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Tumour growth and resistance to gemcitabine of pancreatic cancer cells are decreased by AP-2alpha overexpression.

Jonckheere N, Fauquette V, Stechly L, Saint-Laurent N, Aubert S, Susini C, Huet G, Porchet N, Van Seuningen I, Pigny P - Br. J. Cancer (2009)

Bottom Line: In vivo tumour growth of CAPAN-1 cells overexpressing AP-2alpha was significantly decreased by comparison to control cells.Moreover, AP-2alpha overexpression increased the chemosensitivity of CAPAN-1 cells to low doses of gemcitabine and reduced their in vitro migration capacity.Our data suggested that AP-2alpha overexpression could be exploited to decrease in vivo tumour growth of pancreatic cancer cells and to increase their sensitivity to gemcitabine.

View Article: PubMed Central - PubMed

Affiliation: INSERM, U837, Université de Lille 2, Centre de Recherche Jean-Pierre Aubert, Place de Verdun, 59045 Lille cedex, France.

ABSTRACT

Background: Activator protein-2alpha (AP-2alpha) is a transcription factor that belongs to the family of AP-2 proteins that have essential roles in tumorigenesis. Indeed, AP-2alpha is considered as a tumour-suppressor gene in different tissues such as colonic, prostatic or breast epithelial cells. Moreover, AP-2alpha also participates in the control of colon and breast cancer cells sensitivity towards chemotherapeutic drugs. Despite its potential interest, very few data are available regarding the roles of AP-2alpha in pancreatic cancer.

Methods: We have developed a stable pancreatic CAPAN-1 cell line overexpressing AP-2alpha. Consequences of overexpression were studied in terms of in vivo cell growth, gene expression, migration capacity and chemosensitivity.

Results: In vivo tumour growth of CAPAN-1 cells overexpressing AP-2alpha was significantly decreased by comparison to control cells. An altered expression pattern of cell cycle-controlling factors (CDK-4, CDK-6, cyclin-G1, p27(kip1) and p57(kip2)) was observed in AP-2alpha-overexpressing clones by microarrays and western blot analysis. Promoter activity and ChIP analysis indicated that AP-2alpha induces p27(kip1) protein levels by direct binding to and transactivation of its promoter. Moreover, AP-2alpha overexpression increased the chemosensitivity of CAPAN-1 cells to low doses of gemcitabine and reduced their in vitro migration capacity.

Conclusion: Our data suggested that AP-2alpha overexpression could be exploited to decrease in vivo tumour growth of pancreatic cancer cells and to increase their sensitivity to gemcitabine.

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Effect of AP-2α over expression on tumour growth and cell cycle. (A) In vivo tumour growth of mock CAPAN-1 cells (C5 control clone), and of two clones overexpressing AP-2α s.c. xenografted in athymic female nude mice (n=6 per group). Tumours were measured every 3–6 days and tumour volume was calculated (see Materials and Methods section for further details). Data are shown as mean (points)±s.d. (error bars). *, P<0.05; **, P<0.01; #, P<0.001. (B) Expression levels of regulators of the cell cycle were evaluated by western blotting in control C5, α42 and α27 clones. Bands were quantified by densitometry and a ratio (specific protein to β-actin) was calculated to evaluate differences between mock cells and the clones. Ratio values are indicated under each panel.
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fig2: Effect of AP-2α over expression on tumour growth and cell cycle. (A) In vivo tumour growth of mock CAPAN-1 cells (C5 control clone), and of two clones overexpressing AP-2α s.c. xenografted in athymic female nude mice (n=6 per group). Tumours were measured every 3–6 days and tumour volume was calculated (see Materials and Methods section for further details). Data are shown as mean (points)±s.d. (error bars). *, P<0.05; **, P<0.01; #, P<0.001. (B) Expression levels of regulators of the cell cycle were evaluated by western blotting in control C5, α42 and α27 clones. Bands were quantified by densitometry and a ratio (specific protein to β-actin) was calculated to evaluate differences between mock cells and the clones. Ratio values are indicated under each panel.

Mentions: Three stable clones derived from CAPAN-1 cell line were s.c. implanted in nude mice (n=6 mice per group): α27 and α42 clones that stably overexpressed high and moderate levels of AP-2α transcription factor, respectively, and the control C5 clone. As shown in Figure 2A, the tumour volume was significantly lower in animals xenografted with the α27 or α42 clones than in those with the C5 clone. At day 22, the mean volume was 1766±433 mm3 in controls (n=6), 1014±280 mm3 in α27 (n=6; P<0.01 vs control clone) and 493±189 mm3 in α42 animals (n=6; P<0.001 vs control clone, P<0.01 vs α27). On day 28, the difference of growth was significant only between controls (n=3) and α42 animals (n=3; P<0.001).


