Downregulation of Long Noncoding RNA Myocardial Infarction Associated Transcript Suppresses Cell Proliferation, Migration, Invasion, and Glycolysis by Regulation of miR-488-3p/IGF1R Pathway in Colorectal Cancer

LincRNA PRNCR1 activates the Wnt/β-catenin pathway to drive the deterioration of hepatocellular carcinoma via regulating miR-411-3p/ZEB1 axis

Hepatocellular carcinoma (HCC) is an intractable malignant disease with high incidence rate annually. LincRNA PRNCR1 has been confirmed as a tumor supporter, while its functions in HCC remain unclear. This study aims to explore the mechanism of LincRNA PRNCR1 in hepatocellular carcinoma. The qRT-PCR was applied to the quantification of non-coding RNAs. Cell counting Kit-8 (CCK-8), Transwell assay and flow cytometry assay were applied to reflect the change in the phenotype of HCC cells. Moreover, the databases including Targetscan and Starbase and dual-luciferase reporter assay were applied to investigate the interaction of the genes. The western blot was applied to detect the abundance of proteins and the activity of the related pathways. Elevated LincRNA PRNCR1 was dramatically upregulated in HCC pathological samples and cell lines. MiR-411-3p served as a target of LincRNA PRNCR1, and decreased miR-411-3p was found in the clinical samples and cell lines. LincRNA PRNCR1 downregulation could induce the expression of miR-411-3p, and LincRNA PRNCR1 silence could impede the malignant behaviors via increasing the abundance of miR-411-3p. Zinc finger E-box binding homeobox 1 (ZEB1) was confirmed as a target of miR-411-3p, which remarkably upregulated in HCC cells, and ZEB1 upregulation could significantly rescue the effect of miR-411-3p on malignant behaviors of HCC cells. Moreover, LincRNA PRNCR1 was confirmed to involve the Wnt/β-catenin pathway via regulating miR-411-3p/ZEB1 axis. This study suggested that LincRNA PRNCR1 could drive the malignant progression of HCC via regulating miR-411-3p/ZEB1 axis.

Knockdown of long noncoding RNA MIAT attenuates hypoxia-induced cardiomyocyte injury by regulating the miR-488-3p/Wnt/β-catenin pathway

Dysfunction of cardiomyocytes contributes to the development of acute myocardial infarction (AMI). Nonetheless, the regulatory mechanism of lncRNA myocardial infarction-associated transcript (MIAT) in cardiomyocyte injury remains largely unclear. The cardiomyocyte injury was assessed via cell viability and apoptosis using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) and flow cytometry, respectively. The levels of MIAT, microRNA (miR)-488-3p, and Wnt5a were detected via quantitative real-time polymerase chain reaction and Western blot. After bioinformatical analysis, the binding between miR-488-3p and MIAT or Wnt5a was confirmed via dual-luciferase reporter, RNA immunoprecipitation, and RNA pull-down assays. Our results showed that MIAT expression was increased in AC16 cells after hypoxia treatment. Silencing of MIAT alleviated hypoxia-induced viability reduction, apoptosis increase, and Wnt/β-catenin pathway activation. MIAT directly targeted miR-488-3p. MiR-488-3p might repress hypoxia-induced cardiomyocyte injury, and its knockdown reversed the effect of MIAT depletion on cardiomyocyte injury. Wnt5a was validated as a target of miR-488-3p. Wnt5a expression restoration attenuated the influence of MIAT knockdown on hypoxia-triggered cardiomyocyte injury. Our findings demonstrated that downregulation of MIAT might mitigate hypoxia-induced cardiomyocyte injury partly through miR-488-3p mediated Wnt/β-catenin pathway.

Emerging role of non-coding RNAs in glucose metabolic reprogramming and chemoresistance in colorectal cancer

Metabolic reprogramming plays a critical role in colorectal cancer (CRC). It contributes to CRC by shaping metabolic phenotypes and causing uncontrolled proliferation of CRC cells. Glucose metabolic reprogramming is common in carcinogenesis and cancer progression. Growing evidence has implicated the modifying effects of non-coding RNAs (ncRNAs) in glucose metabolic reprogramming and chemoresistance in CRC. In this review, we have summarized currently published studies investigating the role of ncRNAs in glucose metabolic alterations and chemoresistance in CRC. Elucidating the interplay between ncRNAs and glucose metabolic reprogramming provides insight into exploring novel biomarkers for the diagnosis and prognosis prediction of CRC.

miR-488-3p Protects Cardiomyocytes against Doxorubicin-Induced Cardiotoxicity by Inhibiting CyclinG1

Objective

To investigate the protective effects and regulatory mechanism of miR-488-3p on doxorubicin-induced cardiotoxicity.

Methods

The C57BL/6 mice and primary cardiomyocytes were used to construct doxorubicin-induced cardiomyocyte injury models in vivo and in vitro. The levels of miR-488-3p and its downstream target genes were analyzed by quantitative real-time PCR. Mouse cardiac function, cell survival, cellular injury-related proteins, and the apoptosis level of cardiomyocytes were analyzed by echocardiography, MTT analysis, Western blotting, and DNA laddering separately.

