Adaptation to Estradiol Deprivation Causes Up-Regulation of Growth Factor Pathways and Hypersensitivity to Estradiol in Breast Cancer Cells

  • Richard J. Santen
  • Robert X. Song
  • Shigeru Masamura
  • Wei Yue
  • Ping Fan
  • Tetsuya Sogon
  • Shin-ichi Hayashi
  • Kei Nakachi
  • Hidtek Eguchi
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 630)


Deprivation of estrogen causes breast tumors in women to adapt and develop enhanced sensitivity to this steroid. Accordingly, women relapsing after treatment with oophorectomy, which substantially lowers estradiol for a prolonged period, respond secondarily to aromatase inhibitors with tumor regression. We have utilized in vitro and in vivo model systems to examine the biologic processes whereby Long Term Estradiol Deprivation (LTED) causes cells to adapts and develop hypersensitivity to estradiol. Several mechanisms are associated with this response including up-regulation of ERα and the MAP kinase, PI-3-kinase and mTOR growth factor pathways. ERα is 4–10 fold up-regulated as a result of demethylation of its C promoter, This nuclear receptor then co-opts a classical growth factor pathway using SHC, Grb-2 and Sos. This induces rapid nongenomic effects which are enhanced in LTED cells.

The molecules involved in the nongenomic signaling process have been identified. Estradiol binds to cell membrance-associated ERα which physically associates with the adaptor protein SHC and induces its phosphorylation. In turn, SHC binds Grb-2 and Sos which results in the rapid activation of MAP kinase. These nongenomic effects of estradiol produce biologic effects as evidenced by Elk-1 activation and by morphologic changes in cell membrances. Additional effects include activation of the PI-3-kinase and mTOR pathways through estradiol-induced binding of ERα to the IGF-1 and EGF receptors.

A major question is how ERα locates in the plasma membrance since it does not contain an inherent membrance localization signal. We have provided evidence that the IGF-1 receptor serves as an anchor for ERα in the plasma membrane. Estradiol causes phosphorylation of the adaptor protein, SHC and the IGF-1 receptor itself. SHC, after binding to ERα, serves as the “glue” which tethers ERα to SHC binding sites on the activated IFG-1 receptors. Use of siRNA methodology to knock down SHC allows the conclusion that SHC is needed for ERα to localize in the plasma membrane.

In order to abrogate growth factor induced hypersensitivity, we have utilized a drug, farnesylthiosalicylic acid, which blocks the binding of GTP-Ras to its membrance acceptor protein, galectin 1 and reduces the activation of MAP kinase. We have shown that this drug is a potent inhibitor of mTOR and this provides the major means for inhibition of cell proliferation. The concept of “adaptive hypersensitivity” and the mechanisms responsible for this phenomenon have important clinical implications. The efficacy of aromatase inhibitors in patients relapsing on tamoxifen could be explained by this mechanism and inhibitors of growth factor pathways should reverse the hypersensitivity phenomenon and result in prolongation of the efficacy of hormonal therapy for breast cancer.


