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Multiple receptor tyrosine kinase activation attenuates therapeutic efficacy of the fibroblast growth factor receptor 2 inhibitor AZD4547 in FGFR2 amplified gastric cancer.

Chang J, Wang S, Zhang Z, Liu X, Wu Z, Geng R, Ge X, Dai C, Liu R, Zhang Q, Li W, Li J - Oncotarget (2015)

Bottom Line: However, intrinsic or acquired drug resistance has emerged as a major challenge to their clinical use.The rescue effect was abrogated by inhibiting these RTKs with their targeted tyrosine kinase inhibitors (TKIs).A combination targeted therapeutic strategy may be recommended for treating FGFR2 amplified GC patients with these RTK activations.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Oncology, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.

ABSTRACT
Fibroblast growth factor receptor 2 (FGFR2)-targeted therapy has attracted considerable attention as novel anticancer agents in gastric cancer (GC). However, intrinsic or acquired drug resistance has emerged as a major challenge to their clinical use. In this study, we demonstrated that several receptor tyrosine kinase (RTK), including EGFR, HER3 and MET, activations contributed to AZD4547 (a selective FGFR2 inhibitor) hyposensitivity in FGFR2 amplified GC cells. The rescue effect was abrogated by inhibiting these RTKs with their targeted tyrosine kinase inhibitors (TKIs). In addition, synergy in growth inhibition was observed when the GC cells were treated with a combination of AZD4547 and cetuximab (an EGFR monoclonal antibody) both in vitro and in vivo. More importantly, tissue microarray analysis revealed that these resistance-conferring RTKs were highly expressed in FGFR2 positive GC patients. Taken together, these observations demonstrated RTKs including EGFR, HER3 and MET activations as novel mechanisms of hyposensitivity to AZD4547. It will be clinically valuable to investigate the involvement of RTK-mediated signaling in intrinsicor acquired resistance to FGFR2 TKIs in GC. A combination targeted therapeutic strategy may be recommended for treating FGFR2 amplified GC patients with these RTK activations.

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Synergistic antitumor efficacy of AZD4547 and cetuximab on SNU16 cells both in vitro and in vivoA) Combination therapy with AZD4547 and cetuximab resulted in a significant increase in cell growth toxicity in SNU16 cells. Cells were treated with increasing concentrations of the indicated drugs for 72 hours. The CI/fractional effects curve showed the synergistic anti-proliferative effects of the combination drugs. Multiple drug analyses were conducted by calculating CI values. Data (n = 6) are presented as mean ± SD. * p < 0.01 combination therapy vs. AZD4547 or cetuximab alone. SNU16 cells were treated with 10 nM AZD4547 and 1 uM cetuximab for 24 hours, and the whole cell lysates were collected and analyzed by western blot. Combination therapy with AZD4547 and cetuximab synergistically inhibited phosphorylation of ERK1/2. B) Combination therapy with AZD4547 and cetuximab resulted in synergistic antitumor efficacy in SNU16 xenografts. Groups of SNU16 tumor-bearing mice (n = 6) were treated daily with vehicle (PBS), AZD4547 2 mg/kg q.d., cetuximab 1 mg per animal i.v., and AZD4547 2 mg/kg q.d. plus cetuximab 1 mg per animal i.v.. Cetuximab was administrated on days 1, 4, 7, 11 and 14. The tumor volume, tumor weight and animal body weight were measured and calculated as described in the Materials and Methods. Data (n = 6) are presented as mean ± SD. * p < 0.001 PBS vs. AZD4547, cetuximab and combination therapy.
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Figure 3: Synergistic antitumor efficacy of AZD4547 and cetuximab on SNU16 cells both in vitro and in vivoA) Combination therapy with AZD4547 and cetuximab resulted in a significant increase in cell growth toxicity in SNU16 cells. Cells were treated with increasing concentrations of the indicated drugs for 72 hours. The CI/fractional effects curve showed the synergistic anti-proliferative effects of the combination drugs. Multiple drug analyses were conducted by calculating CI values. Data (n = 6) are presented as mean ± SD. * p < 0.01 combination therapy vs. AZD4547 or cetuximab alone. SNU16 cells were treated with 10 nM AZD4547 and 1 uM cetuximab for 24 hours, and the whole cell lysates were collected and analyzed by western blot. Combination therapy with AZD4547 and cetuximab synergistically inhibited phosphorylation of ERK1/2. B) Combination therapy with AZD4547 and cetuximab resulted in synergistic antitumor efficacy in SNU16 xenografts. Groups of SNU16 tumor-bearing mice (n = 6) were treated daily with vehicle (PBS), AZD4547 2 mg/kg q.d., cetuximab 1 mg per animal i.v., and AZD4547 2 mg/kg q.d. plus cetuximab 1 mg per animal i.v.. Cetuximab was administrated on days 1, 4, 7, 11 and 14. The tumor volume, tumor weight and animal body weight were measured and calculated as described in the Materials and Methods. Data (n = 6) are presented as mean ± SD. * p < 0.001 PBS vs. AZD4547, cetuximab and combination therapy.

Mentions: To determine whether co-targeting FGFR2 and EGFR exhibits a synergistic effect on SNU16 cells, we examined the effect of individual and combination treatment with AZD4547 (FGFR2 TKI) and cetuximab (EGFR monoclonal antibody) after 72 hours of exposure using the CCK-8 assay. The results showed that the combination of AZD4547 and cetuximab resulted in a significant increase in cell growth toxicity when compared with either drug alone (p < 0.01). The combination index (CI)/fractional effect curve showed that the synergistic effects between these two agents became stronger as the concentration increased (Fig. 3A, left).


