Fibroblast-secreted hepatocyte growth factor mediates epidermal growth factor receptor tyrosine kinase inhibitor resistance in triple-negative breast cancers through paracrine activation of Met

Autor: Kelly L. Mueller, Gina L. Zoratti, Charlotte Kuperwasser, Julie M. Madden, Karin List, Julie L. Boerner
Rok vydání: 2012
Předmět:
medicine.medical_specialty
Cell Survival
Gene Expression
Triple Negative Breast Neoplasms
Receptor tyrosine kinase
03 medical and health sciences
Paracrine signalling
0302 clinical medicine
Gefitinib
Breast cancer
Internal medicine
Cell Line
Tumor
Paracrine Communication
medicine
Humans
Epidermal growth factor receptor
Phosphorylation
Protein Kinase Inhibitors
030304 developmental biology
Cell Proliferation
Medicine(all)
0303 health sciences
biology
business.industry
Hepatocyte Growth Factor
Fibroblasts
Proto-Oncogene Proteins c-met
medicine.disease
Coculture Techniques
respiratory tract diseases
ErbB Receptors
Endocrinology
Cell Transformation
Neoplastic
Drug Resistance
Neoplasm
030220 oncology & carcinogenesis
Culture Media
Conditioned
biology.protein
Cancer research
Quinazolines
Hepatocyte growth factor
business
Tyrosine kinase
medicine.drug
Research Article
Zdroj: Breast Cancer Research : BCR
ISSN: 1465-542X
Popis: Introduction Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have shown clinical efficacy in lung, colon, and pancreatic cancers. In lung cancer, resistance to EGFR TKIs correlates with amplification of the hepatocyte growth factor (HGF) receptor tyrosine kinase Met. Breast cancers do not respond to EGFR TKIs, even though EGFR is overexpressed. This intrinsic resistance to EGFR TKIs in breast cancer does not correlate with Met amplification. In several tissue monoculture models of human breast cancer, Met, although expressed, is not phosphorylated, suggesting a requirement for a paracrine-produced ligand. In fact, HGF, the ligand for Met, is not expressed in epithelial cells but is secreted by fibroblasts in the tumor stroma. We have identified a number of breast cancer cell lines that are sensitive to EGFR TKIs. This sensitivity is in conflict with the observed clinical resistance to EGFR TKIs in breast cancers. Here we demonstrate that fibroblast secretion of HGF activates Met and leads to EGFR/Met crosstalk and resistance to EGFR TKIs in triple-negative breast cancer (TNBC). Methods The SUM102 and SUM149 TNBC cell lines were used in this study. Recombinant HGF as well as conditioned media from fibroblasts expressing HGF were used as sources for Met activation. Furthermore, we co-cultured HGF-secreting fibroblasts with Met-expressing cancer cells to mimic the paracrine HGF/Met pathway, which is active in the tumor microenvironment. Cell growth, survival, and transformation were measured by cell counting, clonogenic and MTS assays, and soft agar colony formation, respectively. Student's t test was used for all statistical analysis. Results Here we demonstrate that treatment of breast cancer cells sensitive to EGFR TKIs with recombinant HGF confers a resistance to EGFR TKIs. Interestingly, knocking down EGFR abrogated HGF-mediated cell survival, suggesting a crosstalk between EGFR and Met. HGF is secreted as a single-chain pro-form, which has to be proteolytically cleaved in order to activate Met. To determine whether the proteases required to activate pro-HGF were present in the breast cancer cells, we utilized a fibroblast cell line expressing pro-HGF (RMF-HGF). Addition of pro-HGF-secreting conditioned fibroblast media to TNBC cells as well as co-culturing of TNBC cells with RMF-HGF fibroblasts resulted in robust phosphorylation of Met and stimulated proliferation in the presence of an EGFR TKI. Conclusions Taken together, these data suggest a role for Met in clinical resistance to EGFR TKIs in breast cancer through EGFR/Met crosstalk mediated by tumor-stromal interactions.
Databáze: OpenAIRE
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