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Research Article

Vol. 1 No. 2 (1995)

Apoptosis in Response to Anti-estrogens in MCF-7 Human Mammary Adenocarcinoma Cells

  • Avrum I. Jacobson
  • Jozo Delic, Ph.D.
  • Henri Magdelenat, Ph.D.
November 9, 2020


Programmed Cell Death (PCD) is a highly regulated but not yet fully understood process by which selective gene expression leads to cell demise. The term apoptosis refers to the typical morphological changes observed with PCD. In the present study, we investigated the potential role of apoptosis as a mechanism by which anti-estrogens mediate tumor regression. Estrogen receptor-positive MCF-7 human mammary adenocarcinoma cells were treated with three different estrogen antagonists: RU 58668, ICI 182,780, and 4OH-Tam, in order of increasing potency. At selected time intervals, for up to seven days of culture, the degree of apoptosis induced by the anti-estrogens was assessed. Apoptotic cells were scored on the basis of specific morphological criteria disernable by fluorescence microscopy. It was hypothesised that the more potent the anti-estrogen, the greater the number of apoptotic cells we would observe. However, only minimal apoptosis was noted even at the highest concentration of anti-estrogen assayed (10-5 M). This is in contrast to some, but not all, previous reports. Possible confounding factors are discussed and include the presence of exogenous estrogen in the culture media, as well as a genetic drift in the clonal lineage of MCF-7 cells such that a resistance to induced apoptosis had been acquired. 


