Evaluation of in vitro chemosensitivity of vaccine-associated feline sarcoma cell lines to vincristine and paclitaxel.
OBJECTIVE
To determine the in vitro sensitivity of 4 vaccine-associated feline sarcoma (VAFS) cell lines to the chemotherapeutic agents vincristine and paclitaxel.


METHODS
Cell lines derived from 4 VAFS specimens.


METHODS
Cell lines were cultured in vitro and individually exposed to various concentrations of vincristine and paclitaxel. Survival was estimated after 24 and 72 hours of exposure to each drug, and the drug concentrations that resulted in 50 and 90% reduction in number of viable cells (IC50 and IC90, respectively) were calculated.


RESULTS
Both vincristine and paclitaxel had significant dose-dependent effects on the viability of the VAFS cell lines. After 72 hours of drug exposure, the IC50 and IC90 of vincristine for the 4 cell lines were between 0.005 to 0.039 microg/ml and 0.045 to 1.027 microg/ml, respectively. The IC50 and IC90 values for paclitaxel were between 0.037 to 0.092 microg/ml and 2.450 to 15.413 microg/ml, respectively.


CONCLUSIONS
Results of pharmacokinetic studies on vincristine and paclitaxel in other species suggest that concentrations greater than the IC50 values may be possible for both drugs in feline patients as well. The drug concentrations at which viable cell numbers were reduced by 90% may also be attained in vivo for some cases, but detailed information is needed regarding the distribution, concentration, duration of availability, and toxicity of various drugs in cats. Carefully chosen combinations of antineoplastic agents need to be screened to identify treatment protocols that may be further evaluated clinically for the treatment of VAFS.
Banerji
Nilanjana
N
Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Minnesota, St Paul 55108, USA.
Li
Xia
X
Klausner
Jeffrey S
JS
Kapur
Vivek
V
Kanjilal
Sagarika
S
D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D002371:Cat Diseases / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D002415:Cats; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D005260:Female; D020128:Inhibitory Concentration 50; D008297:Male; D017239:Paclitaxel / Q000494:pharmacology*; D012509:Sarcoma / Q000188:drug therapy / Q000276:immunology / Q000473:pathology / Q000662:veterinary*; D014407:Tumor Cells, Cultured; D014611:Vaccination / Q000009:adverse effects / Q000662:veterinary*; D014750:Vincristine / Q000494:pharmacology*
D000972:Antineoplastic Agents, Phytogenic; D014750:Vincristine; D017239:Paclitaxel