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Pharmacological targeting of NF-kappaB potentiates the effect of the topoisomerase inhibitor CPT-11 on colon cancer cells.

Lagadec P, Griessinger E, Nawrot MP, Fenouille N, Colosetti P, Imbert V, Mari M, Hofman P, Czerucka D, Rousseau D, Berard E, Dreano M, Peyron JF - Br. J. Cancer (2008)

Bottom Line: NF-kappaB interferes with the effect of most anti-cancer drugs through induction of anti-apoptotic genes.Eighty-five and 75% decreases in tumour size were observed when mice were treated with, respectively, 20 or 5 mg kg(-1) AS602868 associated with 30 mg kg(-1) CPT-11 compared to 47% with CPT-11 alone.This study is the first demonstration that a pharmacological inhibitor of the IKK2 kinase can potentiate the therapeutic efficiency of antineoplasic drugs on solid tumours.

View Article: PubMed Central - PubMed

Affiliation: INSERM U526, Nice F-06000, France. lagadec@unice.fr

ABSTRACT
NF-kappaB interferes with the effect of most anti-cancer drugs through induction of anti-apoptotic genes. Targeting NF-kappaB is therefore expected to potentiate conventional treatments in adjuvant strategies. Here we used a pharmacological inhibitor of the IKK2 kinase (AS602868) to block NF-kappaB activation. In human colon cancer cells, inhibition of NF-kappaB using 10 microM AS602868 induced a 30-50% growth inhibitory effect and strongly enhanced the action of SN-38, the topoisomerase I inhibitor and CPT-11 active metabolite. AS602868 also potentiated the cytotoxic effect of two other antineoplasic drugs: 5-fluorouracil and etoposide. In xenografts experiments, inhibition of NF-kappaB potentiated the antitumoural effect of CPT-11 in a dose-dependent manner. Eighty-five and 75% decreases in tumour size were observed when mice were treated with, respectively, 20 or 5 mg kg(-1) AS602868 associated with 30 mg kg(-1) CPT-11 compared to 47% with CPT-11 alone. Ex vivo tumour analyses as well as in vitro studies showed that AS602868 impaired CPT-11-induced NF-kappaB activation, and enhanced tumour cell cycle arrest and apoptosis. AS602868 also enhanced the apoptotic potential of TNFalpha on HT-29 cells. This study is the first demonstration that a pharmacological inhibitor of the IKK2 kinase can potentiate the therapeutic efficiency of antineoplasic drugs on solid tumours.

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In vitro and in vivo effect of AS602868 combined with CPT-11/SN-38 on the NF-κB pathway. (A) IκB-α phosphorylation levels were studied by western blotting either on lysates of HT-29 cells that were stimulated 30 min with indicated concentrations of AS602868 and SN-38 or in tumours from mice treated as indicated. HSP60 was used as loading control. (B–C) NF-κB activation was visualized by EMSA. HT-29 cells were treated with indicated concentrations of AS602868, 30 min before stimulation with SN-38 (3 and 10 nM) for 1 h or with PMA (10 ng ml−1) for 1 h as positive control. These results correspond to one representative experiment from 3. In supershift experiments, nuclear protein extracts of tumours from CPT-11 and AS602868±CPT-11-treated mice were incubated with anti-p50 and anti-p65 antibodies or rabbit IgG as negative control.
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fig3: In vitro and in vivo effect of AS602868 combined with CPT-11/SN-38 on the NF-κB pathway. (A) IκB-α phosphorylation levels were studied by western blotting either on lysates of HT-29 cells that were stimulated 30 min with indicated concentrations of AS602868 and SN-38 or in tumours from mice treated as indicated. HSP60 was used as loading control. (B–C) NF-κB activation was visualized by EMSA. HT-29 cells were treated with indicated concentrations of AS602868, 30 min before stimulation with SN-38 (3 and 10 nM) for 1 h or with PMA (10 ng ml−1) for 1 h as positive control. These results correspond to one representative experiment from 3. In supershift experiments, nuclear protein extracts of tumours from CPT-11 and AS602868±CPT-11-treated mice were incubated with anti-p50 and anti-p65 antibodies or rabbit IgG as negative control.

Mentions: Western blotting experiments (Figure 3A) performed on HT-29 cells (left panel) or tumours (right panel) showed that IκB-α phosphorylation was increased (upper row) while total levels were reduced (intermediate row) upon CPT-11 stimulation (lanes 3 and 3′ compared, respectively, to lanes 1 and 1′). IκB-α phosphorylation was reduced and total IκB-α enhanced when AS602868 was added (lanes 4 and 4′ compared, respectively, to lines 3 and 3′). As a control, we checked that no changes in Hsp60 levels were observed (lower row). Subsequent NF-κB DNA-binding activity was then studied.


