 upregulated and 166 downregulated mRNA sequences in the EMT-Hep3B exo compared with the control Hep3B exo. The most differentially expressed miRNAs and target mRNA sequences were validated by RT-qPCR. Based on the known miRNA targets for specific mRNA sequences, we hypothesized that GADD45A was regulated by miR-374a-5p. Inhibition of miR-374a-5p in Hep3B cells resulted in exosomes that inhibited the proliferation, migration, and invasion of HCC cells. These results enhance our understanding of metastatic progression of liver cancer and provide a foundation for the future development of potential biomarkers for diagnosis and prognosis of hepatic cancer.

miR-140-3p Suppresses Cell Growth And Induces Apoptosis In Colorectal Cancer By Targeting PD-L1

Background

A variety of miRNAs have been recently reported to be abnormally expressed in colorectal cancer (CRC). A growing number of studies have demonstrated that aberrantly expressed miRNAs are closely related to the development and progression of CRC. It has been found that miR-140-3p plays a vital role in several cancers. However, its expression, roles and mechanisms in CRC are remain unknown.

Materials and methods

Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) were used to determine miR-140-3p expression in CRC tissues and cell lines. CCK8, migration, invasion and flow cytometric assays were used to determine the influence of miR-140-3p upregulation on cell proliferation, migration, invasion and apoptosis of CRC cells. Luciferase reporter assays and Western blots were utilized to identify the target genes of miR-140-3p. In addition, the potential mechanism of miR-140-3p action in CRC cells was elucidated.

Results

In our study, miR-140-3p expression was significantly decreased in CRC tissues and cell lines. Overexpression of miR-140-3p attenuated proliferation, migration, and invasion and induced the apoptosis of CRC cells. Bioinformatics analyse and luciferase reporter analysis identified PD-L1 as a putative target gene of miR-140-3p. PD-L1 was overexpressed in CRC tissues and inversely correlated with miR-140-3p expression. Suppression of PD-L1 expression in CRC cells generated biological behaviours in CRC cells that were similar to those observed after treated with miR-140-3p mimics. Restoration of PD-L1 expression partially attenuated the inhibitory effect of miR-140-3p on CRC cells. Western blot were used to verify the effect of PD-L1 expression on PI3K/AKT pathway. In addition, overexpression of miR-140-3p could inhibit CRC tumor growth in vivo.

Conclusion

In general, these data demonstrate that miR-140-3p acts as a tumour suppressor in CRC by directly targeting PD-L1 and inactivating PI3K/AKT pathway, suggesting that miR-140-3p might be a novel target for CRC diagnosis and treatment.

Altered expression of miR-181 affects cell fate and targets drug resistance-related mechanisms

MicroRNAs (miRNAs) are non-coding transcripts which regulate genetic and epigenetic events by interfering with mRNA translation. miRNAs are involved in regulation of cell fate due to their ability of interfering with physiological or pathological processes. In this review paper, we evaluate the role of miR-181 family members as prognostic or diagnostic markers or therapeutic targets in malignant pathologies in connection with the main hallmarks of cancer that are modulated by the family. Also, we take over the dual role of this family in dependency with the tumour suppressor and oncogenic features presented in cell and cancer type specific manner. Restoration of the altered expression levels contributes to the activation of cell death pathways or to a reduction in the invasion and migration mechanism; moreover, the mechanism of drug resistance is also modulated by miR-181 sequences with important applications in therapeutic strategies for malignant cells sensitisation. Overall, the main miR-181 family regulatory mechanisms are presented in a cancer specific context, emphasizing the possible clinical application of this family in terms of novel diagnosis and therapy approaches.

MicroRNA-181 inhibits the proliferation, drug sensitivity and invasion of human glioma cells by targeting Selenoprotein K (SELK)

Gliomas are aggressive type of brain tumors and cause significant human mortality world over. The frequent relapses, development of drug resistance, the adverse effects of the chemotherapy and dearth of the therapeutic targets form the major hurdles in glioma treatment. Several studies suggest that microRNAs (miRs) are involved in the development and progression of different cancers. Herein, the therapeutic potential of miR-181 was explored in human glioma cells. The results showed that miR-181 is significantly downregulated in human glioma cells. Overexpression of miR-181 caused significant inhibition in the proliferation of U87 and U118 glioma cells. The miR-181 triggered growth inhibition was found to be mainly due to the induction of apoptosis which was concomitant with increase in the Bax/Bcl-2 ratio. Additionally, miR-181 enhanced the chemosensitivity of the glioma cells to temozolomide and suppressed their invasion. Bioinformatic analysis showed that miR-181 exerts its effects by inhibiting the expression of Selenoprotein K (SELK). The expression of SELK was found to be significantly upregulated in glioma cells and silencing of SELK suppressed the proliferation of glioma cells. Nonetheless, overexpression of SELK could nullify the effects of miR-181 on the proliferation of the glioma cells. Taken together, miR-181 may exhibit therapeutic implications in the treatment of glioma.