Abstract
Antiestrogens (AE), such as tamoxifen, selectively increase the production of a secreted protein of 37,000 mol wt (Mr) in estrogen receptor-containing human breast cancer cells (MCF-7, but not in estrogen receptor-negative MDA-MB- 231 cells), and the production of this protein by AE is inhibited by concomitant estradiol (E) treatment. Likewise, E increases the production of a 32,000 Mr secreted protein whose synthesis is inhibited by AE. Proteins were detected by [35S]methionine and [35S]cysteine labeling of cells and analysis of proteins by sodium dodecyl sulfate-polyacrylamide gels and fluorography. Enhanced production of the 37,000 Mr protein is observed within 6 h of AE treatment, with maximal synthesis seen at 1–2 days when this protein represents about 6% of the total radiolabeled secreted proteins. This protein is stimulated maximally (-4- fold) by 10-8 M tams-hydroxytamoxifen or LY117018 or 10-6 M tamoxifen, and its AE specificity is seen by the fact that transtamoxifen increases this protein, whereas cw-tamoxifen, an estrogen, does not. In addition to stimulating the synthesis of previously identified 160,000 and 52,000 Mr secreted proteins, E increases the production of a 32,000 Mr secreted protein. When cells are grown in estrogen-free conditions, i.e. in charcoaldextran- treated serum in medium lacking the estrogen phenol red, the basal level of the 32,000 Mr protein is extremely low, and E stimulation results in a 10-fold increase in the production of this protein, with increases observable by 6 h and maximal stimulation at 2 days. Interestingly, the basal level of synthesis of the 37,000 Mr protein is high in the absence of E and is then stimulated only minimally by the addition of AE, suggesting that this protein is clearly produced as an estrogen-antagonistic protein. Amino acid incorporation conducted in the presence of tunicamycin and endoglycosidase H indicates that both of these proteins are glycoproteins. These proteins should serve as useful markers for AE and E action and may be involved in AE and E modulation of cell proliferation and/or cell function.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1140-1151 |
| Number of pages | 12 |
| Journal | Endocrinology |
| Volume | 120 |
| Issue number | 3 |
| DOIs | |
| State | Published - Mar 1987 |
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- Endocrinology
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Antiestrogen stimulation of the production of a 37,000 molecular weight secreted protein and estrogen stimulation of the production of a 32,000 molecular weight secreted protein in mcf-7 human breast cancer cells. / Katzenellenbogen, Benita S.
In: Endocrinology, Vol. 120, No. 3, 03.1987, p. 1140-1151.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Antiestrogen stimulation of the production of a 37,000 molecular weight secreted protein and estrogen stimulation of the production of a 32,000 molecular weight secreted protein in mcf-7 human breast cancer cells
AU - Katzenellenbogen, Benita S.
PY - 1987/3
Y1 - 1987/3
N2 - Antiestrogens (AE), such as tamoxifen, selectively increase the production of a secreted protein of 37,000 mol wt (Mr) in estrogen receptor-containing human breast cancer cells (MCF-7, but not in estrogen receptor-negative MDA-MB- 231 cells), and the production of this protein by AE is inhibited by concomitant estradiol (E) treatment. Likewise, E increases the production of a 32,000 Mr secreted protein whose synthesis is inhibited by AE. Proteins were detected by [35S]methionine and [35S]cysteine labeling of cells and analysis of proteins by sodium dodecyl sulfate-polyacrylamide gels and fluorography. Enhanced production of the 37,000 Mr protein is observed within 6 h of AE treatment, with maximal synthesis seen at 1–2 days when this protein represents about 6% of the total radiolabeled secreted proteins. This protein is stimulated maximally (-4- fold) by 10-8 M tams-hydroxytamoxifen or LY117018 or 10-6 M tamoxifen, and its AE specificity is seen by the fact that transtamoxifen increases this protein, whereas cw-tamoxifen, an estrogen, does not. In addition to stimulating the synthesis of previously identified 160,000 and 52,000 Mr secreted proteins, E increases the production of a 32,000 Mr secreted protein. When cells are grown in estrogen-free conditions, i.e. in charcoaldextran- treated serum in medium lacking the estrogen phenol red, the basal level of the 32,000 Mr protein is extremely low, and E stimulation results in a 10-fold increase in the production of this protein, with increases observable by 6 h and maximal stimulation at 2 days. Interestingly, the basal level of synthesis of the 37,000 Mr protein is high in the absence of E and is then stimulated only minimally by the addition of AE, suggesting that this protein is clearly produced as an estrogen-antagonistic protein. Amino acid incorporation conducted in the presence of tunicamycin and endoglycosidase H indicates that both of these proteins are glycoproteins. These proteins should serve as useful markers for AE and E action and may be involved in AE and E modulation of cell proliferation and/or cell function.
AB - Antiestrogens (AE), such as tamoxifen, selectively increase the production of a secreted protein of 37,000 mol wt (Mr) in estrogen receptor-containing human breast cancer cells (MCF-7, but not in estrogen receptor-negative MDA-MB- 231 cells), and the production of this protein by AE is inhibited by concomitant estradiol (E) treatment. Likewise, E increases the production of a 32,000 Mr secreted protein whose synthesis is inhibited by AE. Proteins were detected by [35S]methionine and [35S]cysteine labeling of cells and analysis of proteins by sodium dodecyl sulfate-polyacrylamide gels and fluorography. Enhanced production of the 37,000 Mr protein is observed within 6 h of AE treatment, with maximal synthesis seen at 1–2 days when this protein represents about 6% of the total radiolabeled secreted proteins. This protein is stimulated maximally (-4- fold) by 10-8 M tams-hydroxytamoxifen or LY117018 or 10-6 M tamoxifen, and its AE specificity is seen by the fact that transtamoxifen increases this protein, whereas cw-tamoxifen, an estrogen, does not. In addition to stimulating the synthesis of previously identified 160,000 and 52,000 Mr secreted proteins, E increases the production of a 32,000 Mr secreted protein. When cells are grown in estrogen-free conditions, i.e. in charcoaldextran- treated serum in medium lacking the estrogen phenol red, the basal level of the 32,000 Mr protein is extremely low, and E stimulation results in a 10-fold increase in the production of this protein, with increases observable by 6 h and maximal stimulation at 2 days. Interestingly, the basal level of synthesis of the 37,000 Mr protein is high in the absence of E and is then stimulated only minimally by the addition of AE, suggesting that this protein is clearly produced as an estrogen-antagonistic protein. Amino acid incorporation conducted in the presence of tunicamycin and endoglycosidase H indicates that both of these proteins are glycoproteins. These proteins should serve as useful markers for AE and E action and may be involved in AE and E modulation of cell proliferation and/or cell function.
UR - http://www.scopus.com/inward/record.url?scp=0023117999&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0023117999&partnerID=8YFLogxK
U2 - 10.1210/endo-120-3-1140
DO - 10.1210/endo-120-3-1140
M3 - Article
C2 - 3803313
AN - SCOPUS:0023117999
VL - 120
SP - 1140
EP - 1151
JO - Endocrinology
JF - Endocrinology
SN - 0013-7227
IS - 3
ER -