Abstract
Potential antiproliferative effects of tocotrienols, the major vitamin E component in palm oil, were investigated on the growth of both estrogen-responsive (ER+) MCF7 human breast cancer cells and estrogen-unresponsive (ER-) MDA-MD-231 human breast cancer cells, and effects were compared with those of α-tocopherol (αT). The tocotrienol-rich fraction (TRF) of palm oil inhibited growth of MCF7 cells in both the presence and absence of estradiol with a nonlinear dose-response but such that complete suppression of growth was achieved at 8 μg/mL. MDA-MB-231 cells were also inhibited by TRF but with a linear dose-response such that 20 μg/mL TRF was needed for complete growth suppression. Separation of the TRF into individual tocotrienols revealed that all fractions could inhibit growth of both ER+ and ER- cells and of ER+ cells in both the presence and absence of estradiol. However, the γ- and δ-fractions were the most inhibitory. Complete inhibition of MCF7 cell growth was achieved at 6 μg/mL of γ-tocotrienol/δ-tocotrienol (γT3/δT3) in the absence of estradiol and 10μm/mL of δT3 in the presence of estradiol, whereas complete suppression of MDA-MB-231 cell growth was not achieved even at concentrations of 10μg/mL of δT3. By contrast to these inhibitory effects of tocotrienols, αT had no inhibitory effect on MCF7 cell growth in either the presence or the absence of estradiol, nor on MDA-MB-231 cell growth. These results confirm studies using other sublines of human breast cancer cells and demonstrate that tocotrienols can exert direct inhibitory effects on the growth of breast cancer cells. In searching for the mechanism of inhibition, studies of the effects of TRF on estrogen-regulated pS2 gene expression in MCF7 cells showed that tocotrienols do not act via an estrogen receptor-mediated pathway and must therefore act differently from estrogen antagonists. Furthermore, tocotrienols did not increase levels of growth-inhibitory insulin-like growth factor binding proteins (IGFBP) in MCF7 cells, implying also a different mechanism from that proposed for retinoic acid inhibition of estrogen-responsive breast cancer cell growth. Inhibition of the growth of breast cancer cells by tocotrienols could have important clinical implications not only because tocotrienols are able to inhibit the growth of both ER+ and ER- phenotypes but also because ER+ cells could be growth-inhibited in the presence as well as in the absence of estradiol. Future clinical applications of TRF could come from potential growth suppression of ER+ breast cancer cells otherwise resistant to growth inhibition by antiestrogens and retinoic acid.
Similar content being viewed by others
Abbreviations
- DCFCS:
-
dextran-charcoal treated fetal calf serum
- ER+:
-
estrogen receptor positive (containing estrogen receptors)
- ER−:
-
estrogen receptor negative (lacking estrogen receptors)
- FCS:
-
fetal calf serum
- IGF:
-
insulin-like growth factor
- IGFBP:
-
insulin-like growth factor binding protein
- PBS:
-
phosphate-buffered saline
- SDS:
-
sodium dodecyl sulfate
- αT:
-
α-tocopherol
- αT3 :
-
α-tocotrienol
- γT3 :
-
γ-tocotrienol
- δT3 :
-
δ-tocotrienol
- TRF:
-
tocotrienol-rich fraction
References
Sebrell, W.H., and Harris, R.S. (1972) The Vitamins, 2nd edn., Vol. 5, pp. 172–173, Academic Press, New York.
Tappel, A.L. (1972) Vitamin E and Free Radical Peroxidation of Lipids, Ann. N.Y. Acad. Sci. 203, 12.
Burton, G.W., and Ingold, K.U. (1989) Vitamin E as in vitro and in vivo Antioxidant, Ann. N.Y. Acad. Sci. 570, 7–22.
Goh, S.H., Hew, N.F., Ong, A.S.H., Choo, Y.M., and Brumby, S. (1990) Tocotrienols from Palm Oil: Electron Spin Resonance Spectra of Tocotrienoxyl Radicals, J. Am. Oil Chem. Soc. 67, 250–254.
Serbinova, E., Kagan, V., Han, D., and Packer, L. (1991) Free Radical Recycling and Intermembrane Mobility in the Antioxidation Properties of Alpha-Tocopherol and Alpha-Tocotrienol, Free Radicals Biol. Med. 10, 263–275.
Ong, A.S.H. (1993) Natural Sources of Tocotrienols in Vitamin E in Health and Disease (Packer, L., and Fuchs, J., eds.) Marcel Dekker, New York, pp. 3–8.
