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[Cancer Research 64, 2143-2147, March 15, 2004]
© 2004 American Association for Cancer Research

Regular Articles

Vitamin D Receptor and p21/WAF1 Are Targets of Genistein and 1,25-Dihydroxyvitamin D3 in Human Prostate Cancer Cells

Anuradha Rao1, April Coan1, Jo-Ellen Welsh3, Wendy W. Barclay1, Constantinos Koumenis1,2 and Scott D. Cramer1

Departments of 1 Cancer Biology and 2 Radiation Oncology, Wake Forest University School of Medicine, Winston-Salem, North Carolina, and 3 Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana


   ABSTRACT
Top
 ABSTRACT
INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
We investigated mechanisms by which genistein and 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] act synergistically to inhibit the growth of the human prostate cancer cell line LNCaP. We demonstrate that 1,25(OH)2D3 and genistein cooperate to up-regulate the vitamin D receptor protein by increasing the stability of the vitamin D receptor. Genistein and 1,25(OH)2D3 also cooperate to up-regulate the levels of p21/WAF1 (p21). Small interfering RNA-mediated knockdown of p21 expression showed that p21 is essential for significant growth inhibition of LNCaP cells in response to either compound or their combination. We conclude that one mechanism of synergism between genistein and 1,25(OH)2D3 is through genistein modulation of vitamin D signaling.


   INTRODUCTION
Top
 ABSTRACT
 INTRODUCTION
MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
Epidemiological, in vitro, and in vivo studies have suggested that the soy and vitamin D-rich Asian diet plays an important role in preventing the progression of latent prostate cancer into the clinically relevant disease (1, 2, 3) . Genistein is an isoflavone found in high quantities in serum after ingestion of a soy-rich meal and has been demonstrated to have potent inhibitory actions on prostate and breast tumor growth in mice (4) . 1,25-Dihydroxyvitamin D3 [1,25(OH)2D3], the active metabolite of vitamin D3, is primarily obtained from endogenous synthesis and from dietary sources such as ocean fish oils (5) . The growth-inhibitory actions of 1,25(OH)2D3 are mediated by the nuclear vitamin D receptor [VDR (6 , 7) ]. However, the exact molecular signaling pathways by which genistein or 1,25(OH)2D3 exert their biological effects on growth have not been clearly elucidated. Both compounds are known to cause inhibition of breast and prostate cancer cell growth by inducing apoptosis and by inhibition of cell cycle progression. The cyclin-dependent kinase inhibitors p21 and p27 have been implicated in cell cycle-regulatory effects of both 1,25(OH)2D3 and genistein (8, 9, 10, 11) . The presence of a functional vitamin D response element in the p21 promoter suggests that p21 is a direct target of VDR transcriptional regulation (12) . Furthermore, we demonstrated previously that genistein and 1,25(OH)2D3, when combined, cause synergistic growth inhibition of prostate cancer cells through cell cycle arrest (13) .

Here we investigated the possible mechanisms by which 1,25(OH)2D3 and genistein may interact to cause synergistic growth inhibition of LNCaP cells. We found that 1,25(OH)2D3 and genistein cooperate to up-regulate VDR and p21 protein levels. Experiments with cycloheximide demonstrate that genistein increases the stability of VDR. Additionally, by silencing expression of p21 using small interfering RNA (siRNA), we demonstrate that the presence of p21 is essential for the growth-inhibitory effects of 1,25(OH)2D3 and genistein, both alone and in combination.


   MATERIALS AND METHODS
Top
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
RESULTS
 DISCUSSION
 REFERENCES
 
Tissue Culture, Media and Supplements.
LNCaP human prostate cancer cells were obtained from American Type Culture Collection (Manassas, VA) and grown in RPMI 1640 supplemented with 10% fetal bovine serum. Source and storage of 1,25(OH)2D3 and genistein (4,5,7-trihydroxyisoflavone) were as reported previously (13) . Cycloheximide was from Sigma (St. Louis, MO). Stocks were prepared in 100% ethanol and stored at -20°C.

