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Interactions between ipriflavone and the estrogen receptor

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Abstract

Estrogen replacement therapy is effective in the prevention of postmenopausal osteoporosis, and a direct action of 17-β-estradiol (17βE2) on osteoblastic and osteoclastic cells has been demonstrated. The inhibition of bone resorption by ipriflavone (IP), an isoflavone derivative devoid of estrogenic properties but active in potentiating the effects of estroge on bone tissue, has been shown in in vitro and in vivo studies and confirmed by clinical data. To investigate the molecular mechanisms that underlie IP effect, we studied the possible interactions of IP and its four main in vivo metabolites (I, II, III, and V) with the estrogen receptor (ER) in the human preosteoclastic cell line FLG 29.1, whose growth and function are modulated by the compound. In parallel experiments, the human breast cancer cell line MCF7 was also analyzed. IP binding sites were demonstrated in the nuclear fraction of FLG 29.1 cells. 17βE2 and other steroid compounds failed to displace IP binding to intact FLG 29.1 cells. Similarly, IP and metabolites I, III, and V were not able to displace 17βE2 binding to intact MCF7 cells, whereas metabolite II showed an IC50 of 61 nM. 17βE2 binding to FLG 29.1 cells was increased after preincubation with metabolites I, III, and V. IP and its metabolites did not induce FR-dependent gene expression in FLG 29.1 and MCF7 cells transfected with a reporter gene and an estrogen response element (ERE). These results suggest that IP effects on osteoclast precursors are not mediated by a direct interaction with the ER, even if a crosstalk between the mechanisms of action of IP and 17βE2 cannot be excluded.

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References

  1. Agnusdei D, Zucchei F, Bigazzi S, Cepollaro C, Nardi P, Montignani M, Gennari C (1989) Metabolic and clinical effects of ipriflavone in established postmenopausal osteoporosis. Drugs Exptl Clin Res 15: 97–104

    Google Scholar 

  2. Tsuda M, Kitazaki T, Ito T, Fujita T (1987) The effect of ipriflavone (TC-80) on bone resorption in bone culture. J Bone Miner Res 1: 207–211

    Google Scholar 

  3. Bonucci E, Ballanti P, Martelli A, Mereto E, Brambilla G, Bianco P, Bufalino L (1992) Ipriflavone inhibits osteoclast differentiation in parathyroid transplanted parietal bone of rats. Calcif Tissue Int 50: 314–319

    Google Scholar 

  4. Notoya K, Yoshida K, Taketomi S, Yamazaki I, Kunegawa M (1992) Inhibitory effect of ipriflavone on pit formation in mouse unfractionated bone cells. Calcif Tissue Int 51: S3-S6

    Google Scholar 

  5. Azria M, Behlar C, Cooper S (1993) Lack of effect of ipriflavone on osteoclast mobility and bone resorption in in vitro and ex vivo studies. Calcif Tissue Int 52: 16–20

    Google Scholar 

  6. Morita I, Sakaguchi K, Kurachi T, Murota S (1992) Ipriflavone inhibits murine osteoclast formation in vitro. Calcif Tissue Int 51: S7-S10

    Google Scholar 

  7. Bonucci E, Silvestrini G, Ballanti P, Masi L, Franchi A, Bufalino L, Brandi ML (1992) Cytological and ultrastructural investigation on osteoblastic and preosteoclastic cells grown in vitro in the presence of ipriflavone: preliminary results. Bone Miner 19: S15-S25

    Google Scholar 

  8. Gattei V, Bernabei PA, Pinto A, Bezzini R, Ringressi A, Formigli L, Tanini A, Attadia V, Brandi ML (1992) Phorbol ester induced osteoclast-like differentiation of a novel human leukemic cell line (FLG 29.1). J Cell Biol 116: 437–447

    Google Scholar 

  9. Petilli M, Frediani U, Benvenuti S, Bianchi S, Brandi ML (1993) Back of stereospecific interactions between ipriflavone and the estrogen receptor (abstract 55) 4th Int Symp on Osteoporosis and Consensus Development Conference, Hong Kong, p 19

  10. Benvenuti S, Frediani U, Petilli M, Tanini A, Brandi ML (1993) Ipriflavone inhibits growth and differentiation of human osteoclast precursor cells (abstract 515) 4th Int Symp on Osteoporosis and Consensus Development Conference, Hong Kong, p 140

  11. Benvenuti S, Petilli M, Frediani U, Tanini A, Fiorelli G, Bianchi S, Bernabei PA, Albanese C, Brandi ML (1994) Binding and bioeffects of ipriflavone on a human preosteoclastic cell line. Biochem Biophys Res Commun 201: 1084–1089

    Google Scholar 

  12. Yamasaki I, Shino A, Tsukuda R (1986) Effects of ipriflavone on osteoporosis induced by ovariectomy in rats. J Bone Miner Metab 3: 205–210

    Google Scholar 

  13. Melis GB, Paoletti AM, Cagnacci A, Bufalino L, Spinetti A, Gambacciani M, Fioretti P (1992) Lack of any estrogenic effect of ipriflavone in postmenopausal women. J Endocrinol Invest 15: 755–761

