Summary
The addition of sodium molybdate (20 mM) to human breast tumor homogenates results in an increased yield of estrogen receptor sites in the cytosol, but reduces the number of sites detectable in salt extracts of purified nuclei. Only about 25% of the increase in cytosol receptor can be accounted for by the loss of nuclear sites. Addition of molybdate to isolated nuclear salt extracts has no inhibitory effect on the estrogen receptor assay, but addition of the oxyanion to the cytosol after separation of the initial nuclear pellet still gives a significant increase in estradiol binding capacity. Furthermore, addition of molybdate to the suspension from the first nuclear pellet still results in loss of binding sites in the nuclear salt extract. This rules out the possibility that the negative effect of molybdate on nuclear receptor recovery is by its inhibition of cytosol receptor activation and translocation during tissue preparation.
The number of nuclei isolated from estrogen receptor-containing tumors does not differ significantly in the presence or absence of molybdate. Estrogen receptor-negative tumors however yield fewer nuclei, particularly when they are processed in the presence of molybdate.
We conclude that when homogenization of tumors is carried out in the presence of molybdate, a significant fraction of estrogen receptor which would normally be present in purified nuclei is lost, perhaps by leakage through the nuclear membrane.
References
Miller LK, Tuazon FB, Niu EM, Sherman MR: Human breast tumor estrogen receptor: effects of molybdate and electrophoretic analysis. Endocrinology 108: 1369–1378, 1981
Niu EM, Neal RM, Pierce VK, Sherman MR: Structural similarity of molybdate-stabilized steroid receptors in human breast tumors, uteri and leukocytes. J Steroid Biochem 15: 1–18, 1981
Gaubert GM, Blancucci S, Shyamala G: A comparison of the cytoplasmic estrogen receptors of mammary gland from virgin and lactating mice. Endocrinology 110: 683–685,1982
Anderson KM, Phelan J, Marogel M, Hendrickson C, Economou S: Sodium molybdate increases the amount of progesterone and estrogen receptor detected in certain human breast cancer cytosols. Steroids 35: 273–280, 1980
Krozowski ZS, Murphy LC: Stabilization of the cytoplasmic oestrogen receptor by molybdate. J Steroid Biochem 14: 363–366, 1981
Gaubert CM, Tremblay RR, Dubé JY: Effect of sodium molybdate on cytosolic androgen receptors in rat prostate. J Steroid Biochem 13: 931–936, 1980
Hawkins EF, Lieskovsky G, Markland FS Jr: Molybdate and the measurement of androgen receptors in prostate cancer. J Clin Endocrinol Metab 53: 456–458, 1981
McGuire WL, Carbone PP, Sears ME, Escher GC: Estrogen receptors in human breast cancer: an overview.In McGuire WL, Carbone PP, Vollmer EP (eds): Estrogen Receptors in Human Breast Cancer. Raven Press, New York, 1975, pp 1–7
McGuire WL: Steroid hormone receptors in breast cancer treatment strategy. Rec Prog Hor Res 36: 135–156, 1980
Leake RE, Laing L, Calman KC, MacBeth FR, Crawford DR, Smith DC: Oestrogen-receptor status and endocrine therapy of breast cancer: response rates and status stability. Br J Cancer 43: 59–66, 1981
Hawkins RA, Roberts MM, Forrest APM: Oestrogen receptors and breast cancer: current status. Brit J Surg 67: 153–169, 1980
Panko WB, McLeod RM: Uncharged nuclear receptors for estrogen in breast cancers. Cancer Res 38: 1948–1951, 1978
Thorsen T: Occupied and unoccupied nuclear oestradiol receptor in human breast tumors: relation to estradiol and progesterone cytosol receptors. J Steroid Biochem 10: 661–668, 1979
Leake RE, Laing L, McArdle C, Smith DC: Soluble and nuclear oestrogen receptor status in human breast cancer in relation to prognosis. Br J Cancer 43: 67–72, 1981
Sato B, Nomura Y, Nakao K, Ochi H, Matsumoto K: DNA binding ability of estrogen receptor from human breast cancer. J Steroid Biochem 14: 295–303, 1981
Fazekas AG, MacFarlane JK: Studies on cytosol and nuclear binding of estradiol in human breast cancer. J Steroid Biochem 13: 613–622, 1980
McGuire WL, Zava DT, Horwitz KB, Garola RE, Chamness GC: Receptors and breast cancer: Do we know it all? J Steroid Biochem 9: 461–466, 1978
Syne JS, Markaverich BM, Clark JH, Panko WB: Estrogen binding sites in the nucleus of normal and malignant human tissue: optimization of an exchange assay for the measurement of specific binding. Cancer Res 42: 4443–4448, 1982
Syne JS, Markaverich BM, Clark JH, Panko WB: Estrogen binding sites in the nucleus of normal and malignant human tissue: characteristics of the multiple nuclear binding sites. Cancer Res 42: 4449–4454, 1982
Osborne CK, Yochmowitz MG, Knight WA, McGuire WL: The value of estrogen and progesterone receptors in the treatment of breast cancer. Cancer 46: 2884–2888, 1980
Edwards DP, Adams DJ, McGuire WL: Specific protein synthesis regulated by estrogen in human breast cancer. J Steroid Biochem 15: 247–259, 1981
Edwards DP, Martin PM, Horwitz KB, Chamness GC, McGuire WL: Subcellular compartmentalization of estrogen receptors in human breast cancer cells. Exptl Cell Res 127: 197–213, 1980
McGuire WL, DeLaGarza M, Chamness GC: Evaluation of estrogen receptor assays in human breast cancer tissue. Cancer Res 37: 637–639, 1977
Lieskovsky G, Bruchovsky N: Assay of nuclear androgen receptor in human prostate. J Urol 121: 54–58, 1979
Burton K: A study of the conditions and mechanisms of the diphenylamine reaction for the colorimetric estimation of deoxyribonucleic acid. Biochem J 62: 315–323, 1956
Leach Kl, Dahmer MK, Hammond WD, Sando JJ, Pratt WB: Molybdate inhibition of glycocorticoid receptor inactivation and transformation. J Biol Chem 254: 11884–11890, 1979
Noma K, Nakao K, Sato B, Nishizawa Y, Matsumoto K, Yamamura Y: Effect of molybdate on activation and stabilization of steroid receptors. Endocrinology 107: 1205–1211, 1980
Steel RGD, Torrie JH: Principles and Procedures of Statistics. McGraw-Hill, New York, 1960, p 405
Osborne CK, Fisher E, Redmond C, Knight WA, Yochmowitz MG, McGuire WL: Estrogen receptor, a marker for human breast cancer differentiation and patient prognosis.In Leavitt WW (ed): Hormones and Cancer, Plenum, New York, 1982, pp 377–385
Trachtenberg J, Hicks LL, Walsh PC: Methods for the determination of androgen receptor content in human prostatic tissue. Invest Urol 18: 349–254, 1981
Barrack ER, Bujnovszky P, Walsh PC: Subcellular distribution of androgen receptors in human normal, benign hyperplastic, and malignant prostatic tissues: characterization of nuclear salt-resistant receptors. Cancer Res 43: 1107–1116, 1983
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Lazier, C.B., Richman, J. & Lonergan, K. The effect of molybdate on the intracellular distribution of estrogen receptor in mammary tumors. Breast Cancer Res Tr 4, 19–26 (1984). https://doi.org/10.1007/BF01806984
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DOI: https://doi.org/10.1007/BF01806984