Cells

Research

Jump to: Review

22 pages, 10349 KiB

Open AccessArticle

FAM64A: A Novel Oncogenic Target of Lung Adenocarcinoma Regulated by Both Strands of miR-99a (miR-99a-5p and miR-99a-3p)

by Keiko Mizuno, Kengo Tanigawa, Nijiro Nohata, Shunsuke Misono, Reona Okada, Shunichi Asai, Shogo Moriya, Takayuki Suetsugu, Hiromasa Inoue and Naohiko Seki

Cells 2020, 9(9), 2083; https://doi.org/10.3390/cells9092083 - 11 Sep 2020

Cited by 16 | Viewed by 2851

Abstract

Lung adenocarcinoma (LUAD) is the most aggressive cancer and the prognosis of these patients is unfavorable. We revealed that the expression levels of both strands of miR-99a (miR-99a-5p and miR-99a-3p) were significantly suppressed in several cancer tissues. Analyses of large The [...] Read more.

Lung adenocarcinoma (LUAD) is the most aggressive cancer and the prognosis of these patients is unfavorable. We revealed that the expression levels of both strands of miR-99a (miR-99a-5p and miR-99a-3p) were significantly suppressed in several cancer tissues. Analyses of large The Cancer Genome Atlas (TCGA) datasets showed that reduced miR-99a-5p or miR-99a-3p expression is associated with worse prognoses in LUAD patients (disease-free survival (DFS): p = 0.1264 and 0.0316; overall survival (OS): p = 0.0176 and 0.0756, respectively). Ectopic expression of these miRNAs attenuated LUAD cell proliferation, suggesting their tumor-suppressive roles. Our in silico analysis revealed 23 putative target genes of pre-miR-99a in LUAD cells. Among these targets, high expressions of 19 genes were associated with worse prognoses in LUAD patients (OS: p < 0.05). Notably, FAM64A was regulated by both miR-99a-5p and miR-99a-3p in LUAD cells, and its aberrant expression was significantly associated with poor prognosis in LUAD patients (OS: p = 0.0175; DFS: p = 0.0276). FAM64A knockdown using siRNAs suggested that elevated FAM64A expression contributes to cancer progression. Aberrant FAM64A expression was detected in LUAD tissues by immunostaining. Taken together, our miRNA-based analysis might be effective for identifying prognostic and therapeutic molecules in LUAD. Full article

(This article belongs to the Special Issue microRNA as Therapeutic Target)

► Show Figures

Figure 1

15 pages, 3696 KiB

Open AccessArticle

The miR-28-5p Targetome Discovery Identified SREBF2 as One of the Mediators of the miR-28-5p Tumor Suppressor Activity in Prostate Cancer Cells

by Sofia Fazio, Gabriele Berti, Francesco Russo, Monica Evangelista, Romina D’Aurizio, Alberto Mercatanti, Marco Pellegrini and Milena Rizzo

Cells 2020, 9(2), 354; https://doi.org/10.3390/cells9020354 - 3 Feb 2020

Cited by 23 | Viewed by 3560

Abstract

miR-28-5p is downregulated in some tumor tissues in which it has been demonstrated to have tumor suppressor (TS) activity. Here, we demonstrate that miR-28-5p acts as a TS in prostate cancer (PCa) cells affecting cell proliferation/survival, as well as migration and invasion. Using [...] Read more.

miR-28-5p is downregulated in some tumor tissues in which it has been demonstrated to have tumor suppressor (TS) activity. Here, we demonstrate that miR-28-5p acts as a TS in prostate cancer (PCa) cells affecting cell proliferation/survival, as well as migration and invasion. Using the miRNA pull out assay and next generation sequencing, we collected the complete repertoire of miR-28-5p targets, obtaining a data set (miR-28-5p targetome) of 191 mRNAs. Filtering the targetome with TargetScan 7, PITA and RNA22, we found that 61% of the transcripts had miR-28-5p binding sites. To assign a functional value to the captured transcripts, we grouped the miR-28-5p targets into gene families with annotated function and showed that six transcripts belong to the transcription factor category. Among them we selected SREBF2, a gene with an important role in PCa. We validated miR-28-5p/SREBF2 interaction, demonstrating that SREBF2 inhibition affects almost all the tumor processes altered by miR-28-5p re-expression, suggesting that SREBF2 is an important mediator of miR-28-5p TS activity. Our findings support the identification of the targetome of cancer-related miRNAs as a tool to discover genes and pathways fundamental for tumor development, and potential new targets for anti-tumor therapy. Full article

(This article belongs to the Special Issue microRNA as Therapeutic Target)