Tumour growth and resistance to gemcitabine of pancreatic cancer cells are decreased by AP-2alpha overexpression.

Jonckheere N, Fauquette V, Stechly L, Saint-Laurent N, Aubert S, Susini C, Huet G, Porchet N, Van Seuningen I, Pigny P - Br. J. Cancer (2009)

Effect of AP-2α over expression on tumour growth and cell cycle. (A) In vivo tumour growth of mock CAPAN-1 cells (C5 control clone), and of two clones overexpressing AP-2α s.c. xenografted in athymic female nude mice (n=6 per group). Tumours were measured every 3–6 days and tumour volume was calculated (see Materials and Methods section for further details). Data are shown as mean (points)±s.d. (error bars). *, P<0.05; **, P<0.01; #, P<0.001. (B) Expression levels of regulators of the cell cycle were evaluated by western blotting in control C5, α42 and α27 clones. Bands were quantified by densitometry and a ratio (specific protein to β-actin) was calculated to evaluate differences between mock cells and the clones. Ratio values are indicated under each panel.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2736821&req=5

fig2: Effect of AP-2α over expression on tumour growth and cell cycle. (A) In vivo tumour growth of mock CAPAN-1 cells (C5 control clone), and of two clones overexpressing AP-2α s.c. xenografted in athymic female nude mice (n=6 per group). Tumours were measured every 3–6 days and tumour volume was calculated (see Materials and Methods section for further details). Data are shown as mean (points)±s.d. (error bars). *, P<0.05; **, P<0.01; #, P<0.001. (B) Expression levels of regulators of the cell cycle were evaluated by western blotting in control C5, α42 and α27 clones. Bands were quantified by densitometry and a ratio (specific protein to β-actin) was calculated to evaluate differences between mock cells and the clones. Ratio values are indicated under each panel.
Mentions: Three stable clones derived from CAPAN-1 cell line were s.c. implanted in nude mice (n=6 mice per group): α27 and α42 clones that stably overexpressed high and moderate levels of AP-2α transcription factor, respectively, and the control C5 clone. As shown in Figure 2A, the tumour volume was significantly lower in animals xenografted with the α27 or α42 clones than in those with the C5 clone. At day 22, the mean volume was 1766±433 mm3 in controls (n=6), 1014±280 mm3 in α27 (n=6; P<0.01 vs control clone) and 493±189 mm3 in α42 animals (n=6; P<0.001 vs control clone, P<0.01 vs α27). On day 28, the difference of growth was significant only between controls (n=3) and α42 animals (n=3; P<0.001).

Bottom Line: In vivo tumour growth of CAPAN-1 cells overexpressing AP-2alpha was significantly decreased by comparison to control cells.Moreover, AP-2alpha overexpression increased the chemosensitivity of CAPAN-1 cells to low doses of gemcitabine and reduced their in vitro migration capacity.Our data suggested that AP-2alpha overexpression could be exploited to decrease in vivo tumour growth of pancreatic cancer cells and to increase their sensitivity to gemcitabine.

View Article: PubMed Central - PubMed

Affiliation: INSERM, U837, Université de Lille 2, Centre de Recherche Jean-Pierre Aubert, Place de Verdun, 59045 Lille cedex, France.

ABSTRACT

Background: Activator protein-2alpha (AP-2alpha) is a transcription factor that belongs to the family of AP-2 proteins that have essential roles in tumorigenesis. Indeed, AP-2alpha is considered as a tumour-suppressor gene in different tissues such as colonic, prostatic or breast epithelial cells. Moreover, AP-2alpha also participates in the control of colon and breast cancer cells sensitivity towards chemotherapeutic drugs. Despite its potential interest, very few data are available regarding the roles of AP-2alpha in pancreatic cancer.

Methods: We have developed a stable pancreatic CAPAN-1 cell line overexpressing AP-2alpha. Consequences of overexpression were studied in terms of in vivo cell growth, gene expression, migration capacity and chemosensitivity.

Results: In vivo tumour growth of CAPAN-1 cells overexpressing AP-2alpha was significantly decreased by comparison to control cells. An altered expression pattern of cell cycle-controlling factors (CDK-4, CDK-6, cyclin-G1, p27(kip1) and p57(kip2)) was observed in AP-2alpha-overexpressing clones by microarrays and western blot analysis. Promoter activity and ChIP analysis indicated that AP-2alpha induces p27(kip1) protein levels by direct binding to and transactivation of its promoter. Moreover, AP-2alpha overexpression increased the chemosensitivity of CAPAN-1 cells to low doses of gemcitabine and reduced their in vitro migration capacity.

Conclusion: Our data suggested that AP-2alpha overexpression could be exploited to decrease in vivo tumour growth of pancreatic cancer cells and to increase their sensitivity to gemcitabine.

Show MeSH
Related in: MedlinePlus