Deletion of miR-15a inhibited glioma development via targeting Smad7 and inhibiting EMT pathway

Therapeutic potential of SMAD7 targeting miRNA in the pathogenesis of diabetic nephropathy

Diabetic nephropathy (DN) is a common complication of diabetes and a leading cause of end-stage renal disease, characterized by progressive kidney fibrosis and inflammation. The transforming growth factor-beta (TGF-β) signaling pathway plays a crucial role in the pathogenesis of diabetes nephropathy, and SMAD7 is a key negative regulator of this pathway. Recent studies have highlighted the involvement of miRNA in the progression of DN. Computational analysis identified 11 potential miRNAs such as miR-424, miR-195, miR-216a, miR-503, miR-15a-5p, miR-15b-5p, miR-665, miR-520h, miR16-5p, miR-21 and miR-32-5p which are predicted to target 3'UTR of SMAD7 mRNA. This review aims to explore the role of these miRNAs in the progression of DN. Notably, these miRNAs have shown therapeutic potential in mitigating fibrosis and inflammation by modulating SMAD7 expression in DN. Future directions can be to investigate the mechanistic pathways through which these miRNAs exert their effects, as well as optimizing delivery systems for effective clinical application. Targeting miRNAs that modulate SMAD7 expression represents a promising strategy for developing specific and effective therapies for diabetic nephropathy.

MicroRNA-15a-5p targets programmed death-ligand 1 to impact progression, prognosis, and tumor immune response in esophageal cancer

BACKGROUND

MicroRNA(miR)-15a-5p and programmed death-ligand 1 (PD-L1) are pivotal in the progression, treatment, and prognosis of various cancer types; however, their involvement in esophageal cancer remains incompletely elucidated.

AIM

To investigate the effects of the expression of miR-15a-5p and PD-L1 on the progression and prognosis of esophageal cancer, to analyze the targeting relationship between the two, and to explore the mechanism underlying their regulatory effect on the biological behaviors of esophageal cancer cells.

METHODS

The expression of miR-15a-5p and PD-L1 genes in esophageal cancer was examined utilizing data from The Cancer Genome Atlas database, Gene Expression Omnibus database, and The Encyclopedia of RNA Interactomes pan-cancer analysis database. The relationship between the expression of miR-15a-5p and PD-L1 and disease-free interval and overall survival of esophageal cancer patients was studied by Kaplan-Meier survival analysis. The targeting relationship between miR-15a-5p and PD-L1 was detected by informatics and fluorescence activity experiments. After transfection of esophageal cancer cells with miR-15a-5p mimics or miR-NC, the expression of PD-L1 was detected by Western blot, flow cytometry, and immunofluorescence assay. The esophageal cancer cells transfected with miR-15a-5p mimics or miR-NC were co-cultured with CD8+ T cells. Interferon-γ (INF-γ)-positive CD8+ T cells were detected by flow cytometry, and INF-γ and interleukin (IL)-2 contents in the supernatant of the co-culture system were detected by ELISA.

RESULTS

The expression level of miR-15a-5p in esophageal cancer tissue was lower than that in adjacent non-cancerous tissue (P < 0.05). With the increase in T stage, tumor size, and occurrence of lymph node metastasis, there was a concomitant rise in the rate of low miR-15a-5p expression when using the median expression level of miR-15a-5p as the threshold (P < 0.05). Compared with patients with esophageal cancer with low expression of miR-15a-5p, high expression of miR-15a-5p was associated with longer disease-free survival and overall survival (P < 0.05), and high expression of miR-15a-5p combined with low expression of PD-L1 was also associated with longer disease-free survival and overall survival (P < 0.05). In esophageal cancer patients with high miR-15a-5p expression, PD-L1 mRNA expression was mostly lower. PD-L1 was the target gene of miR-15a-5p. Overexpression of miR-15a-5p inhibited total PD-L1 and membrane PD-L1 expression in esophageal cancer cells (P < 0.05). Overexpression of miR-15a-5p in esophageal cancer cells promoted the activation of CD8+ T cells in the co-culture system (i.e., the proportion of INF-γ-positive CD8+ T cells in the co-culture system and the contents of INF-γ and IL-2 in the superserum in the co-culture system were increased).

CONCLUSION

miR-15a-5p can enhance the tumor immune response of esophageal cancer cells by targeting PD-L1, and miR-15a-5p/PD-L1 can be used as biomarkers for diagnosis and prognosis of esophageal cancer.