► Show Figures

Figure 1

Figure 1
Effect of miR-28-5p re-expression in PCa cells. (A) Analysis of the miR-28-5p expression level by qRT-PCR in prostate cancer cell lines with respect to the normal cells RNA. (B) Relative expression level of miR-28-5p, evaluated by qRT-PCR, after miR-28-5p transfection in DU-145 cells. Cell migration (C,D) and invasion (E) of DU-145 cells after miR-28-5p overexpression evaluated by wound healing assay (C) and trans-well assay (D,E). (F) Relative expression of E-cadherin 1 (CDH1) and vimentin (VIM) in miR-28-5p overexpressing versus normal DU-145 cells. (G) Number of colonies formed in soft agar in DU-145 cells after miR-28-5p or CT overexpression. * p < 0.05, ** p < 0.01, *** p < 0.001, unpaired t-test. Full article ">Figure 2
Association of miR-28-5p expression with clinical parameters in PCa patients. (A) Analysis of miR-28-5p expression level data of the Memorial Sloan Kettering Cancer Center (MSKCC) study’s patients. The significances according to the Kruskal–Wallis and Wilcoxon test are indicated. (B) Kaplan–Meier curves for recurrence-free survival events between MSKCC patients after dividing samples into two groups according to the 25st quartile of miR-28-5p expression level. Log-rank test’s p-value is shown. The miR-28-5p expression levels (log2RPMK) of TGCA PRAD samples are shown and grouped by pathological T stage (C) and Gleason score (D) with p-value from the Spearman’s test of association. Full article ">Figure 3
Analysis of miR-28-5p targetome. (A) Evaluation of the enrichment of miR-28-5p selected targets in the miR-28BIO compared to miR-28CT pull out samples by qRT-PCR. (B) Pie chart representing the percentage of the predicted/non-predicted targets (upper panel) and the percentage of the targets predicted by one, two or three algorithms (lower panel) in the miR-28-5p targetome. (C) Results of the MSigDB gene sets analyses showing the identified genes families. (D) Enrichment of the miR-28-5p targets belonging to the “transcription factors” family in the miR-28BIO compared to miR-28CT pull out samples by qRT-PCR. * p < 0.05, ** p < 0.01, *** p < 0.001, unpaired t-test. Full article ">Figure 4
Evaluation of the SREBF2 role in DU-145 PCa cells. (A) SREBF2 inhibition by siR-SREBF2 transfection in DU-145 cells analyzed by qRT-PCR and western blot analysis. Evaluation of SREBF2 silencing effect on proliferation (B), survival (D) migration (E,F) and invasion (G) in DU-145 cells. Relative expression of proliferation (Ki-67, c-MYC and cyclin D1 (CCND1)) (C), epithelial (E-cadherin 1 (CDH1)) and mesenchymal markers (Vimentin (VIM)) (H) in miR-28-5p overexpressing versus normal DU-145 cells. (I) Number of colonies formed in soft agar in DU-145 cells after miR-28-5p overexpression or SREBF2 silencing. * p < 0.05, ** p < 0.01, *** p < 0.001, unpaired t-test. ns, not significant. Full article ">Figure 5
Analysis of miR-28-5p/SREBF2 interaction in PCa cells. (A) Quantification of SREBF2 mRNA and protein level in miR-28-5p versus CT transfected DU-145 cells. Relative luciferase activity after the cotransfection of pSREBF23′UTR (B), pSREBF25’UTR-ORFI (C), pSREBF2ORFII (D) and either CT or miR-28-5p. (E) Relative luciferase mRNA level, analyzed with qRT-PCR, in DU-145 cotransfected with miR-28-5p sensor and miR-28-5p mimic or inhibitor versus miR-28-5p sensor/CT cotransfected cells. (F) Relative luciferase mRNA level, analyzed by qRT-PCR, in DU-145 cotransfected with miR-28-5p sensor/siR-SREBF2 versus miR-28-5p sensor/CT cotransfected cells. * p < 0.05, ** p < 0.01, *** p < 0.001, unpaired t-test. ns, not significant. Full article ">

18 pages, 5907 KiB

Open AccessArticle

Regulation of Oncogenic Targets by miR-99a-3p (Passenger Strand of miR-99a-Duplex) in Head and Neck Squamous Cell Carcinoma

by Reona Okada, Keiichi Koshizuka, Yasutaka Yamada, Shogo Moriya, Naoko Kikkawa, Takashi Kinoshita, Toyoyuki Hanazawa and Naohiko Seki

Cells 2019, 8(12), 1535; https://doi.org/10.3390/cells8121535 - 28 Nov 2019

Cited by 28 | Viewed by 4076

Abstract

To identify novel oncogenic targets in head and neck squamous cell carcinoma (HNSCC), we have analyzed antitumor microRNAs (miRNAs) and their controlled molecular networks in HNSCC cells. Based on our miRNA signature in HNSCC, both strands of the miR-99a-duplex (miR-99a-5p: [...] Read more.

