help button home button Endocrine Society JCEM
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Submit a related Letter to the Editor
Right arrow Purchase Article
Right arrow View Shopping Cart
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Copyright Permission
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Sasano, H.
Right arrow Articles by Kimura, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Sasano, H.
Right arrow Articles by Kimura, M.
The Journal of Clinical Endocrinology & Metabolism Vol. 84, No. 2 781-785
Copyright © 1999 by The Endocrine Society

Original Studies

Messenger Ribonucleic Acid in Situ Hybridization Analysis of Estrogen Receptors {alpha} and ß in Human Breast Carcinoma1

Hironobu Sasano, Takashi Suzuki, Yukiko Matsuzaki, Takao Fukaya, Mareyuki Endoh, Hiroshi Nagura and Michio Kimura

Departments of Pathology (H.S., T.S., H.N.) and Obstetrics and Gynecology (Y.M., T.F.), Tohoku University School of Medicine; Department of Pathology (M.E.), Institute of Development, Aging and Cancer, Tohoku University 980-8575; and Department of Surgery (M.K.), Tohoku Kousai Hospital, Sendai, Japan 980-0803

Address all correspondence and requests for reprints to: Hironobu Sasano, M.D., Department of Pathology, Tohoku University School of Medicine, 2–1 Seiryou-machi, Aoba-ku, Sendai, Japan 980-0872. E-mail: hsasano{at}patholo2.med.tohoku.ac.jp


   Abstract
Top
 Abstract
Introduction
 Materials and Methods
 Results
 Discussion
 References
 
We examined the expression of a recently characterized novel estrogen receptor (ER) ß in 25 cases of invasive ductal carcinoma of the breast, using messenger RNA (mRNA) in situ hybridization, and compared the findings with those of ER{alpha}, to study its localization and its possible biological significance in human breast cancer. ER{alpha} and ERß hybridization signals were both detected, predominantly in carcinoma cells and in some stromal cells, in 18 of 25 (72%) and 11 of 25 (44%) cases, respectively. The cases in which more than 25% of carcinoma cells demonstrated mRNA hybridization signals were 13 of 25 (52%) and 2 of 25 (8%) cases for ER{alpha} and ERß, respectively. Among the cases expressing ERß, 10 of 11 (91%) also expressed ER{alpha} mRNA; and in these 10 cases, coexpressing both ER{alpha} and ß, the number of carcinoma cells expressing ER{alpha} was greater than that expressing ERß in 9 cases. Eight cases demonstrated only ER{alpha} mRNA hybridization signals in carcinoma cells. These results indicate that ERß is coexpressed with ER{alpha} in most ERß-positive breast carcinoma cells, which suggests that the expression of ERß depends on the presence of ER{alpha} in the great majority of human breast cancer. In addition, the number of carcinoma cases and/or the ratio of carcinoma cells expressing ER{alpha} was much greater than those expressing ERß. The relative ratio of ER{alpha} and ERß expression in carcinoma cells may be related to various estrogen-dependent biological features of human breast cancer.


   Introduction
Top
 Abstract
 Introduction
Materials and Methods
 Results
 Discussion
 References
 
BIOLOGICAL effects of estrogens are mediated through an initial interaction with the estrogen receptor (ER), a member of the steroid/thyroid/retinoid receptor gene superfamily (1). Multiple forms have been reported in other members of the nuclear receptor superfamily (2, 3). However, until the recent cloning of a second ER (ERß), from rat prostate (4) and human testis (5), ER{alpha} had been considered as the only receptor able to bind estrogen with high affinity. ERß protein is smaller than ER{alpha} protein but has a similar high affinity for estradiol, as does the {alpha} receptor (6, 7, 8, 9). Both receptors demonstrate high conservation of amino acid sequence in regions of the hormone binding domain known to be important in contacting ligands (6, 7, 8, 9). However, tissue distribution and relative expression levels of ERß have been demonstrated to be different from those of ER{alpha} (10, 11, 12), which suggests possible different biological roles of ERß in mammalian estrogen-dependent tissues.

Estrogen signal transduction plays very important roles in both normal and neoplastic mammary tissue. Both Dotzlaw et al. (13) and Vladusic et al. (14) very recently demonstrated the expression of ERß messenger RNA (mRNA) in human breast cancer tissues and breast epithelial cell lines, using RT-PCR. However, human breast carcinoma is composed of stromal and carcinoma cells and is known to be associated with diverse morphological features. Therefore, a more thorough study of the tissue distribution of ERß in human breast cancer, especially that of its localization, is essential to the study of its function. Therefore, we performed mRNA in situ hybridization of both ER{alpha} and ERß in clinical specimens of human breast carcinoma to examine the localization of these receptors, especially whether they are coexpressed in the same cases and, if coexpressed, whether they are expressed in the same cell types.


