Effect of taxol feeding on taxol and related taxane production in Taxus baccata suspension cultures.
To achieve a better understanding of taxol metabolism and accumulation in Taxus cell cultures, a T. baccata cell line growing for 20 days in a selected growth medium was treated at the beginning of the experiment with several concentrations of taxol (25, 50, 100 and 200mgL(-1)). Compared with an untreated control, all these taxol concentrations stimulated cell-associated taxol content (up to 32.7 times in the presence of 200mgL(-1) exogenous taxol), although higher concentrations significantly depressed cell viability. DNA laddering analysis revealed that the viability reduction was not related to apoptosis, suggesting that taxol itself was the primary responsible factor. On the basis of RT-PCR expression analysis of genes encoding taxadiene synthase (ts) and 1-deoxy-d-xylulose-5-phosphate synthase (dxs) from treated and nontreated T. baccata cell line cultures, it was observed that exogenous taxol clearly induced the mRNA levels of both taxane-related enzymes. Additionally, we found that exogenous taxol caused a considerable increase in taxadiene synthase activity, although in no case did this coincide with the highest levels of taxol observed at the end of the culture. The effect of exogenous taxol on the content of other related taxanes was also considered.
Expósito
Oscar
O
Laboratorio de Fisiología vegetal, Facultad de Farmacia, Universidad de Barcelona, Avda. Diagonal 643, E-08028 Barcelona, Spain.
Bonfill
Mercedes
M
Onrubia
Miriam
M
Jané
Albert
A
Moyano
Elisabet
E
Cusidó
Rosa M
RM
Palazón
Javier
J
Piñol
M Teresa
MT
D001952:Bridged-Ring Compounds / Q000378:metabolism*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D017239:Paclitaxel / Q000008:administration & dosage* / Q000378:metabolism*; D043823:Taxoids / Q000378:metabolism*; D020946:Taxus / Q000187:drug effects / Q000378:metabolism*
D001952:Bridged-Ring Compounds; D043823:Taxoids; C080625:taxane; D017239:Paclitaxel