Project description:BackgroundColorectal cancer (CRC) is the leading cause of cancer-related death worldwide. Exosome shave emerged as crucial regulators of intercellular communication and that abundant Circular RNAs (circRNAs) are enriched within exosomes. CircRNAs are novel members of noncoding RNAs regulating cancer proliferation and progression. However, the function and regulatory mechanism of cancer-derived exosomal circRNAs in CRC remains unclear.MethodsCRC cells-derived exosomes were characterized using transmission electron microscopy, nanoparticle tracking analysis (NTA) and western blot. CCK-8, wound healing and transwell assays, and flow cytometry assays were conducted to assess whether exosomes would affect the proliferation, metastasis, and apoptosis of CRC cells, respectively. Moreover, we performed the RNA sequencing and RT-qPCR to identify circRNAs in exosome-stimulated CRC cells. Fluorescence in situ hybridization (FISH) assay was used to detect the cellular distribution of circPACRGL. Bioinformatic analyses (StarBase 2.0) were used to pool the miRNA targets of circPACRGL. Luciferase assays were performed to verify the direct interaction. Finally, flow cytometry was used to detect the differentiation of N1-N2 neutrophils.ResultsOur study identified a novel CRC-derived exosomal circRNA, circPACRGL. We found circPACRGL was significantly upregulated in CRC cells after tumor-derived exosomes addition. Moreover, circPACRGL serves as a sponge for miR-142-3p/miR-506-3p to facilitate the transforming growth factor-β1 (TGF-β1) expression. As a result, circPACRGL promoted CRC cell proliferation, migration and invasion, as well as differentiation of N1 to N2 neutrophils via miR-142-3p/miR-506-3p-TGF-β1 axis.ConclusionOur study, the first to reveal that cancer-derived exosomal circPACRGL plays an oncogenic role in CRC proliferation and metastasis, providing mechanistic insights into the roles of circRNAs in CRC progression and a valuable marker for CRC treatment.
Project description:BackgroundHyaluronan (HA) metabolism by chondrocytes is important for cartilage development and homeostasis. However, information about the function of circular RNAs (circRNAs) in HA metabolism is limited. We therefore profiled the role of the novel HA-related circRNA circHYBID in the progression of osteoarthritis (OA).MethodsCircHYBID function in HA metabolism in chondrocytes was investigated using gain-of-function experiments, and circHYBID mechanism was confirmed via bioinformatics analysis and luciferase assays. The expression of circHYBID-hsa-miR-29b-3p-transforming growth factor (TGF)-β1 axis was examined by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. CircHYBID, TGF-β1, and HA levels in cartilage samples were evaluated using qRT-PCR and pathological examination. Enzyme-linked immunosorbent assay was used to assess HA accumulation in chondrocyte supernatant.ResultsCircHYBID expression was significantly downregulated in damaged cartilage samples compared with that in the corresponding intact cartilage samples. CircHYBID expression was positively correlated with alcian blue score. Interleukin-1β stimulation in chondrocytes downregulated circHYBID expression and decreased HA accumulation. Gain-of-function experiments revealed that circHYBID overexpression in chondrocytes increased HA accumulation by regulating HA synthase 2 and HYBID expression. Further mechanism analysis showed that circHYBID upregulated TGF-β1 expression by sponging hsa-miR-29b-3p.ConclusionsOur results describe a novel HA-related circRNA that could promote HA synthesis and accumulation. The circHYBID-hsa-miR-29b-3p-TGF-β1 axis may play a powerful regulatory role in HA metabolism and OA progression. Thus, these findings will provide new perspectives for studies on OA pathogenesis, and circHYBID may serve as a potential target for OA therapy.