   Materials and Methods
Top
 Abstract
 Introduction
 Materials and Methods
Results
 Discussion
 References
 
Breast cancer tissues

Tissues from twenty-five cases of human breast carcinoma (specimens from mastectomies performed at the Department of Surgery, Tohoku Kousai Hospital) were obtained . The patients were all Japanese, and all carcinomas were invasive ductal carcinoma. Portions of carcinoma tissues were trimmed into tissue slices, measuring 0.8–1 cm in their greatest dimension, and were immediately fixed in 4% paraformaldehyde with 0.5% glutaldehyde at pH 7.4 for 18–36 h at 4 C. They were subsequently embedded in paraffin wax.

Oligonucleotide probes

The sequence of 30-base antisense oligodeoxynucleotide probes for ERs employed for mRNA in situ hybridization were as follows: ER{alpha}: 5'-CAG CTC GTT CCC TTG GAT CTG ATG CAG TAG-3'; and ERß: 5'-TGT TGG CCA CAA CAC ATT TGG GCT TCT GGT-3', which correspond to nucleotides 332–361 and 76–105 of ER{alpha} and ERß genes, respectively. These two sequences had the same guanine, cytosine (GC) content and were selected from the N-terminal A/B domain. Corresponding sense oligonucleotide probes were used as negative controls. The probes were synthesized with 3'-biotinylated tail (Brigati tail; 5'-probe-biotin-biotin-biotin-TAG-TAG-biotin-biotin-biotin-3") (15, 16, 17).

Both of these oligonucleotide probes demonstrated no homology with each other and other known human genes, including glucocorticoid, mineralocorticoid, or progesterone receptors, by a computer-assisted search.

mRNA in situ hybridization

In situ hybridization of ER mRNA was performed with the MicroProbe staining system (Fisher Scientific International, Inc., Pittsburgh, PA) using manual capillary actions, with modification of methods previously published (15, 16, 17). Tissue sections (3 µm, applied to Probe On Plus slides, Fisher Scientific International, Inc.) were rapidly dewaxed, cleared with alcohol, dehydrated with Tris-based buffer (pH 7.4) (Universal Buffer, Research Genetics, Inc., Huntsville, AL), and digested with pepsin (2.5 mg/mL, Research Genetics, Inc.) for 3 min at 105 C. Probe was applied in formamide-free diluent, and the slides were heated to 105 C for 3 min, cooled for approximately 1 min at room temperature, and allowed to hybridize at 45 C for 60 min. The sections were then washed twice with 2x standard saline citrate at 45 C (3 min per wash) and detected with alkaline phosphatase-conjugated streptavidin (Research Genetics, Inc.). After washing three times in AP (alkaline phosphatase) chromogen buffer (pH9.5; Research Genetics, Inc.) at room temperature, hybridization products were visualized with fast red for 10 min at room temperature in all the tissue sections. The slides were counterstained with hematoxylin, air dried, and cover slipped for microscopic examination.

Evaluation of mRNA hybridization signals

We determined the labeling index (i.e. the ratio of cells with relatively strong mRNA hybridization signals) in each carcinoma, according to Watanabe et al. (18), with some modifications (19, 20, 21), as follows. Labeling index was determined by thorough histological examination of the reacted tissue sections, not by actual counting of the cells, because of cytoplasmic localization of histochemical products. After completely reviewing the sections of each carcinoma, two of the authors (H. Sasano and T. Suzuki) independently divided the carcinomas into the following five groups; no hybridization signals (-); 0–5% (±); 5–25% (+); 25–50% (++); and more than 50% (+++) of cells positive for ER{alpha} and ERß. Interobserver differences were 3 of 25 (12). These disconcordant cases between these two observers were simultaneously reevaluated by the same two authors above, using double-headed light microscopy (BH-2, Olympus Corp., Co. Ltd., Tokyo, Japan).


   Results
Top
 Abstract
 Introduction
 Materials and Methods
 Results
Discussion
 References
 
Results were summarized in Table 1Go.


