Abstract
The phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA) (10 nM) produce a marked reduction in the growth, measured by thymidine uptake, of MCF-7 cells in full growth medium, but had only a small effect on MDA-MB-231 and T47D cells. Bryostatin alone also inhibited growth but to a lesser extent than seen with TPA. The effect of TPA on MCF-7 cells was partially reversed by bryostatin, added simultaneously or after TPA, suggesting bryostatin does not simply mimic TPA in this system. Even though both are believed to act via effects on protein kinase C, bryostatin appears to act as antagonist to the effect of TPA as well as a partial agonist on its own. When the oestrogen receptor positive MCF-7 and T47D cells were maintained in charcoal stripped serum, the increase in DNA synthesis on stimulation with oestradiol was inhibited with 50 nM TPA in MCF-7 cells but not in T47D cells. The effects of these treatments on the expression of two well characterised oestrogen responsive genes pNR2(pS2) and pNR100 (Cathepsin-D) were examined. Rather than preventing transcription of these oestrogen responsive genes, TPA alone increased pNR2 and pNR100 levels in MCF-7 cells and the combined effect of oestradiol and TPA had a marked synergistic effect in increasing the transcript levels of these genes. In T47D cells pNR2 transcripts were not detected and the increase in pNR100 mRNA levels were not affected by TPA. We conclude that the inhibitory effects of TPA on the growth stimulation of MCF-7 cells by oestradiol was not due to a general inhibition of the expression of oestrogen responsive genes. An alternative possibility examined was that the growth inhibitory effect of TPA on MCF-7 cells might be due to stimulation of TGF-beta 1, acting as an autocrine inhibitory growth factor. Oestradiol treatment of MCF-7 cells reduced the levels of TGF-beta 1 mRNA whereas TPA produced a marked increase. The combined effect of TPA and oestradiol further increased TGF-beta 1 mRNA above the levels seen with TPA alone. Bryostatin had little effect on TGF-beta 1 expression either alone or in combination with oestradiol. These observations are consistent with the hypothesis that the inhibitory effect of TPA on MCF-7 cells may be partly due to autocrine inhibition by TGF-beta 1.
Full text
PDF





Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Angel P., Baumann I., Stein B., Delius H., Rahmsdorf H. J., Herrlich P. 12-O-tetradecanoyl-phorbol-13-acetate induction of the human collagenase gene is mediated by an inducible enhancer element located in the 5'-flanking region. Mol Cell Biol. 1987 Jun;7(6):2256–2266. doi: 10.1128/mcb.7.6.2256. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Arteaga C. L., Tandon A. K., Von Hoff D. D., Osborne C. K. Transforming growth factor beta: potential autocrine growth inhibitor of estrogen receptor-negative human breast cancer cells. Cancer Res. 1988 Jul 15;48(14):3898–3904. [PubMed] [Google Scholar]
- Berkow R. L., Kraft A. S. Bryostatin, a non-phorbol macrocyclic lactone, activates intact human polymorphonuclear leukocytes and binds to the phorbol ester receptor. Biochem Biophys Res Commun. 1985 Sep 30;131(3):1109–1116. doi: 10.1016/0006-291x(85)90205-0. [DOI] [PubMed] [Google Scholar]
- Borner C., Eppenberger U., Wyss R., Fabbro D. Continuous synthesis of two protein-kinase-C-related proteins after down-regulation by phorbol esters. Proc Natl Acad Sci U S A. 1988 Apr;85(7):2110–2114. doi: 10.1073/pnas.85.7.2110. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brooks G., Brooks S. F. Both tumour-promoting and non-promoting phorbol esters inhibit [125I]EGF binding and stimulate the phosphorylation of an 80 kd protein kinase C substrate protein in intact quiescent swiss 3T3 cells. Carcinogenesis. 1990 Apr;11(4):667–672. doi: 10.1093/carcin/11.4.667. [DOI] [PubMed] [Google Scholar]
- Cavailles V., Garcia M., Rochefort H. Regulation of cathepsin-D and pS2 gene expression by growth factors in MCF7 human breast cancer cells. Mol Endocrinol. 1989 Mar;3(3):552–558. doi: 10.1210/mend-3-3-552. [DOI] [PubMed] [Google Scholar]
- Chomczynski P., Sacchi N. Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction. Anal Biochem. 1987 Apr;162(1):156–159. doi: 10.1006/abio.1987.9999. [DOI] [PubMed] [Google Scholar]