Project description:Although excessive exposure to UV is widely recognized as a major factor leading to skin perturbations and cancer, the complex mechanisms underlying inflammatory skin disorders resulting from UV exposure remain incompletely characterized. The nuclear hormone receptor PPARβ/δ is known to control mouse cutaneous repair and UV-induced skin cancer development. Here, we describe a novel PPARβ/δ-dependent molecular cascade involving TGFβ1 and miR-21-3p, which is activated in the epidermis in response to UV exposure. We establish that the passenger miRNA miR-21-3p, that we identify as a novel UV-induced miRNA in the epidermis, plays a pro-inflammatory function in keratinocytes and that its high level of expression in human skin is associated with psoriasis and squamous cell carcinomas. Finally, we provide evidence that inhibition of miR-21-3p reduces UV-induced cutaneous inflammation in ex vivo human skin biopsies, thereby underlining the clinical relevance of miRNA-based topical therapies for cutaneous disorders.
Project description:The aim of this study was to investigating whether lncRNA H19 promotes myocardial fibrosis by suppressing the miR-29a-3p/miR-29b-3p-VEGFA/TGF-β axis. Patients with atrial fibrillation (AF) and healthy volunteers were included in the study, and their biochemical parameters were collected. In addition, pcDNA3.1-H19, si-H19, and miR-29a/b-3p mimic/inhibitor were transfected into cardiac fibroblasts (CFs), and proliferation of CFs was detected by MTT assay. Expression of H19 and miR-29a/b-3p were detected using real-time quantitative polymerase chain reaction, and expression of α-smooth muscle actin (α-SMA), collagen I, collagen II, matrix metalloproteinase-2 (MMP-2), and elastin were measured by western blot analysis. The dual luciferase reporter gene assay was carried out to detect the sponging relationship between H19 and miR-29a/b-3p in CFs. Compared with healthy volunteers, the level of plasma H19 was significantly elevated in patients with AF, while miR-29a-3p and miR-29b-3p were markedly depressed (P < 0.05). Serum expression of lncRNA H19 was negatively correlated with the expression of miR-29a-3p and miR-29b-3p among patients with AF (rs = -0.337, rs = -0.236). Moreover, up-regulation of H19 expression and down-regulation of miR-29a/b-3p expression facilitated proliferation and synthesis of extracellular matrix (ECM)-related proteins. SB431542 and si-VEGFA are able to reverse the promotion of miR-29a/b-3p on proliferation of CFs and ECM-related protein synthesis. The findings of the present study suggest that H19 promoted CF proliferation and collagen synthesis by suppressing the miR-29a-3p/miR-29b-3p-VEGFA/TGF-β axis, and provide support for a potential new direction for the treatment of AF.
Project description:Molecular targeting is an import strategy to treat advanced colon cancer. The current study demonstrates that expression of GRM3, a metabotropic glutamate receptor mainly expressed in mammalian central nervous system, is significantly upregulated in majority of human colonic adenocarcinomas tested and colon cancer cell lines. Knockdown of GRM3 expression or inhibition of GRM3 activation in colon cancer cells reduces cell survival and anchorage-independent growth in vitro and inhibits tumor growth in vivo. Mechanistically, GRM3 antagonizes TGF?-mediated activation of protein kinase A and inhibition of Protein kinase B (AKT). In addition, TGF? signaling increases GRM3 protein stability and knockdown of GRM3 enhances TGF?-mediated tumor suppressor function. Further studies indicate that miR-487b-3p directly targets GRM3. Overexpression of miR-487b-3p mimics the effects of GRM3 knockdown and suppresses the tumorigenicity of colon cancer cells in vivo. Expression of miR-487b-3p is decreased in colon adenocarcinomas and inversely correlates with GRM3 expression. Taken together, these studies indicate that upregulation of GRM3 expression is a functionally important molecular event in colon cancer, and that GRM3 is a promising molecular target for colon cancer treatment. This is particularly interesting and important from a therapeutic standpoint because numerous metabotropic glutamate receptor antagonists are available, many of which have been found unsuitable for treatment of neuropsychiatric disorders for reasons such as inability to readily penetrate blood brain barriers. As GRM3 is upregulated in colon cancer, but rarely expressed in normal peripheral tissues, targeting GRM3 with such agents would not likely cause adverse neurological or peripheral side effects, making GRM3 an attractive and specific molecular target for colon cancer treatment.