View this table:
[in this window]
[in a new window]
  		Table 1. Summary of results of mRNA in situ hybridization of ER{alpha} and ERß

 
Both ER{alpha} and ERß mRNA hybridization signals, appearing red as a result of fast red salt reaction, were detected predominantly in the cytoplasm of carcinoma cells, and in some stromal cells, including fibroblasts [Figs. 1Go (A, B, and C) and 2A]. In negative controls using the sense oligonucleotide probes, no significant accumulation of mRNA was detected in carcinoma cells (Fig. 1DGo).



View larger version (179K):
[in this window]
[in a new window]
  		Figure 1. In situ hybridization of ER{alpha} and ERß mRNA in invasive ductal carcinoma of a 63-yr-old female (case no. 16 in Table 1Go). A, Hematoxylin-eosin stain; B, ER{alpha} mRNA hybridization signals, appearing red as a result of fast red salt reaction, were detected in carcinoma cells and in some stromal cells (arrows) (x250); C, ERß mRNA hybridization signals were also detected in the same group of carcinoma cells and in some stromal cells (arrows), as in A (x250); D, negative control with a sense oligonucleotide probe of ERß showed no detectable specific mRNA hybridization signals (x200).

 
ER{alpha} mRNA hybridization signals were detected in 18 of 25 cases (72%), whereas ERß signals were detected in 11 of 25 cases (44%). The cases in which more than 25% of carcinoma cells demonstrated mRNA hybridization signals were 13 of 25 for ER{alpha} (52%) and 2 of 25 (8%) for ERß.

Among 11 ERß-positive cases, 10 cases also demonstrated ER{alpha} hybridization signals (Fig. 1Go, A and B). In these 10 cases coexpressing both ER{alpha} and ß, the great majority of ERß-positive carcinoma cells also expressed ER{alpha} mRNA but not vice versa, and the number of carcinoma cells expressing ER{alpha} mRNA was greater than that expressing ERß in all but one case (case no. 16 in Table 1Go). Eight cases demonstrated only ER{alpha} mRNA hybridization signals, but not ERß mRNA hybridization signals, in carcinoma cells (Fig. 2Go, A and B). Both ER{alpha} and ERß mRNA hybridization signals were detected in adjacent nonneoplastic mammary ductal cells and some stromal cells, which were available for examination in 7 cases (Fig. 3Go). However, ER{alpha}-positive cells were much more widely distributed than ERß-positive cells in these nonneoplastic mammary ducts.



View larger version (99K):
[in this window]
[in a new window]
  		Figure 2. In situ hybridization of ER{alpha} and ERß mRNA in invasive ductal carcinoma of a 58-yr-old female (case no. 5 in Table 1Go). A, ER{alpha} mRNA hybridization signals, appearing red as a result of fast red salt reaction, were detected in carcinoma cells (x200); B, ERß mRNA hybridization signals were not detected in the same group of carcinoma cells (x250).

 


View larger version (210K):
[in this window]
[in a new window]
  		Figure 3. In situ hybridization of ERß mRNA in nonneoplastic breast adjacent to carcinoma (case no. 25, 46-yr-old). mRNA hybridization signals were detected in the cytoplasm of ductal epithelial cells and some stromal cells (arrows). (x300)

 

   Discussion
Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
References
 
mRNA in situ hybridization of ERß can provide important information on analysis of the biological features of this newly characterized receptor, through demonstrating localization or in situ distribution of the sites where the receptor protein is actively synthesized. However, in situ hybridization of ERß mRNA has not been reported in human tissues, with an exception of the recent report by Enmark et al. (10), who studied various human organs employing oligonucleotide probes. They demonstrated ERß mRNA hybridization signals not only in classical estrogen target tissues such as uterine endometrium and ductal epithelium of mammalian glands, as demonstrated in our present study, but also in nonclassical estrogen target tissues such as gastrointestinal tract, transitional cell epithelium of renal pelvis, lymph nodes, and others (10).

In this study, we employed oligonucleotides derived from the sequence of the A/B domain of the receptors, because A/B domains of ER{alpha} and ERß are markedly different, compared with other regions of the genes (13, 14). It is well known that there are several splice variant forms with deleted exons of ER{alpha} mRNA in DNA and hormone-binding domains in breast cancer (22, 23, 24). Several ERß mRNA variants also have been reported (25, 26). The oligonucleotide probes employed in our study can detect all of these mRNA species. Therefore, mRNA hybridization signals detected in this study are considered to include both genuine and variant forms of the ER{alpha} and ERß mRNA. We also detected ERß mRNA hybridization signals in epithelial cells of nonneoplastic breast tissues adjacent to carcinoma. Very recently, Vladusic et al. reported that mRNA coding for a variant of ERß was coexpressed with wild-type ERß in breast carcinoma but was not detected in nonneoplastic human breast tissue (14). Therefore, ERß mRNA hybridization signals in nonneoplastic breast may represent wild-type ERß mRNA, but it awaits further investigations for clarification.

