Upregulation of miR181a/miR212 Improves Myogenic Commitment in Murine Fusion-Negative Rhabdomyosarcoma

Comprehensive Analysis of Tumor Microenvironment Reveals Prognostic ceRNA Network Related to Immune Infiltration in Sarcoma

PURPOSE

Sarcoma is the second most common solid tumor type in children and adolescents. The high level of tumor heterogeneity as well as aggressive behavior of sarcomas brings serious difficulties to developing effective therapeutic strategies for clinical application. Therefore, it is of great importance to identify accurate biomarkers for early detection and prognostic prediction of sarcomas.

EXPERIMENTAL DESIGN

In this study, we characterized three subtypes of sarcomas based on tumor immune infiltration levels (TIIL), and constructed a prognosis-related competing endogenous RNA (ceRNA) network to investigate molecular regulations in the sarcoma tumor microenvironment (TME). We further built a subnetwork consisting of mRNAs and lncRNAs that are targets of key miRNAs and strongly correlated with each other in the ceRNA network. After validation using public data and experiments in vivo and in vitro, we deeply dug the biological role of the miRNAs and lncRNAs in a subnetwork and their impact on TME.

RESULTS

Altogether, 5 miRNAs (hsa-mir-125b-2, hsa-mir-135a-1, hsa-mir92a-2, hsa-mir-181a-2, and hsa-mir-214), 3 lncRNAs (LINC00641, LINC01146, and LINC00892), and 10 mRNAs (AGO2, CXCL10, CD86, CASP1, IKZF1, CD27, CD247, CD69, CCR2, and CSF2RB) in the subnetwork were identified as vital regulators to shape the TME. On the basis of the systematic network, we identified that trichostatin A, a pan-HDAC inhibitor, could potentially regulate the TME of sarcoma, thereby inhibiting the tumor growth.

CONCLUSIONS

Our study identifies a ceRNA network as a promising biomarker for sarcoma. This system provides a more comprehensive understanding and a novel perspective of how ceRNAs are involved in shaping sarcoma TME.

Non-coding RNA in rhabdomyosarcoma progression and metastasis

Rhabdomyosarcoma (RMS) is a soft tissue sarcoma of skeletal muscle differentiation, with a predominant occurrence in children and adolescents. One of the major challenges facing treatment success is the presence of metastatic disease at the time of diagnosis, commonly associated with the more aggressive fusion-positive subtype. Non-coding RNA (ncRNA) can regulate gene transcription and translation, and their dysregulation has been associated with cancer development and progression. MicroRNA (miRNA) are short non-coding nucleic acid sequences involved in the regulation of gene expression that act by targeting messenger RNA (mRNA), and their aberrant expression has been associated with both RMS initiation and progression. Other ncRNA including long non-coding RNA (lncRNA), circular RNA (circRNA) and ribosomal RNA (rRNA) have also been associated with RMS revealing important mechanistic roles in RMS biology, but these studies are still limited and require further investigation. In this review, we discuss the established roles of ncRNA in RMS differentiation, growth and progression, highlighting their potential use in RMS prognosis, as therapeutic agents or as targets of treatment.

Suppression of microRNA 124-3p and microRNA 340-5p ameliorates retinoic acid-induced cleft palate in mice

The etiology of cleft lip with or without cleft palate (CL/P), a common congenital birth defect, is complex, with genetic and epigenetic, as well as environmental, contributing factors. Recent studies suggest that fetal development is affected by maternal conditions through microRNAs (miRNAs), a group of short noncoding RNAs. Here, we show that miR-129-5p and miR-340-5p suppress cell proliferation in both primary mouse embryonic palatal mesenchymal cells and O9-1 cells, a neural crest cell line, through the regulation of Sox5 and Trp53 by miR-129-5p, and the regulation of Chd7, Fign and Tgfbr1 by miR-340-5p. Notably, miR-340-5p, but not miR-129-5p, was upregulated following all-trans retinoic acid (atRA; tretinoin) administration, and a miR-340-5p inhibitor rescued the cleft palate (CP) phenotype in 47% of atRA-induced CP mice. We have previously reported that a miR-124-3p inhibitor can also partially rescue the CP phenotype in atRA-induced CP mouse model. In this study, we found that a cocktail of miR-124-3p and miR-340-5p inhibitors rescued atRA-induced CP with almost complete penetrance. Taken together, our results suggest that normalization of pathological miRNA expression can be a preventive intervention for CP.

Therapeutic Implications of miRNAs for Muscle-Wasting Conditions

MicroRNAs (miRNAs) are small, non-coding RNA molecules that are mainly involved in translational repression by binding to specific messenger RNAs. Recently, miRNAs have emerged as biomarkers, relevant for a multitude of pathophysiological conditions, and cells can selectively sort miRNAs into extracellular vesicles for paracrine and endocrine effects. In the overall context of muscle-wasting conditions, a multitude of miRNAs has been implied as being responsible for the typical dysregulation of anabolic and catabolic pathways. In general, chronic muscle disorders are associated with the main characteristic of a substantial loss in muscle mass. Muscular dystrophies (MDs) are a group of genetic diseases that cause muscle weakness and degeneration. Typically, MDs are caused by mutations in those genes responsible for upholding the integrity of muscle structure and function. Recently, the dysregulation of miRNA levels in such pathological conditions has been reported. This revelation is imperative for both MDs and other muscle-wasting conditions, such as sarcopenia and cancer cachexia. The expression levels of miRNAs have immense potential for use as potential diagnostic, prognostic and therapeutic biomarkers. Understanding the role of miRNAs in muscle-wasting conditions may lead to the development of novel strategies for the improvement of patient management.