  1. Schwartz LM, Osborne BA. Programmed cell death, apoptosis and killer genes. Immunology Today 14: 582-590; 1993.
  2. Wyllie AH. Apoptosis (The 1992 Frank Rose Memorial Lecture). British Journal of Cancer 67: 205-208; 1993.
  3. Kerr JFR, Winterford CM, Harmon BV. Apoptosis. Its significance in cancer and cancer therapy. Cancer 73: 2013-2026; 1994.
  4. Tenniswood MP, et al. Active cell death in hormone-dependent tissues. Cancer and Metastasis Reviews 11: 197-220; 1992.
  5. Cohen JJ. Apoptosis. Immunology Today 14: 126-130; 1993.
  6. Kerr JFR, Wyllie AH, Currie AH. Apoptosis, a basic biological phenomenon with wide ranging implications in tissue kinetics. British Journal of Cancer 26: 239-261; 1972.
  7. Dive C, Evans CA, Whetton AD. Induction of apoptosis - new targets for cancer chemotherapy. Seminars in Cancer Biology 3: 417-426; 1992.
  8. Wyllie AH. Glucocorticoid-induced thymocyte apoptosis is associated with endogenous endonuclease activation. Nature 284(5756): 555-556; 1980.
  9. Jacobson MD, Burne JF, Raff MC. Programmed cell death and bcl-2 production in the absence of a nucleus. EMBO Journal 13(8): 1899-1910; 1994.
  10. Savill J, Dransfield I, Hogg N, Haslett C. Vitronectin receptor-mediated phagocytosis of cells undergoing apoptosis. Nature 343(6254): 170-173; 1990.
  11. Duvall E, Wyllie AH, Morris RG. Macrophage recognition of cells undergoing programmed cell death. Immunology 56(2): 351-358; 1985.
  12. Lowe SW, Schmitt EM, Smith SW, Osborne BA, Jacks T. p53 is required for radiation-induced apoptosis in mouse thymocytes. Nature 362(6423): 847-849; 1993.
  13. Shaw P, et al. Induction of apoptosis by wild-type p53 in a human colon tumor-derived cell line. Proceedings of the National Academy of Sciences of the United States of America 89(10): 4495-4499; 1992.
  14. Wyllie AH, et al. Rodent fibroblast tumours expressing human myc and ras genes: growth, metastasis and endogenous oncogene expression. British Journal of Cancer 56(3): 251-259; 1987.
  15. Evan GI, et al. Induction of apoptosis in fibroblast by c-myc protein. Cell 69(1): 119-128; 1992.
  16. Shi Y, et al. Role for c-myc in activation-induced apoptotic cell death in T cell hybridomas. Science 257(5067); 221-224; 1992.
  17. Hengartner MO, Ellis RE, Horvitz HR. Caenorhabditis elegans gene ced-9 protects cells from programmed cell death. Nature 356(6369): 494-499; 1992.
  18. Vaux DL, Aguila HL, Weissman IL. bcl-2 prevents death of factor-deprived cells but fails to prevent apoptosis in targets of cell mediated killing. International Immunology 4(7): 821-824; 1992.
  19. Sentman CL, Shutter JR, Hockenbery D, Kanagawa O, Korsmeyer SJ. Bcl-2 inhibits multiple forms of apoptosis but not negative selection in thymocytes. Cell 67(5): 879-888; 1991.
  20. Hockenbery D, Nunez G., Millliman C., Schreiber RD, Korsmeyer SJ. bcl-2 is an inner mitochondrial membrane protein that blocks programmed cell death. Nature 348(6299): 334-336; 1990.
  21. Nunez G, et al. Deregulated bcl-2 gene expression selectively prolongs survival of growth factor-deprived hemopoietic cell lines. Journal of Immunology 144(9): 3602-3610; 1990.
  22. Vaux DL, Cory S, Adams JM. bcl-2 gene promotes haemopoietic cell survival and cooperates with c-myc to immortalize pre-B cells. Nature 334(6189): 440-442; 1988.
  23. Tsujimoto Y. Stress-resistance conferred by high level of bcl-2 alpha protein in human B lymphoblastoid cell. Oncogene 4(11): 1331-1336; 1989.
  24. Schwartz LM, Myer A, Kosz L, Engelstein M, Maier C. Activation of polyubiquitin gene expression during developmentally programmed cell death. Neuron 5(4): 411-419; 1990.
  25. Kyprianou N, Isaacs JT. "Thymineless" death in androgen-independent prostatic cancer cells. Biochemical and Biophysical Research Communications 165(1): 73-81; 1989.
  26. Buttyan R, et al. Induction of the TRPM-2 gene in cells undergoing programmed death. Molecular and Cellular Biology 9(8): 3473-3481; 1989.
  27. Delic J, Morange M, Magdelenat H. Ubiquitin pathway involvement in human lymphocyte g-irradiaition-induced apoptosis. Molecular and Cellular Biology 13: 4875-4883; 1993.
  28. Itoh N, et al. The polypeptide encoded by the cDNA for human cell surface antigen Fas can mediate apoptosis. Cell 66(2): 233-243; 1991.
  29. Trauth BC, et al. Monoclonal antibody-mediated tumor regression by induction of apoptosis. Science 245(4915): 301-305; 1989.
  30. Kyprianou N, English HF, Davidson NE, Isaacs JT. Programmed cell death during regression of the MCF-7 human breast cancer following estrogen ablation. Cancer Research 51: 162-166; 1991.
  31. Osborne CK, Boldt DH, Estrada P. Human breast cancer cell cycle synchronization by estrogens and antiestrogens in culture. Cancer Research 44: 1433-1439; 1984.
  32. Sutherland RL, Hall RE, Taylor IW. Cell proliferation kinetics of MCF-7 human mammary carcinoma cells in culture and effects of Tamoxifen on exponentially growing and plateau-phase cells. Cancer Research 43: 3993-4006; 1983.
  33. Wilson JW, Wareling AE, Morris ID, Hickman JA, Dive C. MCF-7 human mammary adenocarcinoma cell death in vitro in responce to hormone-withdrawal and DNA damage. International Journal of Cancer; 61(4): 502-508; 1995.
  34. Lykkesfeldt AE, Madsen MW, Briand P. Altered expression of estrogen-regulated genes in a Tamoxifen-resistant and ICI 164,384 and ICI 182,780 sensitive human breast cancer cell line, MCF-7/TamR-11. Cancer Research 54: 1587-1595; 1994.
  35. Wakeling AE, Dukes M, Bowler J. A potent specific pure antiestrogen with clinical potential. Cancer Research 51: 3867-3873; 1991.
  36. DeFriend DJ, et al. Investigation of a new pure antiestrogen (ICI 182,780) in women with primary breast cancer. Cancer Research 54: 408-414; 1994.
  37. Van de Velde P, et al. In vivo activities of RU 58668 on Tamoxifen-sensitive and Tamoxifen-resistant human mammary tumors. Unpublished 1994.
  38. Van de Velde P, et al. Profil des activités pharmacologiques d'un nouvel antiestrogene pur susceptible de traiter certain échappements au tamoxifène. Pathologie Biologie 42: 30; 1994.
  39. Esber HJ, Payne IJ, Bogden AE. Brief communication: Variability of hormone concentration and ratios in commercial sera used for tissue culture. Journal of the National Cancer Institute 50: 559-562; 1973.
  40. Soule HD, Vazquez J, Long A, Albert S, Brennan M. A human cell line from a pleural effusion derived from a breast carcinoma. Journal of the National Cancer Institute 51: 1409-1413; 1973.
  41. Wärri AM, et al. Apoptosis in Toremifene induced growth inhibition of human breast cancer cells in vivo and in vitro. Journal of the National Cancer Institute 85: 1412-1418; 1993.
  42. Bardon S, Vignon F, Montcourrier P, Rochefort H. Steroid receptor-mediated cytotoxicity of an antiestrogen and an antiprogestin in breast cancer cells. Cancer Research 47: 1441-1448; 1987.
  43. Huovinen R, Wärri A, Collan Y. Mitotic activity, apoptosis and TRPM-2 mRNA expression in DMBA-induced rat mammary carcinoma treated with anti-estrogen Toremifene. International Journal of Cancer 55: 685-691; 1993.
  44. Wang TTY, Phang JM. Effects of estrogen on apoptotic pathways in human breast cancer cell line MCF-7. Cancer Research 55: 2487-2489; 1995.
  45. Teixeira C, Reed JC, Pratt MAC. Estrogen promotes chemotherapeutic drug resistance by a mechanism involving bcl-2 proto-oncogene expression in human breast cancer cells. Cancer Research 55: 3902-3907; 1995.
  46. Berthois Y, Katzenellenbogen JA, Katzenellenbogen BS. Phenol red in tissue culture media is a weak estrogen: implications concerning the study of estrogen-responsive cells in culture. Proceedings of the National Academy of Sciences of the United States of America 83: 2496-2500; 1986.
  47. Kristensen CA, Kristjansen PEG, Brunner N, Quistorff B, Spang-Thomsen M. Growth inhibition in response to estrogen withdrawal and Tamoxifen therapy of human breast cancer xenografts evaluated by in vivo 31P magnetic resonance spectroscopy, creatine kinase activity, and apoptotic index. Cancer Research 55: 4146-4150; 1995.
  48. Osborne CK, Hobbs K, Trent JM. Biological differences among MCF-7 human breast cancer cell lines from different laboratories. Breast Cancer Research and Treatment 9(2): 111-121; 1987.


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