Gould, M.N., Haag, J.D., Kennan, W.S., Tanner, M.A., and Elson, C.E. (1991) A Comparison of Tocopherol and Tocotrienol for the Chemoprevention of Chemically Induced Rat Mammary Tumors, Am. J. Clin Nutr. 53, 1068s-1070s.
Tan, B. (1992) Antitumor Effects of Palm Carotenes and Tocotrienols in HRS/J Hairless Female Mice, Nutr. Res. 12, S163–173.
Sylvester, P.W., Russell, M., Ip, M.M., and Ip, C. (1986) Comparative Effects of Different Animal and Vegetable Fats Before and During Carcinogen Administration on Mammary Tumourigenesis, Sexual Maturation and Endocrine Function in Rats, Cancer Res. 46, 757–762.
Sundram, K., Khor, H.T., Ong, A.S.H., and Pathmanathan, R. (1989) Effect of Dietary Palm Oils on Mammary Carcinogenesis in Female Rats Induced by 7, 12 Dimethylbenz(α)anthracene, Cancer Res. 49, 1447–1451.
Kritchevsky, D., Weber, M.M., and Klurfeld, D.M. (1992) Influence of Different Fats (Soyabean Oil, Palm Olein or Hydrogenated Oil) on Chemically-Induced Mammary Tumors in Rats, Nutr. Res. 12, S175–179.
Nesaretnam, K., Khor, H.T., Ganeson, J., Chong, Y.H., Sundram, K., and Gapor, A. (1992) The Effect of Vitamin E Tocotrienols from Palm Oil on Chemically Induced Mammary Carcinogenesis in Female Rats, Nutr. Res. 12, 879–892.
Nesaretnam, K., Guthrie, N., Chambers, A.F., and Carroll, K.K. (1995) Effect of Tocotrienols on the Growth of a Human Breast Cancer Cell Line in Culture, Lipids 30, 1139–1143.
Beck, J.S. (ed.) (1989) Oestrogen and the Human Breast, Proc. Roy. Soc. Edin. 95B, 1–307.
Stewart, H.J., Anderson, T.J., and Forrest, A.P.M. (eds.) (1991) Breast Cancer: New Approaches, Brit Med. Bull. 47, 251–518.
Darbre, P.D., and Daly, R.J. (1989) Effects of Oestrogen on Human Breast Cancer Cells in Culture, Proc. Roy. Soc. Edin. 95B, 119–132.
Lippman, M.E., and Dickson, R.B. (1990) Regulatory Mechanisms in Breast Cancer: Advances in Cellular and Molecular Biology of Breast Cancer, Kluwer Academic Publishers, Boston, pp. 1–452.
Engel, L.W., Young, N.A., Tralka, T.S., Lippman, M.E., O'Brien, S.J., and Joyce, M.J. (1978) Establishment and Characterisation of Three New Continuous Cell Lines Derived from Human Breast Carcinomas, Cancer Res. 38, 3352–3364.
Osborne, C.K., Hobbs, K., and Trent, J.M. (1987) Biological Differences Among MCF-7 Human Breast Cancer Cell Lines from Different Laboratories, Breast Cancer Res. Treat. 9, 111–121.
Yee, D. (1992) Insulin-Like Growth Factors in Breast Cancer, Breast Cancer Res. Treat. 22, 1–106.
Kelley, K.M., Oh, Y., Gargosky, S.E., Gucev, Z., Matsumoto, T., Hwa, V., Ng, L., Simpson, D.M., and Rosenfeld, R.G. (1996) Insulin-Like Growth Factor Binding Proteins (IGFBPs) and Their Regulatory Dynamics, Int. J. Biochem. Cell Biol. 28, 619–637.
Yee, D., Cullen, K.J., Paik, S., Perdue, J.F., Hampton, B., Schwartz, A., Lippman, M.E., and Rosen, N. (1988) Insulin-Like Growth Factor II mRNA Expression in Human Breast Cancer, Cancer Res. 48, 6691–6696.
Stewart, A.J., Johnson, M.D., May, F.E.B., and Westley, B.R. (1990) Role of Insulin-Like Growth Factors and the Type I Insulin-Like Growth Factor Receptor in the Estrogen-Stimulated Proliferation of Human Breast Cancer Cells, J. Biol. Chem. 265, 21172–21178.
Pratt, S.E., and Pollock, M.N. (1993) Estrogen and Antioestrogen Modulation of MCF-7 Human Breast Cancer Cell Proliferation Is Associated with Specific Alterations in Accumulation of Insulin-Like Growth Factor Binding Proteins in Conditioned Media, Cancer Res. 53, 5193–5198.
