Erratum: Skeletal muscle-specific overexpression of miR-486 limits mammary tumor-induced skeletal muscle functional limitations.

[This corrects the article DOI: 10.1016/j.omtn.2022.03.009.].

Skeletal muscle-specific overexpression of miR-486 limits mammary tumor-induced skeletal muscle functional limitations.

miR-486 is a myogenic microRNA, and its reduced skeletal muscle expression is observed in muscular dystrophy. Transgenic overexpression of miR-486 using muscle creatine kinase promoter (MCK-miR-486) partially rescues muscular dystrophy phenotype. We had previously demonstrated reduced circulating and skeletal muscle miR-486 levels with accompanying skeletal muscle defects in mammary tumor models. To determine whether skeletal muscle miR-486 is functionally similar in dystrophies and cancer, we performed functional limitations and biochemical studies of skeletal muscles of MMTV-Neu mice that mimic HER2+ breast cancer and MMTV-PyMT mice that mimic luminal subtype B breast cancer and these mice crossed to MCK-miR-486 mice. miR-486 significantly prevented tumor-induced reduction in muscle contraction force, grip strength, and rotarod performance in MMTV-Neu mice. In this model, miR-486 reversed cancer-induced skeletal muscle changes, including loss of p53, phospho-AKT, and phospho-laminin alpha 2 (LAMA2) and gain of hnRNPA0 and SRSF10 phosphorylation. LAMA2 is a part of the dystrophin-associated glycoprotein complex, and its loss of function causes congenital muscular dystrophy. Complementing these beneficial effects on muscle, miR-486 indirectly reduced tumor growth and improved survival, which is likely due to systemic effects of miR-486 on production of pro-inflammatory cytokines such as IL-6. Thus, similar to dystrophy, miR-486 has the potential to reverse skeletal muscle defects and cancer burden.

hnRNP L is essential for myogenic differentiation and modulates myotonic dystrophy pathologies.

INTRODUCTION: RNA-binding proteins (RBPs) play an important role in skeletal muscle development and disease by regulating RNA splicing. In myotonic dystrophy type 1 (DM1), the RBP MBNL1 (muscleblind-like) is sequestered by toxic CUG repeats, leading to missplicing of MBNL1 targets. Mounting evidence from the literature has implicated other factors in the pathogenesis of DM1. Herein we sought to evaluate the functional role of the splicing factor hnRNP L in normal and DM1 muscle cells. METHODS: Co-immunoprecipitation assays using hnRNPL and MBNL1 expression constructs and splicing profiling in normal and DM1 muscle cell lines were performed. Zebrafish morpholinos targeting hnrpl and hnrnpl2 were injected into one-cell zebrafish for developmental and muscle analysis. In human myoblasts downregulation of hnRNP L was achieved with shRNAi. Ascochlorin administration to DM1 myoblasts was performed and expression of the CUG repeats, DM1 splicing biomarkers, and hnRNP L expression levels were evaluated. RESULTS: Using DM1 patient myoblast cell lines we observed the formation of abnormal hnRNP L nuclear foci within and outside the expanded CUG repeats, suggesting a role for this factor in DM1 pathology. We showed that the antiviral and antitumorigenic isoprenoid compound ascochlorin increased MBNL1 and hnRNP L expression levels. Drug treatment of DM1 muscle cells with ascochlorin partially rescued missplicing of established early biomarkers of DM1 and improved the defective myotube formation displayed by DM1 muscle cells. DISCUSSION: Together, these studies revealed that hnRNP L can modulate DM1 pathologies and is a potential therapeutic target.

Pharmacological ascorbate inhibits pancreatic cancer metastases via a peroxide-mediated mechanism.