To identify novel oncogenic targets in head and neck squamous cell carcinoma (HNSCC), we have analyzed antitumor microRNAs (miRNAs) and their controlled molecular networks in HNSCC cells. Based on our miRNA signature in HNSCC, both strands of the miR-99a-duplex (miR-99a-5p: the guide strand, and miR-99a-3p: the passenger strand) are downregulated in cancer tissues. Moreover, low expression of miR-99a-5p and miR-99a-3p significantly predicts poor prognosis in HNSCC, and these miRNAs regulate cancer cell migration and invasion. We previously showed that passenger strands of miRNAs have antitumor functions. Here, we screened miR-99a-3p-controlled oncogenes involved in HNSCC pathogenesis. Thirty-two genes were identified as miR-99a-3p-regulated genes, and 10 genes (STAMBP, TIMP4, TMEM14C, CANX, SUV420H1, HSP90B1, PDIA3, MTHFD2, BCAT1, and SLC22A15) significantly predicted 5-year overall survival. Notably, among these genes, STAMBP, TIMP4, TMEM14C, CANX, and SUV420H1 were independent prognostic markers of HNSCC by multivariate analyses. We further investigated the oncogenic function of STAMBP in HNSCC cells using knockdown assays. Our data demonstrated that the aggressiveness of phenotypes in HNSCC cells was attenuated by siSTAMBP transfection. Moreover, aberrant STAMBP expression was detected in HNSCC clinical specimens by immunohistochemistry. This strategy may contribute to the clarification of the molecular pathogenesis of this disease. Full article

(This article belongs to the Special Issue microRNA as Therapeutic Target)

► Show Figures

Figure 1

Figure 1
Expression and clinical significance of miR-99a-5p and miR-99a-3p in HNSCC clinical specimens. (A) Expression of miR-99a-5p and miR-99a-3p was significantly reduced in HNSCC clinical specimens and cell lines (FaDu and SAS cells). Data were normalized to the expression of RNU48. (B) Spearman’s rank tests showed positive correlations between expression levels of miR-99a-5p and miR-99a-3p in clinical specimens. (C) Kaplan-Meier survival curve analyses of patients with HNSCC using data from The Cancer Genome Atlas (TCGA) database. Patients were divided into two groups according to miRNA expression, high group and low group (according to median expression). The red line shows the high expression group, and the blue line shows the low expression group. Full article ">Figure 2
Functional assays of cell proliferation, migration, and invasion following ectopic expression of miR-99a-5p and miR-99a-3p in HNSCC cell lines (FaDu and SAS cells). (A) Cell proliferation was assessed using XTT assays. Data were collected 72 h after miRNA transfection (* p < 0.0001). (B) Cell migration was assessed with membrane culture system. Data were collected 48 h after seeding the cells into the chambers (* p < 0.0001). (C) Cell invasion was determined 48 h after seeding miRNA-transfected cells into chambers using Matrigel invasion assays (* p < 0.0001). Full article ">Figure 3
Clinical significance of miR-99a-3p target genes in TCGA database. Among putative targets of miR-99a-3p in HNSCC cells, high expression of 10 genes (STAMBP, TIMP4, TMEM14C, CANX, SUV420H1, HSP90B1, PDIA3, MTHFD2, BCAT1, and SLC22A15) was significantly associated with poor prognosis in patients with HNSCC. Kaplan-Meier curves of 5-year overall survival for each gene are shown. Full article ">Figure 4
Forest plot of multivariate analysis of five genes (STAMBP, TIMP4, TMEM14C, SUV420H1, and CANX), which were independent prognostic factors for overall survival after adjustment for patient age, disease, stage, and pathological grade. Full article ">Figure 5
Expression of STAMBP/STAMBP was directly regulated by miR-99a-3p in HNSCC cells. (A) Expression of STAMBP mRNA was significantly reduced by miR-99a-3p transfection into FaDu and SAS cells (72 h after transfection; * p < 0.0001, N.S.: Not significant). Expression of GAPDH was used as an internal control. (B) Expression of STAMBP protein was reduced by miR-99a-3p transfection into HNSCC cells (72 h after transfection). Expression of GAPDH was used as an internal control. (C) TargetScanHuman database analyses predicted one putative miR-99a-3p binding site in the 3′-UTR of STAMBP. (D) Dual luciferase reporter assays showed that luminescence activities were reduced by cotransfection with wild-type (miR-99a-3p binding site) vectors and miR-99a-3p in FaDu and SAS cells. Normalized data were calculated as Renilla/firefly luciferase activity ratios (N.S.: Not significant). Full article ">Figure 6
Effects of STAMBP knockdown on cell proliferation, migration, and invasion in HNSCC cells. (A) Expression of STAMBP mRNA was significantly reduced by siRNA transfection into HNSCC cells (* p < 0.0001). Expression of GAPDH was used as an internal control. (B) Expression of STAMBP protein was markedly reduced by siRNA transfection into HNSCC cells. Expression of GAPDH was used as an internal control. (C) Cell proliferation was assessed using XTT assays. Data were collected 72 h after miRNA transfection (* p < 0.0001). (D) Cell migration was assessed with a membrane culture system. Data were collected 48 h after seeding the cells into the chambers (* p < 0.0001). (E) Cell invasion was determined 48 h after seeding miRNA-transfected cells into chambers using Matrigel invasion assays (* p < 0.0001). Full article ">Figure 7
Overexpression of STAMBP in HNSCC clinical specimens. (A–I) Expression of STAMBP was investigated by immunohistochemical staining of HNSCC clinical specimens. Overexpression of STAMBP was detected in the nuclei and/or cytoplasm of cancer cells. (J) Extremely weak expression of STAMBP in normal mucosa of larynx and pharynx. Full article ">

Review

Jump to: Research

26 pages, 1117 KiB

Open AccessReview

Current Status of microRNA-Based Therapeutic Approaches in Neurodegenerative Disorders

by Sujay Paul, Luis Alberto Bravo Vázquez, Samantha Pérez Uribe, Paula Roxana Reyes-Pérez and Ashutosh Sharma

Cells 2020, 9(7), 1698; https://doi.org/10.3390/cells9071698 - 15 Jul 2020

Cited by 72 | Viewed by 7607

Abstract

MicroRNAs (miRNAs) are a key gene regulator and play essential roles in several biological and pathological mechanisms in the human system. In recent years, plenty of miRNAs have been identified to be involved in the development of neurodegenerative disorders (NDDs), thus making them [...] Read more.