Parker, M.G. (ed.) (1991) Nuclear Hormone Receptors: Molecular Mechanisms, Cellular Functions, Clinical Abnormalities, Academic Press, London, pp. 1–404.
Parker, M.G. (ed.) (1993) Steroid Hormone Action, IRL Press, Oxford, pp. 1–210.
Wakeling, A.E. (1993) The Future of New Pure Antiestrogens in Clinical Breast Cancer, Breast Cancer Res. Treat. 25, 1–9.
Perachiotti, A., and Darbre, P.D. (1994) Coculture Inserts Possess an Intrinsic Ability to Alter Growth Regulation of Human Breast Cancer Cells, Exp. Cell Res. 213, 404–411.
Masiakowski, P., Breathnach, R., Bloch, J., Gannon, F., Krust, A., and Chambon, P. (1982) Cloning of cDNA Sequences of Hormone-Regulated Genes from the MCF-7 Human Breast Cancer Cell Line, Nucleic Acids Res. 10, 7895–7903.
Sundram, K., and Gapor, A. (1992) Vitamin E from Palm Oil Its Extraction and Nutritional Properties, Lipid Technolog. Peter J. Barnes, Bridgwater, England, November/December, pp. 137–141.
Darbre, P., Yates, J., Curtis, S., and King, R.J.B. (1983) Effect of Estradiol on Human Breast Cancer Cells in Culture, Cancer Res. 43, 349–354.
Maniatis, T., Fitsch, F.F., and Sambrook, J. (1982) Molecular Cloning. A Laboratory Manual, Cold Spring Harbor Laboratory, New York, pp. 1–545.
Brown, A.M.C., Jeltsch, J.M., Roberts, M., and Chambon, P. (1984) Activation of pS2 Gene Transcription Is a Primary Response to Estrogen in the Human Breast Cancer Cell Line MCF-7, Proc. Natl. Acad. Sci. USA 81, 6344–6348.
Hossenlopp, P., Seurin, D., Segovia-Quinson, B., Hardouin, S., and Binoux, M. (1986) Analysis of Serum Insulin-Like Growth Factor Binding Proteins Using Western Blotting: Use of the Method for Titration of the Binding Proteins and Competitive Binding Studies, Anal. Biochem. 154, 138–143.
Salacinski, P.R.P., McLean, C., Sykes, J.E.C., Clement-Jones, V.V., and Lowry, P.J. (1981) Iodination of Proteins, Glycoproteins and Peptides Using a Solid Phase Oxidising Agent 1,3,4,6-Tetrachloro-3,6-diphenylglycouril (Iodogen), Anal. Biochem. 117, 136–146.
Corcoran, D., Perachiotti, A., and Darbre, P.D. (1996) Increased Autocrine Production of Insulin-Like Growth Factor II (IGF-II) Alters Serum Sensitivity of MCF7 Human Breast Cancer Cell Proliferation, Cell Prolif. 29, 479–493.
Carroll, K.K., Guthrie, N., Nesaretnam, K., Gapor, A., and Chambers, A.F. (1995) Anti-Cancer Properties of Tocotrienols from Palm Oil, in Nutrition, Lipids, Health and Disease (Ong, A.S.H., Niki, E., and Packer, L., eds.) AOCS Press, Champaign, pp. 117–121.
Guthrie, N., Chambers, A.F., Gapor, A., and Carroll, K.K. (1995) In vitro Inhibition of Proliferation of Receptor-Positive MCF-7 Human Breast Cancer Cells by Palm Oil Tocotrienols, FASEB J. 9, A968 (abstract 5735).
Guthrie, N., Gapor, A., Chambers, A.F., and Carroll, K.K. (1997) Inhibition of Proliferation of Estrogen Receptor-Negative MDA-MB-435 and-Positive MCF-7 Human Breast Cancer Cells by Palm Oil Tocotrienols and Tamoxifen, Alone and in Combination, J. Nutr 127, 544S-548S.
Guthrie, N., Gapor, A., Chambers, A.F., and Carroll, K.K. (1997) Palm Oil Tocotrienols and Plant Flavonoids Act Synergistically to Inhibit Proliferation of Estrogen Receptor-Negative MDA-MB-231 and-Positive MCF-7 Human Breast Cancer Cells in Culture, Asia Pacific J. Clin. Nutr. 6, 41–45.