Aromatase Inhibitor Growth Factor Pathway Focal Adhesion Point Potent Aromatase Inhibitor Farnesylthiosalicylic Acid 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Santen RJ, Manni A, Harvey H et al. Endocrine treatment of breast cancer in women. Endocr Rev 1990; 11(2):221–265.CrossRefPubMedGoogle Scholar
  2. 2.
    McMahon LP, Yue W, Santen RJ et al. Farnesylthiosalicylic acid inhibits mammalian target of rapamycin (mTOR) activity both in cells and in vitro by promoting dissociation of the mTOR-raptor complex. J Mol Endocrinol 2005; 19(1):175–183.Google Scholar
  3. 3.
    Santen RJ, Song RX, Zhang Z et al. Long-term estradiol deprivation in breast cells up-regulates growth factor signaling and enhances estrogen sensitivity. Endocr Relat Cancer 2005; 12(Suppl. 1): S61–73.CrossRefPubMedGoogle Scholar
  4. 4.
    Shim WS, DiRenzo J, DeCaprio JA et al. Segregation of steroid receptor coactivator-1 from steroid receptors in mammary epithelium. Proc Natl Acad Sci USA 1999; 96(1):208–13.CrossRefPubMedGoogle Scholar
  5. 5.
    Shim WS, Conaway M, Masamura S et al. Estradiol hypersensitivity and mitogen-activated protein kinase expression in long-term estrogen deprived human breast cancer cells in vivo. Endocrinology 2000; 141(1):396–405.CrossRefPubMedGoogle Scholar
  6. 6.
    Yue W, Wang J, Li Y et al. Farnesylthiosalicylic acid blocks mammalian target of rapamycin signaling in breast cancer cells. Int J Cancer 2005; 117(5):746–754.CrossRefPubMedGoogle Scholar
  7. 7.
    Yue W, Wang JP, Conaway M et al. Activation of the MAPK pathway enhances sensitivity of MCF-7 breast cancer cells to the mitogenic effect of estradiol. Endocrinology 2002; 143(9):3221–3229.CrossRefPubMedGoogle Scholar
  8. 8.
    Yue W, Wang JP, Conaway MR et al. Adaptive hypersensitivity following long-term estrogen deprivation: involvement of multiple signal pathways. Journal of Steroid Biochemistry_& Molecular Biology 2003; 86(3–5):265–74.CrossRefGoogle Scholar
  9. 9.
    Song RX. Membrane-initiated steroid signaling action of estrogen and breast cancer. Seminars in Reproductive Medicine 2007; 25(3):187–197.CrossRefPubMedGoogle Scholar
  10. 10.
    Song RX, Fan P, Yue W, Chen Y, Santen RJ. Role of receptor complexes in the extranuclear actions of estrogen receptor alpha in breast cancer. Endocrine-Related Cancer 2006; 13 (Suppl 1):S3–S13.CrossRefPubMedGoogle Scholar
  11. 11.
    Jeng MH, Yue W, Eischeid A et al. Role of MAP kinase in the enhanced cell proliferation of long term estrogen deprived human breast cancer cells. Breast Cancer Res Treat 2000; 62(3):167–175.CrossRefPubMedGoogle Scholar
  12. 12.
    Masamura S, Santner SJ, Heitjan DF et al. Estrogen deprivation causes estradiol hypersensitivity in human breast cancer cells. J Clin Endocrinol Metab 1995; 80(10):2918–2925.CrossRefPubMedGoogle Scholar
  13. 13.
    Jeng MH, Shupnik MA, Bender TP et al. Estrogen receptor expression and function in long-term estrogen-deprived human breast cancer cells. Endocrinology 1998; 139(10):4164–74.CrossRefPubMedGoogle Scholar
  14. 13a.
    Sogon T, Masamura S, Hayashi S-I et al. J Steroid Biochem Mol Biol 2007; 105(1–3):106–14.CrossRefPubMedGoogle Scholar
  15. 14.
    Pelicci G, Lanfrancone L, Salcini AE et al. Constitutive phosphorylation of SHC proteins in human tumors. Oncogene 1995; 11(5):899–907.PubMedGoogle Scholar
  16. 15.
    Pelicci G, Dente L, De Giuseppe A et al. A family of SHC related proteins with conserved PTB, CH1 and SH2 regions. Oncogene 1996; 13(3):633–641.PubMedGoogle Scholar
