Limits...
cMET Activation and EGFR-Directed Therapy Resistance in Triple-Negative Breast Cancer.

Sohn J, Liu S, Parinyanitikul N, Lee J, Hortobagyi GN, Mills GB, Ueno NT, Gonzalez-Angulo AM - J Cancer (2014)

Bottom Line: However, anti-EGFR therapies have not been effective in these patients.In western blotting, combination therapy resulted in abrogation of pAKT and pMAPK while monotherapy did not.Targeting both EGFR and MET receptors may provide an effective therapeutic strategy in TNBC.

View Article: PubMed Central - PubMed

Affiliation: 1. Department of Breast Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA ; 2. Division of Medical Oncology, Department of Internal Medicine, Breast Cancer Clinic, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.

ABSTRACT

Background: EGFR expression and pathway activation are common in triple-negative breast cancer (TNBC). However, anti-EGFR therapies have not been effective in these patients. We aimed to study the efficacy of targeting MET in overcoming resistance to EGFR therapy in TNBC cell lines.

Methods: TNBC lines (MDA-MB-468, HCC-1395, and MDA-MB-231), and a hormone receptor-positive breast cancer line (T47D) were stimulated with epidermal growth factor (EGF) and hepatocyte growth factor (HGF). Lines were then treated with different concentrations of EGFR inhibitors (gefitinib or cetuximab), with or without a MET tyrosine kinase inhibitor (EMD 1214063). Proliferation was measured by MTS assay, in soft agar and with a matrigel assay. Synergy was measured with Calcusyn. Protein expression and signaling were examined with immunoblotting.

Results: There was activation of ligand-receptor-downstream signaling pathways in MDA-MB-468 and HCC-1395 upon stimulation with EGF and HGF. In these cell lines, we observed synergism when combining EGFR and MET inhibitors. These results were observed across assays. In western blotting, combination therapy resulted in abrogation of pAKT and pMAPK while monotherapy did not.

Conclusion: Our data demonstrate that dual EGFR/MET inhibition is synergistic in TNBC. Targeting both EGFR and MET receptors may provide an effective therapeutic strategy in TNBC.

No MeSH data available.


Related in: MedlinePlus

Matrigel assay in TNBC cell lines, and T47D. Thawed 45ul Matrigel on ice were placed in each well of a pre-cooled 8-well glass chamber slide. After 30 minutes of solidification, TNBC cell lines and T47D mixed in ice-cold medium with 2% Matrigel and drugs were loaded in each well of the 8-chamber slide and incubated at 37°C. Media with 2% Matrigel and various concentrations of drugs were changed every three days. Drug concentrations were as follows; Gefitinib 1um, EMD 121463 1uM and Cetuximab 200ug/ml in MDA-MB-468, Gefitinib 1um, EMD 121463 5uM and Cetuximab 200ug/ml in HCC 1395, Gefitinib 5um, EMD 121463 2uM and Cetuximab 200ug/ml in T47D.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC4216798&req=5

Figure 3: Matrigel assay in TNBC cell lines, and T47D. Thawed 45ul Matrigel on ice were placed in each well of a pre-cooled 8-well glass chamber slide. After 30 minutes of solidification, TNBC cell lines and T47D mixed in ice-cold medium with 2% Matrigel and drugs were loaded in each well of the 8-chamber slide and incubated at 37°C. Media with 2% Matrigel and various concentrations of drugs were changed every three days. Drug concentrations were as follows; Gefitinib 1um, EMD 121463 1uM and Cetuximab 200ug/ml in MDA-MB-468, Gefitinib 1um, EMD 121463 5uM and Cetuximab 200ug/ml in HCC 1395, Gefitinib 5um, EMD 121463 2uM and Cetuximab 200ug/ml in T47D.

Mentions: We also observed three-dimensional morphology of the cell lines in Matrigel with the drugs as described above. Again, MDA-MB-468 showed remarkable regression when the drug combination was applied but not with the other cell lines assessed (Fig. 3).


cMET Activation and EGFR-Directed Therapy Resistance in Triple-Negative Breast Cancer.