Pharmacological ascorbate (P-AscH-, high-dose, intravenous vitamin C) is cytotoxic to tumor cells in doses achievable in humans. Phase I studies in pancreatic cancer (PDAC) utilizing P-AscH- have demonstrated increases in progression free survival, suggesting a reduction in metastatic disease burden. The purpose of this study was to determine the effects of P-AscH- on metastatic PDAC. Several in vitro and in vivo mechanisms involved in PDAC metastases were investigated following treatment with P-AscH-. Serum from PDAC patients in clinical trials with P-AscH- were tested for the presence and quantity of circulating tumor cell-derived nucleases. P-AscH- inhibited invasion, basement membrane degradation, decreased matrix metalloproteinase expression, as well as clonogenic survival and viability during exposure to fluid shear stress. In vivo, P-AscH- significantly decreased formation of ascites, tumor burden over time, circulating tumor cells, and hepatic metastases. Both in vitro and in vivo findings were reversed with the addition of catalase suggesting that the effect of P-AscH- on metastatic disease is mediated by hydrogen peroxide. Finally, P-AscH- decreased CTC-derived nucleases in subjects with stage IV PDAC in a phase I clinical trial. We conclude that P-AscH- attenuates the metastatic potential of PDAC and may prove to be effective for treating advanced disease.

Noggin regulates foregut progenitor cell programming, and misexpression leads to esophageal atresia.

Esophageal atresia (EA/TEF) is a common congenital abnormality present in 1 of 4000 births. Here we show that atretic esophagi lack Noggin (NOG) expression, resulting in immature esophagus that contains respiratory glands. Moreover, when using mouse esophageal organoid units (EOUs) or tracheal organoid units (TOUs) as a model of foregut development and differentiation in vitro, NOG determines whether foregut progenitors differentiate toward esophageal or tracheal epithelium. These results indicate that NOG is a critical regulator of cell fate decisions between esophageal and pulmonary morphogenesis, and its lack of expression results in EA/TEF.

Arachidonate 12-lipoxygenase and 12-hydroxyeicosatetraenoic acid contribute to stromal aging-induced progression of pancreatic cancer.

The incidence of pancreatic cancer increases with age, suggesting that chronological aging is a significant risk factor for this disease. Fibroblasts are the major nonmalignant cell type in the stroma of human pancreatic ductal adenocarcinoma (PDAC). In this study, we investigated whether the chronological aging of normal human fibroblasts (NHFs), a previously underappreciated area in pancreatic cancer research, influences the progression and therapeutic outcomes of PDAC. Results from experiments with murine xenografts and 2D and 3D co-cultures of NHFs and PDAC cells revealed that older NHFs stimulate proliferation of and confer resistance to radiation therapy of PDAC. MS-based metabolite analysis indicated that older NHFs have significantly increased arachidonic acid 12-lipoxygenase (ALOX12) expression and elevated levels of its mitogenic metabolite, 12-(S)-hydroxy-5,8,10,14-eicosatetraenoic acid (12-(S)-HETE) compared with their younger counterparts. In co-cultures with older rather than with younger NHFs, PDAC cells exhibited increases in mitogen-activated protein kinase signaling and cellular metabolism, as well as a lower oxidation state that correlated with their enhanced proliferation and resistance to radiation therapy. Expression of ALOX12 was found to be significantly lower in PDAC cell lines and tumor biopsies, suggesting that PDAC cells rely on a stromal supply of mitogens for their proliferative needs. Pharmacological (hydroxytyrosol) and molecular (siRNA) interventions of ALOX12 in older NHFs suppressed their ability to stimulate proliferation of PDAC cells. We conclude that chronological aging of NHFs contributes to PDAC progression and that ALOX12 and 12-(S)-HETE may be potential stromal targets for interventions that seek to halt progression and improve therapy outcomes.

Dual Oxidase-Induced Sustained Generation of Hydrogen Peroxide Contributes to Pharmacologic Ascorbate-Induced Cytotoxicity.

Pharmacologic ascorbate treatment (P-AscH-, high-dose, intravenous vitamin C) results in a transient short-term increase in the flux of hydrogen peroxide that is preferentially cytotoxic to cancer cells versus normal cells. This study examines whether an increase in hydrogen peroxide is sustained posttreatment and potential mechanisms involved in this process. Cellular bioenergetic profiling following treatment with P-AscH- was examined in tumorigenic and nontumorigenic cells. P-AscH- resulted in sustained increases in the rate of cellular oxygen consumption (OCR) and reactive oxygen species (ROS) in tumor cells, with no changes in nontumorigenic cells. Sources for this increase in ROS and OCR were DUOX 1 and 2, which are silenced in pancreatic ductal adenocarcinoma, but upregulated with P-AscH- treatment. An inducible catalase system, to test causality for the role of hydrogen peroxide, reversed the P-AscH--induced increases in DUOX, whereas DUOX inhibition partially rescued P-AscH--induced toxicity. In addition, DUOX was significantly downregulated in pancreatic cancer specimens compared with normal pancreas tissues. Together, these results suggest that P-AscH--induced toxicity may be enhanced by late metabolic shifts in tumor cells, resulting in a feed-forward mechanism for generation of hydrogen peroxide and induction of metabolic stress through enhanced DUOX expression and rate of oxygen consumption. SIGNIFICANCE: A high dose of vitamin C, in addition to delivering an acute exposure of H2O2 to tumor cells, activates DUOX in pancreatic cancer cells, which provide sustained production of H2O2.

