RESUMO
A newly synthesized taxoid originally from the Japanese yew Taxus cuspidata, 5-O-benzoylated taxinine K (BTK) was examined for its ability to reverse P-glycoprotein (P-gp) and multidrug resistance protein (MRP)-mediated multidrug resistance. BTK reversed the resistance to paclitaxel, doxorubicin (ADM), and vincristine (VCR) of KB-8-5 and KB-C2 cells that overexpress P-gp by directly interacting with P-gp. BTK also moderately reversed the resistance to ADM of KB/MRP cells that overexpress MRP. However, BTK neither inhibited the transporting activity of MRP nor reduced intracellular glutathione levels in KB/MRP cells. BTK shifted the distribution of ADM in KB/MRP cells from punctate cytoplasmic compartments to the nucleoplasm and cytoplasm by inhibiting acidification of cytoplasmic organelles. These two functions of BTK make it able to reverse both P-gp- and MRP-mediated MDR. BTK in combination with ADM should be useful for treating patients with tumors that overexpress both P-gp and MRP.
Assuntos
Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Transportadores de Cassetes de Ligação de ATP/metabolismo , Antineoplásicos/farmacologia , Hidrocarbonetos Aromáticos com Pontes/farmacologia , Taxoides , Subfamília B de Transportador de Cassetes de Ligação de ATP/efeitos dos fármacos , Transportadores de Cassetes de Ligação de ATP/efeitos dos fármacos , Azidas/metabolismo , Transporte Biológico/efeitos dos fármacos , Di-Hidropiridinas/metabolismo , Doxorrubicina/farmacologia , Resistencia a Medicamentos Antineoplásicos , Ensaios de Seleção de Medicamentos Antitumorais , Glutationa/metabolismo , Humanos , Células KB , Leucotrieno C4/metabolismo , Proteínas Associadas à Resistência a Múltiplos Medicamentos , Proteínas de Neoplasias/metabolismo , Organelas/efeitos dos fármacos , Organelas/fisiologia , Paclitaxel/farmacologia , Marcadores de Fotoafinidade , Plantas Medicinais , Taxus/química , Trítio , Partículas de Ribonucleoproteínas em Forma de Abóbada/metabolismoRESUMO
Bordetella Pertussis Tohama phase I was cultured in a 300-liter fermentor using a medium containing 0.1% heptakis (2,5-0-dimethyl) beta-cyclodextrin (MeCD). Pertussis toxin (PT) and filamentous hamagglutinin (FHA) were purified using affinity and ion exchange gel column chromatographies. Endotoxin contents of these antigens (10 micrograms PN/ml) were less than 10 ngLPS/ml. PT and FHA were independently treated with formalin in the presence of amino acid and were mixed at a protein concentration ratio of 1:4, the same ratio of our commercialized acellular pertussis vaccine. PDT vaccine containing 2 micrograms PN of PT and 8 micrograms PN of FHA per milliliter was prepared. This PDT vaccine satisfied all the items of the Japanese Minimum Requirements including potency and toxicity tests. Even after this vaccine was incubated for 4 weeks at 37 degrees C, no deaths of the inoculated mice were observed after challenge with 4 mg of histamine on the 4th and 12th day of the inoculation. Compared with the conventional vaccine, this new vaccine caused less swelling in the mouse footpad test. A field trial of our two vaccines, one manufactured by the conventional method (lot No. 21A) and the other produced by the new method (lot No. KC8702), revealed that children receiving KC8702 showed almost the same anti-PT and anti-FHA antibody levels as those given 21A. Those who received KC8702 suffered from less local side effects such as redness, swelling or induration than those given 21A. Our new method for the production of acellular pertussis vaccine permits us the economical manufacturing of the vaccine with uniform quality in a closed system.
