Protein pathway activation mapping reveals molecular networks associated with antiestrogen resistance in breast cancer cell lines

Ton Van Agthoven*, Marcia F.E. Godinho, Julia D. Wulfkuhle, Emanuel F. Petricoin, Lambert C.J. Dorssers

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

23 Scopus citations


Previously, we have identified a panel of breast cancer antiestrogen resistance (BCAR) genes. Several of these genes have clinical relevance because mRNA or protein levels associate with tamoxifen resistance or tumor aggressiveness. We postulated that changes in activation status of protein signaling networks induced by BCAR genes may provide better insight into the mechanisms underlying antiestrogen resistance. Key signal transduction pathways were analyzed for changes in activation or expression using reverse-phase protein microarrays probed with 78 antibodies against signaling proteins with known roles in tumorigenesis. We used ZR-75-1-derived cell lines transduced with AKT1, AKT2, BCAR1, BCAR3, BCAR4, EGFR, GRB7, HRAS, HRAS v12 or HEF1 and MCF7-derived cell lines transduced with BCAR3, BCAR4 or EGFR. In the antiestrogen-resistant cell lines, we observed increased phosphorylation of several pathways involved in cell proliferation and survival. All tamoxifen-resistant cell lines contained high levels of phosphorylated AKT and its biochemically linked substrates Forkhead box O1/3. The activation of ERBB2, ERBB3 and the downstream modulators focal adhesion kinase and SHC were activated in cells with overexpression of BCAR4. Remarkable differences were observed for the levels of activated AMPK alpha1, cyclins, STAT5, STAT6, ERK1/2 and BCL2. The comparison of the cell signaling networks in estrogen-dependent and -independent cell lines revealed biochemically linked kinase-substrate markers that comprised systemically activated signaling pathways involved in tamoxifen resistance. Our results show that this model provides insights into the molecular and cellular mechanisms of breast cancer progression and antiestrogen resistance. This knowledge may help the development of novel targeted treatments.

Original languageEnglish
Pages (from-to)1998-2007
Number of pages10
JournalInternational Journal of Cancer
Issue number9
StatePublished - 1 Nov 2012
Externally publishedYes


  • AKT
  • BCAR1
  • BCAR3
  • BCAR4
  • EGFR
  • phosphorylation
  • signaling pathway
  • tamoxifen resistance


Dive into the research topics of 'Protein pathway activation mapping reveals molecular networks associated with antiestrogen resistance in breast cancer cell lines'. Together they form a unique fingerprint.

Cite this