Project description:Congenital heart disease (CHD) is the most common noninfectious cause of death during the neonatal stage. T-box transcription factor 1 (TBX1) is the main genetic determinant of 22q11.2 deletion syndrome (22q11.2DS), which is a common cause of CHD. Moreover, ferroptosis is a newly discovered kind of programmed cell death. In this study, the interaction among TBX1, miR-193a-3p, and TGF-β2 was tested using quantitative reverse transcription polymerase chain reaction (qRT-PCR), Western blotting, and dual-luciferase reporter assays. TBX1 silencing was found to promote TGF-β2 messenger ribonucleic acid (mRNA) and protein expression by downregulating the miR-193a-3p levels in H9c2 cells. In addition, the TBX1/miR-193a-3p/TGF-β2 axis was found to promote ferroptosis based on assessments of lipid reactive oxygen species (ROS) levels, Fe2+ concentrations, mitochondrial ROS levels, and malondialdehyde (MDA) contents; Cell Counting Kit-8 (CCK-8) assays and transmission electron microscopy; and Western blotting analysis of glutathione peroxidase 4 (GPX4), nuclear factor erythroid 2-related factor 2 (NRF2), heme oxygenase-1 (HO-1), NADPH oxidase 4 (NOX4), and acyl-CoA synthase long-chain family member 4 (ACSL4) protein expression. The protein expression of NRF2, GPX4, HO-1, NOX4, and ACSL4 and the level of MDA in human CHD specimens were also detected. In addition, TBX1 and miR-193a-3p expression was significantly downregulated and TGF-β2 levels were high in human embryonic CHD tissues, as indicated by the H9c2 cell experiments. In summary, the TBX1/miR-193a-3p/TGF-β2 axis mediates CHD by inducing ferroptosis in cardiomyocytes. TGF-β2 may be a target gene for CHD diagnosis and treatment in children.
Project description:Transforming growth factor-beta 1 (TGF-β1) suppresses T cell function, promoting tumor immune escape. Yet, whether the depression of TGF-β1 on T cell function is mediated by co-inhibitory molecules B7-H3 and B7-H4 remains largely unclear. Here, we demonstrated that TGF-β1 elevated the expression of miR-155 in colorectal cancer cells through SMAD3 and SMAD4. The upregulated miR-155 attenuated miR-143 by inhibiting its direct target, the transcription factor CEBPB. Consequently, the direct target genes of miR-143, B7-H3 and B7-H4, were augmented in the cytoplasm and membrane of tumor cells. Over-expression of B7-H3 and B7-H4 in HCT-116 cells induced T cells to secrete TGF-β1 and the immunosuppressive cytokines IL-2, IL-6, and IL-17. Restoration of miR-143 inhibited the growth of HCT-116 xenograft tumors in mice, and also repressed the expression of B7-H3 and B7-H4 in the tumors. Thus, this study reveals the mechanism by which TGF-β1 leads to T cell-mediated tumor evasion through an increase in B7-H3 and B7-H4 expression.
Project description:The extracellular matrix protein biglycan (BGN) has oncogenic or tumor suppressive potential depending on the cellular origin. HER-2/neu overexpression in murine fibroblasts and human model systems is inversely correlated with BGN expression. Upon its restoration BGNhigh HER-2/neu+ fibroblasts were less tumorigenic in immune competent mice when compared to BGNlow/neg HER-2/neu+ cells, which was associated with enhanced immune cell responses and higher frequencies of immune effector cells in tumors and peripheral blood. The increased immunogenicity of BGNhigh HER-2/neu+ fibroblasts appears to be due to upregulated MHC class I surface antigens and reduced expression levels of transforming growth factor (TGF)-? isoforms and the TGF-? receptor 1 suggesting a link between BGN, TGF-? pathway and HER-2/neu-mediated downregulation of MHC class I antigens. Treatment of BGNlow/neg HER-2/neu+ cells with recombinant BGN or an inhibitor of TGF-? enhanced MHC class I surface antigens in BGNlow/neg HER-2/neu-overexpressing murine fibroblasts, which was mediated by a transcriptional upregulation of major MHC class I antigen processing components. Furthermore, BGN expression in HER-2/neu+ cells was accompanied by an increased expression of the proteoglycan decorin (DCN). Since recombinant DCN also elevated MHC class I surface expression in BGNlow/neg HER-2/neu+ cells, both proteoglycans might act synergistically. This was in accordance with in silico analyses of mRNA data obtained from The Cancer Genome Atlas (TCGA) dataset available for breast cancer (BC) patients. Thus, our data provide for the first time evidence that proteoglycan signatures are modulated by HER-2/neu and linked to MHC class I-mediated immune escape associated with an altered TGF-? pathway.