Preparation of Cell Lysates and Western Blot Analyses.
LNCaP cells were plated on 10-cm tissue culture plates at 6 x 105 cells/plate. Cells were incubated for 48–60 h and then treated with experimental media containing control (0.1% ethanol and 0.1% DMSO), 10 nM 1,25(OH)2D3, 5 µM genistein, or the combination of 10 nM 1,25(OH)2D3 and 5 µM genistein. At the indicated times, cells were harvested, and cell lysates were prepared. Immunoblots with 50 µg total protein/lane were performed using previously reported protocols (14) . Protein signal was detected using the enhanced chemiluminescence detection kit (Amersham-Pharmacia, Buckinghamshire, England). Signals for p21 (PharMingen, San Diego, CA), p27 (BD Transduction Laboratories, Lexington, KY), and VDR (9A7; Neomarkers, Fremont, CA), were normalized to ß-actin (Sigma).

To determine the stability of VDR protein, LNCaP cells were treated as described above, with the addition of 10 µM cycloheximide to every treatment. Cell lysates were prepared at the indicated time points, and Western blot analysis for VDR was performed as described above.

p21 Silencing Using siRNA.
LNCaP cells were plated at 2.5 x 105 cells/60-mm plate. Twenty-four h after plating, cells were transfected with either control siRNA (against luciferase) or p21 siRNA (Dharmacon Research, Lafayette, CO). The sequence of the luciferase siRNA used as control was 5'-CGU-ACG-CGG-AAU-ACU-UCG-A-dTdT and dTdT-GCA-UGC-GCC-UUA-UGA-AGC-U-5'. The sequence of the siRNA used to "knock-down" p21 expression was 5'-AA-UGG-CGG-GCU-GCA-UCC-AGG-A-dTdT and dTdT-UU-ACC-GCC-CGA-CGU-AGG-UCC-U-5'.

Transfection of siRNA was carried out according to manufacturer’s instructions (Gibco, Grand Island, NY) after optimization of the amount of siRNA to maximize p21 suppression. Briefly, either siRNA (1.92 µM) was mixed with OPTI-MEM medium (Gibco). In a separate tube, 1.68 nM Oligofectamine (Gibco) was mixed with OPTI-MEM and incubated at room temperature for 10 min. The siRNA- and Oligofectamine-containing tubes were mixed and incubated for 25 min at room temperature. Plates were then rinsed with OPTI-MEM once, and 1 ml of OPTI-MEM was added to plates. One ml of this Oligofectamine-siRNA mix was added drop-wise to cells. After 4 h, the Oligofectamine-siRNA mix was replaced with RPMI 1640/10% fetal bovine serum. Thirty-six h later, cells were treated with vehicle control (0.1% ethanol and 0.1% DMSO), 10 µM genistein, 100 nM 1,25(OH)2D3, or the combination of the two agents. Cells were incubated in experimental media for 72 h with a media change after 48 h. At the end of incubation, the number of viable cells was determined by trypan blue exclusion. Each treatment was carried out in triplicate. Differences between experimental treatment groups were detected by ANOVA with post-hoc analysis by Fisher’s test. Ps of <0.05 were considered significant.


   RESULTS
Top
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
DISCUSSION
 REFERENCES
 
Up-Regulation of VDR in LNCaP Cells by 1,25(OH)2D3 and Genistein.
Using flow cytometry, we have shown previously that 1,25(OH)2D3 and genistein synergistically inhibit prostatic cell growth via cell cycle arrest (13) . Further exploration of these cell cycle effects suggested that genistein increased the block at G0-G1 induced by 1,25(OH)2D3 (data not shown). Because the action of 1,25(OH)2D3 is mediated by the VDR, we carried out immunoblot analyses to examine the levels of VDR in LNCaP cells treated with 10 nM 1,25(OH)2D3 and 5 µM genistein, alone or in combination. Fig. 1ACitation is a representative immunoblot for VDR expression, and Fig. 1BCitation is the quantitative data from two independent experiments. As seen in Fig. 1, A and BCitation , LNCaP cells treated with 10 nM 1,25(OH)2D3 alone exhibited a modest (25–50%) up-regulation of VDR levels within 6 h that persisted for at least 48 h. At 48 h, there was a 1.5-fold increase in VDR expression in 1,25(OH)2D3-treated cells compared with control. Treatment with 5 µM genistein had no effect. However, when cells were treated with the combination of 1,25(OH)2D3 and genistein, there was a more robust up-regulation of VDR within 4 h that was sustained throughout the entire time course, suggesting a potentiation by genistein on 1,25(OH)2D3 regulation of VDR levels. At 4 h, there was a 1.4-fold up-regulation, whereas at 48 h, the up-regulation was 2.5-fold over control. This potentiation effect of genistein on 1,25(OH)2D3 regulation of VDR levels continued for 120 h after initial treatment, at which time there was a 2.2-fold increase over control levels (data not shown).