MicroRNAs (miRNAs) are a key gene regulator and play essential roles in several biological and pathological mechanisms in the human system. In recent years, plenty of miRNAs have been identified to be involved in the development of neurodegenerative disorders (NDDs), thus making them an attractive option for therapeutic approaches. Hence, in this review, we provide an overview of the current research of miRNA-based therapeutics for a selected set of NDDs, either for their high prevalence or lethality, such as Alzheimer’s, Parkinson’s, Huntington’s, Amyotrophic Lateral Sclerosis, Friedreich’s Ataxia, Spinal Muscular Atrophy, and Frontotemporal Dementia. We also discuss the relevant delivery techniques, pertinent outcomes, their limitations, and their potential to become a new generation of human therapeutic drugs in the near future. Full article

(This article belongs to the Special Issue microRNA as Therapeutic Target)

► Show Figures

Figure 1

23 pages, 1374 KiB

Open AccessFeature PaperReview

The Promise and Challenges of Developing miRNA-Based Therapeutics for Parkinson’s Disease

by Simoneide S. Titze-de-Almeida, Cristina Soto-Sánchez, Eduardo Fernandez, James B. Koprich, Jonathan M. Brotchie and Ricardo Titze-de-Almeida

Cells 2020, 9(4), 841; https://doi.org/10.3390/cells9040841 - 31 Mar 2020

Cited by 52 | Viewed by 5821

Abstract

MicroRNAs (miRNAs) are small double-stranded RNAs that exert a fine-tuning sequence-specific regulation of cell transcriptome. While one unique miRNA regulates hundreds of mRNAs, each mRNA molecule is commonly regulated by various miRNAs that bind to complementary sequences at 3’-untranslated regions for triggering the [...] Read more.

MicroRNAs (miRNAs) are small double-stranded RNAs that exert a fine-tuning sequence-specific regulation of cell transcriptome. While one unique miRNA regulates hundreds of mRNAs, each mRNA molecule is commonly regulated by various miRNAs that bind to complementary sequences at 3’-untranslated regions for triggering the mechanism of RNA interference. Unfortunately, dysregulated miRNAs play critical roles in many disorders, including Parkinson’s disease (PD), the second most prevalent neurodegenerative disease in the world. Treatment of this slowly, progressive, and yet incurable pathology challenges neurologists. In addition to L-DOPA that restores dopaminergic transmission and ameliorate motor signs (i.e., bradykinesia, rigidity, tremors), patients commonly receive medication for mood disorders and autonomic dysfunctions. However, the effectiveness of L-DOPA declines over time, and the L-DOPA-induced dyskinesias commonly appear and become highly disabling. The discovery of more effective therapies capable of slowing disease progression –a neuroprotective agent–remains a critical need in PD. The present review focus on miRNAs as promising drug targets for PD, examining their role in underlying mechanisms of the disease, the strategies for controlling aberrant expressions, and, finally, the current technologies for translating these small molecules from bench to clinics. Full article

(This article belongs to the Special Issue microRNA as Therapeutic Target)

► Show Figures

Figure 1

Figure 1
Biological synthesis of endogenous microRNAs (miRNAs) and modulation by synthetic oligonucleotides. miRNAs are coded in mammalian DNA genes and transcribed by RNA polymerase II (Pol II) to form the primary miRNA (pri-miRNA). This long RNA receives the first processing by Drosha and DGCR8 enzymes in cell nucleus, with remotion of nucleotides outside the hairpin. The resulting miRNA precursor (pre-miRNA) moves to cytoplasm carried by Exportin 5. Dicer and TRBP enzymes execute the second round of processing, resulting in miRNA duplexes with 18–25 nucleotides. Sense strand is removed. The guide (or antisense) strand is the mature miRNA that will guide the RISC complex (miRISC) to target mRNAs bearing partially complementary sequences in 3’-UTR region. Silencing of miRNA-targeted mRNAs occurs through translational repression or degradation. AGO—Argonaute 2; CDS—Coding sequence region of mRNA; 3’-UTR-3’ untranslated region; DGCR8—DiGeorge syndrome critical region gene 8; Dicer—a ribonuclease enzyme; Drosha—a ribonuclease enzyme; miRISC—RISC complex associated with a miRNA; Pol II—RNA polymerase II; pre-miRNA—miRNA precursor; pri-miRNA—primary miRNA; RISC—RNA-induced silencing complex; TRBP—HIV-1 Trans-activation response (TAR) RNA-binding protein. Reprinted with permission from Titze-de-Almeida and Titze-de-Almeida 2018, with modifications [<a href="#B34-cells-09-00841" class="html-bibr">34</a>]. Full article ">Figure 2
Schematic representation of miRNAs in the healthy and Parkinsonian brain. MicroRNAs expressed in the central nervous system contributes to brain development and cell physiology. Instead, aberrantly expressed miRNAs play a role in pathological mechanisms in a parkinsonian brain (PD brain). Translating to clinics, miRNAs are candidate biomarkers of disease progression and promising targets for miRNA-based therapeutics. Full article ">

