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Long non-coding RNA-MIR181A1HG acts as an oncogene and contributes to invasion and metastasis in gastric cancer
Dysregulation of long non-coding RNAs (lncRNA) plays an essential role in cancer development and progression. However, their functions and mechanisms of action in gastric cancer (GC) remain largely unknown. Gene expression in GC was evaluated using quantitative real-time PCR, western blotting, immunofluorescence, immunohistochemistry, and RNA in situ hybridization. The impact of MIR181A1HG on GC cells was explored in vitro and in vivo using cell proliferation, migration, invasion assays and animal models. Biotinylated RNA pull-down, RNA immunoprecipitation, co-immunoprecipitation, chromatin immunoprecipitation, and luciferase reporter assays were performed to evaluate the molecular interactions. LncRNA-MIR181A1HG was upregulated in GC and associated with malignant progression. MIR181A1HG physically interacts with ELAVL1 to regulate epithelial-mesenchymal transition (EMT) in GC cells. MIR181A1HG intron-derived miR-181a-5p/miR-181b-5p triggers MIR181A1HG transcription through binding to and destabilizing SOCS3 messenger RNA. Specifically, SOCS3 interacts with NFATC2 and downregulated SOCS3 enhances the NFATC2-mediated transcriptional activation of the MIR181A1HG promoter. Collectively, MIR181A1HG, activated by miR-181a-5p/miR-181b-5p-SOCS3-NFATC2 positive feedback loop, contributes to GC progression through stabilizing ELAVL1. MIR181A1HG expression correlates positively with ELAVL1, miR-181a-5p, miR-181b-5p, and NFATC2 and negatively with SOCS3 in fresh GC samples. These data demonstrate that MIR181A1HG plays an important role in tumor progression by promoting invasion, metastasis, and EMT, indicating its potential as a prognostic biomarker in GC.
The feedback loop between miR-222-3p and ZEB1 harnesses metastasis in renal cell carcinoma
Renal cell carcinoma (RCC) is an aggressive malignancy originating from the renal parenchyma, often leading to high mortality due to local invasion and distant metastasis. MicroRNAs (miRNAs) play essential roles in RCC progression. Through miRNA sequencing, we identified significant upregulation of miR-222-3p in metastatic RCC tissues. Exosomes from highly metastatic RCC cells were found to transfer miR-222-3p to low-metastatic cells, enhancing their migration and invasion. Mechanistically, miR-222-3p directly targets the 3′ untranslated region (3′UTR) of the tumor-suppressor TRPS1, reducing its expression. TRPS1 downregulation releases its inhibitory effect on ZEB1, a key regulator of epithelial-mesenchymal transition (EMT), thereby promoting EMT and metastatic traits. ZEB1 further transactivates miR-222-3p, establishing a positive feedback loop. Additionally, miR-222-3p promotes a pre-metastatic niche by inducing M2 macrophage polarization, facilitating distant metastasis. These findings highlight miR-222-3p as a critical driver of RCC metastasis and suggest its potential as a diagnostic marker and therapeutic target for RCC.
Exosomal miR-17-5p derived from epithelial cells is involved in aberrant epithelium-fibroblast crosstalk and induces the development of oral submucosal fibrosis
Oral submucous fibrosis (OSF) is a chronic and inflammatory mucosal disease caused by betel quid chewing, which belongs to oral potentially malignant disorders. Abnormal fibroblast differentiation leading to disordered collagen metabolism is the core process underlying OSF development. The epithelium, which is the first line of defense against the external environment, can convert external signals into pathological signals and participate in the remodeling of the fibrotic microenvironment. However, the specific mechanisms by which the epithelium drives fibroblast differentiation remain unclear. In this study, we found that Arecoline-exposed epithelium communicated with the fibrotic microenvironment by secreting exosomes. MiR-17-5p was encapsulated in epithelial cell-derived exosomes and absorbed by fibroblasts, where it promoted cell secretion, contraction, migration and fibrogenic marker (α-SMA and collagen type I) expression. The underlying molecular mechanism involved miR-17-5p targeting Smad7 and suppressing the degradation of TGF-β receptor 1 (TGFBR1) through the E3 ubiquitination ligase WWP1, thus facilitating downstream TGF-β pathway signaling. Treatment of fibroblasts with an inhibitor of miR-17-5p reversed the contraction and migration phenotypes induced by epithelial-derived exosomes. Exosomal miR-17-5p was confirmed to function as a key regulator of the phenotypic transformation of fibroblasts. In conclusion, we demonstrated that Arecoline triggers aberrant epithelium-fibroblast crosstalk and identified that epithelial cell-derived miR-17-5p mediates fibroblast differentiation through the classical TGF-β fibrotic pathway, which provided a new perspective and strategy for the diagnosis and treatment of OSF.