The SINE Compound KPT-350 Blocks Dystrophic Pathologies in DMD Zebrafish and Mice.

Duchenne muscular dystrophy (DMD) is an X-linked muscle wasting disease that is caused by the loss of functional dystrophin protein in cardiac and skeletal muscles. DMD patient muscles become weakened, leading to eventual myofiber breakdown and replacement with fibrotic and adipose tissues. Inflammation drives the pathogenic processes through releasing inflammatory cytokines and other factors that promote skeletal muscle degeneration and contributing to the loss of motor function. Selective inhibitors of nuclear export (SINEs) are a class of compounds that function by inhibiting the nuclear export protein exportin 1 (XPO1). The XPO1 protein is an important regulator of key inflammatory and neurological factors that drive inflammation and neurotoxicity in various neurological and neuromuscular diseases. Here, we demonstrate that SINE compound KPT-350 can ameliorate dystrophic-associated pathologies in the muscles of DMD models of zebrafish and mice. Thus, SINE compounds are a promising novel strategy for blocking dystrophic symptoms and could be used in combinatorial treatments for DMD.

Enhanced Pharmacological Ascorbate Oxidation Radiosensitizes Pancreatic Cancer.

Pharmacologic ascorbate (P-AscH-) is emerging as a promising adjuvant for advanced pancreatic cancer. P-AscH- generates hydrogen peroxide (H2O2), leading to selective cancer cell cytotoxicity. Catalytic manganoporphyrins, such as MnT4MPyP, can increase the rate of oxidation of P-AscH-, thereby increasing the flux of H2O2, resulting in increased cytotoxicity. We hypothesized that a multimodal treatment approach, utilizing a combination of P-AscH-, ionizing radiation and MnT4MPyP, would result in significant flux of H2O2 and pancreatic cancer cytotoxicity. P-AscH- with MnT4MPyP increased the rate of oxidation of P-AscH- and produced radiosensitization in all pancreatic cancer cell lines tested. Three-dimensional (3D) cell cultures demonstrated resistance to P-AscH-, radiation or MnT4MPyP treatments alone; however, combined treatment with P-AscH- and MnT4MPyP resulted in the inhibition of tumor growth, particularly when also combined with radiation. In vivo experiments using a murine model demonstrated an increased rate of ascorbate oxidation when combinations of P-AscH- with MnT4MPyP were given, thus acting as a radiosensitizer. The translational potential was demonstrated by measuring increased ascorbate oxidation ex vivo, whereby MnT4MPyP was added exogenously to plasma samples from patients treated with P-AscH- and radiation. Combination treatment utilizing P-AscH-, manganoporphyrin and radiation results in significant cytotoxicity secondary to enhanced ascorbate oxidation and an increased flux of H2O2. This multimodal approach has the potential to be an effective treatment for pancreatic ductal adenocarcinoma.

Pharmacological Ascorbate as a Means of Sensitizing Cancer Cells to Radio-Chemotherapy While Protecting Normal Tissue.

Chemoradiation has remained the standard of care treatment for many of the most aggressive cancers. However, despite effective toxicity to cancer cells, current chemoradiation regimens are limited in efficacy due to significant normal cell toxicity. Thus, efforts have been made to identify agents demonstrating selective toxicity, whereby treatments simultaneously sensitize cancer cells to protect normal cells from chemoradiation. Pharmacological ascorbate (intravenous infusions of vitamin C resulting in plasma ascorbate concentrations ≥20 mM; P-AscH-) has demonstrated selective toxicity in a variety of preclinical tumor models and is currently being assessed as an adjuvant to standard-of-care therapies in several early phase clinical trials. This review summarizes the most current preclinical and clinical data available demonstrating the multidimensional role of P-AscH- in cancer therapy including: selective toxicity to cancer cells via a hydrogen peroxide (H2O2)-mediated mechanism; action as a sensitizing agent of cancer cells to chemoradiation; a protectant of normal tissues exposed to chemoradiation; and its safety and tolerability in clinical trials.