  17. 16.
    Yue W, Wang JP, Li Y et al. Farnesylthiosalicylic acid blocks mammalian target of rapamycin signaling in breast cancer cells. Int J Cancer 2005; 117(5):746–54.CrossRefPubMedGoogle Scholar
  18. 17.
    Migliaccio A, Di Domenico M, Castoria G et al. Tyrosine kinase/p21ras/MAP-kinase pathway activation by estradiol-receptor complex in MCF-7 cells. EMBO J 1996; 15(6):1292–1300.PubMedGoogle Scholar
  19. 18.
    Kelly MJ, Lagrange AH, Wagner EJ et al. Rapid effects of estrogen to modulate G protein-coupled receptors via activation of protein kinase A and protein kinase C pathways. Steroids 1999; 64(1–2):64–75.CrossRefPubMedGoogle Scholar
  20. 19.
    Valverde MA, Rojas P, Amigo J et al. Acute activation of Maxi-K channels (hSlo) by estradiol binding to the beta subunit [see comments]. Science 1999; 285(5435):1929–1931.CrossRefPubMedGoogle Scholar
  21. 20.
    Song RX, McPherson RA, Adam L et al. Linkage of rapid estrogen action to MAPK activation by ERalpha-SHC association and SHC pathway activation. J Mol Endocrinol 2002; 16(1):116–127.CrossRefGoogle Scholar
  22. 21.
    Dikic I, Batzer AG, Blaikie P et al. SHC binding to nerve growth factor receptor is mediated by the phosphotyrosine interaction domain. J Biol Chem 1995; 270(25):15125–15129.CrossRefPubMedGoogle Scholar
  23. 22.
    Boney CM, Gruppuso PA, Faris RA et al. The critical role of SHC in insulin-like growth factor-I-mediated mitogenesis and differentiation in 3T3-L1 preadipocytes. J Mol Endocrinol 2000; 14(6):805–813.CrossRefGoogle Scholar
  24. 23.
    Collins P, Webb C. Estrogen hits the surface. [see comments]. Nature Medicine 1999; 5(10):1130–1131.CrossRefPubMedGoogle Scholar
  25. 24.
    Watson CS, Campbell CH, Gametchu B. Membrane oestrogen receptors on rat pituitary tumour cells: immuno-identification and responses to oestradiol and xenoestrogens. [Review] [45 refs]. Exp Physiol 1999; 84(6):1013–1022.CrossRefPubMedGoogle Scholar
  26. 25.
    Watson CS, Norfleet AM, Pappas TC et al. Rapid actions of estrogens in GH3/B6 pituitary tumor cells via a plasma membrane version of estrogen receptor-alpha. Steroids 1999; 64(1–2):5–13.CrossRefPubMedGoogle Scholar
  27. 26.
    Duan R, Xie W, Burghardt RC et al. Estrogen receptor-mediated activation of the serum response element in MCF-7 cells through MAPK-dependent phosphorylation of Elk-1. J Biol Chem 2001; 276(15):11590–11598.CrossRefPubMedGoogle Scholar
  28. 27.
    Roberson MS, Misra-Press A, Laurance ME et al. A role for mitogen-activated protein kinase in mediating activation of the glycoprotein hormone alpha-subunit promoter by gonadotropin-releasing hormone. Mol Cell Biol 1995; 15(7):3531–3539.PubMedGoogle Scholar
  29. 28.
    Song RX, Barnes CJ, Zhang Z et al. The role of SHC and insulin-like growth factor 1 receptor in mediating the translocation of estrogen receptor alpha to the plasma membrane. Proc Natl Acad Sci USA 2004; 101(7):2076–81.CrossRefPubMedGoogle Scholar
  30. 29.
    Song RX, Santen RJ. Role of IFG-1R in mediating nongenomic effects of estrogen receptor alpha. Paper presented at: The Endocrine Society’s 85th Annual Meeting (USA). Philadelphia, 2003.Google Scholar
  31. 29a.
    Pedram A, Razandi M, Sainson RC et al. A conserved mechanism for steroid receptor translocation to the plasma membrane. J Biol Chem. 2007; 282(31):22278–88.CrossRefPubMedGoogle Scholar
  32. 30.
