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Overexpression of neuropilin-1 promotes constitutive MAPK signalling and chemoresistance in pancreatic cancer cells.

Wey JS, Gray MJ, Fan F, Belcheva A, McCarty MF, Stoeltzing O, Somcio R, Liu W, Evans DB, Klagsbrun M, Gallick GE, Ellis LM - Br. J. Cancer (2005)

Bottom Line: Neuropilin-1 overexpression in FG cells enhanced anoikis resistance and increased survival of cells by > 30% after exposure to clinically relevant levels of gemcitabine and 5-FU.In contrast, downregulation of NRP-1 expression in Panc-1 cells markedly increased chemosensitivity, inducing > 50% more cell death at clinically relevant concentrations of gemcitabine.Neuropilin-1 overexpression also increased expression of the antiapoptotic regulator, MCL-1.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgical Oncology, Unit 444, The University of Texas, MD Anderson Cancer Center, PO Box 301402, Houston, TX 77230-1402, USA.

ABSTRACT
Neuropilin-1 (NRP-1) is a novel co-receptor for vascular endothelial growth factor (VEGF). Neuropilin-1 is expressed in pancreatic cancer, but not in nonmalignant pancreatic tissue. We hypothesised that NRP-1 expression by pancreatic cancer cells contributes to the malignant phenotype. To determine the role of NRP-1 in pancreatic cancer, NRP-1 was stably transfected into the human pancreatic cancer cell line FG. Signal transduction was assessed by Western blot analysis. Susceptibility to anoikis (detachment induced apoptosis) was evaluated by colony formation after growth in suspension. Chemosensitivity to gemcitabine or 5-fluorouracil (5-FU) was assessed by MTT assay in pancreatic cancer cells following NRP-1 overexpression or siRNA-induced downregulation of NRP-1. Differential expression of apoptosis-related genes was determined by gene array and further evaluated by Western blot analysis. Neuropilin-1 overexpression increased constitutive mitogen activated protein kinase (MAPK) signalling, possibly via an autocrine loop. Neuropilin-1 overexpression in FG cells enhanced anoikis resistance and increased survival of cells by > 30% after exposure to clinically relevant levels of gemcitabine and 5-FU. In contrast, downregulation of NRP-1 expression in Panc-1 cells markedly increased chemosensitivity, inducing > 50% more cell death at clinically relevant concentrations of gemcitabine. Neuropilin-1 overexpression also increased expression of the antiapoptotic regulator, MCL-1. Neuropilin-1 overexpression in pancreatic cancer cell lines is associated with (a) increased constitutive MAPK signalling, (b) inhibition of anoikis, and (c) chemoresistance. Targeting NRP-1 in pancreatic cancer cells may downregulate survival signalling pathways and increase sensitivity to chemotherapy.

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Related in: MedlinePlus

Effect of NRP-1 overexpression on the antiapoptotic protein, MCL-1. Analysis of apoptosis-related gene expression by gene microarray revealed a three-fold increase in gene expression of the antiapoptotic Bcl-2 homologue, MCL-1. In order to confirm upregulation of the MCL-1 protein, Western blot analysis of the FG mock transfectants and NRP-1 transfectants was performed. A nearly two-fold increase in MCL-1 protein expression was observed in the NRP-1-overexpressing cells. Actin levels are shown as a loading control.
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fig7: Effect of NRP-1 overexpression on the antiapoptotic protein, MCL-1. Analysis of apoptosis-related gene expression by gene microarray revealed a three-fold increase in gene expression of the antiapoptotic Bcl-2 homologue, MCL-1. In order to confirm upregulation of the MCL-1 protein, Western blot analysis of the FG mock transfectants and NRP-1 transfectants was performed. A nearly two-fold increase in MCL-1 protein expression was observed in the NRP-1-overexpressing cells. Actin levels are shown as a loading control.

Mentions: In order to confirm these findings, Western blot analysis of the FG-NRP-1 and mock-transfected cells was carried out to assess relative protein expression levels of DFF45 and MCL-1. While DFF45 protein levels were relatively similar in NRP-1 overexpressing cells and controls (data not shown), MCL-1 protein levels were nearly two-fold higher in NRP-1-transfected cells (Figure 7). The reproducibility of MCL-1 induction by NRP-1 overexpression and the significance of this gene on survival/chemoresistance in other cell lines have yet to be determined.


