MiR-20a acted as a ceRNA of lncRNA PTENPL and promoted bladder cancer cell proliferation and migration by regulating PDCD4

Exosome, the glass slipper for Cinderella of cancer-bladder cancer?

Exosomes are lipid bilayer vesicles with a diameter of 40-100 nm secreted by almost all cells. They have been found play crucial regulatory roles in various diseases. With the development of exosomes engineering technology, exosome-based drug delivery has also rapidly evolved. Bladder cancer is a worldwide disease with high morbidity and recurrence but lack of funding, so it is also called Cinderella. Some explorations have demonstrated that exosomes are important in the development, prognosis, diagnosis and drug delivery of bladder cancer. With the rapid development of Mass spectrometry and next-generation sequencing, increasing numbers of differentially expressed molecules derived from exosomes have been found in bladder cancer. Exosomes and their contents are largely involved in bladder cancer progression, engineering of these exosomes with the targeted genes improves their potential for drug delivery of bladder cancer. Furthermore, exosomes and their contents are relate to many characteristics of bladder cancer. Herein, we briefly search 59 researches to explore the cargoes encapsuled in exosomes of bladder cancer patients. We also summarize the biogenesis, function, expression profiles, engineering approaches and biological mechanisms of exosomes and their contents for the diagnosis, prognosis and drug delivery for bladder cancer. We aim to make it clear whether exosomes are the glass slippers of Cinderella.

BMSC-derived exosomal lncRNA PTENP1 suppresses the malignant phenotypes of bladder cancer by upregulating SCARA5 expression

LncRNAs can be transported to tumor cells where they exert regulatory effects by bone marrow mesenchymal stem cells (BMSC)-derived exosomes. Here, we aimed to investigate the functional mechanism of BMSC-derived exosomal lncRNA PTENP1 in the progression of bladder cancer (BC). Methods of BMSC were identified by detecting surface markers through flow cytometry. Exosomes from BMSC were identified by transmission electron microscopy, nanoparticle tracking analysis (NTA), and western blot analysis of exosome markers. Cellular internalization of BMSC-derived exosomes (BMSC-Exo) into BC cells was detected by confocal microscopy. CCK-8, colony formation, flow cytometry, wound healing, and transwell assays were adopted to estimate cell proliferation, apoptosis, migration, and invasion abilities, respectively. Interplay between miR-17 and lncRNA PTENP1 or SCARA5 was verified by dual-luciferase reporter, RNA pull down, and/or RNA immunoprecipitation (RIP) assays. Tumor xenograft assay was conducted in nude mice to study the role of exosomal lncRNA PTENP1 in BC progression in vivo. We showed exosomal lncRNA PTENP1 can be delivered into and suppress the malignant phenotypes of BC cells. LncRNA PTENP1 was identified as a sponge of miR-17, and SCARA5 was identified as a target gene of miR-17. The exosomes derived from PTENP1-overexpressing BMSC (BMSC^OE-PTENP1-Exo) abolished the promotive effects of miR-17 overexpression or SCARA5 knockdown on the malignant phenotypes of BC cells. Moreover, exosomal lncRNA PTENP1 was demonstrated to inhibit BC tumor growth in nude mice by miR-17/SCARA5 axis. In conclusion, BMSC-derived exosomal PTENP1 suppressed the BC progression by upregulating the expression of SCARA5 via sponging miR-17, offering a potential novel therapeutic target for BC therapy.

Identification and verification of the pyroptosis-related prognostic signature and its associated regulatory axis in bladder cancer

Background: Pyroptosis is an inflammatory form of cell death triggered by certain inflammasomes. Accumulating studies have shown the involvement of pyroptosis in the proliferation, invasion, and metastasis and prognosis of cancer. The prognostic value of pyroptosis-related genes (PRGs) and their association with immune infiltration in bladder cancer have not yet been elucidated.

Methods: We performed a comprehensive analysis of the prognostic value and immune infiltrates of PRGs in bladder cancer using the TCGA dataset. qRT-PCR was also performed to verify our result.

