The fusion between liposome-liposome, liposome-biomembarnes induced by acid-sensitive polymers has been systematically investigated. The polymer-liposomes were constructed by post-insertion method with the poly (2-ethylacrylic acid) (PEAA) alkylamide derivatives. The liposomal fusion was studied by use of fluorescence resonance energy transfer assay, particle size, fluorescent-photometer. The results indicated that the poly (2-ethylacrylic acid)-liposomes has very strong acidic induced fusion capability. Under acidic conditions, acid-sensitive polymer liposomes fused each other, the fusion closely related to the molecular weight of acid sensitivity polymer on the surface of liposomes. The acidic fusion of polymer-liposomes was dependent upon the lipids composition, the degree of fusion was reversely related to the cholesterol contents. Acid-en ci-nsitive polymer liposomes fused with erythrocyte ghosts. The liposomal fusion induced by acid-sensitive polymer associated with the increase of membrane permeability. The good acid-sensitivity of PEAA has been further demonstrated by membrane fusion in current experiments, and the liposomes prepared with lipid anchored-poly (2-ethylacrylic acid) were developeds s a potential pH sensitive delivery system.
Acrylates ; chemistry ; Alkylation ; Drug Carriers ; Drug Delivery Systems ; Erythrocyte Membrane ; metabolism ; Humans ; Hydrogen-Ion Concentration ; Lipids ; chemistry ; Liposomes ; chemistry ; Membrane Fusion ; Molecular Weight ; Particle Size ; Polymers ; Temperature

Oxidative stress was evaluated for anthracene (Ant) and alkyl-Ants (9-methylanthracene [9-MA] and 9,10-dimethylanthracene [9,10-DMA]) in Caenorhabditis elegans to compare changes in toxicity due to the degree of alkylation. Worms were exposed at 1) the same external exposure concentration and 2) the maximum water-soluble concentration. Formation of reactive oxygen species, superoxide dismutase activity, total glutathione concentration, and lipid peroxidation were determined under constant exposure conditions using passive dosing. The expression of oxidative stress-related genes (daf-2, sir-2.1, daf-16, sod-1, sod-2, sod-3 and cytochrome 35A/C family genes) was also investigated to identify and compare changes in the genetic responses of C. elegans exposed to Ant and alkyl-Ant. At the same external concentration, 9,10-DMA induced the greatest oxidative stress, as evidenced by all indicators, except for lipid peroxidation, followed by 9-MA and Ant. Interestingly, 9,10-DMA led to greater oxidative stress than 9-MA and Ant when worms were exposed to the maximum water-soluble concentration, although the maximum water-soluble concentration of 9,10-DMA is the lowest. Increased oxidative stress by alkyl-Ants would be attributed to higher lipid-water partition coefficient and the π electron density in aromatic rings by alkyl substitution, although this supposition requires further confirmation.
Alkylation ; Ants ; Caenorhabditis elegans* ; Caenorhabditis* ; Cytochromes ; Gene Expression ; Glutathione ; Humans ; Lipid Peroxidation ; Oxidative Stress* ; Polycyclic Hydrocarbons, Aromatic ; Reactive Oxygen Species ; Superoxide Dismutase

Oxidative stress was evaluated for anthracene (Ant) and alkyl-Ants (9-methylanthracene [9-MA] and 9,10-dimethylanthracene [9,10-DMA]) in Caenorhabditis elegans to compare changes in toxicity due to the degree of alkylation. Worms were exposed at 1) the same external exposure concentration and 2) the maximum water-soluble concentration. Formation of reactive oxygen species, superoxide dismutase activity, total glutathione concentration, and lipid peroxidation were determined under constant exposure conditions using passive dosing. The expression of oxidative stress-related genes (daf-2, sir-2.1, daf-16, sod-1, sod-2, sod-3 and cytochrome 35A/C family genes) was also investigated to identify and compare changes in the genetic responses of C. elegans exposed to Ant and alkyl-Ant. At the same external concentration, 9,10-DMA induced the greatest oxidative stress, as evidenced by all indicators, except for lipid peroxidation, followed by 9-MA and Ant. Interestingly, 9,10-DMA led to greater oxidative stress than 9-MA and Ant when worms were exposed to the maximum water-soluble concentration, although the maximum water-soluble concentration of 9,10-DMA is the lowest. Increased oxidative stress by alkyl-Ants would be attributed to higher lipid-water partition coefficient and the π electron density in aromatic rings by alkyl substitution, although this supposition requires further confirmation.
Alkylation ; Ants ; Caenorhabditis elegans ; Caenorhabditis ; Cytochromes ; Gene Expression ; Glutathione ; Humans ; Lipid Peroxidation ; Oxidative Stress ; Polycyclic Hydrocarbons, Aromatic ; Reactive Oxygen Species ; Superoxide Dismutase

Effects of feeding 2(3)-tert-butyl 4-hydroxyanisole (BHA) and 3, 5-di-tert-butyl 4-hydroxytoluene (BHT) on the rates of mixed function oxidation and conjugation enzyme reactions have been determined using isolated hepatic microsomal fractions and isolated perfused livers of mice. The treatments with either of the antioxidants have increased the rates of O-demethylation for p-nitroanisole and of O-deethylation for 7-ethoxycoumarin up to 2-fold, both in microsomes and in perfused liver. Analysis of the perfusate showed that the increased amounts of p-nitrophenol and 7-hydroxycoumarin produced by the elevated mixed-function oxidase activities were reflected by the increase in the amounts of glucuronide conjugates and not in the increase for the amounts of the sulfate ester conjugates. Comparison of results also indicated that in the perfused liver, the maximal rate of metabolite conjugation is limited by the maximal rates of the initial mixed function oxidase activities.
Alkylation ; Animal ; Anisoles/metabolism ; Anisoles/pharmacology* ; Butylated Hydroxyanisole/administration & dosage ; Butylated Hydroxyanisole/pharmacology* ; Butylated Hydroxytoluene/administration & dosage ; Butylated Hydroxytoluene/analogs & derivatives* ; Butylated Hydroxytoluene/pharmacology ; Comparative Study ; Coumarins/metabolism ; Female ; Glucuronosyltransferase/metabolism ; Liver/metabolism* ; Mice ; Microsomes, Liver/enzymology ; Microsomes, Liver/metabolism* ; Mixed Function Oxygenases/metabolism ; Oxidation-Reduction ; Perfusion ; Support, U.S. Gov't, P.H.S.

DNA methylation is a frequent change in epigenetics of leukemia. In the development of leukemia, methylation plays an important role in the genetic expression regulation and genetic structure stabilization. Hematopoietic stem cell transplantation (HSCT) and chemotherapy are the common methods to cure leukemia at present. Unfortunately, it is very hard to find suitable donor for transplantation, while the relapse and drug resistance are the unresolved problems in chemotherapy. Because of the reversibility of methylation, the drugs reducing the level of methylation become a new way to cure leukemia. Decitabine is the most common medicament used to reduce the level of methylation. In this article, the methylation and tumor, methylation and hematologic diseases, methylation detection methods, demethylation therapy in leukemia and so on are reviewed.
DNA Methylation ; Humans ; Leukemia

No abstract available.
Chromatin* ; DNA* ; Epigenomics* ; Histones* ; Methylation*

DNA methylation is an important and reversible epigenetic modification which regulates genomic stability. Methylation is essential for mammalian development. Generally, gene expression level and DNA methylation are negative correlation. Transcriptional silencing via methylation of CpG islands in the promoter is important for cell growth and differentiation and plays a key role in tumorigenesis. Demethylation drug can modify chromatin and restore the ability of anti-oncogene. Demethylation therapy as a new therapy may treat efficiently hematological malignancies with resistance and relapse. In this review, DNA methylation mechanism, relationship between aberrant methylation and hematologic malignancies, mechanism of demethylation therapy, the advance of research on the demethylation therapy of hematological malignancies, such as acute and chronic leukemia, lymphoma, myelodysplastic syndrome were summarized.
DNA Methylation ; Hematologic Neoplasms ; genetics ; metabolism ; therapy ; Humans ; Methylation

The disorders of DNA and histone methylation have a close relationship with the development and progression of tumors. Epigenetic regulation is critical in maintaining the stability and integrity of the expression profiles of different cell types by modifying DNA methylation and histone methylation. However, the abnormal changes of methylation often result in the development and progression of tumors. This review summarized the theory of tumor genomic and histone methylation, detection methods of methylation and their applications, and the clinical application of methylation as biological markers and drug targets.
DNA Methylation ; Histones ; metabolism ; Humans ; Methylation ; Neoplasms ; genetics ; metabolism

Chemical modification of DNA bases in recent years has been one of the hot areas of life science research. DNA methylation is a common epigenetic phenomenon and can change the genetic performance without changing the DNA sequence. Various stress factors can induce the variation of DNA methylation in plants, but the response mechanism is still unknown. In this paper, the progress of DNA methylation in plants was reviewed. In combination with the researchconclusions of our own research group, the DNA methylation variation induced by 7Li ion beam and gamma ray was reported to provide a basis for DNA methylation, which may be involved in the phenotypic plasticity of plants.
DNA Methylation ; Epigenesis, Genetic ; Epigenomics ; Plants ; genetics

Epigenetic abnormalities play an important role in the pathogenesis of hematological malignancies, especially acute leukemia (AL). Similar to DNA methylation and histone modifications, RNA methylation is another important epigenetic modification. m6A methylation is one of the most prevalent and extensively studied RNA methylation. m6A methylation is involved in many biological and pathological process. Recent studies have found that m6A methylation is involved in the occurrence, development and drug-resistance of AL. This review focuses on the research progress of m6A methylation in AL.
DNA Methylation ; Epigenesis, Genetic ; Humans ; Leukemia