We then demonstrated both ER{alpha} and ERß mRNA hybridization signals in parenchymal or epithelial cells and some stromal cells of human breast carcinoma, using biotinylated oligonucleotide probes and manual capillary actions. The presence of ERß mRNA hybridization signals in human breast carcinoma cells is consistent with the recent study of Dotzlaw et al. (26) (who demonstrated ERß mRNA in both human breast epithelial cell lines, growing in culture, and some clinical specimens of breast cancer, using RT-PCR study) and that of Enmark et al. (10) (who showed ERß mRNA hybridization signals in some breast carcinoma cases). Dotzlaw et al. (13) did not detect any correlation between ER{alpha} and ERß expression; but in our present study, the great majority of breast carcinoma cells with ERß mRNA hybridization signals did express ER{alpha} but not vice versa. This finding is consistent with previous reports of tissue distribution of ER{alpha} and ERß in classical estrogen-dependent tissues, i.e. ERß is expressed in an over-lapping but nonidentical tissue distribution to ER{alpha}, and the biological functions of ERß may be dependent on the presence of ER{alpha} in certain types of cells, especially in classical estrogen-dependent tissues (2, 3, 12). Both the number of the carcinoma cases and the ratio of carcinoma cells expressing ER{alpha} was much greater than those expressing ERß in invasive ductal carcinomas of the breast examined in this study. We also detected ER{alpha} and ERß mRNA hybridization signals in a small number of stromal cells in both neoplastic and nonneoplastic breast tissue. This finding may be consistent with the recent report of Cooke et al. (27), who demonstrated that ER of both epithelial and stromal cells, possibly through paracrine actions, are required for estradiol-induced uterine epithelial cell proliferation. However, further investigations are required for clarifying the possible biological significance of ER{alpha} and ERß in stromal cells of human breast.

Brandenberger et al. very recently reported marked decrease of ERß mRNA levels in 10 cases of serous cystadenocarcinoma of the ovary, which is also estrogen-dependent carcinoma, as in breast carcinomas, using RT-PCR (28). Biological roles or functions of ERß have not been established in both normal and pathological human tissues. However, both ER{alpha} and ERß are considered to interact with similar DNA response element(s), through the course of estrogen actions, although their A/B domains and activation function-1 regions are quite different, which suggests that their transcriptional activation of different estrogen-responsive genes may be different (29, 30). The mechanism of estrogenic or antiestrogenic actions is well known to be very complicated, but the analysis of ER{alpha} and ERß expression in clinical specimens of breast cancer can provide new insights into endocrinological characteristics of individual carcinoma cases. However, it awaits further investigations, including the correlation between the level of ERß expression and clinical outcome and/or response to antiestrogens, to clarify biological significance of ERß in human breast carcinoma.


   Acknowledgments
 
The authors appreciate the excellent technical assistance of Ms. Fumiko Date, Department of Pathology, Tohoku University School of Medicine.


   Footnotes
 
1 This work was supported, in part, by a research grant from the Ministry of Education, Japan, and by a grant from Public Trust Haraguchi Memorial Cancer Research, Tokyo, Japan. Back

Received April 29, 1998.

Revised October 20, 1998.

Accepted October 25, 1998.