14 pages, 743 KiB

Open AccessReview

Nanoparticle-Based Delivery of Tumor Suppressor microRNA for Cancer Therapy

by Clodagh P. O’Neill and Róisín M. Dwyer

Cells 2020, 9(2), 521; https://doi.org/10.3390/cells9020521 - 24 Feb 2020

Cited by 66 | Viewed by 7475

Abstract

Improved understanding of microRNA expression and function in cancer has revealed a range of microRNAs that negatively regulate many oncogenic pathways, thus representing potent tumor suppressors. Therapeutic targeting of the expression of these microRNAs to the site of tumors and metastases provides a [...] Read more.

Improved understanding of microRNA expression and function in cancer has revealed a range of microRNAs that negatively regulate many oncogenic pathways, thus representing potent tumor suppressors. Therapeutic targeting of the expression of these microRNAs to the site of tumors and metastases provides a promising avenue for cancer therapy. To overcome challenges associated with microRNA degradation, transient expression and poor targeting, novel nanoparticles are being developed and employed to shield microRNAs for tumor-targeted delivery. This review focuses on studies describing a variety of both natural and synthetic nanoparticle delivery vehicles that have been engineered for tumor-targeted delivery of tumor suppressor microRNAs in vivo. Full article

(This article belongs to the Special Issue microRNA as Therapeutic Target)

► Show Figures

Figure 1

27 pages, 1939 KiB

Open AccessEditor’s ChoiceReview

RNA-Based Therapeutics: From Antisense Oligonucleotides to miRNAs

by Sarah Bajan and Gyorgy Hutvagner

Cells 2020, 9(1), 137; https://doi.org/10.3390/cells9010137 - 7 Jan 2020

Cited by 245 | Viewed by 17693

Abstract

The first therapeutic nucleic acid, a DNA oligonucleotide, was approved for clinical use in 1998. Twenty years later, in 2018, the first therapeutic RNA-based oligonucleotide was United States Food and Drug Administration (FDA) approved. This promises to be a rapidly expanding market, as [...] Read more.

The first therapeutic nucleic acid, a DNA oligonucleotide, was approved for clinical use in 1998. Twenty years later, in 2018, the first therapeutic RNA-based oligonucleotide was United States Food and Drug Administration (FDA) approved. This promises to be a rapidly expanding market, as many emerging biopharmaceutical companies are developing RNA interference (RNAi)-based, and RNA-based antisense oligonucleotide therapies. However, miRNA therapeutics are noticeably absent. miRNAs are regulatory RNAs that regulate gene expression. In disease states, the expression of many miRNAs is measurably altered. The potential of miRNAs as therapies and therapeutic targets has long been discussed and in the context of a wide variety of infections and diseases. Despite the great number of studies identifying miRNAs as potential therapeutic targets, only a handful of miRNA-targeting drugs (mimics or inhibitors) have entered clinical trials. In this review, we will discuss whether the investment in finding potential miRNA therapeutic targets has yielded feasible and practicable results, the benefits and obstacles of miRNAs as therapeutic targets, and the potential future of the field. Full article

(This article belongs to the Special Issue microRNA as Therapeutic Target)