A limb-girdle muscular dystrophy 2I model of muscular dystrophy identifies corrective drug compounds for dystroglycanopathies.

Zebrafish are a powerful tool for studying muscle function owing to their high numbers of offspring, low maintenance costs, evolutionarily conserved muscle functions, and the ability to rapidly take up small molecular compounds during early larval stages. Fukutin-related protein (FKRP) is a putative protein glycosyltransferase that functions in the Golgi apparatus to modify sugar chain molecules of newly translated proteins. Patients with mutations in the FKRP gene can have a wide spectrum of clinical symptoms with varying muscle, eye, and brain pathologies depending on the location of the mutation in the FKRP protein. Patients with a common L276I FKRP mutation have mild adult-onset muscle degeneration known as limb-girdle muscular dystrophy 2I (LGMD2I), whereas patients with more C-terminal pathogenic mutations develop the severe Walker-Warburg syndrome (WWS)/muscle-eye-brain (MEB) disease. We generated fkrp-mutant zebrafish that phenocopy WWS/MEB pathologies including severe muscle breakdowns, head malformations, and early lethality. We have also generated a milder LGMD2I-model zebrafish via overexpression of a heat shock-inducible human FKRP (L276I) transgene that shows milder muscle pathology. Screening of an FDA-approved drug compound library in the LGMD2I zebrafish revealed a strong propensity towards steroids, antibacterials, and calcium regulators in ameliorating FKRP-dependent pathologies. Together, these studies demonstrate the utility of the zebrafish to both study human-specific FKRP mutations and perform compound library screenings for corrective drug compounds to treat muscular dystrophies.

Pharmacologic Ascorbate Reduces Radiation-Induced Normal Tissue Toxicity and Enhances Tumor Radiosensitization in Pancreatic Cancer.

: Chemoradiation therapy is the mainstay for treatment of locally advanced, borderline resectable pancreatic cancer. Pharmacologic ascorbate (P-AscH-, i.e., intravenous infusions of ascorbic acid, vitamin C), but not oral ascorbate, produces high plasma concentrations capable of selective cytotoxicity to tumor cells. In doses achievable in humans, P-AscH- decreases the viability and proliferative capacity of pancreatic cancer via a hydrogen peroxide (H2O2)-mediated mechanism. In this study, we demonstrate that P-AscH- radiosensitizes pancreatic cancer cells but inhibits radiation-induced damage to normal cells. Specifically, radiation-induced decreases in clonogenic survival and double-stranded DNA breaks in tumor cells, but not in normal cells, were enhanced by P-AscH-, while radiation-induced intestinal damage, collagen deposition, and oxidative stress were also reduced with P-AscH- in normal tissue. We also report on our first-in-human phase I trial that infused P-AscH- during the radiotherapy "beam on." Specifically, treatment with P-AscH- increased median overall survival compared with our institutional average (21.7 vs. 12.7 months, P = 0.08) and the E4201 trial (21.7 vs. 11.1 months). Progression-free survival in P-AscH--treated subjects was also greater than our institutional average (13.7 vs. 4.6 months, P < 0.05) and the E4201 trial (6.0 months). Results indicated that P-AscH- in combination with gemcitabine and radiotherapy for locally advanced pancreatic adenocarcinoma is safe and well tolerated with suggestions of efficacy. Because of the potential effect size and minimal toxicity, our findings suggest that investigation of P-AscH- efficacy is warranted in a phase II clinical trial. SIGNIFICANCE: These findings demonstrate that pharmacologic ascorbate enhances pancreatic tumor cell radiation cytotoxicity in addition to offering potential protection from radiation damage in normal surrounding tissue, making it an optimal agent for improving treatment of locally advanced pancreatic adenocarcinoma.

Pharmacologic ascorbate (P-AscH-) suppresses hypoxia-inducible Factor-1α (HIF-1α) in pancreatic adenocarcinoma.