   References
Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
 References
 

  1. Tsai MJ, O’Malley BW. 1994 Molecular mechanisms of action of steroid/thyroid receptor superfamily. Annu Rev Biochem. 63:451–486.[CrossRef][Medline]
  2. Mangelsdorf DJ, Thummel C, Beato M, et al. 1995 The nuclear receptor superfamily: the second decade. Cell. 83:835–839.[CrossRef][Medline]
  3. Perker MG. 1993 Steroid and related receptors. Curr Opin Cell Biol. 5:499–504.[CrossRef][Medline]
  4. Kuiper GGJM, Enmark E, Puelto-Huiko M, Nilsson S, Gustafsson J-Å. 1996 Cloning of a novel estrogen receptor expressed in rat prostate and ovary. Proc Natl Acad Sci USA. 93:2925–2930.
  5. Mosselman S, Polman J, Dijkema R. 1996 ER-ß: identification and characterization of a novel human estrogen receptor. FEBS Lett. 392:49–53.[CrossRef][Medline]
  6. Kuiper GGJM, Enmark E, Pelto-Huikko M, Nilsson S, Gustafsson J-Å. 1997 Comparison of the ligand binding specificity and transcript tissue distribution of estrogen receptors {alpha} and ß. Endocrinology. 138:863–870.[Abstract/Free Full Text]
  7. Katzenellenbogen BS, Bhardwaj B, Fang H, et all. 1993 Hormone binding and transcription activation by estrogen receptors: analyses using mammalian and yeast systems. J Steroid Biochem Mol Biol. 47:39–48.[CrossRef][Medline]
  8. Katzenellenbogen BS. 1996 Estrogen receptors: bioactivities and interactions with cell signaling pathways. Biol Reprod. 54:287–293.[Abstract]
  9. Ekena KE, Weis KE, Katzenellenbogen JA, Katzenellenbogen BS. 1996 Identification of amino acids in the hormone binding domain of the human estrogen receptor important in estrogen binding. J Biol Chem. 271:20053–20059.[Abstract/Free Full Text]
  10. Enmark E, Pelto-Huikko M, Grandien K, et al. 1997 Human estrogen receptor ß-gene structure, chromosomal localization, and expression pattern. J Clin Endocrinol Metab. 82:4258–4265.[Abstract/Free Full Text]
  11. Brandenberger AW, Tee MK, Lee JY, Chao V, Jaffe RB. 1997 Tissue distribution of estrogen receptors {alpha} (ER-{alpha}) and ß (ER-ß) mRNA in the midgestational human fetus. J Clin Endocrinol Metab. 82:3509–3512.[Abstract/Free Full Text]
  12. Couse JF, Lindzey J, Grandien K, Gustafsson J-Å, Korach KS. 1997 Tissue distribution and quantitative analysis of estrogen receptor-{alpha} (ER{alpha}) and estrogen receptor-ß (ERß) messenger rebonucleic acid in the wild-type and ER{alpha}-knockout mouse. Endocrinology. 138:4613–4621.[Abstract/Free Full Text]
  13. Dotzlaw H, Leygue E, Watson PH, Murphy LC. 1997 Expression of estrogen receptor-ß in human breast tumors. J Clin Endocrinol Metab. 82:2371–2374.[Abstract/Free Full Text]
  14. Vladusic EA, Homby AE, Guerra-Vladusic FK, Lupu R. 1998 Expression of estrogen receptor ß messenger RNA variant in breast cancer. Cancer Res. 58:210–214.[Abstract/Free Full Text]
  15. Sasano H, Uzuki M, Sawai T, et al. 1997 Aromatase in human bone tissue. J Bone Miner Res. 12:1416–1423.[CrossRef][Medline]
  16. Felger RE, Montone KT, Furthe EE. 1996 A rapid method for the detection of hepatitis C virus RNA but in situ hybridization. Mod Pathol. 9:696–702.[Medline]
  17. Iino K, Sasano H, Oki Y, et al. 1997 Urocortin expression in human pituitary gland and pituitary adenoma. J Clin Endocrinol Metab. 82:3842–3850.[Abstract/Free Full Text]
  18. Watanabe K, Sasano H, Harada N, Sato S, Nagura H, Yajima A. 1995 Aromatase in human endometrial carcinoma and hyperplasia. Am J Pathol. 146:491–500.[Abstract]
  19. Sasano H, Nagura H, Harada N, Goukon Y, Kimura M. 1994 Immunolocalization of aromatase and other steroidogenic enzymes in human breast disorders. Hum Pathol. 25:530–535.[CrossRef][Medline]
  20. Sasano H, Frost AR, Saitoh R, et al. 1996 Aromatase and 17ß-hydroxysteroid dehydrogenase type 1 in human breast carcinoma. J Clin Endocrinol Metab. 81:4042–4246.[Abstract/Free Full Text]
  21. Sasano H, Kimura M, Shizawa S, Kimura N, Nagura H. 1996 Aromatase and steroid receptors in gynecomastia and male breast carcinoma; an immunohistochemical study. J Clin Endocrinol Metab. 81:3063–3067.[Abstract]
  22. Tonetti DA, Jordan VC. 1997 The role of estrogen receptor mutations in tamoxifen-stimulated breast cancer. J Steroid Biochem Mol Biol. 62:119–128.[CrossRef][Medline]
  23. Madsen MW, Reiter BE, Lykkesfeldt AE. 1995 Differential expression of estrogen receptor mRNA splice variants in the tamoxifen resistant human breast cancer cell line, MCF-7/TAMR-1 compared to the parental MCF-7 cell line. Mol Cell Endocrinol. 109:197–207.[CrossRef][Medline]
  24. Madsen MW, Reiter BE, Larsen SS, Briand P, Lykkesfeldt AE. 1997 Estrogen receptor messenger RNA splice variants are not involved in antiestrogen resistance in sublines of MCF-7 human breast cancer cells. Cancer Res. 57:585–589.[Abstract/Free Full Text]
  25. Vladusic EA, Hornby AE, Guerra-Vladusic FK, Lupu R. 1998 Expression of estrogen receptor beta messenger RNA variant in breast cancer. Cancer Res. 58:210–214.
  26. Dotzlaw H, Leygue E, Watson PH, Murphy LC. 1997 Expression of estrogen receptor-ß in human breast tumors. J Clin Endocrinol Metab. 82:2371–2374.
  27. Cooke PS, Buchanan DL, Young P, et al. 1997 Stromal estrogen receptors mediate mitogenic effects of estradiol on uterine epithelium. Proc Natl Acad Sci USA. 94:6535–6540.[Abstract/Free Full Text]
  28. Brandenberger A, Tee MK, Jaffe RB. 1998 Estrogen receptor {alpha} (ER-{alpha}) and ß (ER-ß) mRNAs in normal ovary, ovarian serous cystadenocarcinoma and ovarian cancer cell lines: Down-regulation of ERß in neoplastic tissues. J Clin Endocrinol Metab. 83:1025–1028.[Abstract/Free Full Text]
  29. Katzenellenbogen JA, O’Malley BW, Katzenellenbogen BS. 1996 Tripartite steroid hormone receptor pharmacology: interactions with multiple effector sites as a basis for the cell- and promoter-specific action of these hormones. Mol Endocrinol. 10:119–131.[CrossRef][Medline]
  30. Tzukerman MT, Esty A, Santiso-Mere D, et al. 1994 Human estrogen receptor transactivational capacity is determined by both cellular and promoter context and mediated by two functionally distinct intramolecular regions. Mol Endocrinol. 8:21–30.[Abstract]