    Google Scholar 

  14. Jilka RL, Hangoc G, Girasole G, Williams DC, Abrams JS, Boyce B, Broxmeyer H, Manolagas SC (1992) Increased osteoclast development after estrogen loss: mediation by interleukin 6. Science 257: 88–91

    Google Scholar 

  15. Lufkin EG, Carpenter PC, Ory SJ, Malkasian GD, Edmondson JH (1988) Estrogen replacement therapy: current recommendations. Mayo Clin Proc 63: 453–460

    Google Scholar 

  16. Oursler MJ, Osdoby P, Pyfferoen J, Riggs BL, Spelsberg TC (1991) Avian osteoclasts as estrogen target cells. PNAS 88: 6613–6617

    Google Scholar 

  17. Pensler J, Radosevich JA, Higbee R, Langman CB (1990) Osteoclasts isolated from membranous bone in children exhibited nuclear estrogen and progesterone receptors. J Bone Miner Res 5: 797–802

    Google Scholar 

  18. Fiorelli G, Petilli M, Gori F, Benvenuti S, De Bellis A, Brandi ML (1994) Evidence of estrogen receptor in a human preosteoclastic cell line. Abstracts of the First International Conference on Steroids and Bone. Calcif Tissue Int 54: 339

    Google Scholar 

  19. Sato T, Koite T, Hamda A, Okashi M, Shimazu A (1986) Pharmacokinetics of ipriflavone tablets in long-term administration to patients with osteoporosis. Jpn Pharm Ther J 14: 873–883

    Google Scholar 

  20. Lees JA, Fawell SE, Parker MG (1989) Identification of two transactivation domains in the mouse estrogen receptor. Nucleic Acids Res 17: 5477–5488

    Google Scholar 

  21. Kushner PJ, Hort E, Shine J, Baxter JD, Greene GL (1990) Construction of cell lines that express high levels of the human estrogen receptor and are killed by estrogens. Mol Endocrinol 4: 1465–1473

    Google Scholar 

  22. Strobl JS, Kasid A, Huff K, Lippman ME (1984) Kinetic alterations in the estrogen receptor associated with estrogen receptor processing in human breast cancer cells. Endocrinology 115: 116–125

    Google Scholar 

  23. Scatchard G (1949) The attraction of protein for small molecules and ions. Am NY Acad Sci 51: 660

    Google Scholar 

  24. Fiorelli G, Zoppi S, Kohen F, Motta M (1989) Synergistic effect of testosterone and of a luteinizing hormone-releasing hormone agonist on androgen receptor content in the ventral prostate of castrated rats. Steroids 53: 195–217

    Google Scholar 

  25. Green B, Leake RE (1987) Steroid hormones—a practical approach. IRL Press, pp. 213–214

  26. Maniatis T, Fritsch EF, Sambrook J (1989) Molecular cloning—a laboratory manual. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY

    Google Scholar 

  27. Bradford M (1976) A rapid and sensitive method for the quantitation of microgram quantities of protein utilising the principle of protein dye binding. Anal Biochem 72–248

  28. Markiewicz L, Garey J, Adlercreutz H, Gurpide E (1993) In vitro bioassays of non-steroidal phytoestrogens. J Steroid Biochem Mol Biol 45: 399–405

    Google Scholar 

  29. Scambia G, Ranelletti FO, Benedetti Pacini P, Piantelli M, Bonanno G, De Vincenzo R, Ferrandina G, Rumi C, Larocca LM, Mancuso S (1990) Inhibitory effect of quercetin on OVCA cells and presence of type II oestrogen binding sites in primary ovarian tumours and cultured cells. Br J Cancer 62: 942–946

    Google Scholar 

  30. Benvenuti S, Tanini A, Frediani U, Bianchi S, Masi L, Casano R, Bufalino L, Serio M, Brandi ML (1991) Effects of ipriflavone and its metabolites on a clonal osteoblastic cell line. J Bone Miner Res 6: 987–996

    Google Scholar 

  31. Lippman ME, Bolan G (1975) Oestrogen responsive human breast cancer cells in long-term tissue culture. Nature 256: 592–594

    Google Scholar 

  32. Carson-Jurica MA, Schrader WT, O'Malley BW (1990) Steroid receptor family: structure and function. Endocrinol Rev 11: 201–220

    Google Scholar 

  33. Read LD, Greene GL, Katzenellenbogen BS (1989) Regulation of estrogen receptor messenger ribonucleic acid and protein levels in human breast cancer cell lines by sex steroid hormones, their antagonists, and growth factors. Mol Endocrinol 3: 295–304

    Google Scholar 

  34. Ali S, Metzger D, Bornert JM, Chambon P (1993) Modulation of transcriptional activation by ligand-dependent phosphorylation of the human estrogen receptor A/B region. EMBO J 12: 1153–1160

    Google Scholar 

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Petilli, M., Fiorelli, G., Benvenuti, S. et al. Interactions between ipriflavone and the estrogen receptor. Calcif Tissue Int 56, 160–165 (1995). https://doi.org/10.1007/BF00296349

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