Results: Among 33 PRGs, 14 PRGs were upregulated or downregulated in bladder cancer tissue versus normal tissue. We also summarized copy number variations and somatic mutations of PRGs in bladder cancer. By using consensus clustering analysis of PRGs with prognostic significance, we divided the bladder cancer cohort into two subtypes significantly by different prognosis and immune infiltration. Using the LASSO Cox regression analysis, a prognostic signature including six PRGs was constructed for bladder cancer and the patients could be classified into a low- or high-risk group. Interestingly, this prognostic signature had a favorable performance for predicting the prognosis of bladder cancer patients. Moreover, further analysis demonstrated a significant difference in gender, tumor grade, clinical stage, TNM stage, immunoScore, and immune cell infiltration between the high- and low-risk groups in bladder cancer. We also identified an lncRNA SNHG14/miR-20a-5p/CASP8 regulatory axis in bladder cancer by constructing a ceRNA network.

Conclusion: We identified a PRG-associated prognostic signature associated with the prognosis and immune infiltrates for bladder cancer and targeting pyroptosis may be an alternative approach for therapy. Further vivo and vitro experiments are necessary to verify these results.

CircMKLN1 Suppresses the Progression of Human Retinoblastoma by Modulation of miR-425-5p/PDCD4 Axis

Purpose: Circular RNAs (circRNAs) are essential regulators in tumorigenesis and development. In this study, we focused on the functions of circRNA muskelin 1 (circMKLN1) in retinoblastoma (RB) progression.Materials and Methods: Quantitative real-time polymerase chain reaction (qRT-PCR) assay was conducted to determine the levels of circMKLN1, microRNA-425-5p (miR-425-5p) and programmed cell death 4 (PDCD4). The characteristic of circMKLN1 was analyzed using RNase R assay. Cell Counting Kit-8 (CCK-8) assay and colony formation assay were employed to explore cell proliferation ability. The transwell assay was utilized for cell migration and invasion. A Western blot assay was performed for protein levels. The dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were conducted to demonstrate the relationships among circMKLN1, miR-425-5p and PDCD4. Murine xenograft model assay was adopted to investigate the role of circMKLN1 in vivo.Results: CircMKLN1 was downregulated in RB tissues and cells. High levels of circMKLN1 were related to a favorable outcome of RB patients. CircMKLN1 was resistant to RNase R digestion and circMKLN1 overexpression repressed RB cell proliferation, migration and invasion in vitro. MiR-425-5p was identified as the target of circMKLN1 and miR-425-5p elevation reversed the effects of circMKLN1 overexpression on RB cell malignant behaviors. Furthermore, as the target gene of miR-425-5p, PDCD4 silencing could ameliorate the suppressive roles of circMKLN1 in RB cell growth and metastasis. Additionally, circMKLN1 overexpression hampered tumor growth in vivo.Conclusions: CircMKLN1 overexpression decelerated the progression of RB through sponging miR-425-5p and elevating PDCD4.

MicroRNAs Possibly Involved in the Development of Bone Metastasis in Clear-Cell Renal Cell Carcinoma

Simple Summary

Bone metastases cause substantial morbidity and implicate worse clinical outcomes for clear-cell renal cell carcinoma patients. MicroRNAs are small RNA molecules that modulate gene translation and are involved in the development of cancer and metastasis. We identified six microRNAs that are potentially specifically involved in metastasis to bone, of which two seem protective and four implicate a higher risk. This aids further understanding of the process of metastasizing to bone. Furthermore, these microRNA hold potential for biomarkers or therapeutic targets.

Abstract

Bone metastasis in clear-cell renal cell carcinoma (ccRCC) leads to substantial morbidity through skeletal related adverse events and implicates worse clinical outcomes. MicroRNAs (miRNA) are small non-protein coding RNA molecules with important regulatory functions in cancer development and metastasis. In this retrospective analysis we present dysregulated miRNA in ccRCC, which are associated with bone metastasis. In particular, miR-23a-3p, miR-27a-3p, miR-20a-5p, and miR-335-3p specifically correlated with the earlier appearance of bone metastasis, compared to metastasis in other organs. In contrast, miR-30b-3p and miR-139-3p were correlated with less occurrence of bone metastasis. These miRNAs are potential biomarkers and attractive targets for miRNA inhibitors or mimics, which could lead to novel therapeutic possibilities for bone targeted treatment in metastatic ccRCC.