- Dale I. L., Gescher A. Effects of activators of protein kinase C, including bryostatins 1 and 2, on the growth of A549 human lung carcinoma cells. Int J Cancer. 1989 Jan 15;43(1):158–163. doi: 10.1002/ijc.2910430129. [DOI] [PubMed] [Google Scholar]
- Darbon J. M., Oury F., Clamens S., Bayard F. TPA induces subcellular translocation and subsequent down-regulation of both phorbol ester binding and protein kinase C activities in MCF-7 cells. Biochem Biophys Res Commun. 1987 Jul 31;146(2):537–546. doi: 10.1016/0006-291x(87)90562-6. [DOI] [PubMed] [Google Scholar]
- Dell'Aquila M. L., Herald C. L., Kamano Y., Pettit G. R., Blumberg P. M. Differential effects of bryostatins and phorbol esters on arachidonic acid metabolite release and epidermal growth factor binding in C3H 10T1/2 cells. Cancer Res. 1988 Jul 1;48(13):3702–3708. [PubMed] [Google Scholar]
- Derynck R., Jarrett J. A., Chen E. Y., Eaton D. H., Bell J. R., Assoian R. K., Roberts A. B., Sporn M. B., Goeddel D. V. Human transforming growth factor-beta complementary DNA sequence and expression in normal and transformed cells. Nature. 1985 Aug 22;316(6030):701–705. doi: 10.1038/316701a0. [DOI] [PubMed] [Google Scholar]
- Dickson R. B., Bates S. E., McManaway M. E., Lippman M. E. Characterization of estrogen responsive transforming activity in human breast cancer cell lines. Cancer Res. 1986 Apr;46(4 Pt 1):1707–1713. [PubMed] [Google Scholar]
- Fabbro D., Regazzi R., Costa S. D., Borner C., Eppenberger U. Protein kinase C desensitization by phorbol esters and its impact on growth of human breast cancer cells. Biochem Biophys Res Commun. 1986 Feb 26;135(1):65–73. doi: 10.1016/0006-291x(86)90943-5. [DOI] [PubMed] [Google Scholar]
- Feinberg A. P., Vogelstein B. A technique for radiolabeling DNA restriction endonuclease fragments to high specific activity. Anal Biochem. 1983 Jul 1;132(1):6–13. doi: 10.1016/0003-2697(83)90418-9. [DOI] [PubMed] [Google Scholar]
- Guerrin M., Darbon J. M., Guilbaud N., Monsarrat B., Valette A. Transforming growth factor beta (TGF-beta) reverses phorbol diester resistance of a breast adenocarcinoma (MCF-7) subline. Biochem Biophys Res Commun. 1990 Jan 30;166(2):687–694. doi: 10.1016/0006-291x(90)90864-j. [DOI] [PubMed] [Google Scholar]
- Issandou M., Bayard F., Darbon J. M. Activation by phorbol esters of protein kinase C in MCF-7 human breast cancer cells. FEBS Lett. 1986 May 12;200(2):337–342. doi: 10.1016/0014-5793(86)81164-4. [DOI] [PubMed] [Google Scholar]
- Issandou M., Bayard F., Darbon J. M. Inhibition of MCF-7 cell growth by 12-O-tetradecanoylphorbol-13-acetate and 1,2-dioctanoyl-sn-glycerol: distinct effects on protein kinase C activity. Cancer Res. 1988 Dec 1;48(23):6943–6950. [PubMed] [Google Scholar]
- Jeltsch J. M., Roberts M., Schatz C., Garnier J. M., Brown A. M., Chambon P. Structure of the human oestrogen-responsive gene pS2. Nucleic Acids Res. 1987 Feb 25;15(4):1401–1414. doi: 10.1093/nar/15.4.1401. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jetten A. M., George M. A., Pettit G. R., Rearick J. I. Effects of bryostatins and retinoic acid on phorbol ester- and diacylglycerol-induced squamous differentiation in human tracheobronchial epithelial cells. Cancer Res. 1989 Jul 15;49(14):3990–3995. [PubMed] [Google Scholar]
- Kim S. J., Denhez F., Kim K. Y., Holt J. T., Sporn M. B., Roberts A. B. Activation of the second promoter of the transforming growth factor-beta 1 gene by transforming growth factor-beta 1 and phorbol ester occurs through the same target sequences. J Biol Chem. 1989 Nov 15;264(32):19373–19378. [PubMed] [Google Scholar]
- Knabbe C., Lippman M. E., Wakefield L. M., Flanders K. C., Kasid A., Derynck R., Dickson R. B. Evidence that transforming growth factor-beta is a hormonally regulated negative growth factor in human breast cancer cells. Cell. 1987 Feb 13;48(3):417–428. doi: 10.1016/0092-8674(87)90193-0. [DOI] [PubMed] [Google Scholar]
- Kraft A. S., Reeves J. A., Ashendel C. L. Differing modulation of protein kinase C by bryostatin 1 and phorbol esters in JB6 mouse epidermal cells. J Biol Chem. 1988 Jun 15;263(17):8437–8442. [PubMed] [Google Scholar]