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  		Fig. 1. Up-regulation of vitamin D receptor (VDR) in LNCaP cells by 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] and genistein from 2 to 48 h. A, representative immunoblot for VDR expression. LNCaP cells were treated with vehicle control, 10 nM 1,25(OH)2D3, 5 µM genistein, or the combination of both agents. Cells were harvested at 2, 4, 6, 12, 24, and 48 h, and cell lysates were prepared as described in "Materials and Methods." Proteins were separated by electrophoresis on a 10% gel, and the blot was probed for VDR and actin. B, induction of VDR in LNCaP cells after treatment with vehicle control, 10 nM 1,25(OH)2D3, 5 µM genistein, or the combination of both agents, normalized to actin. Data are the means ± SE of two independent experiments. C, LNCaP cells were treated with vehicle control, 10 nM 1,25(OH)2D3, 5 µM genistein, or the combination of both agents in the presence of 10 µM cycloheximide, and blots were probed for VDR and actin. D, half-life of VDR protein in LNCaP cells treated with vehicle control, 10 nM 1,25(OH)2D3, 5 µM genistein, or the combination of both agents with 10 µM cycloheximide. VDR levels were normalized to actin.

 
Real-time PCR showed that there was no effect of 1,25(OH)2D3 or genistein treatments, either alone or in combination, on VDR mRNA (data not shown). To determine whether genistein could alter the stability of the VDR, we carried out experiments with cycloheximide. As seen in Fig. 1, C and DCitation , treatment with 10 nM 1,25(OH)2D3 alone increased VDR T1/2 (half life) by 1 h [3 h for control versus 4 h for 1,25(OH)2D3-treated cells], 5 µM genistein alone increased T1/2 by about 3.5 h when compared with control (T1/2 of about 6 h and 30 min), whereas the combination of the two increased T1/2 by 6.5 h (T1/2 is approximately 10 h). Two additional repeats of this experiment showed similar results (data not shown).

Induction of p21 in LNCaP Cells by 1,25(OH)2D3 and Genistein.
The cyclin-dependent kinase inhibitors p21 and p27 have both been implicated as downstream mediators of the growth-inhibitory actions of 1,25(OH)2D3, and there is a functional vitamin D response element in the p21 promoter. Therefore, we examined the ability of 1,25(OH)2D3 and genistein to induce p21 and p27 in LNCaP cells. As seen in Fig. 2, A and BCitation , 10 nM 1,25(OH)2D3 up-regulated p21 expression at 12 and 24 h after initial treatment (1.5- and 1.3-fold up-regulation over control levels, respectively). Five µM genistein alone up-regulated p21 levels at 6 and 12 h after treatment (1.3- and 2.3-fold increase over control levels, respectively). By 24 h, the levels of p21 in the genistein-treated samples were equivalent to that of control. When LNCaP cells were treated with a combination of 10 nM 1,25(OH)2D3 and 5 µM genistein, there was a robust increase in the up-regulation of p21 levels at 4 and 6 h after initial treatment (1.4- and 2.9-fold increase over control levels, respectively). Subsequent levels were either equivalent or intermediate to either treatment alone. There was no effect of any treatment on p27 expression (data not shown).



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  		Fig. 2. Induction of p21 in LNCaP cells by 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] and genistein. A, LNCaP cells were treated with vehicle control, 10 nM 1,25(OH)2D3, 5 µM genistein, or the combination of both agents for the indicated times, and cell lysates were prepared as described in "Materials and Methods." The blot was probed for p21 and actin. B, induction of p21 in LNCaP cells on treatment with vehicle control, 10 nM 1,25(OH)2D3, 5 µM genistein, or the combination of both agents, normalized to actin.

 
p21 Is Essential for the Action of 1,25(OH)2D3 and Genistein in LNCaP Cells.
We suppressed p21 expression using siRNA to determine whether p21 was necessary for the growth-inhibitory actions of 1,25(OH)2D3 and genistein, both alone and in combination. The ability of the siRNA construct to specifically decrease p21 expression was demonstrated by comparing p21 versus p27 levels over a 5-day time period. Fig. 3ACitation shows that p21 levels were suppressed 60–70% within 24 h after transfection and remained suppressed over the 5-day period. In contrast, cells treated with the p21 siRNA exhibited an elevation of p27 levels 24 h after transfection but were unchanged compared with control cells at other time points.