Overexpression of neuropilin-1 promotes constitutive MAPK signalling and chemoresistance in pancreatic cancer cells.

Wey JS, Gray MJ, Fan F, Belcheva A, McCarty MF, Stoeltzing O, Somcio R, Liu W, Evans DB, Klagsbrun M, Gallick GE, Ellis LM - Br. J. Cancer (2005)

Effect of NRP-1 overexpression on the antiapoptotic protein, MCL-1. Analysis of apoptosis-related gene expression by gene microarray revealed a three-fold increase in gene expression of the antiapoptotic Bcl-2 homologue, MCL-1. In order to confirm upregulation of the MCL-1 protein, Western blot analysis of the FG mock transfectants and NRP-1 transfectants was performed. A nearly two-fold increase in MCL-1 protein expression was observed in the NRP-1-overexpressing cells. Actin levels are shown as a loading control.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2361553&req=5

fig7: Effect of NRP-1 overexpression on the antiapoptotic protein, MCL-1. Analysis of apoptosis-related gene expression by gene microarray revealed a three-fold increase in gene expression of the antiapoptotic Bcl-2 homologue, MCL-1. In order to confirm upregulation of the MCL-1 protein, Western blot analysis of the FG mock transfectants and NRP-1 transfectants was performed. A nearly two-fold increase in MCL-1 protein expression was observed in the NRP-1-overexpressing cells. Actin levels are shown as a loading control.
Mentions: In order to confirm these findings, Western blot analysis of the FG-NRP-1 and mock-transfected cells was carried out to assess relative protein expression levels of DFF45 and MCL-1. While DFF45 protein levels were relatively similar in NRP-1 overexpressing cells and controls (data not shown), MCL-1 protein levels were nearly two-fold higher in NRP-1-transfected cells (Figure 7). The reproducibility of MCL-1 induction by NRP-1 overexpression and the significance of this gene on survival/chemoresistance in other cell lines have yet to be determined.

Bottom Line: Neuropilin-1 overexpression in FG cells enhanced anoikis resistance and increased survival of cells by > 30% after exposure to clinically relevant levels of gemcitabine and 5-FU.In contrast, downregulation of NRP-1 expression in Panc-1 cells markedly increased chemosensitivity, inducing > 50% more cell death at clinically relevant concentrations of gemcitabine.Neuropilin-1 overexpression also increased expression of the antiapoptotic regulator, MCL-1.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgical Oncology, Unit 444, The University of Texas, MD Anderson Cancer Center, PO Box 301402, Houston, TX 77230-1402, USA.

ABSTRACT
Neuropilin-1 (NRP-1) is a novel co-receptor for vascular endothelial growth factor (VEGF). Neuropilin-1 is expressed in pancreatic cancer, but not in nonmalignant pancreatic tissue. We hypothesised that NRP-1 expression by pancreatic cancer cells contributes to the malignant phenotype. To determine the role of NRP-1 in pancreatic cancer, NRP-1 was stably transfected into the human pancreatic cancer cell line FG. Signal transduction was assessed by Western blot analysis. Susceptibility to anoikis (detachment induced apoptosis) was evaluated by colony formation after growth in suspension. Chemosensitivity to gemcitabine or 5-fluorouracil (5-FU) was assessed by MTT assay in pancreatic cancer cells following NRP-1 overexpression or siRNA-induced downregulation of NRP-1. Differential expression of apoptosis-related genes was determined by gene array and further evaluated by Western blot analysis. Neuropilin-1 overexpression increased constitutive mitogen activated protein kinase (MAPK) signalling, possibly via an autocrine loop. Neuropilin-1 overexpression in FG cells enhanced anoikis resistance and increased survival of cells by > 30% after exposure to clinically relevant levels of gemcitabine and 5-FU. In contrast, downregulation of NRP-1 expression in Panc-1 cells markedly increased chemosensitivity, inducing > 50% more cell death at clinically relevant concentrations of gemcitabine. Neuropilin-1 overexpression also increased expression of the antiapoptotic regulator, MCL-1. Neuropilin-1 overexpression in pancreatic cancer cell lines is associated with (a) increased constitutive MAPK signalling, (b) inhibition of anoikis, and (c) chemoresistance. Targeting NRP-1 in pancreatic cancer cells may downregulate survival signalling pathways and increase sensitivity to chemotherapy.

Show MeSH
Related in: MedlinePlus