This article has been cited by other articles:


Home page
 Mol. Cell. Biol.Home page
X. Li, J. Huang, P. Yi, R. A. Bambara, R. Hilf, and M. Muyan
Single-Chain Estrogen Receptors (ERs) Reveal that the ER{alpha}/{beta} Heterodimer Emulates Functions of the ER{alpha} Dimer in Genomic Estrogen Signaling Pathways
Mol. Cell. Biol., September 1, 2004; 24(17): 7681 - 7694.
[Abstract] [Full Text] [PDF]

Home page
 J. Clin. Endocrinol. Metab.Home page
V. Speirs, I. P. Adams, D. S. Walton, and S. L. Atkin
Identification of Wild-Type and Exon 5 Deletion Variants of Estrogen Receptor {beta} in Normal Human Mammary Gland
J. Clin. Endocrinol. Metab., April 1, 2000; 85(4): 1601 - 1605.
[Abstract] [Full Text]

Home page
 Proc. Natl. Acad. Sci. USAHome page
S. Saji, E. V. Jensen, S. Nilsson, T. Rylander, M. Warner, and J.-A. Gustafsson
Estrogen receptors alpha and beta in the rodent mammary gland
PNAS, January 4, 2000; 97(1): 337 - 342.
[Abstract] [Full Text] [PDF]

Home page
 Mol Hum ReprodHome page
S. Matsuzaki, T. Fukaya, T. Suzuki, T. Murakami, H. Sasano, and A. Yajima
Oestrogen receptor {alpha} and ß mRNA expression in human endometrium throughout the menstrual cycle
Mol. Hum. Reprod., June 1, 1999; 5(6): 559 - 564.
[Abstract] [Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Submit a related Letter to the Editor
Right arrow Purchase Article
Right arrow View Shopping Cart
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Copyright Permission
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Sasano, H.
Right arrow Articles by Kimura, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Sasano, H.
Right arrow Articles by Kimura, M.

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Endocrinology Endocrine Reviews J. Clin. End. & Metab.
Molecular Endocrinology Recent Prog. Horm. Res. All Endocrine Journals