Kyprianou, N., English, H.F., Davidson, N.E., and Isaacs, J.T. (1991) Programmed Cell Death During Regression of the MCF-7 Human Breast Cancer Following Estrogen Ablation, Cancer Res. 51, 162–166.
Tenniswood, M.P., Guenette, R.S., Lakins, J., Mooibroek, M., Wong, P., and Welsch, J.E. (1992) Active Cell Death in Hormone-Dependent Tissues, Cancer Metastasis Rev. 11, 197–220.
Warri, A.M., Huovinen, R.L., Martikainen, P.M., and Harkonen, P.L. (1993) Apoptosis in Toremifene-Induced Growth Inhibition of Human Breast Cancer Cells in vivo and in vitro, J. Natl. Cancer. Inst. 85, 1412–1418.
Pagliacci, M.C., Tognellini, R., Grignani, F., and Nicoletti, I. (1991) Inhibition of Human Breast Cancer Cell (MCF-7) Growth in vitro by Somatostatin Analog SMS 201-995: Effects on Cell Cycle Parameters and Apoptotic Cell Death, Endocrinology 129, 2555–2562.
Armstrong, D.K., Isaacs, J.T., Ottaviano, Y.L., and Davidson, N.E. (1992) Programmed Cell Death in an Estrogen-Independent Human Breast Cancer Cell Line MDA-MB-468, Cancer Res. 52, 3418–3424.
McCloskey, D.E., Casero, R.A., Woster, P.M., and Davidson, N.E. (1995) Induction of Programmed Cell Death in Human Breast Cancer Cells by an Unsymmetrically Alkylated Polyamine Analogue, Cancer Res. 55, 3233–3236.
Chatelain, E., Boscoboinik, D.O., Bartoli, G.M., Kagan, V.E., Gey, F.K., Packer, L., and Azzi, A. (1993) Inhibition of Smooth Muscle Cell Proliferation and Protein Kinase C Activity by Tocopherols and Tocotrienols, Biochim. Biophys. Acta 1176, 83–89.
Gundimeda, U., Chen, Z.H., and Gopalakrishna, R. (1996) Tamoxifen Modulates Protein Kinase C via Oxidative Stress in Estrogen Receptor-Negative Breast Cancer Cells, J. Biol. Chem. 271, 13504–13514.
Koba, K., Abe, K., Ikeda, I., and Sugano, M. (1992) Effects of Alpha-Tocopherol and Tocotrienols on Blood Pressure and Linoleic Acid Metabolism in the Spontaneously Hypertensive Rat, Biosci. Biotechnol. Biochem. 56, 1420–1423.
Rose, D.P., Connolly, J.M., and Liu, X.H. (1994) Effects of Linoleic Acid on the Growth and Metastasis of Two Human Breast Cancer Cell Lines in Nude Mice and the Invasive Capacity of These Cell Lines in vitro, Cancer Res. 54, 6557–6562.
Glover, J.F., Irwin, J.T., and Darbre, P.D. (1988) Interaction of Phenol Red with Estrogenic and Antiestrogenic Action on Growth of Human Breast Cancer Cells ZR-75-1 and T-47-D, Cancer Res. 48, 3693–3697.
Gucev, Z.S., Oh, Y., Kelley, K.M., and Rosenfeld, R.G. (1996) Insulin-Like Growth Factor Binding Protein 3 Mediates Retinoic Acid- and Transforming Growth Factor β2-Induced Growth Inhibition in Human Breast Cancer Cells, Cancer Res. 56, 1545–1550.
Darbre, P.D., and Daly, R.J. (1990) Transition of Human Breast Cancer Cells from an Oestrogen Responsive to Unresponsive State, J. Steroid Biochem. Molec. Biol. 37, 753–763.
Horwitz, K.B. (1994) How Do Breast Cancers Become Hormone Resistant? J. Steroid Biochem. Molec. Biol. 49, 295–302.
Stephen, R., Corcoran, D., and Darbre, P.D. (1996) Retinoic Acid Inhibits Growth of Breast Cancer Cells in the Short-Term but Not the Long-Term, Biochem. Soc. Trans. 24, 365S.
Author information
Authors and Affiliations
Corresponding author
About this article
Cite this article
Nesaretnam, K., Stephen, R., Dils, R. et al. Tocotrienols inhibit the growth of human breast cancer cells irrespective of estrogen receptor status. Lipids 33, 461–469 (1998). https://doi.org/10.1007/s11745-998-0229-3
Received:
Revised:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/s11745-998-0229-3