Τίτλος:
Polyadenylate polymerase modulations in human epithelioid cervix and
breast cancer cell lines, treated with etoposide or cordycepin, follow
cell cycle rather than apoptosis induction
Περίληψη:
Cancer results from an imbalance between cell cycle progression and
apoptosis. Therefore, most anticancer drugs exert their anti
proliferative and cytotoxic activity via cell cycle arrest and induction
of apoptosis, a controlled form of cell death that is dysregulated in
cancer. Many polyadenylation trans-acting factors, including
polyadenylate polymerase (PAP), are increasingly found to be involved in
cell cycle, apoptosis and cancer prognosis. The objective of the present
study was to identify PAP modulations in the response of two epithelial
cancer cell lines (HeLa and MCF-7) to apoptosis induction by the
anticancer drugs etoposide and cordycepin. Cells were assessed for PAP
activity and isoforms by the highly sensitive PAP activity assay and
Western blotting, respectively. Induction of apoptosis was determined by
endonucleosomal DNA cleavage, 4’6-diamidino-2-phenylindol (DAPI)
staining and caspase-6 activity assay, whereas cytotoxicity and cell
cycle status were assessed by trypan blue staining,
3-(4,5-dimethylthiazol-2-yl)-2,5diphenyltetrazolium bromide (MTT) assay
and flow cytometry. Our results indicate that PAP changes very early in
response to either etoposide or cordycepin treatment, even prior to the
hallmarks of apoptosis (chromatin condensation and cleavage), in both
cell lines tested, but in a different mode. Our results suggest, for the
first time, that in the epithelial cancer cell lines used, PAP
modulations follow cell cycle progression rather than the course of
apoptosis.
Συγγραφείς:
Thomadaki, H
Tsiapalis, CM
Scorilas, A
