Publications by authors named "Feng-yi Li"

Hepatitis A virus (HAV), a member of the genus ( HepV), remains a significant viral pathogen, frequently causing enterically transmitted hepatitis worldwide. In this study, we conducted an epidemiological survey of HepVs carried by small terrestrial mammals in the wild in Yunnan Province, China. Utilizing HepV-specific broad-spectrum RT-PCR, next-generation sequencing (NGS), and QNome nanopore sequencing (QNS) techniques, we identified and characterized two novel HepVs provisionally named EpMa-HAV and EpLe-HAV, discovered in the long-tailed mountain shrew () and long-tailed brown-toothed shrew (), respectively.

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Background: Targeting DNA damage repair factors, such as DNA-dependent protein kinase catalytic subunit (DNA-PKcs), may offer an opportunity for effective treatment of multiple myeloma (MM). In combination with DNA damage-inducing agents, this strategy has been shown to improve chemotherapies partially via activation of cGAS-STING pathway by an elevated level of cytosolic DNA. However, as cGAS is primarily sequestered by chromatin in the nucleus, it remains unclear how cGAS is released from chromatin and translocated into the cytoplasm upon DNA damage, leading to cGAS-STING activation.

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Article Synopsis
  • Scientists are using a special tool called paired Cas9 nickases (Cas9n) to edit genes, which helps reduce mistakes.
  • They found that a protein called TREX2 can help improve the success of this gene editing when they deal with tricky parts called 3'-overhanging ends.
  • By teaming up TREX2 with Cas9n, they made the editing process safer and more efficient, making it easier to change genes for various purposes.
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Background: Primary liver cancer has significant intratumor genetic heterogeneity (IGH), which drives cancer evolution and prevents effective cancer treatment. CRISPR/Cas9-induced mouse liver cancer models can be used to elucidate how IGH is developed. However, as CRISPR/Cas9 could induce chromothripsis and extrachromosomal DNA in cells in addition to targeted mutations, we wondered whether this effect contributes to the development of IGH in CRISPR/Cas9-induced mouse liver cancer.

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In CRISPR/Cas9 genome editing, the tight and persistent target binding of Cas9 provides an opportunity for efficient genetic and epigenetic modification on genome. In particular, technologies based on catalytically dead Cas9 (dCas9) have been developed to enable genomic regulation and live imaging in a site-specific manner. While post-cleavage target residence of CRISPR/Cas9 could alter the pathway choice in repair of Cas9-induced DNA double strand breaks (DSBs), it is possible that dCas9 residing adjacent to a break may also determine the repair pathway for this DSB, providing an opportunity to control genome editing.

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Background: Due to post-cleavage residence of the Cas9-sgRNA complex at its target, Cas9-induced DNA double-strand breaks (DSBs) have to be exposed to engage DSB repair pathways. Target interaction of Cas9-sgRNA determines its target binding affinity and modulates its post-cleavage target residence duration and exposure of Cas9-induced DSBs. This exposure, via different mechanisms, may initiate variable DNA damage responses, influencing DSB repair pathway choices and contributing to mutational heterogeneity in genome editing.

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Article Synopsis
  • Analysis of human cancer genomes indicates that BRCA1-deficient tumors have distinctive mutation patterns, but the reasons behind these patterns are still unclear.
  • The study found that one-ended DNA double strand breaks (DSBs) created by CRISPR/Cas9 are more likely to cause genetic abnormalities in BRCA1-deficient cells than in normal cells, as they rely on DNA replication for repair.
  • Faulty repair of these one-ended DSBs leads to specific mutations commonly seen in BRCA1-deficient tumors, suggesting that DNA nicks play a significant role in the cancer mutations associated with BRCA1 loss.
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Background: No guideline recommends antiviral therapy for hepatitis B e antigen (HBeAg)-positive chronic hepatitis B patients with persistently normal alanine aminotransferase levels and a high hepatitis B virus (HBV) DNA viral load.

Aim: To evaluate the feasibility and safety of a Chinese herbal formula as a therapeutic option for chronic HBV infection.