Engineered mitochondria in diseases: mechanisms, strategies, and applications
Mitochondrial diseases represent one of the most prevalent and debilitating categories of hereditary disorders, characterized by significant genetic, biological, and clinical heterogeneity, which has driven the development of the field of engineered mitochondria. With the growing recognition of the pathogenic role of damaged mitochondria in aging, oxidative disorders, inflammatory diseases, and cancer, the application of engineered mitochondria has expanded to those non-hereditary contexts (sometimes referred to as mitochondria-related diseases). Due to their unique non-eukaryotic origins and endosymbiotic relationship, mitochondria are considered highly suitable for gene editing and intercellular transplantation, and remarkable progress has been achieved in two promising therapeutic strategies—mitochondrial gene editing and artificial mitochondrial transfer (collectively referred to as engineered mitochondria in this review) over the past two decades. Here, we provide a comprehensive review of the mechanisms and recent advancements in the development of engineered mitochondria for therapeutic applications, alongside a concise summary of potential clinical implications and supporting evidence from preclinical and clinical studies. Additionally, an emerging and potentially feasible approach involves ex vivo mitochondrial editing, followed by selection and transplantation, which holds the potential to overcome limitations such as reduced in vivo operability and the introduction of allogeneic mitochondrial heterogeneity, thereby broadening the applicability of engineered mitochondria.
Haploinsufficiency of miR-143 and miR-145 reveal targetable dependencies in resistant del(5q) myelodysplastic neoplasm
Myelodysplastic neoplasms (MDS) are stem cell disorders characterized by ineffective hematopoiesis and risk of transformation to acute myeloid leukemia (AML). Chromosomal alterations are frequent in MDS, with interstitial deletion of chromosome 5q (del(5q)) being the most common. Lenalidomide is the current first-line treatment for del(5q) MDS and its efficacy relies on degradation of CK1α which is encoded by the CSNK1A1 gene located in the commonly deleted region (CDR) of chromosome 5q. However, lenalidomide-resistance is common, often secondary to loss-of-function mutations in TP53 or RUNX1. The CDR in del(5q) harbors several genes, including noncoding miRNAs, the loss of which contribute to disease phenotypes. miR-143 and miR-145 are located within the del(5q) CDR, but precise understanding of their role in human hematopoiesis and in the pathogenesis of del(5q) MDS is lacking. Here we provide evidence that deficiency of miR-143 and miR-145 plays a role in clonal expansion of del(5q) MDS. We show that insulin-like growth factor 1 receptor (IGF-1R) is a direct target of both miR-143 and miR-145. Our data demonstrate that IGF-1R inhibition reduces proliferation and viability of del(5q) cells in vitro and in vivo, and that lenalidomide-resistant del(5q) MDS cells depleted of either TP53 or RUNX1 are sensitive to IGF-1R inhibition. Resistant del(5q) MDS-L cells, as well as primary MDS marrow cells, are also sensitive to targeting of IGF-1R-related dependencies in del(5q) MDS, which include the Abl and MAPK signaling pathways. This work thus provides potential new therapeutic avenues for lenalidomide-resistant del(5q) MDS.
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