Evaluation of Serum miR-17-92 Cluster as Noninvasive Biomarkers for Bladder Cancer Diagnosis

Previous studies have shown that the miR-17-92 cluster is involved in the occurrence and development of bladder cancer. However, the role of serum miR-17-92 cluster in the diagnosis of bladder cancer has not been studied. In the present study, we evaluated the expression of miR-17-92 cluster members in bladder cancer tissues by analyzing 428 cases from TCGA database. Next, we collected the sera of 74 bladder cancer patients and 90 controls, and used qRT-PCR to detect the relative expression of the cluster. The results showed that the expression of the cluster members in the sera of patients were significantly higher than that of the controls, and they were positively correlated with the clinical stage and pathological grade of the patients. We evaluated their ability to diagnose bladder cancer using ROC, of which miR-92a-3p (AUC = 0.902), miR-17-5p (AUC = 0.845) and miR-20a-5p (AUC = 0.806) were the most prominent. Finally, we established a diagnostic model by logistic regression (AUC = 0.969). We further validated the results of the study using another dataset from the GEO database. Moreover, we evaluated the prognostic value of the cluster. The results revealed that miR-20a-5p was correlated with recurrence of bladder cancer. In summary, the present study validated the overexpression of serum miR-17-92 cluster in bladder cancer. The model composed of the three cluster members were confirmed to be a promising noninvasive biomarker for bladder cancer diagnosis.

Comprehensive Analysis of Long Non-coding RNA-Associated Competing Endogenous RNA Network in Duchenne Muscular Dystrophy

Duchenne muscular dystrophy (DMD) is one of the most severe neuromuscular disorders. Long non-coding RNAs (lncRNAs) are a group of non-coding transcripts, which could regulate messenger RNA (mRNA) by binding the mutual miRNAs, thus acting as competing endogenous RNAs (ceRNAs). So far, the role of lncRNA in DMD pathogenesis remains unclear. In the current study, expression profile from a total of 33 DMD patients and 12 healthy people were downloaded from Gene Expression Omnibus (GEO) database (GSE38417 and GSE109178). Differentially expressed (DE) lncRNAs were discovered and targeted mRNAs were predicted. The ceRNA network of lncRNAs-miRNAs-mRNAs was then constructed. Genome Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses of the putative mRNAs in the ceRNA network were performed through Database for Annotation, Visualization and Integration Discovery (DAVID) website. Topological property of the network was analyzed using Cytoscape to disclose the hub lncRNAs. According to our assessments, 19 common DElncRNAs and 846 common DEmRNAs were identified in DMD compared to controls. The created ceRNA network contained 6 lncRNA nodes, 69 mRNA nodes, 27 miRNA nodes and 102 edges, while four hub lncRNAs (XIST, AL132709, LINC00310, ALDH1L1-AS2) were uncovered. In conclusion, our latest bioinformatic analysis demonstrated that lncRNA is likely involved in DMD. This work highlights the importance of lncRNA and provides new insights for exploring the molecular mechanism of DMD. The created ceRNA network contained 6 lncRNA nodes, 69 mRNA nodes, 27 miRNA nodes and 102 edges, while four hub lncRNAs (XIST, AL132709, LINC00310, ALDH1L1-AS2) were uncovered. Remarkably, KEGG analysis indicated that targeted mRNAs in the network were mainly enriched in "microRNAs in cancer" and "proteoglycans in cancer". Our study may offer novel perspectives on the pathogenesis of DMD from the point of lncRNAs. This work might be also conducive for exploring the molecular mechanism of increased incidence of tumorigenesis reported in DMD patients and experimental models.