► Show Figures

Figure 1

Figure 1
Mechanisms of RNA-based therapeutics that are dependent on the endogenous microRNA (miRNA) pathway. (A) miRNAs are encoded in the genome, often in the intron of protein-coding genes. The transcript, produced by RNA polymerase II, containing the miRNA forms a characteristic stem-loop structure which is processed in the nucleus by an RNases III enzyme, Drosha, to form an RNA hairpin (approx. 70 nucleotides) called the pre-miRNA. Pre-miRNA moves into the cytoplasm via exportin-5 (XPO-5), where it is further processed by Dicer, producing a double-stranded miRNA–miRNA* duplex. One strand of this duplex is loaded onto an Argonaute (Ago protein) to from the RNA-induced silencing complex (RISC). The other strand of the duplex (the passenger strand) is degraded. RISC is guided by the loaded miRNA strand which imperfectly binds to complementary sites commonly found in the 3’ untranslated region (UTR) of target mRNAs. RISC inhibits the translation of the bound mRNA and can cause deadenylation and degradation of the targeted transcript. Therapeutic miRNA mimics (B) are synthesized as miRNA duplexes. Upon entry into the cell, one strand binds to an endogenous Ago protein forming RISC, while the passenger strand degrades. The synthesized miRNA acts as a guide, directing the RISC to the therapeutic target, and inhibiting its translation. (C) AntagomiRs are single-stranded, synthesized, modified RNA molecules which are complementary to an endogenous miRNA. Upon entry into the cell, the antagomiR will bind to its target miRNA, preventing the miRNA from being loaded onto an Ago protein and forming RISC. (D) Once therapeutic siRNA duplexes enter the cell, one strand is loaded onto an Ago2 protein forming RISC. RISC is directed to the target mRNA by the loaded siRNA which binds with 100% complementarity to its target, Ago2 then cleaves the transcript. (E) DNA plasmids designed to encode short hairpin (sh) RNA enter the cell nucleus, where they are transcribed, producing an RNA with a characteristic stem-loop structure, allowing the RNA to enter the endogenous miRNA biogenesis pathway. Full article ">Figure 2
Common Delivery Methods for RNA-based Therapeutics. (A) RNA-based therapeutics are often encapsulated, or attached on the surface of, nanoparticles to aid delivery of the drug into the cell. These nanoparticles are often modified with moieties such as cholesterol or polyethylene glycol (PEG) which aid uptake of the nanoparticle via the cell membrane. Some nanoparticles are directed to particular cells by the addition of a targeting moiety, often a ligand for a cell surface receptor specifically expressed on the target cell. Commonly, the nanoparticle enters the cell via endocytosis, forming an endosome, which, after environmental changes (e.g., lowered pH), degrades, releasing the RNA therapeutic into the cell. (B) Alternatively, some RNA therapeutics are directly conjugated to moieties to aid their transport across the cell membrane, e.g., cholesterol (C) Synthesized RNA therapeutics can be chemically modified to increase their stability and binding affinity and decrease their toxicity. LNA: locked nucleic acid (2′4′-methylene; 2′OMe: 2′-O-methyl; 2′MOE: 2′-O-methoxyethyl. Full article ">Figure 3
Mechanism of approved therapeutics. (A) Nusinersen regulates splicing of the Survival Motor Neuron (SMN) 2 gene to treat patients with spinal muscular atrophy (SMA). Due to weak splice site, masked by the binding of hnRNP, the SMN2 gene usually produces a truncated transcript lacking exon 7, which, when translated, produces a non-functional and unstable protein (SMN2∆7). Nusinersen (SpinrazaTM, Biogen) is an antisense oligonucleotide (ASO) therapy that binds, via complementarity, to SMN2 pre-mRNA, displacing hnRNP, exposing the splice site and increasing the inclusion of exon 7, forming a full-length, mature SMN2 transcript. Once translated, this produces a full-length, functional SMN protein, which improves patient’s motor neuron function and slows disease progression. (B) Patisiran (Onpattro) reduces the production of transthyrethin (TTR) protein to reduce the formation of amyloid fibrils in hereditary transthyretin-mediated (hATTR) amyloidosis. Mutations in the TTR gene causes misfolding of the TTR protein, the misfolded protein aggregates into amyloid fibrils. Patisiran is a synthesized siRNA therapy, which is 100% complementary to a specific sequence in the 3′ UTR of the TTR mRNA. Once Patisiran enters the cell, one strand of the short interfering RNA (siRNA) duplex is loaded onto an Ago2 protein, forming RISC. RISC binds to the TTR transcript, which is subsequently cleaved by Ago2, therefore reducing TTR protein production, preventing further amyloidosis and improving patient’s quality of life. Full article ">

39 pages, 3490 KiB

Open AccessReview

by Lisa Linck-Paulus, Claus Hellerbrand, Anja K. Bosserhoff and Peter Dietrich

Cells 2020, 9(1), 114; https://doi.org/10.3390/cells9010114 - 2 Jan 2020

Cited by 15 | Viewed by 5255

Abstract

In this review, we summarize the current knowledge on miRNAs as therapeutic targets in two cancer types that were frequently described to be driven by miRNAs—melanoma and hepatocellular carcinoma (HCC). By focusing on common microRNAs and associated pathways in these—at first sight—dissimilar cancer [...] Read more.

In this review, we summarize the current knowledge on miRNAs as therapeutic targets in two cancer types that were frequently described to be driven by miRNAs—melanoma and hepatocellular carcinoma (HCC). By focusing on common microRNAs and associated pathways in these—at first sight—dissimilar cancer types, we aim at revealing similar molecular mechanisms that are evolved in microRNA-biology to drive cancer progression. Thereby, we also want to outlay potential novel therapeutic strategies. After providing a brief introduction to general miRNA biology and basic information about HCC and melanoma, this review depicts prominent examples of potent oncomiRs and tumor-suppressor miRNAs, which have been proven to drive diverse cancer types including melanoma and HCC. To develop and apply miRNA-based therapeutics for cancer treatment in the future, it is essential to understand how miRNA dysregulation evolves during malignant transformation. Therefore, we highlight important aspects such as genetic alterations, miRNA editing and transcriptional regulation based on concrete examples. Furthermore, we expand our illustration by focusing on miRNA-associated proteins as well as other regulators of miRNAs which could also provide therapeutic targets. Finally, design and delivery strategies of miRNA-associated therapeutic agents as well as potential drawbacks are discussed to address the question of how miRNAs might contribute to cancer therapy in the future. Full article

(This article belongs to the Special Issue microRNA as Therapeutic Target)

► Show Figures

Figure 1

19 pages, 2749 KiB

Open AccessReview

Precision Medicine in Neurodegenerative Diseases: Some Promising Tips Coming from the microRNAs’ World

by Nicoletta Nuzziello, Loredana Ciaccia and Maria Liguori

Cells 2020, 9(1), 75; https://doi.org/10.3390/cells9010075 - 27 Dec 2019

Cited by 11 | Viewed by 4611

Abstract

Novel insights in the development of a precision medicine approach for treating the neurodegenerative diseases (NDDs) are provided by emerging advances in the field of pharmacoepigenomics. In this context, microRNAs (miRNAs) have been extensively studied because of their implication in several disorders related [...] Read more.