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  		Fig. 3. p21 is essential for the growth-inhibitory actions of genistein, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], and the combination in LNCaP cells A, p21 small interfering RNA (siRNA) decreases p21 expression in LNCaP cells. LNCaP cells were mock transfected or transfected with p21 siRNA as described in "Materials and Methods." At the indicated time points, total protein was harvested, and blots were prepared and probed for p21, p27, and actin. +, cells transfected with p21 siRNA, -; mock-transfected cells. B, LNCaP cells were transfected with control siRNA against luciferase () or p21 siRNA ({square}) as described in "Materials and Methods." Cells were then treated with vehicle control, 10 µM genistein, 100 nM 1,25(OH)2D3, or the combination. The number of viable cells was assessed after 72 h by trypan blue exclusion. Values significantly less then vehicle control are indicated by an asterisk. P < 0.05 was considered significant.

 
We next tested the growth responsiveness of cultures treated with p21 siRNA. For these experiments, we used higher individual and combined doses of 1,25(OH)2D3 and genistein than the doses used for the cooperative effects on VDR and p21 presented in Figs. 1Citation and 2Citation . This was by design to increase the growth-inhibitory effects on the cultures treated with either agent alone so that we could make statements about the individual effects of these agents. Cultures transfected with control siRNA and treated with 10 µM genistein, 100 nM 1,25(OH)2D3, or the combination for 72 h exhibited growth reductions of 37%, 33%, and 44%, respectively, which were statistically significantly different from cells treated with vehicle (ANOVA, P < 0.05). These are similar to results reported previously by us (13) . In contrast, there was no significant growth inhibition in response to 100 nM 1,25(OH)2D3, 10 µM genistein, or the combination in cells transfected with p21 siRNA. Although there was a trend toward growth suppression in the combination treatment in the presence of the p21 siRNA, this difference was not statistically significantly different from control (ANOVA, P > 0.05).


   DISCUSSION
Top
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
REFERENCES
 
We have previously demonstrated synergistic growth inhibition between 1,25(OH)2D3 and genistein (13) . In this study we examined potential mechanisms of this synergy between 1,25(OH)2D3 and genistein, using LNCaP cells as a model system. The major findings from these studies are that 1,25(OH)2D3 and genistein cooperatively increase expression of the VDR and the cell cycle inhibitor p21 and that p21 is required for the growth-inhibitory actions of both 1,25(OH)2D3 and genistein.

These findings provide new information regarding genistein regulation of the VDR, which is known to be required for the growth-inhibitory effects of 1,25(OH)2D3 (7) . Both in vivo and in vitro studies support the concept that increases in VDR as modest as 2-fold can enhance cellular sensitivity to 1,25(OH)2D3 (15, 16, 17) . In a previous study with MCF-7 cells, Jensen et al. (18) examined VDR induction in two clones that were hypersensitive and two clones that were more resistant to the growth-inhibitory actions of 1,25(OH)2D3. VDR was increased by 1,25(OH)2D3 treatment only in hypersensitive clones, suggesting that VDR induction correlates with sensitivity to 1,25(OH)2D3 (18) . Therefore, it is possible that the cooperative increase in VDR protein caused by genistein and 1,25(OH)2D3 makes LNCaP cells more sensitive to 1,25(OH)2D3-mediated growth inhibition.

In contrast to studies in breast cancer cells (17) , we found no evidence that the up-regulation of VDR protein in 1,25(OH)2D3- or genistein-treated LNCaP cells was the result of enhanced transcription of the VDR gene. Instead, our data indicate that genistein increased VDR stability and that VDR stability was highest in cells treated with the combination of 1,25(OH)2D3 and genistein. Additional studies are necessary to define the mechanism by which genistein modulates VDR turnover. However, our observations supporting a role for genistein in enhancing VDR signaling are consistent with work of Farhan et al. (19) . They reported inhibition of CYP24, the vitamin D catabolic enzyme, in genistein-treated prostate cancer cells. Thus, genistein appears to enhance vitamin D signaling in cancer cells through multiple mechanisms.

