MiR-3175 promotes epithelial-mesenchymal transition by targeting Smad7 in human conjunctiva and pterygium

Gallic acid attenuates metastatic potential of human colorectal cancer cells through the miR-1247-3p-modulated integrin/FAK axis

Colorectal cancer (CRC) exhibits highly metastatic potential even in the early stages of tumor progression. Gallic acid (GA), a common phenolic compound in plants, is known to possess potent antioxidant and anticancer activities, thereby inducing cell death or cell cycle arrest. However, whether GA reduces the invasiveness of CRC cells without inducing cell death remains unclear. Herein, we aimed to investigate the antimetastatic activity of low-dose GA on CRC cells and determine its underlying mechanism. Cell viability and tumorigenicity were analyzed by MTS, cell adhesion, and colony formation assay. Invasiveness was demonstrated using migration and invasion assays. Changes in protein phosphorylation and expression were assessed by Western blot. The involvement of microRNAs was validated by microarray analysis and anti-miR antagonist. Our findings showed that lower dose of GA (≤100 μM) did not affect cell viability but reduced the capabilities of colony formation, cell adhesion, and invasiveness in CRC cells. Cellularly, GA downregulated the cellular level of integrin αV/β3, talin-1, and tensin and diminished the phosphorylated FAK, paxillin, Src, and AKT in DLD-1 cells. Microarray results revealed that GA increased miR-1247-3p expression, and pretreatment of anti-miR antagonist against miR-1247-3p restored the GA-reduced integrin αV/β3 and the GA-inhibited paxillin activation in DLD-1 cells. Consistently, the in vivo xenograft model showed that GA administration inhibited tumor growth and liver metastasis derived from DLD-1 cells. Collectively, our findings indicated that GA inhibited the metastatic capabilities of CRC cells, which may result from the suppression of integrin/FAK axis mediated by miR1247-3p.

Single-cell RNA sequencing reveals the complex cellular niche of pterygium

PURPOSE

Pterygium is a vision-threatening conjunctival fibrovascular degenerated disease with a high global prevalence up to 12 %, while no absolute pharmacotherapy has been applied in clinics. In virtue of single-cell RNA sequencing (scRNA-seq) technique, our study investigated underlying pathogeneses and potential therapeutic targets of pterygium from the cellular transcriptional level.

METHODS

A total of 45605 cells from pterygium of patients and conjunctiva of normal controls (NC) were conducted with scRNA-seq, and then analyzed via integrated analysis, pathway enrichment, pseudotime trajectory, and cell-cell communications. Besides, immunofluorescence and western blot were performed in vivo and in vitro to verify our findings.

RESULTS

In brief, 9 major cellular types were defined, according to canonical markers. Subsequently, we further determined the subgroups of each major cell lineages. Several newly identified cell sub-clusters could promote pterygium, including immuno-fibroblasts, epithelial mesenchymal transition (EMT)-epithelial cells, and activated vascular endothelial cells (activated-vEndo). Besides, we also probed the enrichment of immune cells in pterygium. Particularly, macrophages, recruited by ACKR1+activated-vEndo, might play an important role in the development of pterygium by promoting angiogenesis, immune suppression, and inflammation.

CONCLUSION

An intricate cellular niche was revealed in pterygium via scRNA-seq analysis and the interactions between macrophages and ACKR1+ activated-vEndo might be the key part in the development of pterygia.