Novel insights in the development of a precision medicine approach for treating the neurodegenerative diseases (NDDs) are provided by emerging advances in the field of pharmacoepigenomics. In this context, microRNAs (miRNAs) have been extensively studied because of their implication in several disorders related to the central nervous system, as well as for their potential role as biomarkers of diagnosis, prognosis, and response to treatment. Recent studies in the field of neurodegeneration reported evidence that drug response and efficacy can be modulated by miRNA-mediated mechanisms. In fact, miRNAs seem to regulate the expression of pharmacology target genes, while approved (conventional and non-conventional) therapies can restore altered miRNAs observed in NDDs. The knowledge of miRNA pharmacoepigenomics may offers new clues to develop more effective treatments by providing novel insights into interindividual variability in drug disposition and response. Recently, the therapeutic potential of miRNAs is gaining increasing attention, and miRNA-based drugs (for cancer) have been under observation in clinical trials. However, the effective use of miRNAs as therapeutic target still needs to be investigated. Here, we report a brief review of representative studies in which miRNAs related to therapeutic effects have been investigated in NDDs, providing exciting potential prospects of miRNAs in pharmacoepigenomics and translational medicine. Full article

(This article belongs to the Special Issue microRNA as Therapeutic Target)

► Show Figures

Figure 1

32 pages, 1696 KiB

Open AccessReview

MicroRNA-Based Combinatorial Cancer Therapy: Effects of MicroRNAs on the Efficacy of Anti-Cancer Therapies

by Hyun Ah Seo, Sokviseth Moeng, Seokmin Sim, Hyo Jeong Kuh, Soo Young Choi and Jong Kook Park

Cells 2020, 9(1), 29; https://doi.org/10.3390/cells9010029 - 20 Dec 2019

Cited by 45 | Viewed by 7818

Abstract

The susceptibility of cancer cells to different types of treatments can be restricted by intrinsic and acquired therapeutic resistance, leading to the failure of cancer regression and remission. To overcome this problem, a combination therapy has been proposed as a fundamental strategy to [...] Read more.

The susceptibility of cancer cells to different types of treatments can be restricted by intrinsic and acquired therapeutic resistance, leading to the failure of cancer regression and remission. To overcome this problem, a combination therapy has been proposed as a fundamental strategy to improve therapeutic responses; however, resistance is still unavoidable. MicroRNA (miRNAs) are associated with cancer therapeutic resistance. The modulation of dysregulated miRNA levels through miRNA-based therapy comprising a replacement or inhibition approach has been proposed to sensitize cancer cells to other anti-cancer therapies. The combination of miRNA-based therapy with other anti-cancer therapies (miRNA-based combinatorial cancer therapy) is attractive, due to the ability of miRNAs to target multiple genes associated with the signaling pathways controlling therapeutic resistance. In this article, we present an overview of recent findings on the role of therapeutic resistance-related miRNAs in different types of cancer. We review the feasibility of utilizing dysregulated miRNAs in cancer cells and extracellular vesicles as potential candidates for miRNA-based combinatorial cancer therapy. We also discuss innate properties of miRNAs that need to be considered for more effective combinatorial cancer therapy. Full article

(This article belongs to the Special Issue microRNA as Therapeutic Target)

► Show Figures

Figure 1

Figure 1
Micro-RNA (MiRNA)-mediated regulation of the expression of drug transporters. Rounded rectangles indicate miRNAs (light green), transcription factors (orange), cytoplasmic signaling molecules (light blue), and a transmembrane receptor (red). Activation is denoted by solid line arrows, and inhibitory effects are indicated by perpendicular lines. Dashed arrows represent the nuclear translocation of transcription factors. Several miRNAs impact the efficacy of cancer therapeutic agents by transcriptionally regulating the levels of drug transporters, as described in <a href="#sec2dot3-cells-09-00029" class="html-sec">Section 2.3</a>. Full article ">Figure 2
MiRNA-mediated regulation of the factors associated with cancer stemness. Rounded rectangles denote miRNAs (light green), stemness factors (orange), and upstream regulators of stemness factors (light blue, red, and green). Inhibitory effects are indicated by perpendicular lines. The positive regulation of stemness factors by each upstream factor is represented by solid lines. The effects of miRNAs on anti-cancer therapies are described in <a href="#sec5dot7dot2-cells-09-00029" class="html-sec">Section 5.7.2</a> and <a href="#cells-09-00029-t004" class="html-table">Table 4</a>. Full article ">Figure 3
Extracellular vesicle miRNAs are responsible for therapeutic resistance. Exosomes and microvesicles (EVs), derived from cancer-associated cells, drug-resistant cancer cells, and cancer stem cells (CSCs), confer neighboring cells resistance to various anti-cancer treatments via transferring miRNAs, which regulate several factors associated with resistance mechanisms. Rounded rectangles represent miRNAs (light green), miRNA targets (orange), and signaling factors/cellular events affected by miRNA targets (light orange). Activation is indicated by solid line arrows, and inhibitory effects are demonstrated by perpendicular lines. The secretion of extracellular vesicles is denoted by dashed arrows. Potential mechanisms underlying the role of extracellular vesicle miRNAs in therapeutic resistance are explained in <a href="#sec7-cells-09-00029" class="html-sec">Section 7</a>. Full article ">

