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The role of apoptotic cell death in the radiosensitising effect of gemcitabine.

Pauwels B, Vermorken JB, Wouters A, Ides J, Van Laere S, Lambrechts HA, Pattyn GG, Vermeulen K, Meijnders P, Lardon F - Br. J. Cancer (2009)

Bottom Line: When cell-cycle distribution returned to pre-treatment levels, an increased induction of apoptosis was observed with activation of caspase 8 and 9 and a reduction of the mitochondrial membrane potential.A role for the cell-cycle perturbations and the induction of apoptosis could be attributed to the radiosensitising effect of gemcitabine.Apoptosis induction was comparable with the apoptotic pathway observed after the TRAIL treatment, that is the involvement of the extrinsic apoptosis pathway.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Cancer Research and Clinical Oncology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium. bea.pauwels@ua.ac.be

ABSTRACT

Background: The aim of this study was to evaluate the radiosensitising effect of gemcitabine, in terms of cell-cycle progression, induction of apoptosis, and to investigate the molecular events regulating apoptosis.

Methods: Tumour cells were treated with gemcitabine, radiation, or the combination. 0-72 h after treatment, cells were collected for cell-cycle analysis and apoptosis determination. Caspase 8 and 9, Bid and tBid expression were determined by western blot. The mitochondrial membrane potential was determined using flow cytometry. An RT(2) Profiler PCR Array for human apoptotic genes was performed after the combination or TRAIL treatment.

Results: Gemcitabine and radiation resulted in an early S-phase block immediately after treatment, after which the cells moved synchronously through the cell cycle. When cell-cycle distribution returned to pre-treatment levels, an increased induction of apoptosis was observed with activation of caspase 8 and 9 and a reduction of the mitochondrial membrane potential. Gene expression after treatment with radiosensitising conditions was comparable with expression after the TRAIL treatment.

Conclusion: A role for the cell-cycle perturbations and the induction of apoptosis could be attributed to the radiosensitising effect of gemcitabine. Apoptosis induction was comparable with the apoptotic pathway observed after the TRAIL treatment, that is the involvement of the extrinsic apoptosis pathway.

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Related in: MedlinePlus

Radiation dose–response curves of ECV304 and H292 cells after treatment with gemcitabine (0–8 nM) during 24 h, immediately before or after radiotherapy (0–8 Gy).
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fig1: Radiation dose–response curves of ECV304 and H292 cells after treatment with gemcitabine (0–8 nM) during 24 h, immediately before or after radiotherapy (0–8 Gy).

Mentions: A clear concentration-dependent radiosensitising effect of gemcitabine was observed in ECV304 and H292 cells, when cells were treated during 24 h with gemcitabine before radiotherapy (Figure 1). This radiosensitising effect was not observed when cells were treated with gemcitabine during 24 h immediately after irradiation. When gemcitabine treatment preceded radiation, DEFs ranged from 1.39 to 3.05 (CI values 1.05–0.65) in ECV304 cells and from 1.20 to 2.67 (CI values 1.21–0.76) in H292 cells (Pauwels et al, 2003a). When gemcitabine followed radiotherapy DEFs ranged from 0.98 to 1.02 and from 1.12 to 1.19 for ECV304 and H292 cells, respectively, with CI values above 0.827 for ECV304 and above 1.071 for H292 cells. Statistical analysis using two-way ANOVA revealed that cell survival was significantly influenced by the concentration of gemcitabine, the dose of radiation, and the treatment schedule (gemcitabine before or after radiotherapy) in both cell lines. Post hoc analysis showed in ECV304 significant differences among all radiation doses and also among 0, 1, and 2 nM gemcitabine. No significant difference was observed between 2 and 4 nM gemcitabine (P=0.865). In H292 cells, significant differences were observed among all radiation doses and between 0 and 4 nM gemcitabine. No significant differences were observed among 4, 6, and 8 nM gemcitabine (P>0.724).