Project description:BackgroundLong non-coding RNAs (lncRNA) plasmacytoma variant translocation 1 (PVT1) has been shown to be associated with liver fibrosis. Nevertheless, the role of PVT1 in atrial fibrosis remains undefined. This study aims to elucidate the pathophysiological role of lncRNA PVT1 in the regulation of atrial fibrosis and to explore the underlying mechanism.MethodsExpression of PVT1, miR-128-sp, and Sp1 were examined in human atrial muscle tissues and angiotensin-II (Ang-II)-induced human atrial fibroblasts. Furthermore, the role of PVT1 in regulating atrial fibrosis in Ang-II-treated human atrial fibroblasts and Ang-II-induced atrial fibrosis in mice was investigated. Moreover, the interaction among PVT1, miR-128-3p, and Sp1 were examined using bioinformatics, expression correlation analysis, gain- or loss-of-function assays, RIP assays, and luciferase reporter assays. The involvement of transforming growth factor beta 1 (TGF-β1)/Smad pathway in this process was also explored.ResultsPVT1 was increased in atrial muscle tissues from AF patients and positively with collagen I and collagen III. In vitro assay revealed that PVT1 overexpression facilitated the Ang-II-induced atrial fibroblasts proliferation, collagen production, and TGF-β1/Smad signaling activation, whereas PVT1 knockdown caused the opposite effect. In vivo assay further confirmed that PVT1 knockdown attenuated the Ang-II-induced mouse atrial fibrosis. Mechanically, PVT1 acted as a sponge for miR-128-3p to facilitate Sp1 expression, thereby activating the TGF-β1/Smad signaling pathway.ConclusionLncRNA PVT1 promotes atrial fibrosis via miR-128-3p-SP1-TGF-β1-Smad axis in atrial fibrillation.
Project description:Oral-gut pathogens are closely associated with pancreatic cancer, such as Campylobacter jejuni, Clostridium difficile, Enterococcus faecalis, Escherichia coli, Fusobacterium nucleatum, Helicobacter pylori, Porphyromonas gingivalis, and Vibrio cholera, but the related mechanisms remain not well understood. Phosphatase and tensin homolog (PTEN, a widely known tumor suppressor) play a key role in the anti-cancer immune system. Pancreatic cancer cells with PTEN loss are often in the immunosuppressive tumor microenvironment regulated by myeloid-derived suppressor cells (MDSCs), regulatory T cells (Tregs), and M2 macrophages, which are regarded as the mechanism in the immune escape of cancers. The miR-21, as an oncogene in human cancers, plays an important role in pancreatic cancer progression, downregulates the levels of PTEN, and may promote cancer to evade host immune surveillance. Some oral-gut pathogens have been found to promote miR-21 expression and reduce PTEN expression. On the other hand, most gut pathogens infection is thought to produce reactive oxygen species (ROS) or activate inflammatory cytokines, which may also induce ROS-mediated miR-21 expression. These pathogens' infection is involved with the cell density of MDSCs, Tregs, and M2 macrophages. Therefore, it is quite reasonable to propose that oral-gut pathogens possibly promote pancreatic cancer escaping from host immune surveillance by activating the miR-21/PTEN axis and immune-suppressive cells. The present exploration suggests that an increased understanding of the pattern of the effects of gut pathogens on the miR-21/PTEN axis will lead to better insights into the specific mechanisms associated with the immune escape of pancreatic cancer caused by oral-gut microbiota.