Sohn J, Liu S, Parinyanitikul N, Lee J, Hortobagyi GN, Mills GB, Ueno NT, Gonzalez-Angulo AM - J Cancer (2014)

Matrigel assay in TNBC cell lines, and T47D. Thawed 45ul Matrigel on ice were placed in each well of a pre-cooled 8-well glass chamber slide. After 30 minutes of solidification, TNBC cell lines and T47D mixed in ice-cold medium with 2% Matrigel and drugs were loaded in each well of the 8-chamber slide and incubated at 37°C. Media with 2% Matrigel and various concentrations of drugs were changed every three days. Drug concentrations were as follows; Gefitinib 1um, EMD 121463 1uM and Cetuximab 200ug/ml in MDA-MB-468, Gefitinib 1um, EMD 121463 5uM and Cetuximab 200ug/ml in HCC 1395, Gefitinib 5um, EMD 121463 2uM and Cetuximab 200ug/ml in T47D.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4216798&req=5

Figure 3: Matrigel assay in TNBC cell lines, and T47D. Thawed 45ul Matrigel on ice were placed in each well of a pre-cooled 8-well glass chamber slide. After 30 minutes of solidification, TNBC cell lines and T47D mixed in ice-cold medium with 2% Matrigel and drugs were loaded in each well of the 8-chamber slide and incubated at 37°C. Media with 2% Matrigel and various concentrations of drugs were changed every three days. Drug concentrations were as follows; Gefitinib 1um, EMD 121463 1uM and Cetuximab 200ug/ml in MDA-MB-468, Gefitinib 1um, EMD 121463 5uM and Cetuximab 200ug/ml in HCC 1395, Gefitinib 5um, EMD 121463 2uM and Cetuximab 200ug/ml in T47D.
Mentions: We also observed three-dimensional morphology of the cell lines in Matrigel with the drugs as described above. Again, MDA-MB-468 showed remarkable regression when the drug combination was applied but not with the other cell lines assessed (Fig. 3).

Bottom Line: However, anti-EGFR therapies have not been effective in these patients.In western blotting, combination therapy resulted in abrogation of pAKT and pMAPK while monotherapy did not.Targeting both EGFR and MET receptors may provide an effective therapeutic strategy in TNBC.

View Article: PubMed Central - PubMed

Affiliation: 1. Department of Breast Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA ; 2. Division of Medical Oncology, Department of Internal Medicine, Breast Cancer Clinic, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.

ABSTRACT

Background: EGFR expression and pathway activation are common in triple-negative breast cancer (TNBC). However, anti-EGFR therapies have not been effective in these patients. We aimed to study the efficacy of targeting MET in overcoming resistance to EGFR therapy in TNBC cell lines.

Methods: TNBC lines (MDA-MB-468, HCC-1395, and MDA-MB-231), and a hormone receptor-positive breast cancer line (T47D) were stimulated with epidermal growth factor (EGF) and hepatocyte growth factor (HGF). Lines were then treated with different concentrations of EGFR inhibitors (gefitinib or cetuximab), with or without a MET tyrosine kinase inhibitor (EMD 1214063). Proliferation was measured by MTS assay, in soft agar and with a matrigel assay. Synergy was measured with Calcusyn. Protein expression and signaling were examined with immunoblotting.

Results: There was activation of ligand-receptor-downstream signaling pathways in MDA-MB-468 and HCC-1395 upon stimulation with EGF and HGF. In these cell lines, we observed synergism when combining EGFR and MET inhibitors. These results were observed across assays. In western blotting, combination therapy resulted in abrogation of pAKT and pMAPK while monotherapy did not.

Conclusion: Our data demonstrate that dual EGFR/MET inhibition is synergistic in TNBC. Targeting both EGFR and MET receptors may provide an effective therapeutic strategy in TNBC.

No MeSH data available.


Related in: MedlinePlus