The role of apoptotic cell death in the radiosensitising effect of gemcitabine.

Pauwels B, Vermorken JB, Wouters A, Ides J, Van Laere S, Lambrechts HA, Pattyn GG, Vermeulen K, Meijnders P, Lardon F - Br. J. Cancer (2009)

Radiation dose–response curves of ECV304 and H292 cells after treatment with gemcitabine (0–8 nM) during 24 h, immediately before or after radiotherapy (0–8 Gy).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2736812&req=5

fig1: Radiation dose–response curves of ECV304 and H292 cells after treatment with gemcitabine (0–8 nM) during 24 h, immediately before or after radiotherapy (0–8 Gy).
Mentions: A clear concentration-dependent radiosensitising effect of gemcitabine was observed in ECV304 and H292 cells, when cells were treated during 24 h with gemcitabine before radiotherapy (Figure 1). This radiosensitising effect was not observed when cells were treated with gemcitabine during 24 h immediately after irradiation. When gemcitabine treatment preceded radiation, DEFs ranged from 1.39 to 3.05 (CI values 1.05–0.65) in ECV304 cells and from 1.20 to 2.67 (CI values 1.21–0.76) in H292 cells (Pauwels et al, 2003a). When gemcitabine followed radiotherapy DEFs ranged from 0.98 to 1.02 and from 1.12 to 1.19 for ECV304 and H292 cells, respectively, with CI values above 0.827 for ECV304 and above 1.071 for H292 cells. Statistical analysis using two-way ANOVA revealed that cell survival was significantly influenced by the concentration of gemcitabine, the dose of radiation, and the treatment schedule (gemcitabine before or after radiotherapy) in both cell lines. Post hoc analysis showed in ECV304 significant differences among all radiation doses and also among 0, 1, and 2 nM gemcitabine. No significant difference was observed between 2 and 4 nM gemcitabine (P=0.865). In H292 cells, significant differences were observed among all radiation doses and between 0 and 4 nM gemcitabine. No significant differences were observed among 4, 6, and 8 nM gemcitabine (P>0.724).

Bottom Line: When cell-cycle distribution returned to pre-treatment levels, an increased induction of apoptosis was observed with activation of caspase 8 and 9 and a reduction of the mitochondrial membrane potential.A role for the cell-cycle perturbations and the induction of apoptosis could be attributed to the radiosensitising effect of gemcitabine.Apoptosis induction was comparable with the apoptotic pathway observed after the TRAIL treatment, that is the involvement of the extrinsic apoptosis pathway.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Cancer Research and Clinical Oncology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium. bea.pauwels@ua.ac.be

ABSTRACT

Background: The aim of this study was to evaluate the radiosensitising effect of gemcitabine, in terms of cell-cycle progression, induction of apoptosis, and to investigate the molecular events regulating apoptosis.

Methods: Tumour cells were treated with gemcitabine, radiation, or the combination. 0-72 h after treatment, cells were collected for cell-cycle analysis and apoptosis determination. Caspase 8 and 9, Bid and tBid expression were determined by western blot. The mitochondrial membrane potential was determined using flow cytometry. An RT(2) Profiler PCR Array for human apoptotic genes was performed after the combination or TRAIL treatment.

Results: Gemcitabine and radiation resulted in an early S-phase block immediately after treatment, after which the cells moved synchronously through the cell cycle. When cell-cycle distribution returned to pre-treatment levels, an increased induction of apoptosis was observed with activation of caspase 8 and 9 and a reduction of the mitochondrial membrane potential. Gene expression after treatment with radiosensitising conditions was comparable with expression after the TRAIL treatment.

Conclusion: A role for the cell-cycle perturbations and the induction of apoptosis could be attributed to the radiosensitising effect of gemcitabine. Apoptosis induction was comparable with the apoptotic pathway observed after the TRAIL treatment, that is the involvement of the extrinsic apoptosis pathway.

Show MeSH
Related in: MedlinePlus