HIF-1α is a transcriptional regulator that functions in the adaptation of cells to hypoxic conditions; it strongly impacts the prognosis of patients with cancer. High-dose, intravenous, pharmacological ascorbate (P-AscH-), induces cytotoxicity and oxidative stress selectively in cancer cells by acting as a pro-drug for the delivery of hydrogen peroxide (H2O2); early clinical data suggest improved survival and inhibition of metastasis in patients being actively treated with P-AscH-. Previous studies have demonstrated that activation of HIF-1α is necessary for P-AscH- sensitivity. We hypothesized that pancreatic cancer (PDAC) progression and metastasis could be be targeted by P-AscH- via H2O2-mediated inhibition of HIF-1α stabilization. Our study demonstrates an oxygen- and prolyl hydroxylase-independent regulation of HIF-1α by P-AscH-. Additionally, P-AscH- decreased VEGF secretion in a dose-dependent manner that was reversible with catalase, consistent with an H2O2-mediated mechanism. Pharmacological and genetic manipulations of HIF-1α did not alter P-AscH--induced cytotoxicity. In vivo, P-AscH- inhibited tumor growth and VEGF expression. We conclude that P-AscH- suppresses the levels of HIF-1α protein in hypoxic conditions through a post-translational mechanism. These findings suggest potential new therapies specifically designed to inhibit the mechanisms that drive metastases as a part of PDAC treatment.

A model for the detection of pancreatic ductal adenocarcinoma circulating tumor cells.

Metastatic disease is the leading cause of pancreatic ductal adenocarcinoma (PDAC) associated death. PDAC cells invade and enter the bloodstream early, before frank malignancy can be detected. Our objective was to develop an in vivo assay enabling the identification and quantification of circulating tumor cells (CTCs) from primary orthotopic PDAC tumors. Human PDAC cells expressing luciferase and green fluorescent protein were orthotopically injected into the pancreas of mice utilizing ultrasound guidance. Bioluminescent imaging was conducted to identify and track tumor growth. CTCs were then isolated and analyzed by flow cytometry to detect GFP-expressing cancer cells. Tumor growth as measured by bioluminescent imaging increased over time. The concentration of CTCs correlated with the strength of bioluminescent imaging signal. In addition, livers bearing macroscopic disease were harvested for further imaging under fluorescence stereomicroscopy and confocal microscopy, which confirmed the presence of metastases. This study represents an orthotopic animal model that reliably detects the presence of CTCs from PDAC. There is a positive correlation between the concentrations of CTCs with overall tumor burden.

Superoxide Dismutases in Pancreatic Cancer.

The incidence of pancreatic cancer is increasing as the population ages but treatment advancements continue to lag far behind. The majority of pancreatic cancer patients have a K-ras oncogene mutation causing a shift in the redox state of the cell, favoring malignant proliferation. This mutation is believed to lead to nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation and superoxide overproduction, generating tumorigenic behavior. Superoxide dismutases (SODs) have been studied for their ability to manage the oxidative state of the cell by dismuting superoxide and inhibiting signals for pancreatic cancer growth. In particular, manganese superoxide dismutase has clearly shown importance in cell cycle regulation and has been found to be abnormally low in pancreatic cancer cells as well as the surrounding stromal tissue. Likewise, extracellular superoxide dismutase expression seems to favor suppression of pancreatic cancer growth. With an increased understanding of the redox behavior of pancreatic cancer and key regulators, new treatments are being developed with specific targets in mind. This review summarizes what is known about superoxide dismutases in pancreatic cancer and the most current treatment strategies to be advanced from this knowledge.

The NOTCH1/SNAIL1/MEF2C Pathway Regulates Growth and Self-Renewal in Embryonal Rhabdomyosarcoma.

Tumor-propagating cells (TPCs) share self-renewal properties with normal stem cells and drive continued tumor growth. However, mechanisms regulating TPC self-renewal are largely unknown, especially in embryonal rhabdomyosarcoma (ERMS)-a common pediatric cancer of muscle. Here, we used a zebrafish transgenic model of ERMS to identify a role for intracellular NOTCH1 (ICN1) in increasing TPCs by 23-fold. ICN1 expanded TPCs by enabling the de-differentiation of zebrafish ERMS cells into self-renewing myf5+ TPCs, breaking the rigid differentiation hierarchies reported in normal muscle. ICN1 also had conserved roles in regulating human ERMS self-renewal and growth. Mechanistically, ICN1 upregulated expression of SNAIL1, a transcriptional repressor, to increase TPC number in human ERMS and to block muscle differentiation through suppressing MEF2C, a myogenic differentiation transcription factor. Our data implicate the NOTCH1/SNAI1/MEF2C signaling axis as a major determinant of TPC self-renewal and differentiation in ERMS, raising hope of therapeutically targeting this pathway in the future.

