The essentially infinite expansion potential and pluripotency of human embryonic stem cells (hESCs) makes them attractive for cell-based therapeutics. In contrast to mouse embryonic stem cells (mESCs), hESCs normally undergo high rates of spontaneous apoptosis and differentiation, making them difficult to maintain in culture. Here we demonstrate that p53 protein accumulates in apoptotic hESCs induced by agents that damage DNA. However, despite the accumulation of p53, it nevertheless fails to activate the transcription of its target genes. This inability of p53 to activate its target genes has not been observed in other cell types, including mESCs. We further demonstrate that p53 induces apoptosis of hESCs through a mitochondrial pathway. Reducing p53 expression in hESCs in turn reduces both DNA damage-induced apoptosis as well as spontaneous apoptosis. Reducing p53 expression also reduces spontaneous differentiation and slows the differentiation rate of hESCs. Our studies reveal the important roles of p53 as a critical mediator of human embryonic stem cells survival and differentiation.
Abstract Background Acquired chemoresistance is a major challenge in the clinical treatment of glioblastoma (GBM). Circular RNAs have been verified to play a role in tumor chemoresistance. However, the underlying mechanisms remain unclear. The aim of this study was to elucidate the potential role and molecular mechanism of circular (circ)RNA ADP-ribosylation factor GTPase activating proteins with Src homology 3 domain, ankyrin repeat and Pleckstrin homology domain 1 (circASAP1) in temozolomide (TMZ) resistance of GBM. Methods We analyzed circRNA alterations in recurrent GBM tissues relative to primary GBM through RNA sequencing. Real-time quantitative reverse transcription PCR verified the expression of circASAP1 in tissues and cells. Knockdown and overexpressed plasmids were used to evaluate the effect of circASAP1 on GBM cell proliferation and TMZ-induced apoptosis. Mechanistically, fluorescent in situ hybridization, dual-luciferase reporter, and RNA immunoprecipitation assays were performed to confirm the regulatory network of circASAP1/miR-502-5p/neuroblastoma Ras (NRAS). An intracranial tumor model was used to verify our findings in vivo. Results CircASAP1 expression was significantly upregulated in recurrent GBM tissues and TMZ-resistant cell lines. CircASAP1 overexpression enhanced GBM cell proliferation and TMZ resistance, which could be reduced by circASAP1 knockdown. Further experiments revealed that circASAP1 increased the expression of NRAS via sponging miR-502-5p. Moreover, circASAP1 depletion effectively restored the sensitivity of TMZ-resistant xenografts to TMZ treatment in vivo. Conclusions Our data demonstrate that circASAP1 exerts regulatory functions in GBM and that competing endogenous (ce)RNA-mediated microRNA sequestration might be a potential therapeutic strategy for GBM treatment.
To analyze the biological function of LINC00339 in the progression of colorectal cancer (CRC). We aim to provide directions in the early-stage treatment of CRC. LINC00339 level in 60 paired CRC tissues and paracancerous tissues was examined by quantitative real-time polymerase chain reaction (qRT-PCR). The correlation between the LINC00339 level and clinical parameters was analyzed. Moreover, the LINC00339 level in CRC cell lines was determined as well. LINC00339 expression was changed in HCT-8 and HCT-116 cell lines by transfection of LINC00339 overexpression plasmid or anti-LINC00339. The regulatory effects of LINC00339 on the migratory and invasive abilities of CRC cells were evaluated through a series of functional experiments. Dual-luciferase reporter gene assay and rescue experiments were conducted to verify the interaction of LINC00339 and miRNA-30a-5p in mediating the progression of CRC. LINC00339 was upregulated in CRC tissues relative to paracancerous tissues. CRC patients with higher levels of LINC00339 had higher rates of lymph node metastasis and distant metastasis, and worse prognosis than those with lower levels. Knockdown of LINC00339 attenuated migratory and invasive abilities of HCT-116 cells. Overexpression of LINC00339 in HCT-8 obtained the opposite trends. In addition, we verified a negative correlation between LINC00339 and miRNA-30a-5p in CRC tissues. LINC00339 served as a ceRNA to absorb miRNA-30a-5p. Rescue experiments confirmed that miRNA-30a-5p knockdown revered the regulatory effects of LINC00339 on the migratory and invasive abilities of CRC cells. LINC00339 was closely correlated to metastasis and poor prognosis of CRC. It accelerates CRC cells to migrate and invade via mediating miRNA-30a-5p.
