Exosomal miR-18a-5p promotes EMT and metastasis of NPC cells via targeting BTG3 and activating the Wnt/β-catenin signaling pathway

microRNA-18a-5p promotes vascular smooth muscle cell phenotypic switch by targeting Notch2 as therapeutic targets in vein grafts restenosis

Vascular smooth muscle cells (VSMCs) phenotype switching plays a crucial role in vein graft restenosis following coronary artery bypass grafting (CABG) surgery. To discover novel clinically relevant therapeutic targets for vein graft restenosis after CABG, we therefore investigated whether miRNA-18a-5p mediated phenotype switching plays a critical role in the development of vein graft restenosis. We studied miRNA-18a-5p expression in plasma samples of patients with or without vein graft restenosis at 1, 3 and 5 years after coronary artery bypass graft surgery, and in normal vs. atherosclerotic human femoral artery samples, to prove its role in VSMC phenotype switching. We found that the expression of miRNA-18a-5p significantly increased in vein grafts restenosis rat model after bypass surgery at 7, 14, 28 days and human blood specimens with vein grafts failure after grafting surgery. Through gain- and loss-of-function approaches, we determined that miRNA-18a-5p affects VSMC proliferation, migration, differentiation, and contractility. Notch2 was found to be a direct target of miRNA-18a-5p, which is critical for VSMC phenotype switching. Finally, miRNA-18a-5p knockdown used miRNA sponge via AAV6 locally delivery in vivo, miRNA-18a-5p sponge gene transfer therapy reduced the neointimal area, neointimal thickness, and intimal/media area ratio in vein grafts compared with the controls and improved vein graft hemodynamics. miRNA-18a-5p is a critical modulator of VSMC phenotypic switch during development of vein graft restenosis by downregulating Notch2, therefore targeting miRNA-18a-5p may be a helpful strategy for the treatment of vein grafts restenosis or failure after CABG surgery.

miR-18a-5p promotes osteogenic differentiation of BMSC by inhibiting Notch2

Postmenopausal osteoporosis (PMOP) is a metabolic disorder characterized by the loss of bone density, which increases the risk of developing complications such as fractures. A pivotal factor contributing to the onset of PMOP is the diminished osteogenic differentiation capacity of bone marrow mesenchymal stem cells (BMSCs). MicroRNAs (miRNAs) play a substantial role in this process; however, their specific impact on regulating BMSCs osteogenesis remains unclear. Studies have evidenced a reduced expression of miR-18a-5p in PMOP, and concomitantly, our observations indicate an augmented expression of miR-18a-5p during the osteogenic differentiation of BMSCs. This investigation seeks to elucidate the regulatory influence of miR-18a-5p on BMSC osteogenic differentiation and the underlying mechanisms. In vitro experiments demonstrated that the overexpression of miR-18a-5p facilitated the osteogenic differentiation of BMSCs, while the downregulation of miR-18a-5p yielded converse outcomes. Mechanistically, We employed bioinformatics techniques to screen out the target gene Notch2 of miR-18a-5p. Subsequently, dual-luciferase reporter gene assays and rescue experiments substantiated that miR-18a-5p promotes BMSC osteogenic differentiation by suppressing Notch2. Finally, miR-18a-5p was overexpressed via adenovirus injection into the femoral bone marrow cavity, with results demonstrating its capability to enhance osteogenic differentiation and alleviate PMOP symptoms. Our findings disclose that miR-18a-5p fosters osteogenic differentiation of BMSC by inhibiting Notch2, thereby offering novel targets and strategies for PMOP treatment.

Exosomal miRNAs: the tumor's trojan horse in selective metastasis

Organs of future metastasis are not passive receivers of circulating tumor cells, but are instead selectively and actively modified by the primary tumor before metastatic spread has even occurred. Tumors orchestrate a pre-metastatic program by conditioning distant organs to create microenvironments that foster the survival and proliferation of tumor cells before their arrival, thereby establishing pre-metastatic niches. Primary tumor-derived exosomes modulate these pre-metastatic niches, generating a permissive environment that facilitates the homing and expansion of tumor cells. Moreover, microRNAs have emerged as a key component of exosomal cargo, serving not only to induce the formation of pre-metastatic niches but also to prime these sites for the arrival and colonization of specific secondary tumor populations. Against this backdrop, this review endeavors to elucidate the impact of tumor-derived exosomal microRNAs on the genesis of their individualized pre-metastatic niches, with a view towards identifying novel means of specifying cancer metastasis and exploiting this phenomenon for cancer immunotherapy.

Interplay between Wnt signaling molecules and exosomal miRNAs in breast cancer (Review)

Breast cancer (BC) is the most common malignancy in women worldwide. Wnt signaling is involved in tumorigenesis and cancer progression, and is closely associated with the characteristics of BC. Variation in the expression of exosomal microRNAs (miRNAs) modulates key cancer phenotypes, such as cellular proliferation, epithelial‑mesenchymal transition, metastatic potential, immune evasion and treatment resistance. The present review aimed to discuss the importance of Wnt signaling and exosomal miRNAs in regulating the occurrence and development of BC. In addition, the present review determined the crosstalk between Wnt signaling and exosomal miRNAs, and highlighted potential diagnostic biomarkers and therapeutic targets.

Unfolding the Complexity of Exosome-Cellular Interactions on Tumour Immunity and Their Clinical Prospects in Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma (NPC) is an epithelial malignancy situated in the posterolateral nasopharynx. NPC poses grave concerns in Southeast Asia due to its late diagnosis. Together with resistance to standard treatment combining chemo- and radiotherapy, NPC presents high metastatic rates and common recurrence. Despite advancements in immune-checkpoint inhibitors (ICIs) and cytotoxic-T-lymphocytes (CTLs)-based cellular therapy, the exhaustive T cell profile and other signs of immunosuppression within the NPC tumour microenvironment (TME) remain as concerns to immunotherapy response. Exosomes, extracellular vesicles of 30-150 nm in diameter, are increasingly studied and linked to tumourigenesis in oncology. These bilipid-membrane-bound vesicles are packaged with a variety of signalling molecules, mediating cell-cell communications. Within the TME, exosomes can originate from tumour, immune, or stromal cells. Although there are studies on tumour-derived exosomes (TEX) in NPC and their effects on tumour processes like angiogenesis, metastasis, therapeutic resistance, there is a lack of research on their involvement in immune evasion. In this review, we aim to enhance the comprehension of how NPC TEX contribute to cellular immunosuppression. Furthermore, considering the detectability of TEX in bodily fluids, we will also discuss the potential development of TEX-related biomarkers for liquid biopsy in NPC as this could facilitate early diagnosis and prognostication of the disease.