Repression of phosphatidylinositol transfer protein α ameliorates the pathology of Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is a progressive muscle wasting disease caused by X-linked inherited mutations in the DYSTROPHIN (DMD) gene. Absence of dystrophin protein from the sarcolemma causes severe muscle degeneration, fibrosis, and inflammation, ultimately leading to cardiorespiratory failure and premature death. Although there are several promising strategies under investigation to restore dystrophin protein expression, there is currently no cure for DMD, and identification of genetic modifiers as potential targets represents an alternative therapeutic strategy. In a Brazilian golden retriever muscular dystrophy (GRMD) dog colony, two related dogs demonstrated strikingly mild dystrophic phenotypes compared with those typically observed in severely affected GRMD dogs despite lacking dystrophin. Microarray analysis of these "escaper" dogs revealed reduced expression of phosphatidylinositol transfer protein-α (PITPNA) in escaper versus severely affected GRMD dogs. Based on these findings, we decided to pursue investigation of modulation of PITPNA expression on dystrophic pathology in GRMD dogs, dystrophin-deficient sapje zebrafish, and human DMD myogenic cells. In GRMD dogs, decreased expression of Pitpna was associated with increased phosphorylated Akt (pAkt) expression and decreased PTEN levels. PITPNA knockdown by injection of morpholino oligonucleotides in sapje zebrafish also increased pAkt, rescued the abnormal muscle phenotype, and improved long-term sapje mutant survival. In DMD myotubes, PITPNA knockdown by lentiviral shRNA increased pAkt and increased myoblast fusion index. Overall, our findings suggest PIPTNA as a disease modifier that accords benefits to the abnormal signaling, morphology, and function of dystrophic skeletal muscle, and may be a target for DMD and related neuromuscular diseases.

CD82 Is a Marker for Prospective Isolation of Human Muscle Satellite Cells and Is Linked to Muscular Dystrophies.

Cell-surface markers for prospective isolation of stem cells from human skeletal muscle have been difficult to identify. Such markers would be powerful tools for studying satellite cell function during homeostasis and in pathogenesis of diseases such as muscular dystrophies. In this study, we show that the tetraspanin KAI/CD82 is an excellent marker for prospectively isolating stem cells from human fetal and adult skeletal muscle. Human CD82+ muscle cells robustly engraft into a mouse model of muscular dystrophy. shRNA knockdown of CD82 in myogenic cells reduces myoblast proliferation, suggesting it is functionally involved in muscle homeostasis. CD82 physically interacts with alpha7beta1 integrin (α7ß1-ITG) and with α-sarcoglycan, a member of the Dystrophin-Associated Glycoprotein Complex (DAPC), both of which have been linked to muscular dystrophies. Consistently, CD82 expression is decreased in Duchenne muscular dystrophy patients. Together, these findings suggest that CD82 function may be important for muscle stem cell function in muscular disorders.

Skeletal Muscle MicroRNAs: Their Diagnostic and Therapeutic Potential in Human Muscle Diseases.

MicroRNAs (miRNAs) are small 21-24 nucleotide RNAs that are capable of regulating multiple signaling pathways across multiple tissues. MicroRNAs are dynamically regulated and change in expression levels during periods of early development, tissue regeneration, cancer, and various other disease states. Recently, microRNAs have been isolated from whole serum and muscle biopsies to identify unique diagnostic signatures for specific neuromuscular disease states. Functional studies of microRNAs in cell lines and animal models of neuromuscular diseases have elucidated their importance in contributing to neuromuscular disease progression and pathologies. The ability of microRNAs to alter the expression of an entire signaling pathway opens up their unique ability to be used as potential therapeutic entry points for the treatment of disease. Here, we will review the recent findings of key microRNAs and their dysregulation in various neuromuscular diseases. Additionally, we will highlight the current strategies being used to regulate the expression of key microRNAs as they have become important players in the clinical treatment of some of the neuromuscular diseases.