The cyclin-dependent kinase inhibitors p21 and p27 play an important role in progression through the cell cycle by inhibiting cyclin-cyclin-dependent kinase activity and causing G0-G1 arrest (20 , 21) . We show here that p21, not p27, is up-regulated in LNCaP by either 1,25(OH)2D3 or genistein. This is consistent with reports from other groups (10) . However, these are the first studies to show a cooperative up-regulation of p21 by the combination of 1,25(OH)2D3 and genistein. It is probable that a modest induction of p21 at low levels of either 1,25(OH)2D3 or genistein may cause a small percentage of cells to arrest in G0-G1. However, when 1,25(OH)2D3 and genistein are used together, the higher levels of p21 may cause a larger proportion of cells to undergo G0-G1 arrest. Previous flow cytometry data from our laboratory support this idea (13) . Here, the cooperative increase in p21 was only observed at 4 and 6 h; however, the total area under the curve was greatly enhanced in the treatment with both agents combined. Because even a short 2-h exposure to 1,25(OH)2D3 results in irreversible growth inhibition of prostatic cells (22) , we hypothesize that the early, transient, but cooperative increase in p21 causes a greater proportion of cells to undergo a G0-G1 arrest when treated with the combination of 1,25(OH)2D3 and genistein.

In this study, we demonstrate that the presence of p21 is essential for the growth-inhibitory actions of 1,25(OH)2D3 and genistein, both alone and in combination. The importance of p21 for 1,25(OH)2D3 action has been demonstrated previously using ALVA-31 human prostate cancer cells. In those studies, inhibiting p21 expression by stable transfection with antisense p21 cDNA resulted in significantly less growth inhibition on treatment with 1,25(OH)2D3 when compared with cells transfected with a control vector (11) . Although previous studies have demonstrated that genistein increases p21, ours are the first data to demonstrate the requirement for p21 in genistein-mediated growth inhibition of any cell type. Interestingly, the lack of significant growth inhibition by the combination of 1,25(OH)2D3 and genistein in the absence of p21 demonstrates the central role of p21 in growth inhibition. However, treatment of p21 siRNA-transfected LNCaP cells with the combination did cause a trend (19%) toward growth inhibition compared with control. Whereas this was not statistically significant, the growth inhibition was far greater then that observed in cells treated with 10 µM genistein or 100 nM 1,25(OH)2D3 alone. Because siRNA technology causes a "knock-down" but not a complete lack of p21 expression, it is possible that residual p21 expression was sufficient to cause the growth inhibition when the two compounds are used together. For instance, if the combination of 1,25(OH)2D3 and genistein has effects on p21 protein stability, then a small amount of residual p21 mRNA expression may translate into a large increase in p21 protein in the presence of both agents. Alternatively, treatment with both genistein and 1,25(OH)2D3 may activate both p21-dependent and p21-independent pathways to inhibit growth, resulting in the synergistic growth inhibition observed.

In summary, we have identified the VDR signaling pathway through p21 as a potential target of genistein that contributes to synergistic growth inhibition with 1,25(OH)2D3.


   FOOTNOTES
 
The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

Requests for reprints: Scott D. Cramer, Department of Cancer Biology, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina 27157. Phone: (336) 713-7651; Fax: (336) 713-7660; E-mail: scramer{at}wfubmc.edu

Received 11/ 6/03. Revised 1/ 6/04. Accepted 1/19/04.


