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HER3 as biomarker and therapeutic target in pancreatic cancer: new insights in pertuzumab therapy in preclinical models.

Thomas G, Chardès T, Gaborit N, Mollevi C, Leconet W, Robert B, Radosevic-Robin N, Penault-Llorca F, Gongora C, Colombo PE, Lazrek Y, Bras-Goncalves R, Savina A, Azria D, Bazin H, Pèlegrin A, Larbouret C - Oncotarget (2014)

Bottom Line: We correlated in vitro and in vivo HER3 expression and neuregulin dependency with the inhibitory effect of pertuzumab on cell viability and tumor progression.Finally, HER2 and HER3 were co-expressed in 11% and HER3 alone in 27% of the 45 pancreatic ductal adenocarcinomas analyzed by immunohistochemistry.Further studies in clinical samples are required to confirm these findings and the interest of combining anti-HER2 and anti-HER3 therapeutic antibodies.

View Article: PubMed Central - PubMed

Affiliation: IRCM, Institut de Recherche en Cancérologie de Montpellier, Montpellier, F-34298, France; INSERM, Unit 896, Montpellier, F-34298, France; Université Montpellier1, Montpellier, F-34298, France; ICM, Montpellier, France. Institut Roche de Recherche et Médecine Translationnelle, Boulogne Bilancourt, France.

ABSTRACT
The anti-HER2 antibody pertuzumab inhibits HER2 dimerization and affects HER2/HER3 dimer formation and signaling. As HER3 and its ligand neuregulin are implicated in pancreatic tumorigenesis, we investigated whether HER3 expression could be a predictive biomarker of pertuzumab efficacy in HER2low-expressing pancreatic cancer. We correlated in vitro and in vivo HER3 expression and neuregulin dependency with the inhibitory effect of pertuzumab on cell viability and tumor progression. HER3 knockdown in BxPC-3 cells led to resistance to pertuzumab therapy. Pertuzumab treatment of HER3-expressing pancreatic cancer cells increased HER3 at the cell membrane, whereas the anti-HER3 monoclonal antibody 9F7-F11 down-regulated it. Both antibodies blocked HER3 and AKT phosphorylation and inhibited HER2/HER3 heterodimerization but affected differently HER2 and HER3 homodimers. The pertuzumab/9F7-F11 combination enhanced tumor inhibition and the median survival time in mice xenografted with HER3-expressing pancreatic cancer cells. Finally, HER2 and HER3 were co-expressed in 11% and HER3 alone in 27% of the 45 pancreatic ductal adenocarcinomas analyzed by immunohistochemistry. HER3 is essential for pertuzumab efficacy in HER2low-expressing pancreatic cancer and HER3 expression might be a predictive biomarker of pertuzumab efficacy in such cancers. Further studies in clinical samples are required to confirm these findings and the interest of combining anti-HER2 and anti-HER3 therapeutic antibodies.

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Characteristics of the six pancreatic cancer cell linesA, Flow cytometry analysis of EGFR, HER2 and HER3 expression in the six pancreatic cancer cell lines. Black lines depict cell surface staining with the anti-EGFR, anti-HER2 or anti-HER3 antibodies. The filled dark grey peaks represent controls, obtained with cells incubated only with the FITC-labeled secondary antibody. B, The six cell lines were serum-starved for 24h and then incubated with 1, 10 or 100 ng/ml of NRG1β1 for 5 days. Cell proliferation was measured by MTS. Data are the mean ± SD, n=4. *** p < 0.001, ** p < 0.01.
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Figure 1: Characteristics of the six pancreatic cancer cell linesA, Flow cytometry analysis of EGFR, HER2 and HER3 expression in the six pancreatic cancer cell lines. Black lines depict cell surface staining with the anti-EGFR, anti-HER2 or anti-HER3 antibodies. The filled dark grey peaks represent controls, obtained with cells incubated only with the FITC-labeled secondary antibody. B, The six cell lines were serum-starved for 24h and then incubated with 1, 10 or 100 ng/ml of NRG1β1 for 5 days. Cell proliferation was measured by MTS. Data are the mean ± SD, n=4. *** p < 0.001, ** p < 0.01.

Mentions: The expression of HER family members and NRG1β1-induced proliferation was assessed in five pancreatic cancer cell lines that harbor KRAS mutations and in one cell line (BxPC-3) wild type. All of them were wild type PTEN/PIK3CA. These data are consistent with patterns described in pancreatic tumors (supplementary Table 1). Flow cytometry showed that HER3 was expressed in CFPAC-1, HPAC and BxPC-3, but not in Capan-1, MiaPaCa-2 and PancPec cells. Comparably moderate HER2 and higher EGFR levels were observed in all cell lines (Figure1A). HER4 expression could not be detected in the six cell lines [data not shown]. Incubation with NRG1β1 induced cell proliferation in a dose-dependent manner only in the HER3-positive (BxPC-3, CFPAC-1 and HPAC) cell lines (Figure 1B). However, the finding that NRG1β1 effect was highest in CFPAC-1 cells, which had the lowest HER3 expression level, indicates that it is independent of the HER3 membrane expression level.