Recent insights into the microRNA-dependent modulation of gliomas from pathogenesis to diagnosis and treatment

Gliomas are the most lethal primary brain tumors in adults. These highly invasive tumors have poor 5-year survival for patients. Gliomas are principally characterized by rapid diffusion as well as high levels of cellular heterogeneity. However, to date, the exact pathogenic mechanisms, contributing to gliomas remain ambiguous. MicroRNAs (miRNAs), as small noncoding RNAs of about 20 nucleotides in length, are known as chief modulators of different biological processes at both transcriptional and posttranscriptional levels. More recently, it has been revealed that these noncoding RNA molecules have essential roles in tumorigenesis and progression of multiple cancers, including gliomas. Interestingly, miRNAs are able to modulate diverse cancer-related processes such as cell proliferation and apoptosis, invasion and migration, differentiation and stemness, angiogenesis, and drug resistance; thus, impaired miRNAs may result in deterioration of gliomas. Additionally, miRNAs can be secreted into cerebrospinal fluid (CSF), as well as the bloodstream, and transported between normal and tumor cells freely or by exosomes, converting them into potential diagnostic and/or prognostic biomarkers for gliomas. They would also be great therapeutic agents, especially if they could cross the blood–brain barrier (BBB). Accordingly, in the current review, the contribution of miRNAs to glioma pathogenesis is first discussed, then their glioma-related diagnostic/prognostic and therapeutic potential is highlighted briefly.

Peripheral blood circular RNA hsa_circ_0058493 as a potential novel biomarker for silicosis and idiopathic pulmonary fibrosis

Existing studies reported that some circular RNAs (circRNAs) play vital roles in the development of pulmonary fibrosis. However, few studies explored the biomarker potential of circRNAs for pulmonary fibrosis based on population data. Therefore, we aimed to identify peripheral blood circRNAs as potential biomarkers for diagnosing silicosis and idiopathic pulmonary fibrosis (IPF). In brief, an RNA-seq screening based on 4 silicosis cases and 4 controls was initially performed. Differentially expressed circRNAs were combined with the human serum circRNA dataset to identify overlapping serum-detectable circRNAs, followed by validation using the GEO dataset (3 IPF cases and 3 controls) and subsequent qRT-PCR, including 84 additional individuals. Following the above steps, 243 differentially expressed circRNAs were identified during the screening stage, with fold changes ≥ 1.5 and P < 0.05. Of note, the human serum circRNA dataset encompassed 28 of 243 circRNAs. GEO (GSE102660) validation revealed two highly expressed circRNAs (P < 0.05) in the IPF case group. Furthermore, at the enlarged sample validation stage, hsa_circ_0058493 was highly expressed in both silicosis and IPF cases (silicosis: P = 1.16 × 10^-6; IPF: P = 7.46 × 10^-5). Additionally, hsa_circ_0058493 expression was significantly increased in MRC-5 cells upon TGF-β1 treatment, while hsa_circ_0058493 knockdown inhibited the expression of fibrotic molecules by affecting the epithelial-mesenchymal transition process. These shreds of evidence indicated that hsa_circ_0058493 might serve as a novel biomarker for diagnosing silicosis and IPF.

DCAF1-targeting microRNA-3175 activates Nrf2 signaling and inhibits dexamethasone-induced oxidative injury in human osteoblasts

Activation of nuclear-factor-E2-related factor 2 (Nrf2) signaling can protect human osteoblasts from dexamethasone-induced oxidative injury. DDB1 and CUL4 associated factor 1 (DCAF1) is a novel ubiquitin E3 ligase for Nrf2 protein degradation. We identified a novel DCAF1-targeting miRNA, miR-3175. RNA pull-down, Argonaute 2 RNA-immunoprecipitation, and RNA fluorescent in situ hybridization results confirmed a direct binding between miR-3175 and DCAF1 mRNA in primary human osteoblasts. DCAF1 3′-untranslated region luciferase activity and its expression were significantly decreased after miR-3175 overexpression but were augmented with miR-3175 inhibition in human osteoblasts and hFOB1.19 osteoblastic cells. miR-3175 overexpression activated Nrf2 signaling, causing Nrf2 protein stabilization, antioxidant response (ARE) activity increase, and transcription activation of Nrf2-dependent genes in human osteoblasts and hFOB1.19 cells. Furthermore, dexamethasone-induced oxidative injury and apoptosis were largely attenuated by miR-3175 overexpression in human osteoblasts and hFOB1.19 cells. Importantly, shRNA-induced silencing or CRISPR/Cas9-mediated Nrf2 knockout abolished miR-3175 overexpression-induced osteoblast cytoprotection against dexamethasone. Conversely, DFAC1 knockout, by the CRISPR/Cas9 method, activated the Nrf2 cascade and inhibited dexamethasone-induced cytotoxicity in hFOB1.19 cells. Importantly, miR-3175 expression was decreased in necrotic femoral head tissues of dexamethasone-taking patients, where DCAF1 mRNA was upregulated. Together, silencing DCAF1 by miR-3175 activated Nrf2 signaling to inhibit dexamethasone-induced oxidative injury and apoptosis in human osteoblasts.