Enhancing the computational efficiency of on-device Deep Neural Networks (DNNs) remains a significant challengein mobile and edge computing. As we aim to execute increasingly complex tasks with constrained computational resources, much of the research has focused on compressing neural network structures and optimizing systems. Although many studies have focused on compressing neural network structures and parameters or optimizing underlying systems, there has been limited attention on optimizing the fundamental building blocks of neural networks: the neurons. In this study, we deliberate on a simple but important research question: Can we design artificial neurons that offer greater efficiency than the traditional neuron paradigm? Inspired by the threshold mechanisms and the excitation-inhibition balance observed in biological neurons, we propose a novel artificial neuron model, Threshold Neurons. Using Threshold Neurons, we can construct neural networks similar to those with traditional artificial neurons, while significantly reducing hardware implementation complexity. Our extensive experiments validate the effectiveness of neural networks utilizing Threshold Neurons, achieving substantial power savings of 7.51x to 8.19x and area savings of 3.89x to 4.33x at the kernel level, with minimal loss in precision. Furthermore, FPGA-based implementations of these networks demonstrate 2.52x power savings and 1.75x speed enhancements at the system level. The source code will be made available upon publication.
Circular RNAs (circRNAs) play an important role in cancer development and progression by regulating gene expression. The present study aimed to investigate the function of circRNA_100859 in colon cancer. circRNA expression profiles from a human circRNAs chip were analyzed. The effects of circRNA_100859 on cell proliferation and apoptosis were assessed in vitro and interactions between circRNA_100859 and its micro (mi)RNA and target genes were analyzed. The diagnostic and prognostic significance of circRNA_100859 was also investigated. It was identified that circRNA_100859 was overexpressed in colon cancer tissues and promoted cell proliferation and inhibited cell apoptosis. Additionally, bioinformatics and a dual-luciferase reporter assay confirmed that circRNA_100859 acted as a miR-217 sponge, and miR-217 directly targeted hypoxia-inducible factor (HIF)-1α. Rescue assays demonstrated that HIF-1α protein and mRNA expression levels and cell proliferation were regulated by the circRNA_100859/miR-217 axis (P<0.05). Furthermore, statistical analysis showed that the circRNA_100859-miR-217-HIF-1α axis was associated with Tumor-Node-Metastasis (TNM) stage, histological grade, and KRAS mutations, and also showed high diagnostic and prognostic value for patients with colon cancer (P<0.05). Therefore, it was concluded that circRNA_100859 functions as an oncogene in colon cancer by sponging the miR-217-HIF-1α pathway. In addition, the circRNA_100859-miR-217-HIF-1α axis may serve as a novel diagnostic and prognostic biomarker for patients with colon cancer.
Osteoarthritis (OA) is a common joint disease characterized by progressive cartilage degradation. Circular RNAs (circRNAs) are involved in the initiation and development of OA. This study aimed to explore the potential role and mechanism of circRNA protein kinase C eta (circ-PRKCH) in OA.A total of 30 cartilage specimens were collected from OA patients or normal subjects. Human chondrocytes (CHON-001) were stimulated with interleukin-1β (IL-1β) to establish an in vitro OA model. The expression levels of circ-PRKCH, microRNA-502-5p (miR-502-5p) and circ-PRKCH or A disintegrin and metalloproteases metallopeptidase with thrombospondin type 1 motif 5 (ADAMTS5) in cartilage specimens and IL-1β-treated chondrocytes were detected by quantitative real-time PCR or Western blot, and their correlation in OA cartilage specimens was analysed by Spearman's correlation coefficient. The targeted relationship between miR-502-5p and circ-PRKCH or ADAMTS5 was verified by dual-luciferase reporter assay and RNA Immunoprecipitation (RIP) assay. Cell Counting Kit-8 (CCK-8), 5-Ethynyl-2'-deoxyuridine (EDU), flow cytometry, wound healing and enzyme-linked immunosorbent assay (ELISA) assays were applied to evaluate cell proliferation, apoptosis, migration and inflammatory response in IL-1β-treated chondrocytes. Exosomes were identified by transmission electron microscope (TEM) and Western blot.Circ-PRKCH and ADAMTS5 expression levels were up-regulated, while miR-502-5p expression was down-regulated in OA cartilage tissues and IL-1β-treated chondrocytes. Depletion of circ-PRKCH relieved IL-1β-treated chondrocyte cell phenotypic changes by promoting cell proliferation and migration, as well as inhibiting apoptosis and inflammatory response. Mechanically, circ-PRKCH acted as a sponge for miR-502-5p to regulate ADAMTS5 expression, thereby contributing to IL-1β-treated chondrocyte cell phenotypic changes. Moreover, exosomes derived from IL-1β-treated chondrocytes could transfer circ-PRKCH across cells.Circ-PRKCH contributed to IL-1β-treated cell phenotypic changes in chondrocytes via modulating miR-502-5p/ADAMTS5 pathway, which might provide a promising biomarker for OA treatment.