   REFERENCES
Top
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 

  1. Severeson R, Nomura A, Grove J, Stemmermann G. A prospective study of demographics, diet, and prostate cancer among men of Japanese ancestry in Hawaii. Cancer Res, 49: 1857-60, 1989.[Abstract/Free Full Text]
  2. Schwartz GG, Hulka BS. Is vitamin D deficiency a risk factor for prostate cancer? (Hypothesis). Anticancer Res, 10: 1307-11, 1990.[Medline]
  3. Hanchette CL, Schwartz GG. Geographic patterns of prostate cancer mortality. Evidence for a protective effect of ultraviolet radiation. Cancer (Phila.), 70: 2861-9, 1992.
  4. Lamartiniere C, Cotroneo M, Fritz W, et al Genistein chemoprevention: timing and mechanisms of action in murine mammary and prostate. J Nutr, 132: 552S-8S, 2002.[Abstract/Free Full Text]
  5. Takeuchi T, Okano T, Ayame M, et al High performance liquid chromatographic determination of vitamin D3 in fish and liver oils and eel body oils. J Nutr Sci Vitaminol, 30: 421-30, 1984.
  6. Holick M. Vitamin D: photobiology, metabolism, mechanism of action Favus M eds. . Primer on the metabolic bone diseases and disorders of mineral metabolism, 3rd ed. p. 74-81, Lippencott-Raven Philadelphia 1996.
  7. Zinser G, McEleney K, Welsh J. Characterization of mammary tumor cell lines from wild type and vitamin D receptor knockout mice. Mol Cell Endocrinol, 200: 67-80, 2003.[CrossRef][Medline]
  8. Davis J, Singh B, Bhuiyan M, Sarkar F. Genistein-induced upregulation of p21, downregulation of cyclin B, and induction of apoptosis in prostate cancer cells. Nutr Cancer, 32: 123-31, 1998.[Medline]
  9. Shen J-C, Klein R, Wei Q, et al Low-dose gensitein induces cyclin-dependent kinase inhibitors and G1 cell-cycle arrest in human prostate cancer cells. Mol Carcinog, 29: 92-102, 2000.[CrossRef][Medline]
  10. Zhuang SH, Burnstein KL. Antiproliferative effect of 1{alpha},25-dihydroxyvitamin D3 in human prostate cancer cell line LNCaP involves reduction of cyclin-dependent kinase 2 activity and persistent G1 accumulation. Endocrinology, 139: 1197-207, 1998.[Abstract/Free Full Text]
  11. Moffatt K, Johannes W, Hedlund T, Miller G. Growth inhibitory effects of 1,25-dihydroxyvitamin D3 are mediated by increased levels of p21 in the prostatic carcinoma cell line ALVA-31. Cancer Res, 61: 7122-9, 2001.[Abstract/Free Full Text]
  12. Liu M, Lee M, Cohen M, Bommakanti M, Freedman L. Transcriptional activation of the Cdk inhibitor p21 by vitamin D3 leads to the induced differentiation of the myelomonocytic cell line U937. Genes Dev, 10: 142-53, 1996.[Abstract/Free Full Text]
  13. Rao A, Woodruff R, Wade W, Kute T, Cramer S. Synergistic inhibition of prostatic epithelial cell growth by genistein and vitamin D. J Nutr, 132: 3191-4, 2002.[Abstract/Free Full Text]
  14. Wade W, Willingham J, Koumenis C, Cramer S. p27Kip1 is required for 1,25(OH)2D3-mediated growth inhibition of primary mouse cells. J Biol Chem, 277: 37301-6, 2002.[Abstract/Free Full Text]
  15. Schwartz B, Smirnoff P, Shany S, Liel Y. Estrogen controls expression and bioresponse of 1,25-dihydroxyvitamin D receptors in the rat colon. Mol Cell Biochem, 203: 87-93, 2000.[CrossRef][Medline]
  16. Shao A, Wood R, Fleet J. Increased vitamin D receptor level enhances 1,25-dihydroxyvitamin D3-mediated gene expression and calcium transport in Caco-2 cells. J Bone Miner Res, 16: 615-25, 2001.[CrossRef][Medline]
  17. Weitzke J, Welsh J. Phytoestrogen regulation of a vitamin D3 promoter and 1,25-dihydroxyvitamin D3 actions in human breast cancer cells. J Steroid Biochem Mol Biol, 84: 149-57, 2003.[CrossRef][Medline]
  18. Jensen S, Madsen M, Lukas J, Bartek J, Binderup L. Sensitivity to growth suppression by 1{alpha},25-dihydroxyvitamin D3 among MCF-7 clones correlates with vitamin D receptor protein induction. J Steroid Biochem Mol Biol, 81: 123-33, 2002.[CrossRef][Medline]
  19. Farhan H, Wahala K, Cross H. Genistein inhibits vitamin D hydroxylases CYP24 and CYP27B1 expression in prostate cancer cells. J Steroid Biochem Mol Biol, 84: 423-9, 2003.[CrossRef][Medline]
  20. Xiong Y, Hannon G, Zhang H, et al p21 is a universal inhibitor of cyclin kinases. Nature (Lond.), 366: 701-4, 1993.[CrossRef][Medline]
  21. Polyak K, Lee M, Erdjument-Brommage H, et al Cloning of p27KIP1 a cyclin-dependent kinase inhibitor and a potential mediator of extracellular antimitogenic signals. Cell, 78: 59-66, 1994.[CrossRef][Medline]
  22. Peehl DM, Skowronski RJ, Leung GK, et al Antiproliferative effects of 1,25-dihydroxyvitamin D3 on primary cultures of human prostatic cells. Cancer Res, 54: 805-10, 1994.[Abstract/Free Full Text]



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