HER3 as biomarker and therapeutic target in pancreatic cancer: new insights in pertuzumab therapy in preclinical models.

Thomas G, Chardès T, Gaborit N, Mollevi C, Leconet W, Robert B, Radosevic-Robin N, Penault-Llorca F, Gongora C, Colombo PE, Lazrek Y, Bras-Goncalves R, Savina A, Azria D, Bazin H, Pèlegrin A, Larbouret C - Oncotarget (2014)

Characteristics of the six pancreatic cancer cell linesA, Flow cytometry analysis of EGFR, HER2 and HER3 expression in the six pancreatic cancer cell lines. Black lines depict cell surface staining with the anti-EGFR, anti-HER2 or anti-HER3 antibodies. The filled dark grey peaks represent controls, obtained with cells incubated only with the FITC-labeled secondary antibody. B, The six cell lines were serum-starved for 24h and then incubated with 1, 10 or 100 ng/ml of NRG1β1 for 5 days. Cell proliferation was measured by MTS. Data are the mean ± SD, n=4. *** p < 0.001, ** p < 0.01.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4196190&req=5

Figure 1: Characteristics of the six pancreatic cancer cell linesA, Flow cytometry analysis of EGFR, HER2 and HER3 expression in the six pancreatic cancer cell lines. Black lines depict cell surface staining with the anti-EGFR, anti-HER2 or anti-HER3 antibodies. The filled dark grey peaks represent controls, obtained with cells incubated only with the FITC-labeled secondary antibody. B, The six cell lines were serum-starved for 24h and then incubated with 1, 10 or 100 ng/ml of NRG1β1 for 5 days. Cell proliferation was measured by MTS. Data are the mean ± SD, n=4. *** p < 0.001, ** p < 0.01.
Mentions: The expression of HER family members and NRG1β1-induced proliferation was assessed in five pancreatic cancer cell lines that harbor KRAS mutations and in one cell line (BxPC-3) wild type. All of them were wild type PTEN/PIK3CA. These data are consistent with patterns described in pancreatic tumors (supplementary Table 1). Flow cytometry showed that HER3 was expressed in CFPAC-1, HPAC and BxPC-3, but not in Capan-1, MiaPaCa-2 and PancPec cells. Comparably moderate HER2 and higher EGFR levels were observed in all cell lines (Figure1A). HER4 expression could not be detected in the six cell lines [data not shown]. Incubation with NRG1β1 induced cell proliferation in a dose-dependent manner only in the HER3-positive (BxPC-3, CFPAC-1 and HPAC) cell lines (Figure 1B). However, the finding that NRG1β1 effect was highest in CFPAC-1 cells, which had the lowest HER3 expression level, indicates that it is independent of the HER3 membrane expression level.

Bottom Line: We correlated in vitro and in vivo HER3 expression and neuregulin dependency with the inhibitory effect of pertuzumab on cell viability and tumor progression.Finally, HER2 and HER3 were co-expressed in 11% and HER3 alone in 27% of the 45 pancreatic ductal adenocarcinomas analyzed by immunohistochemistry.Further studies in clinical samples are required to confirm these findings and the interest of combining anti-HER2 and anti-HER3 therapeutic antibodies.

View Article: PubMed Central - PubMed

Affiliation: IRCM, Institut de Recherche en Cancérologie de Montpellier, Montpellier, F-34298, France; INSERM, Unit 896, Montpellier, F-34298, France; Université Montpellier1, Montpellier, F-34298, France; ICM, Montpellier, France. Institut Roche de Recherche et Médecine Translationnelle, Boulogne Bilancourt, France.

ABSTRACT
The anti-HER2 antibody pertuzumab inhibits HER2 dimerization and affects HER2/HER3 dimer formation and signaling. As HER3 and its ligand neuregulin are implicated in pancreatic tumorigenesis, we investigated whether HER3 expression could be a predictive biomarker of pertuzumab efficacy in HER2low-expressing pancreatic cancer. We correlated in vitro and in vivo HER3 expression and neuregulin dependency with the inhibitory effect of pertuzumab on cell viability and tumor progression. HER3 knockdown in BxPC-3 cells led to resistance to pertuzumab therapy. Pertuzumab treatment of HER3-expressing pancreatic cancer cells increased HER3 at the cell membrane, whereas the anti-HER3 monoclonal antibody 9F7-F11 down-regulated it. Both antibodies blocked HER3 and AKT phosphorylation and inhibited HER2/HER3 heterodimerization but affected differently HER2 and HER3 homodimers. The pertuzumab/9F7-F11 combination enhanced tumor inhibition and the median survival time in mice xenografted with HER3-expressing pancreatic cancer cells. Finally, HER2 and HER3 were co-expressed in 11% and HER3 alone in 27% of the 45 pancreatic ductal adenocarcinomas analyzed by immunohistochemistry. HER3 is essential for pertuzumab efficacy in HER2low-expressing pancreatic cancer and HER3 expression might be a predictive biomarker of pertuzumab efficacy in such cancers. Further studies in clinical samples are required to confirm these findings and the interest of combining anti-HER2 and anti-HER3 therapeutic antibodies.

Show MeSH
Related in: MedlinePlus