40 pages, 1243 KiB

Open AccessReview

TGF-β and microRNA Interplay in Genitourinary Cancers

by Joanna Boguslawska, Piotr Kryst, Slawomir Poletajew and Agnieszka Piekielko-Witkowska

Cells 2019, 8(12), 1619; https://doi.org/10.3390/cells8121619 - 12 Dec 2019

Cited by 19 | Viewed by 5490

Abstract

Genitourinary cancers (GCs) include a large group of different types of tumors localizing to the kidney, bladder, prostate, testis, and penis. Despite highly divergent molecular patterns, most GCs share commonly disturbed signaling pathways that involve the activity of TGF-β (transforming growth factor beta). [...] Read more.

Genitourinary cancers (GCs) include a large group of different types of tumors localizing to the kidney, bladder, prostate, testis, and penis. Despite highly divergent molecular patterns, most GCs share commonly disturbed signaling pathways that involve the activity of TGF-β (transforming growth factor beta). TGF-β is a pleiotropic cytokine that regulates key cancer-related molecular and cellular processes, including proliferation, migration, invasion, apoptosis, and chemoresistance. The understanding of the mechanisms of TGF-β actions in cancer is hindered by the “TGF-β paradox” in which early stages of cancerogenic process are suppressed by TGF-β while advanced stages are stimulated by its activity. A growing body of evidence suggests that these paradoxical TGF-β actions could result from the interplay with microRNAs: Short, non-coding RNAs that regulate gene expression by binding to target transcripts and inducing mRNA degradation or inhibition of translation. Here, we discuss the current knowledge of TGF-β signaling in GCs. Importantly, TGF-β signaling and microRNA-mediated regulation of gene expression often act in complicated feedback circuits that involve other crucial regulators of cancer progression (e.g., androgen receptor). Furthermore, recently published in vitro and in vivo studies clearly indicate that the interplay between microRNAs and the TGF-β signaling pathway offers new potential treatment options for GC patients. Full article

(This article belongs to the Special Issue microRNA as Therapeutic Target)

► Show Figures

Figure 1

19 pages, 3039 KiB

Open AccessReview

Mapping Research in the Obesity, Adipose Tissue, and MicroRNA Field: A Bibliometric Analysis

by João Manoel Alves, Ramon Handerson Gomes Teles, Camila do Valle Gomes Gatto, Vitor Rosetto Muñoz, Márcia Regina Cominetti and Ana Cláudia Garcia de Oliveira Duarte

Cells 2019, 8(12), 1581; https://doi.org/10.3390/cells8121581 - 6 Dec 2019

Cited by 16 | Viewed by 5459

Abstract

Recent studies have investigated the control of adipose tissue expansion and inflammatory process by microRNAs (miRNAs). These two processes are of great interest because both are associated with obesity and metabolic syndrome. However, despite the great relevance of the role of miRNAs in [...] Read more.

Recent studies have investigated the control of adipose tissue expansion and inflammatory process by microRNAs (miRNAs). These two processes are of great interest because both are associated with obesity and metabolic syndrome. However, despite the great relevance of the role of miRNAs in obesity and adipose tissue, no qualitative and quantitative analysis on the subject has been performed. Thus, we aimed to examine global research activity and current trends with respect to the interaction between obesity, adipose tissue and miRNAs through a bibliometric analysis. This research was performed on the Scopus database for publications containing miRNA, obesity, and adipose tissue keyword combinations. In total, 898 articles were analyzed and the most frequently occurring keywords were selected and clustered into three well-defined groups. As a result, first group of keywords pointed to the research area on miRNAs expressed in obesity-associated diseases. The second group demonstrated the regulation of the adipogenesis process by miRNAs, while the third group highlighted brown adipose tissue and thermogenesis as one of the latest global research trends related to the theme. The studies selected in this paper describe the expression and performance of different miRNAs in obesity and comorbidities. Most studies have focused on identifying miRNAs and signaling pathways associated with obesity, type 2 diabetes mellitus, and cardiovascular disease. Thus, the miRNA profile for these diseases may be used as biomarkers and therapeutic targets in the prevention and treatment of obesity-associated diseases. Full article

(This article belongs to the Special Issue microRNA as Therapeutic Target)

► Show Figures

Figure 1

Journal Menu

Journal Browser

microRNA as Therapeutic Target

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Published Papers (12 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI