Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027960 (mole)
 21,279 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The chemical composition and serological activity of free lipid A from Proteus were studied. Only two fatty acids: myristic acid and 3-hydroxymyristic acid were detected. When calculated for glucosamine disaccharide unit, 2 moles of ester-linked and 1 mole of amide-linked fatty acid are present. Amino group of glucosaminyl residue is substituted by 3-hydroxymyristic acid. The occurence of an uncommon (4-aminoarabinose) substituent, attached outside the backbone, was noticed. The results of serological investigation indicate the great similarity between antigenic determinants of Proteus lipid A and Salmonella-type of lipid.
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PMID:Immunochemical studies on free lipid A from Proteus mirabilis 1959. 37 79

Certain tumors, including many that are found in the lung, overexpress the CD44 cell-surface marker. CD44 is a receptor that binds to hyaluronan (HA), a carbohydrate consisting of beta1,3 N-acetyl glucosaminyl-beta1,4 glucuronide. We hypothesized that the incorporation of phosphatidylethanolamine lipid derivatives-containing HA oligosaccharides (HA-PE) into liposomes could target drug-containing liposomes to tumor cells that express CD44. HA-PE containing palmitoyl oleoyl phosphatidylethanolamine or dipalmitoyl phosphatidylethanolamine (HAn-PE) were incorporated into the lipid bilayer at various mole percentages of the total lipids; and the physicochemical properties (diameter, surface charge, and stability) of the resulting liposome preparations were characterized. HA-targeted liposomes (HALs) avidly bound to the CD44-high-expressing B16F10 murine melanoma cell line but not to the CV-1 African green monkey kidney cells, which express CD44 at low levels. Binding of the HALs to the B16F10 cells was rapid, concentration dependent, and saturated at a lipid concentration of about 250 microM. HAL binding to B16F10 was inhibited by HA with high Mr and by an anti-CD44 monoclonal antibody. Binding to the B16 melanoma cells occurred at a lipid composition that contained a > or =0.1 mol % of the HAn-PE lipid. The bound liposomes were internalized by a temperature-dependent process. The IC50s of doxorubicin (DOX) encapsulated in either HALs or nontargeted liposomes and of nonencapsulated DOX were compared in two protocols: continuous exposure of the cells to treatment for 24 h and transient exposure in which the treatment was applied for a 3-h period, and in which non-cell-associated drug was replaced with drug-free medium for the duration of the experiment. The IC50s of free DOX, DOX-loaded nontargeted liposomes, and DOX-loaded HAL (HAL-DOX) for the transient exposure were 6.4 microM, > 172 microM, and 0.78 microM, respectively. For the continuous exposure protocol, the IC50s were 0.60 microm, 25.0 microl, and 0.14 microm, respectively. Thus, in both protocols, delivered DOX was significantly more potent than the nonencapsulated DOX in cells expressing high levels of CD44, which suggests that HALs may be a useful targeted drug carrier to treat CD44-expressing tumors.
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PMID:Liposome-encapsulated doxorubicin targeted to CD44: a strategy to kill CD44-overexpressing tumor cells. 1128 36