- Kraft A. S., Smith J. B., Berkow R. L. Bryostatin, an activator of the calcium phospholipid-dependent protein kinase, blocks phorbol ester-induced differentiation of human promyelocytic leukemia cells HL-60. Proc Natl Acad Sci U S A. 1986 Mar;83(5):1334–1338. doi: 10.1073/pnas.83.5.1334. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kraft A. S., William F., Pettit G. R., Lilly M. B. Varied differentiation responses of human leukemias to bryostatin 1. Cancer Res. 1989 Mar 1;49(5):1287–1293. [PubMed] [Google Scholar]
- Lee C. S., Koga M., Sutherland R. L. Modulation of estrogen receptor and epidermal growth factor receptor mRNAs by phorbol ester in MCF 7 breast cancer cells. Biochem Biophys Res Commun. 1989 Jul 14;162(1):415–421. doi: 10.1016/0006-291x(89)92013-5. [DOI] [PubMed] [Google Scholar]
- May F. E., Westley B. R. Cloning of estrogen-regulated messenger RNA sequences from human breast cancer cells. Cancer Res. 1986 Dec;46(12 Pt 1):6034–6040. [PubMed] [Google Scholar]
- May F. E., Westley B. R. Identification and characterization of estrogen-regulated RNAs in human breast cancer cells. J Biol Chem. 1988 Sep 15;263(26):12901–12908. [PubMed] [Google Scholar]
- McBain J. A., Pettit G. R., Mueller G. C. Bryostatin 1 antagonizes the terminal differentiating action of 12-O-tetradecanoylphorbol-13-acetate in a human colon cancer cell. Carcinogenesis. 1988 Jan;9(1):123–129. doi: 10.1093/carcin/9.1.123. [DOI] [PubMed] [Google Scholar]
- Osborne C. K., Hamilton B., Nover M., Ziegler J. Antagonism between epidermal growth factor and phorbol ester tumor promoters in human breast cancer cells. J Clin Invest. 1981 Apr;67(4):943–951. doi: 10.1172/JCI110144. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pasti G., Rivedal E., Yuspa S. H., Herald C. L., Pettit G. R., Blumberg P. M. Contrasting duration of inhibition of cell-cell communication in primary mouse epidermal cells by phorbol 12,13-dibutyrate and by bryostatin 1. Cancer Res. 1988 Jan 15;48(2):447–451. [PubMed] [Google Scholar]
- Pettit G. R., Day J. F., Hartwell J. L., Wood H. B. Antineoplastic components of marine animals. Nature. 1970 Aug 29;227(5261):962–963. doi: 10.1038/227962a0. [DOI] [PubMed] [Google Scholar]
- Ramsdell J. S., Pettit G. R., Tashjian A. H., Jr Three activators of protein kinase C, bryostatins, dioleins, and phorbol esters, show differing specificities of action on GH4 pituitary cells. J Biol Chem. 1986 Dec 25;261(36):17073–17080. [PubMed] [Google Scholar]
- Sako T., Yuspa S. H., Herald C. L., Pettit G. R., Blumberg P. M. Partial parallelism and partial blockade by bryostatin 1 of effects of phorbol ester tumor promoters on primary mouse epidermal cells. Cancer Res. 1987 Oct 15;47(20):5445–5450. [PubMed] [Google Scholar]
- Scotto L., Vaduva P. I., Wager R. E., Assoian R. K. Type beta 1 transforming growth factor gene expression. A corrected mRNA structure reveals a downstream phorbol ester responsive element in human cells. J Biol Chem. 1990 Feb 5;265(4):2203–2208. [PubMed] [Google Scholar]
- Sing G. K., Ruscetti F. W., Beckwith M., Keller J. R., Ellingsworth L., Urba W. J., Longo D. L. Growth inhibition of a human lymphoma cell line: induction of a transforming growth factor-beta-mediated autocrine negative loop by phorbol myristate acetate. Cell Growth Differ. 1990 Nov;1(11):549–557. [PubMed] [Google Scholar]
- Smith J. B., Smith L., Pettit G. R. Bryostatins: potent, new mitogens that mimic phorbol ester tumor promoters. Biochem Biophys Res Commun. 1985 Nov 15;132(3):939–945. doi: 10.1016/0006-291x(85)91898-4. [DOI] [PubMed] [Google Scholar]
- Takaishi K., Kawata S., Ito N., Tamura S., Shirai Y., Tarui S. Effects of phorbol ester on cell growth inhibition by transforming growth factor beta 1 in human hepatoma cell lines. Biochem Biophys Res Commun. 1990 Aug 31;171(1):91–96. doi: 10.1016/0006-291x(90)91360-5. [DOI] [PubMed] [Google Scholar]
- Valette A., Gas N., Jozan S., Roubinet F., Dupont M. A., Bayard F. Influence of 12-O-tetradecanoylphorbol-13-acetate on proliferation and maturation of human breast carcinoma cells (MCF-7): relationship to cell cycle events. Cancer Res. 1987 Mar 15;47(6):1615–1620. [PubMed] [Google Scholar]
- Zugmaier G., Ennis B. W., Deschauer B., Katz D., Knabbe C., Wilding G., Daly P., Lippman M. E., Dickson R. B. Transforming growth factors type beta 1 and beta 2 are equipotent growth inhibitors of human breast cancer cell lines. J Cell Physiol. 1989 Nov;141(2):353–361. doi: 10.1002/jcp.1041410217. [DOI] [PubMed] [Google Scholar]