Results

Cardiomyocyte injury caused by a variety of stimuli can lead to the reduction of miR-488-3p level, especially when stimulated with doxorubicin. Doxorubicin led to significant decrease in cardiac function, cell autophagic flux blockage, and apoptosis in vivo and in vitro. The expression of miR-488-3p's target gene, CyclinG1, increased remarkably in the doxorubicin-treated neonatal mouse cardiomyocytes. Overexpression of miR-488-3p inhibited CyclinG1 expression, increased cardiomyocyte viability, and attenuated doxorubicin-induced cardiomyocyte autophagic flux blockage and apoptosis.

Conclusions

miR-488-3p is one of the important protective miRNAs in doxorubicin-induced cardiotoxicity by inhibiting the expression of CyclinG1, which provides insight into the possible clinical application of miR-488-3p/CyclinG1 as therapeutic targets in doxorubicin-induced cardiovascular diseases.

Downregulation of MIAT reduces the proliferation and migratory and invasive abilities of retinoblastoma cells by sponging miR-665 and regulating LASP1

Long non-coding RNAs (lncRNAs) can function as onco-lncRNAs in several types of human cancer, including retinoblastoma (Rb). The present study investigated the potential role and regulatory mechanism of the lncRNA myocardial infarction-associated transcript (MIAT) in Rb. To do so, the expression levels of MIAT, microRNA (miR)-665, and LIM and SH3 protein 1 (LASP1) in Rb tissues from patients or Rb cells were analysed using reverse transcription quantitative PCR. The interactions between miR-665 and MIAT/LASP1 were confirmed by the dual-luciferase reporter assay. MTT, Transwell (to assess migration and invasion) and western blotting assays were used to explore the functions of the MIAT/miR-665/LASP1 axis on Rb progression in vitro. The results of the present study indicated that MIAT targeted miR-665. In Rb tissues and cell lines, high expression of MIAT was observed, whereas miR-665 was downregulated in Rb tissues. Furthermore, the proliferation and migratory and invasive abilities of Rb Y79 and HXO-RB44 cells were decreased following MIAT downregulation or miR-665 overexpression. In addition, LASP1 was identified as a target gene of miR-665. Both the decreased expression of miR-665 and the elevated expression of LASP1 reversed the suppressive effects of MIAT knockdown on the proliferation and migratory and invasive abilities of Y79 cells. Furthermore, MIAT silencing attenuated the development of Rb by regulating the miR-665/LASP1 axis. Taken together, these findings suggested that MIAT may be considered as a possible therapeutic target for Rb.

Serum extracellular vesicles containing MIAT induces atrial fibrosis, inflammation and oxidative stress to promote atrial remodeling and atrial fibrillation via blockade of miR-485-5p-mediated CXCL10 inhibition

BACKGROUND

Atrial fibrillation (AF), a supraventricular arrhythmia that impairs cardiac function, is a main source of morbidity and mortality. Serum-derived extracellular vesicles (EVs) have been identified to carry potential biomarker or target for the diagnosis and treatment of AF. We intended to dissect out the role of lncRNA MIAT enriched in serum-derived EVs in AF.

METHODS

MIAT expression was quantified in EVs isolated from serum samples of AF patients. Mouse and cell models of AF were developed after angiotensin II (Ang II) induction. Relationship between MIAT, miR-485-5p, and CXCL10 was identified. Ectopic expression and depletion assays were implemented in Ang II-treated mice or HL-1 cells, or those co-cultured with serum-derived EVs to explore the roles of EV-carried MIAT.

RESULTS

MIAT was upregulated in EVs from serum samples of AF patients. Further analysis indicated that MIAT enriched in serum-derived EVs promoted atrial fibrosis, inflammation and oxidative stress, and aggravated the atrial remodeling and resultant AF. Mechanistically, MIAT bound to miR-485-5p and weakened its inhibitory role on the target CXCL10, which was responsible for the role of serum-derived EV containing MIAT in cellular fibrosis, oxidative stress and inflammation, and atrial remodeling in vivo.

CONCLUSIONS

In conclusion, serum-derived EV containing MIAT facilitates atrial remodeling and exacerbates the AF by abolishing the miR-485-5p-mediated CXCL10 inhibition. This finding aids in the deeper understanding about the pathophysiology of AF.

MicroRNAs as important contributors in the pathogenesis of colorectal cancer

Colorectal cancer (CRC) is the third most fatal and fourth most frequently diagnosed neoplasm in the world. Numerous non-coding RNAs have been shown to contribute in the development of CRC. MicroRNAs (miRNAs) are among the mostly assessed non-coding RNAs in CRC. These transcripts influence expression and activity of TGF-β, Wnt/β-catenin, MAPK, PI3K/AKT and other CRC-related pathways. In the context of CRC, miRNAs interact with long non-coding RNAs to influence CRC course. Stool and serum levels of miRNAs have been used to distinguish CRC patients from healthy controls, indicating diagnostic roles of these transcripts in CRC. Therapeutic application of miRNAs in CRC has been assessed in animal models, yet has not been verified in clinical settings. In the current review, we have provided a recent update on the role of miRNAs in CRC development as well as diagnostic and prognostic approaches.