Circular RNA circWNK1 inhibits the progression of gastric cancer via regulating the miR-21-3p/SMAD7 axis

Gastric cancer (GC) is a highly aggressive malignancy with limited treatment options for advanced-stage patients. Recent studies have highlighted the role of circular RNA (circRNA) as a novel regulator of cancer progression in various malignancies. However, the underlying mechanisms by which circRNA contributes to the development and progression of GC remain poorly understood. In this study, we utilized microarrays and real-time quantitative polymerase chain reaction (qRT-PCR) to identify and validate a downregulated circRNA, hsa_circ_0003251 (referred to as circWNK1), in paired GC and normal tissues. Through a series of in vitro and in vivo gain-of-function and loss-of-function assays, we demonstrated that circWNK1 exerts inhibitory effects on the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of GC cells. Additionally, we discovered that circWNK1 acts as a competitive endogenous RNA (ceRNA) for SMAD7 by sequestering miR-21-3p. Our findings were supported by comprehensive biological information analysis, as well as RNA pull-down, luciferase reporter gene, and western blot assays. Notably, the downregulation of circWNK1 in GC cells resulted in reduced SMAD7 expression, subsequently activating the TGF-β signaling pathway. Collectively, our study reveals that circWNK1 functions as a tumor suppressor in GC by regulating the miR-21-3p/SMAD7-mediated TGF-β signaling pathway. Furthermore, circWNK1 holds promise as a potential biomarker for the diagnosis and treatment of GC.

Platycodin D inhibits glioblastoma cell proliferation, migration, and invasion by regulating DEPDC1B-mediated epithelial-to-mesenchymal transition

BACKGROUND

Platycodin D (PD) is a potent bioactive constituent in the medicinal herb Platycodon grandiflorum. It has shown anticancer properties, particularly against glioblastoma (GB) and other human malignancies. DEPDC1B (DEP domain-containing protein 1B) is an oncogene associated with epithelial-mesenchymal transition (EMT). It is highly expressed in GB and correlated with tumor grade and patient prognosis. In this study, we investigated whether the antiglioma effect of PD was associated with downregulation of DEPDC1B.

METHODS

Gene expression and clinical data were obtained from the China Glioma Genome Atlas and The Cancer Genome Atlas databases for glioma samples. In vitro experiments were conducted using Cell Counting Kit-8 and Transwell assays to assess the impact of PD on the proliferation, migration, and invasion of GB cells. mRNA and protein expression was evaluated using real-time polymerase chain reaction and western blotting, respectively.

RESULTS

PD exerted inhibitory effects on the proliferation and motility of GB cells. PD downregulated DEPDC1B protein as well as several markers associated with EMT, namely N-cadherin, vimentin, and Snail. The suppressive effects of PD were enhanced when DEPDC1B was knocked down in GB cells, while overexpression of DEPDC1B in cells reversed the inhibitory effects of PD.

CONCLUSION

PD exerts an antiglioma effect by regulating DEPDC1B-mediated EMT.

Role of Non-Coding RNAs in TGF-β Signalling in Glioma

Brain tumours and Gliomas, in particular, are among the primary causes of cancer mortality worldwide. Glioma diagnosis and therapy have not significantly improved despite decades of efforts. Autocrine TGF-β signalling promotes glioma proliferation, invasion, epithelial-to-mesenchymal transition (EMT), and drug resistance. Non-coding RNAs such as miRNA, lncRNA, and circRNAs have emerged as critical transcriptional and post-transcriptional regulators of TGF-β pathway components in glioma. Here, we summarize the complex regulatory network among regulatory ncRNAs and TGF-β pathway during Glioma pathogenesis and discuss their role as potential therapeutic targets for Gliomas.

Exosomal miRNAs contribute to coal dust particle-induced pulmonary fibrosis in rats

Coal workers' pneumoconiosis (CWP) is a fatal occupational disease caused by inhalation of coal dust particles, which leads to progressive pulmonary fibrosis. Recently, as new signal carriers for intercellular communication, exosomal miRNAs have been validated in the pathogenesis of multiple diseases. However, the research on exosomal miRNAs in CWP is still in the preliminary stage. Here, using miRNA sequencing, exosomal miRNA profiles in bronchoalveolar lavage fluid (BALF) from rats with pulmonary fibrosis induced by coal dust particles were analyzed, and the underlying biological function of putative target genes was explored by GO term analysis and KEGG pathway enrichment analysis. According to the results, intratracheal instillation of coal dust particles can alter the exosomal miRNAs expression in the BALF of rats. Further bioinformatics analysis provided some clues to reveal their function in pathological process of pneumoconiosis. More importantly, we identified 4 differentially expressed exosomal miRNAs (miRNA-21-5p, miRNA-29a-3p, miRNA-26a-5p, and miRNA-34a-5p) by qRT‑PCR and further verified the temporal changes in the expression of these exosomal miRNAs in animal models from 2 weeks to 16 weeks postexposure. In addition, we conducted a preliminary study on Smad7 as a potential target of miRNA-21-5p and found that exosomal miRNA 21-5p/Smad7 may contribute to the pulmonary fibrosis induced by coal dust particles. Our study confirmed the contribution of exosomal miRNAs to coal dust particle-induced pulmonary fibrosis and provided new insights into the pathogenesis of CWP.