Multiple receptor tyrosine kinase activation attenuates therapeutic efficacy of the fibroblast growth factor receptor 2 inhibitor AZD4547 in FGFR2 amplified gastric cancer.

Chang J, Wang S, Zhang Z, Liu X, Wu Z, Geng R, Ge X, Dai C, Liu R, Zhang Q, Li W, Li J - Oncotarget (2015)

Synergistic antitumor efficacy of AZD4547 and cetuximab on SNU16 cells both in vitro and in vivoA) Combination therapy with AZD4547 and cetuximab resulted in a significant increase in cell growth toxicity in SNU16 cells. Cells were treated with increasing concentrations of the indicated drugs for 72 hours. The CI/fractional effects curve showed the synergistic anti-proliferative effects of the combination drugs. Multiple drug analyses were conducted by calculating CI values. Data (n = 6) are presented as mean ± SD. * p < 0.01 combination therapy vs. AZD4547 or cetuximab alone. SNU16 cells were treated with 10 nM AZD4547 and 1 uM cetuximab for 24 hours, and the whole cell lysates were collected and analyzed by western blot. Combination therapy with AZD4547 and cetuximab synergistically inhibited phosphorylation of ERK1/2. B) Combination therapy with AZD4547 and cetuximab resulted in synergistic antitumor efficacy in SNU16 xenografts. Groups of SNU16 tumor-bearing mice (n = 6) were treated daily with vehicle (PBS), AZD4547 2 mg/kg q.d., cetuximab 1 mg per animal i.v., and AZD4547 2 mg/kg q.d. plus cetuximab 1 mg per animal i.v.. Cetuximab was administrated on days 1, 4, 7, 11 and 14. The tumor volume, tumor weight and animal body weight were measured and calculated as described in the Materials and Methods. Data (n = 6) are presented as mean ± SD. * p < 0.001 PBS vs. AZD4547, cetuximab and combination therapy.
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Related In: Results  -  Collection

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Figure 3: Synergistic antitumor efficacy of AZD4547 and cetuximab on SNU16 cells both in vitro and in vivoA) Combination therapy with AZD4547 and cetuximab resulted in a significant increase in cell growth toxicity in SNU16 cells. Cells were treated with increasing concentrations of the indicated drugs for 72 hours. The CI/fractional effects curve showed the synergistic anti-proliferative effects of the combination drugs. Multiple drug analyses were conducted by calculating CI values. Data (n = 6) are presented as mean ± SD. * p < 0.01 combination therapy vs. AZD4547 or cetuximab alone. SNU16 cells were treated with 10 nM AZD4547 and 1 uM cetuximab for 24 hours, and the whole cell lysates were collected and analyzed by western blot. Combination therapy with AZD4547 and cetuximab synergistically inhibited phosphorylation of ERK1/2. B) Combination therapy with AZD4547 and cetuximab resulted in synergistic antitumor efficacy in SNU16 xenografts. Groups of SNU16 tumor-bearing mice (n = 6) were treated daily with vehicle (PBS), AZD4547 2 mg/kg q.d., cetuximab 1 mg per animal i.v., and AZD4547 2 mg/kg q.d. plus cetuximab 1 mg per animal i.v.. Cetuximab was administrated on days 1, 4, 7, 11 and 14. The tumor volume, tumor weight and animal body weight were measured and calculated as described in the Materials and Methods. Data (n = 6) are presented as mean ± SD. * p < 0.001 PBS vs. AZD4547, cetuximab and combination therapy.
Mentions: To determine whether co-targeting FGFR2 and EGFR exhibits a synergistic effect on SNU16 cells, we examined the effect of individual and combination treatment with AZD4547 (FGFR2 TKI) and cetuximab (EGFR monoclonal antibody) after 72 hours of exposure using the CCK-8 assay. The results showed that the combination of AZD4547 and cetuximab resulted in a significant increase in cell growth toxicity when compared with either drug alone (p < 0.01). The combination index (CI)/fractional effect curve showed that the synergistic effects between these two agents became stronger as the concentration increased (Fig. 3A, left).

Bottom Line: However, intrinsic or acquired drug resistance has emerged as a major challenge to their clinical use.The rescue effect was abrogated by inhibiting these RTKs with their targeted tyrosine kinase inhibitors (TKIs).A combination targeted therapeutic strategy may be recommended for treating FGFR2 amplified GC patients with these RTK activations.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Oncology, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.

ABSTRACT
Fibroblast growth factor receptor 2 (FGFR2)-targeted therapy has attracted considerable attention as novel anticancer agents in gastric cancer (GC). However, intrinsic or acquired drug resistance has emerged as a major challenge to their clinical use. In this study, we demonstrated that several receptor tyrosine kinase (RTK), including EGFR, HER3 and MET, activations contributed to AZD4547 (a selective FGFR2 inhibitor) hyposensitivity in FGFR2 amplified GC cells. The rescue effect was abrogated by inhibiting these RTKs with their targeted tyrosine kinase inhibitors (TKIs). In addition, synergy in growth inhibition was observed when the GC cells were treated with a combination of AZD4547 and cetuximab (an EGFR monoclonal antibody) both in vitro and in vivo. More importantly, tissue microarray analysis revealed that these resistance-conferring RTKs were highly expressed in FGFR2 positive GC patients. Taken together, these observations demonstrated RTKs including EGFR, HER3 and MET activations as novel mechanisms of hyposensitivity to AZD4547. It will be clinically valuable to investigate the involvement of RTK-mediated signaling in intrinsicor acquired resistance to FGFR2 TKIs in GC. A combination targeted therapeutic strategy may be recommended for treating FGFR2 amplified GC patients with these RTK activations.

Show MeSH
Related in: MedlinePlus