Methods: In total, 395 patients (30-65 years old) with confirmed HBeAg-positive chronic hepatitis B infection and persistently normal alanine aminotransferase were randomized to receive either Chinese herbal formula or placebo for 96 wk.

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Background: Many applications of CRISPR/Cas9-mediated genome editing require Cas9-induced non-homologous end joining (NHEJ), which was thought to be error prone. However, with directly ligatable ends, Cas9-induced DNA double strand breaks may be repaired preferentially by accurate NHEJ.

Results: In the repair of two adjacent double strand breaks induced by paired Cas9-gRNAs at 71 genome sites, accurate NHEJ accounts for about 50% of NHEJ events.

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Phosphorylated histone H2AX, termed 'γH2AX', mediates the chromatin response to DNA double strand breaks (DSBs) in mammalian cells. H2AX deficiency increases the numbers of unrepaired DSBs and translocations, which are partly associated with defects in non-homologous end joining (NHEJ) and contributing to genomic instability in cancer. However, the role of γH2AX in NHEJ of general DSBs has yet to be clearly defined.

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Objective: To evaluate the clinical efficacy and safety of Yinchen Zhufu Decoction (, YCZFD) in the treatment of acute-on-chronic liver failure caused by hepatitis B virus (HBV-ACLF) with cold pattern in Chinese medicine (CM).

Methods: This is a multi-center randomized controlled trial of integrative treatment of CM and Western medicine (WM) for the management of HBV-ACLF patients. A total of 200 HBV-ACLF patients with cold pattern were equally randomly assigned to receive YCZFD and WM (integrative treatment) or WM conventional therapy alone respectively for 4 weeks.

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Molecular characterization of individual patients' tumor cells is becoming increasingly important in offering effective treatment for patients in clinical practice. Recent advances in the field have indicated that circulating tumor DNA (ctDNA) has huge potential to serve as a biomarker for early detection and precision treatment as well as prognosis of hepatocellular carcinoma (HCC). As ctDNA in HCC patients harbors the molecular characteristics of HCC tumor cells, ctDNA analysis in the blood may be sufficient for convenient, non-invasive and accurate detection, providing information for HCC diagnosis, treatment and prognosis.

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Cellular response to DNA double-strand breaks (DSBs), the most deleterious type of DNA damage, is highly influenced by higher-order chromatin structure in eukaryotic cells. Compared with euchromatin, the compacted structure of heterochromatin not only protects heterochromatic DNA from damage, but also adds an extra layer of control over the response to DSBs occurring in heterochromatin. One key step in this response is the decondensation of heterochromatin structure.

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Objectives: In this study, we studied the N and H genes from wild type measles viruses (MeVs) isolated during the 2013-2014 outbreak.

Methods: Clinical samples were collected, and the genotyping, phylogenetic analysis were performed.

Results: The vaccination rate of the study population was 4%.

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Objective: 5-Fluorouracil (5-FU)-based combination therapies are standard treatments for gastrointestinal cancer, where the modulation of autophagy is becoming increasingly important in offering effective treatment for patients in clinical practice. This review focuses on the role of autophagy in 5-FU-induced tumor suppression and cancer therapy in the digestive system.

Data Sources: All articles published in English from 1996 to date those assess the synergistic effect of autophagy and 5-FU in gastrointestinal cancer therapy were identified through a systematic online search by use of PubMed.

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Treatment determination based on syndrome differentiation is the key of Chinese medicine. A feasible way of improving the clinical therapy effectiveness is needed to correctly differentiate the syndrome classifications based on the clinical manifestations. In this paper, a novel data mining method based on manifold ranking (MR) is proposed to explore the relation between syndromes and symptoms for viral hepatitis.

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Objective: To investigate the epidemiological characteristics of intolerance to 14 foods in children and the relationship between food intolerance and disease of various systems.

Methods: Serum samples of 2434 children with diseases were collected for food intolerance testing between January 2009 and October 2012. Allergen-specific IgG antibodies to 14 foods were detected using enzyme-linked immunosorbent assay.