Pharmacological targeting of NF-kappaB potentiates the effect of the topoisomerase inhibitor CPT-11 on colon cancer cells.

Lagadec P, Griessinger E, Nawrot MP, Fenouille N, Colosetti P, Imbert V, Mari M, Hofman P, Czerucka D, Rousseau D, Berard E, Dreano M, Peyron JF - Br. J. Cancer (2008)

In vitro and in vivo effect of AS602868 combined with CPT-11/SN-38 on the NF-κB pathway. (A) IκB-α phosphorylation levels were studied by western blotting either on lysates of HT-29 cells that were stimulated 30 min with indicated concentrations of AS602868 and SN-38 or in tumours from mice treated as indicated. HSP60 was used as loading control. (B–C) NF-κB activation was visualized by EMSA. HT-29 cells were treated with indicated concentrations of AS602868, 30 min before stimulation with SN-38 (3 and 10 nM) for 1 h or with PMA (10 ng ml−1) for 1 h as positive control. These results correspond to one representative experiment from 3. In supershift experiments, nuclear protein extracts of tumours from CPT-11 and AS602868±CPT-11-treated mice were incubated with anti-p50 and anti-p65 antibodies or rabbit IgG as negative control.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2361441&req=5

fig3: In vitro and in vivo effect of AS602868 combined with CPT-11/SN-38 on the NF-κB pathway. (A) IκB-α phosphorylation levels were studied by western blotting either on lysates of HT-29 cells that were stimulated 30 min with indicated concentrations of AS602868 and SN-38 or in tumours from mice treated as indicated. HSP60 was used as loading control. (B–C) NF-κB activation was visualized by EMSA. HT-29 cells were treated with indicated concentrations of AS602868, 30 min before stimulation with SN-38 (3 and 10 nM) for 1 h or with PMA (10 ng ml−1) for 1 h as positive control. These results correspond to one representative experiment from 3. In supershift experiments, nuclear protein extracts of tumours from CPT-11 and AS602868±CPT-11-treated mice were incubated with anti-p50 and anti-p65 antibodies or rabbit IgG as negative control.
Mentions: Western blotting experiments (Figure 3A) performed on HT-29 cells (left panel) or tumours (right panel) showed that IκB-α phosphorylation was increased (upper row) while total levels were reduced (intermediate row) upon CPT-11 stimulation (lanes 3 and 3′ compared, respectively, to lanes 1 and 1′). IκB-α phosphorylation was reduced and total IκB-α enhanced when AS602868 was added (lanes 4 and 4′ compared, respectively, to lines 3 and 3′). As a control, we checked that no changes in Hsp60 levels were observed (lower row). Subsequent NF-κB DNA-binding activity was then studied.

Bottom Line: NF-kappaB interferes with the effect of most anti-cancer drugs through induction of anti-apoptotic genes.Eighty-five and 75% decreases in tumour size were observed when mice were treated with, respectively, 20 or 5 mg kg(-1) AS602868 associated with 30 mg kg(-1) CPT-11 compared to 47% with CPT-11 alone.This study is the first demonstration that a pharmacological inhibitor of the IKK2 kinase can potentiate the therapeutic efficiency of antineoplasic drugs on solid tumours.

View Article: PubMed Central - PubMed

Affiliation: INSERM U526, Nice F-06000, France. lagadec@unice.fr

ABSTRACT
NF-kappaB interferes with the effect of most anti-cancer drugs through induction of anti-apoptotic genes. Targeting NF-kappaB is therefore expected to potentiate conventional treatments in adjuvant strategies. Here we used a pharmacological inhibitor of the IKK2 kinase (AS602868) to block NF-kappaB activation. In human colon cancer cells, inhibition of NF-kappaB using 10 microM AS602868 induced a 30-50% growth inhibitory effect and strongly enhanced the action of SN-38, the topoisomerase I inhibitor and CPT-11 active metabolite. AS602868 also potentiated the cytotoxic effect of two other antineoplasic drugs: 5-fluorouracil and etoposide. In xenografts experiments, inhibition of NF-kappaB potentiated the antitumoural effect of CPT-11 in a dose-dependent manner. Eighty-five and 75% decreases in tumour size were observed when mice were treated with, respectively, 20 or 5 mg kg(-1) AS602868 associated with 30 mg kg(-1) CPT-11 compared to 47% with CPT-11 alone. Ex vivo tumour analyses as well as in vitro studies showed that AS602868 impaired CPT-11-induced NF-kappaB activation, and enhanced tumour cell cycle arrest and apoptosis. AS602868 also enhanced the apoptotic potential of TNFalpha on HT-29 cells. This study is the first demonstration that a pharmacological inhibitor of the IKK2 kinase can potentiate the therapeutic efficiency of antineoplasic drugs on solid tumours.

Show MeSH
Related in: MedlinePlus