Paclitaxel-induced apoptosis in non-small cell lung cancer cell lines is associated with increased caspase-3 activity.
OBJECTIVE
Our objective was to determine whether paclitaxel-induced apoptosis in human lung cancer cells is Fas dependent.


METHODS
Human lung cancer cell lines were evaluated for morphologic evidence of apoptosis, DNA fragmentation (TUNEL positivity), and caspase-3 activation after paclitaxel treatment. Human lung adenocarcinoma, squamous cell carcinoma, undifferentiated lung carcinoma, and bronchoalveolar carcinoma cell lines were each cultured in 10 micromol/L paclitaxel.


RESULTS
After 24 hours of culture in paclitaxel, a 22% to 69% increase in the number of apoptotic cells was evident by means of methylene blue-azure A-eosin staining with characteristic blebbing and nuclear condensation. TUNEL assay also confirmed an increase of 19.9% to 73.0% of cells with nuclear fragmentation. Caspase-3 activity, assayed by Z-DEVD cleavage, increased from 20% to 215% (P <.05). ZB4, an antagonistic anti-Fas antibody, did not block paclitaxel induction of caspase-3 activity (155.8 vs 165.8 U, not significant). Apoptotic morphologic changes were inhibited in cells cultured in the presence of paclitaxel and Ac-DEVD-CHO, a caspase-3 inhibitor.


CONCLUSIONS
Paclitaxel induces apoptosis in lung cancer cell lines, as assessed by a consistent increase in caspase-3 activity, DNA laddering, and characteristic morphologic changes. Paclitaxel-induced apoptosis in human lung cancer cells is associated with caspase-3 activation but is not Fas dependent.
Weigel
T L
TL
Section of Thoracic Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
Lotze
M T
MT
Kim
P K
PK
Amoscato
A A
AA
Luketich
J D
JD
Odoux
C
C
D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D002289:Carcinoma, Non-Small-Cell Lung / Q000737:chemistry / Q000201:enzymology / Q000473:pathology*; D053148:Caspase 3; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism*; D053938:DNA Fragmentation; D006801:Humans; D020287:In Situ Nick-End Labeling; D008175:Lung Neoplasms / Q000737:chemistry / Q000201:enzymology / Q000473:pathology*; D009842:Oligopeptides / Q000494:pharmacology; D017239:Paclitaxel / Q000494:pharmacology*; D014407:Tumor Cells, Cultured; D019014:fas Receptor / Q000032:analysis
D000972:Antineoplastic Agents, Phytogenic; D061945:Caspase Inhibitors; D009842:Oligopeptides; C099158:acetyl-aspartyl-glutamyl-valyl-aspartal; D019014:fas Receptor; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; D017239:Paclitaxel