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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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Effect of pertuzumab on HER3-positive or -negative pancreatic cancer cell linesCells were directly incubated with pertuzumab for 5 days (A) or serum-deprived for 24h and stimulated with 10 ng/ml NRG1β1 added two hours after pertuzumab treatment (B). Cell proliferation was analyzed by MTS. Data are the mean ± SD, n=3. Results were expressed relative to untreated cells. *** p < 0.001, ** p < 0.01 * p < 0.05, n.s., not significant. C, Pancreatic cancer cells were xenografted in nude mice that were then treated with 2 or 10 mg/kg pertuzumab (P2 and P10) or sterile PBS twice/week. Results are presented as the mean tumor volume of each group. Bars = SEM.
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Figure 2: Effect of pertuzumab on HER3-positive or -negative pancreatic cancer cell linesCells were directly incubated with pertuzumab for 5 days (A) or serum-deprived for 24h and stimulated with 10 ng/ml NRG1β1 added two hours after pertuzumab treatment (B). Cell proliferation was analyzed by MTS. Data are the mean ± SD, n=3. Results were expressed relative to untreated cells. *** p < 0.001, ** p < 0.01 * p < 0.05, n.s., not significant. C, Pancreatic cancer cells were xenografted in nude mice that were then treated with 2 or 10 mg/kg pertuzumab (P2 and P10) or sterile PBS twice/week. Results are presented as the mean tumor volume of each group. Bars = SEM.

Mentions: We then investigated the ability of pertuzumab to inhibit the growth of the six pancreatic cancer cell lines after stimulation, or not, by NRG1β1. In the absence of ligand stimulation, pertuzumab reduced the growth of the HER3-positive cell lines in a dose-dependent manner [between 10% and 35%], but did not affect the viability of the HER3-negative cell lines (Figure 2A). Pertuzumab growth inhibition of the HER3-positive pancreatic cancer cell line BxPC-3 was significantly increased following stimulation with NRG1β1 (60% inhibition with neuregulin stimulation versus 35% without it) (Figure 2B). Conversely, no NRG1β1 effect was observed in HER3-negative Capan-1 cells (Figure 2B). These results demonstrate that pertuzumab is efficient in HER3-positive pancreatic cancer cells independently of NRG1β1 stimulation; however, neuregulin signaling through HER3 potentiates its inhibitory effect on pancreatic cell growth.


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)

Effect of pertuzumab on HER3-positive or -negative pancreatic cancer cell linesCells were directly incubated with pertuzumab for 5 days (A) or serum-deprived for 24h and stimulated with 10 ng/ml NRG1β1 added two hours after pertuzumab treatment (B). Cell proliferation was analyzed by MTS. Data are the mean ± SD, n=3. Results were expressed relative to untreated cells. *** p < 0.001, ** p < 0.01 * p < 0.05, n.s., not significant. C, Pancreatic cancer cells were xenografted in nude mice that were then treated with 2 or 10 mg/kg pertuzumab (P2 and P10) or sterile PBS twice/week. Results are presented as the mean tumor volume of each group. Bars = SEM.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 2: Effect of pertuzumab on HER3-positive or -negative pancreatic cancer cell linesCells were directly incubated with pertuzumab for 5 days (A) or serum-deprived for 24h and stimulated with 10 ng/ml NRG1β1 added two hours after pertuzumab treatment (B). Cell proliferation was analyzed by MTS. Data are the mean ± SD, n=3. Results were expressed relative to untreated cells. *** p < 0.001, ** p < 0.01 * p < 0.05, n.s., not significant. C, Pancreatic cancer cells were xenografted in nude mice that were then treated with 2 or 10 mg/kg pertuzumab (P2 and P10) or sterile PBS twice/week. Results are presented as the mean tumor volume of each group. Bars = SEM.
Mentions: We then investigated the ability of pertuzumab to inhibit the growth of the six pancreatic cancer cell lines after stimulation, or not, by NRG1β1. In the absence of ligand stimulation, pertuzumab reduced the growth of the HER3-positive cell lines in a dose-dependent manner [between 10% and 35%], but did not affect the viability of the HER3-negative cell lines (Figure 2A). Pertuzumab growth inhibition of the HER3-positive pancreatic cancer cell line BxPC-3 was significantly increased following stimulation with NRG1β1 (60% inhibition with neuregulin stimulation versus 35% without it) (Figure 2B). Conversely, no NRG1β1 effect was observed in HER3-negative Capan-1 cells (Figure 2B). These results demonstrate that pertuzumab is efficient in HER3-positive pancreatic cancer cells independently of NRG1β1 stimulation; however, neuregulin signaling through HER3 potentiates its inhibitory effect on pancreatic cell growth.

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