Abstract Purpose Nectin-4 is specifically up-regulated in various tumors, exert crucial effects on tumor occurrence and development. Nevertheless, the role and molecular mechanism of Nectin-4 in osteosarcoma (OS) are rarely studied. Methods The expression of Nectin-4 and its relationship with clinical characteristics of OS were investigated using OS clinical tissues, tissue microarrays, TCGA, and GEO databases. Moreover, the effect of Nectin-4 on cell growth and mobility was detected by CCK-8, colony formation, transwell, and wound-healing assays. The RT-qPCR, Western blotting, and luciferase reporter assays were performed to explore molecular mechanisms through which Nectin-4 mediates the expression of miR-520c-3p, thus modulating PI3K/AKT/NF-κB signaling. In vivo mice models constructed by subcutaneous transplantation and tail vein injection were used to validate the functional roles of Nectin-4 and miR-520c-3p. Results Nectin-4 displayed a higher expression in OS tumor tissues compared with normal tissues, and its overexpression was positively associated with tumor stage and metastasis in OS patients. Functionally, Nectin-4 enhanced OS cells growth and mobility in vitro. Mechanistically, Nectin-4 down-regulated the levels of miR-520c-3p that directly targeted AKT-1 and P65, thus leading to the stimulation of PI3K/AKT/NF-κB signaling. In addition, the expression of miR-520c-3p was apparently lower in OS tissues than in normal tissues, and its low expression was significantly related to tumor metastasis. Furthermore, ectopic expression of miR-520c-3p markedly blocked the effect of Nectin-4 on OS cell growth and mobility. Knockdown of Nectin-4 could suppress the tumorigenesis and metastasis in vivo, which could be remarkably reversed by miR-520c-3p silencing. Conclusions Nectin-4 as an oncogene can promote OS progression and metastasis by activating PI3K/AKT/NF-κB signaling via down-regulation of miR-520c-3p, which could represent a novel avenue for identifying a potential therapeutic target for improving patient outcomes.
To establish and verify the method for detecting the immune phenotype of peripheral blood T lymphocytes by cellular immune chip technology, analyze the immune status, and discuss its clinical diagnostic value of different populations in the Qingyuan area.First, a cellular immune chip was used to detect the number of T lymphocyte subsets CD3+, CD4+, CD8+, and CD4/CD8, followed by evaluating the accuracy and precision through a comparison with flow cytometry. After passing the performance verification, a large-scale detection was performed by a cellular immune chip in 8389 cases. Immunochip technology detects the expression of T lymphocyte subsets and analyzes the differences in cellular immune function among people with physical examination, inflammation, and cancer, as well as different cancer types and in genders.The cell immunochip method and flow cytometry method have the same accuracy and precision in detecting specimens, and the former is fast and simple, and is suitable for clinical use; big data analysis is expected to establish a reference range for CD3+, CD4+, and CD8+ T cell counts in Qingyuan. There are statistical differences in CD3+, CD4+, CD8+ T cell counts in physical examination, inflammation and cancer populations; there are also certain differences in CD3+, CD4+, CD8+ T cell counts and CD4/CD8 ratios between different cancer types and different diseases.The method of cell immunochip technology to detect T lymphocyte subsets is simple and practical, with accurate results and rapid detection. It can be used for immune function monitoring and treatment prognosis evaluation of people with different diseases, and it is worthy of popularization and application in clinical practice.
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