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Objective: To study the molecular mechanism of apoptosis of leukemic cells (K562 cells) induced by iron chelating agent deferoxamine (DFO).

Methods: The exponentially growing K562 cells were used (1×10(6)/mL) in this study. The K562 cells were treated with different concentrations of DFO (10, 50 and 100 mmol/L), DFO+FeCl3 (10 μmol/L each) or normal saline (blank control).

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Objective: To investigate the anti-neoplastic effects of Valproic acid (VPA) on leukemic cells, especially drug-resistant lines, and to investigate whether modulation of GSH-redox status is involved in VPA-induced apoptosis.

Methods: After the treatment of VPA at various concentrations for indicated times, cellular proliferation of the Jurkat, CEM, HL-60, K562, K562/AO2 cells were evaluated via MTT assay; and the activities of Caspase-3, Caspase-8 and Caspase-9 were quantitatively analyzed by colorimetric assay. The morphological change and cell cycle distribution were also examined on Jurkat (Dexamethasone-resistant) and K562/AO2 (Doxorubicin-resistant) cell lines.

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This study was purpose to investigate the expression levels of HSP70 and MDR1 genes under heat shock and/or adriamycin (ADM) chemotherapy stimulation. The K562 cells were bathed in water at 43 degrees C for 1 hour, then the heat-treated K562 cells were collected and were cultured at 37 degrees C. The expression of HSP70 was assayed by immunocytochemistry, the growth suppression rate of K562 cells was detected by MTT assay, the function of P-gp and the expressions of HSP70 mRNA, MDR1 mRNA were detected by flow cytometry and real-time quantitative PCR (RT-PCR) respectively.

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Objective: To determine the incidence of TEL-AML1 fusion gene in childhood acute lymphoblastic leukemia (ALL) and to compare the clinical features between TEL-AML1 positive and negative patients.

Methods: Samples of bone marrow or peripheral blood were collected from 95 newly diagnosed ALL children and the TEL-AML1 fusion gene was detected using nested reverse transcription-polymerase chain reaction (RT-PCR). The ALL patients were stratified into TEL-AML1 positive and negative groups and the clinical features were compared.

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To explore a rapid and easy method to detect labile iron of pool (LIP) in cells, HL-60 and K562 cells were cultured at a concentration 1 x 10(6)/ml in RPMI 1640 containing 10% heat-inactivated fetal bovine serum. The iron deprivation was induced by adding desferrioxamine (DFO) 10 - 100 micromol/L for 0 - 48 hours. The intracellular LIP was measured by probe calcein-AM.

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The objective of this study was to investigate antineoplastic effects of valproic acid (VPA) and trichostatin (TSA) on HL-60 and K562 cells in vitro, and the synergic effects of VPA or TSA in combination with ATRA. The inhibitory effects of VPA, TSA and ATRA in various concentrations and different combinations on proliferation of HL-60 and K562 cells were observed by cell growth curves, 50% inhibitory concentration (IC(50)), as well as inhibition of leukemia colony growth at different time points. The characteristics of cell differentiation or apoptosis were analyzed by cytochemical staining, differentiation antigen detection, cell cycle assay and A(NBT)/A(MMT) value determination.

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Objective: To investigate the effect of truncated PDGF-alpha receptor on proliferation expression of c-sis mRNA of pulmonary artery vascular smooth muscular cells(VSMC).

Methods: Tissue mass culture was done to get vascular smooth muscular cells of pulmonary artery. Different concentrations of truncated PDGF-alpha receptor and adenoviral recombined body (Ad5CMV-PalphaRtr, ACP) were added into the cultures.

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Objective: Functionally, erythropoietin (EPO) can promote the proliferation and growth of erythroid progenitor cells, and it is widely used in the treatment of anemia in chronic diseases caused by tumor and inflammation. However, it is unclear whether EPO has any effect on tumor cell iron metabolism and tumor cell proliferation. The purpose of this study was to explore the effects of recombinant human EPO (rhEPO) on the expression of transferrin receptor (TfR, CD(71) antigen) of leukemic cell K562 and its relation to cell cycle.

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