Current perspectives on inhibitory SMAD7 in health and disease

Transforming growth factor β (TGF-β) family members play an extensive role in cellular communication that orchestrates both early development and adult tissue homeostasis. Aberrant TGF-β family signaling is associated with a pathological outcome in numerous diseases, and in-depth understanding of molecular and cellular processes could result in therapeutic benefit for patients. Canonical TGF-β signaling is mediated by receptor-regulated SMADs (R-SMADs), a single co-mediator SMAD (Co-SMAD), and inhibitory SMADs (I-SMADs). SMAD7, one of the I-SMADs, is an essential negative regulator of the pleiotropic TGF-β and bone morphogenetic protein (BMP) signaling pathways. In a negative feedback loop, SMAD7 inhibits TGF-β signaling by providing competition for TGF-β type-1 receptor (TβRI), blocking phosphorylation and activation of SMAD2. Moreover, SMAD7 recruits E3 ubiquitin SMURF ligases to the type I receptor to promote ubiquitin-mediated proteasomal degradation. In addition to its role in TGF-β and BMP signaling, SMAD7 is regulated by and implicated in a variety of other signaling pathways and functions as a mediator of crosstalk. This review is focused on SMAD7, its function in TGF-β and BMP signaling, and its role as a downstream integrator and crosstalk mediator. This crucial signaling molecule is tightly regulated by various mechanisms. We provide an overview of the ways by which SMAD7 is regulated, including noncoding RNAs (ncRNAs) and post-translational modifications (PTMs). Finally, we discuss its role in diseases, such as cancer, fibrosis, and inflammatory bowel disease (IBD).

Silencing of microRNA-3175 represses cell proliferation and invasion in prostate cancer by targeting the potential tumor-suppressor SCN4B

MicroRNA-3175 (miR-3175) expression is upregulated in prostate cancer, but its roles and the underlying mechanisms in prostate cancer cell growth and invasion need to be elucidated. This study aimed to uncover the roles of miR-3175 in regulating cell growth and migration, as well as the expression of its predicted target gene cardiac sodium channel β4-subunit gene (SCN4B). Real-time quantitative PCR (RT-qPCR) and/or western blotting techniques were used to measure miR-3175 and SCN4B expression levels in prostate cancer cells. Inhibitor or mimics transfections were used to overexpress or silence miR-3175 in prostate cancer cells. MTT and Edu assays were applied to assess cell viability. Scratch assay and transwell chambers were used to examine cell migration and invasion abilities. The interaction between miR-3175 and SCN4B was determined by means of luciferase gene reporter, RT-qPCR, and western blotting assays. The results showed that miR-3175 expression was increased and SCN4B expression was decreased in prostate cancer cell lines as compared with normal human prostatic epithelial cells. Compared with the control group, knockdown of miR-3175 resulted in strong inhibitions of cell growth, migration, invasion, and N-cadherin expression, together with an increase in E-cadherin expression. In addition, knockdown of miR-3175 dramatically increased the luciferase activity of the luciferase vector of SCN4B, and increased SCN4B expression. Together, this study illustrated that downregulation of miR-3175 repressed the proliferation and invasion of prostate cancer cells, which might be induced by SCN4B downregulation.