    Haklai R, Weisz MG, Elad G et al. Dislodgment and accelerated degradation of Ras. Biochemistry 1998; 37(5):1306–14.CrossRefPubMedGoogle Scholar
  33. 31.
    Harris TE, Lawrence JC Jr. TOR signaling. [Review] [221 refs]. Science’s Stke [Electronic Resource]: Sci STKE 2003; (212):ref 15.Google Scholar
  34. 32.
    Lawrence JC Jr, Brunn GJ. Insulin signaling and the control of PHAS-I phosphorylation. [Review] [102 refs]. Prog Mol Subcell Biol 2001; 26:1–31.PubMedGoogle Scholar
  35. 33.
    Brunn GJ, Hudson CC, Sekulic A et al. Phosphorylation of the translational repressor PHAS-I by the mammalian target of rapamycin. Science 1997; 277(5322):99–101.CrossRefPubMedGoogle Scholar
  36. 34.
    Berstein L, Zheng H, Yue W et al. New approaches to the understanding of tamoxifen action and resistance. Endocr Relat Cancer. 2003; 10(2):267–77.CrossRefPubMedGoogle Scholar
  37. 35.
    Fan P, Wang J, Santen RJ et al. Long-term treatment with tamoxifen facilitates translocation of estrogen receptor alpha out of the nucleus and enhances its interaction with EGFR in MCF-7 breast cancer cells. Cancer Res 2007; 67(3):1352–1360.CrossRefPubMedGoogle Scholar
  38. 36.
    Osborne CK, Hamilton B, Titus G et al. Epidermal growth factor stimulation of human breast cancer cells in culture. Cancer Res 1980; 40(7):2361–2366.PubMedGoogle Scholar
  39. 37.
    Osborne CK, Fuqua SA. Mechanisms of Tamoxifen Resistance. Breast Cancer Res Treat 1994; 32:49–55.CrossRefPubMedGoogle Scholar
  40. 38.
    Hiscox S, Morgan L, Green TP et al. Elevated Src activity promotes cellular invasion and motility in tamoxifen resistant breast cancer cells. Breast Cancer Res Treat 2006; 97(3):263–274.CrossRefPubMedGoogle Scholar
  41. 39.
    Hiscox S, Morgan L, Barrow D et al. Tamoxifen resistance in breast cancer cells is accompanied by an enhanced motile and invasive phenotype: inhibition by gefitinib (‘Iressa’, ZD1839). Clin Exp Metastasis 2004; 21(3):201–212.CrossRefPubMedGoogle Scholar
  42. 40.
    Schiff R, Massarweh SA, Shou J et al. Advanced concepts in estrogen receptor biology and breast cancer endocrine resistance: implicated role of growth factor signaling and estrogen receptor coregulators. [Review] [97 refs]. Cancer Chemother Pharmacol 2005; 56(Suppl 1):10–20.CrossRefPubMedGoogle Scholar
  43. 41.
    Mackey JR, Kaufman B, Clemens M et al. Trastuzumab prolongs progression-free survival in hormone dependent and HER2-positive metastatic breast cancer. Breast Cancer Res Treat 2006: 100:(Suppl 1): S5, Ab 3.Google Scholar

Copyright information

© Landes Bioscience and Springer Science+Business Media 2008

Authors and Affiliations

  • Richard J. Santen
    • 1
  • Robert X. Song
    • 1
  • Shigeru Masamura
    • 2
  • Wei Yue
    • 1
  • Ping Fan
    • 1
  • Tetsuya Sogon
    • 3
    • 4
  • Shin-ichi Hayashi
    • 5
  • Kei Nakachi
    • 3
    • 4
  • Hidtek Eguchi
    • 3
    • 4
  1. 1.Division of Endocrinology and MetabolismUniversity of Virginia Health Sciences CenterCharlottesvilleUSA
  2. 2.Department of Surgery Tokyo Dental CollegeIchikawa General HospitalSugano, IchikawaJapan
  3. 3.Department of Molecular EpidemiologyHiroshima University Graduate School of Biomedical SciencesHiroshimaJapan
  4. 4.Department of Radiobiology and Molecular EpidemiologyRadiation Effects Research FoundationHiroshimaJapan
  5. 5.Department of Medical TechnologyTohoku University School of MedicineHiroshimaJapan

Personalised recommendations