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Geng S, Zhou S, Glowacki J. Effects of 25-hydroxyvitamin D(3) on proliferation and osteoblast differentiation of human marrow stromal cells require CYP27B1/1α-hydroxylase. J Bone Miner Res 2011; 26:1145-53. [PMID: 21542014 PMCID: PMC3179303 DOI: 10.1002/jbmr.298] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
1,25-Dihydroxyvitamin D(3)[1,25(OH)(2)D(3)] has many noncalcemic actions that rest on inhibition of proliferation and promotion of differentiation in malignant and normal cell types. 1,25(OH)(2)D(3) stimulates osteoblast differentiation of human marrow stromal cells (hMSCs), but little is known about the effects of 25-hydroxyvitamin D(3)[25(OH)D(3)] on these cells. Recent evidence shows that hMSCs participate in vitamin D metabolism and can activate 25(OH)D(3) by CYP27B1/1α-hydroxylase. These studies test the hypothesis that antiproliferative and prodifferentiation effects of 25(OH)D(3) in hMSCs depend on CYP27B1. We studied hMSCs that constitutively express high (hMSCs(hi-1α) ) or low (hMSCs(lo-1α)) levels of CYP27B1 with equivalent expression of CYP24A1 and vitamin D receptor. In hMSCs(hi-1α), 25(OH)D(3) reduced proliferation, downregulated proliferating cell nuclear antigen (PCNA), upregulated p21(Waf1/Cip1), and decreased cyclin D1. Unlike 1,25(OH)(2)D(3), the antiapoptotic effects of 25(OH)D(3) on Bax and Bcl-2 were blocked by the P450 inhibitor ketoconazole. The antiproliferative effects of 25(OH)D(3) in hMSCs(hi-1α) and of 1,25(OH)(2)D(3) in both samples of hMSCs were explained by cell cycle arrest, not by increased apoptosis. Stimulation of osteoblast differentiation in hMSCs(hi-1α) by 25(OH)D(3) was prevented by ketoconazole and upon transfection with CYP27B1 siRNA. These data indicate that CYP27B1 is required for 25(OH)D(3)'s action in hMSCs. Three lines of evidence indicate that CYP27B1 is required for the antiproliferative and prodifferentiation effects of 25(OH)D(3) on hMSCs: Those effects were not seen (1) in hMSCs with low constitutive expression of CYP27B1, (2) in hMSCs treated with ketoconazole, and (3) in hMSCs in which CYP27B1 expression was silenced. Osteoblast differentiation and skeletal homeostasis may be regulated by autocrine/paracrine actions of 25(OH)D(3) in hMSCs.
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Affiliation(s)
- Shuo Geng
- Department of Orthopedic Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
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Lambert JR, Eddy VJ, Young CD, Persons KS, Sarkar S, Kelly JA, Genova E, Lucia MS, Faller DV, Ray R. A vitamin D receptor-alkylating derivative of 1α,25-dihydroxyvitamin D3 inhibits growth of human kidney cancer cells and suppresses tumor growth. Cancer Prev Res (Phila) 2011; 3:1596-607. [PMID: 21149334 DOI: 10.1158/1940-6207.capr-10-0122] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
1,25-Dihydroxyvitamin D₃ [1,25(OH)₂D₃] has shown strong promise as an antiproliferative agent in several malignancies, yet its therapeutic use has been limited by its toxicity leading to search for analogues with antitumor property and low toxicity. In this study, we evaluated the in vitro and in vivo properties of 1,25-dihydroxyvitamin D₃-3-bromoacetate [1,25(OH)₂D₃-3-BE], an alkylating derivative of 1,25(OH)₂D₃, as a potential therapeutic agent for renal cancer. Dose response of 1,25(OH)₂D₃-3-BE in 2 kidney cancer cell lines was evaluated for its antiproliferative and apoptotic properties, and mechanisms were evaluated by Western blot and FACS analyses. Therapeutic potential of 1,25(OH)₂D₃-3-BE was assessed both by determining its stability in human serum and by evaluating its efficacy in a mouse xenograft model of human renal tumor. We observed that 1,25(OH)₂D₃-3-BE is significantly more potent than an equivalent concentration of 1,25(OH)₂D₃ in inhibiting growth of A498 and Caki 1 human kidney cancer cells. 1,25(OH)₂D₃-3-BE-mediated growth inhibition was promoted through inhibition of cell-cycle progression by downregulating cyclin A and induction of apoptosis by stimulating caspase activity. Moreover, 1,25(OH)₂D₃-3-BE strongly inhibited Akt phosphorylation and phosphorylation of its downstream target, caspase-9. 1,25(OH)₂D₃-3-BE seemed to be stable in human serum. In xenograft mouse model of human renal tumor, 1,25(OH)₂D₃-3-BE was more potent at reducing tumor size than 1,25(OH)₂D₃, which was accompanied by an increase in apopotosis and reduction of cyclin A staining in the tumors. These results suggest a translational potential of this compound as a therapeutic agent in renal cell carcinoma. Data from this study and extensive studies of vitamin D for the prevention of many malignancies support the potential of 1,25(OH)₂D₃-3-BE for preventing renal cancer and the development of relevant in vivo prevention models for assessing this potential, which do not exist at present.
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Affiliation(s)
- James R Lambert
- Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
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Bobilev I, Novik V, Levi I, Shpilberg O, Levy J, Sharoni Y, Studzinski GP, Danilenko M. The Nrf2 transcription factor is a positive regulator of myeloid differentiation of acute myeloid leukemia cells. Cancer Biol Ther 2011; 11:317-29. [PMID: 21099366 DOI: 10.4161/cbt.11.3.14098] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
1α,25-dihydroxyvitamin D3 (1,25D) is a powerful differentiation agent, which has potential for treatment of acute myeloid leukemia (AML), but induces severe hypercalcemia at pharmacologically active doses. We have previously shown that carnosic acid (CA), the polyphenolic antioxidant from rosemary plant, markedly potentiates differentiation induced by low concentrations of 1,25D in human AML cell lines. Here, we demonstrated similar enhanced differentiation responses to the 1,25D/CA combination in primary leukemic cells derived from patients with AML, and determined the role of the Nrf2/antioxidant response element (Nrf2/ARE) pathway in these effects using U937 human monoblastic leukemia cells as the model. CA strongly transactivated the ARE-luciferase reporter gene, induced the ARE-responsive genes, NADP(H)-quinone oxidoreductase and the γ-glutamylcysteine synthetase heavy subunit, and elevated cellular glutathione levels. Interestingly, 1,25D potentiated the effects of CA on these activities. Stable transfection of wild-type (wt) Nrf2 resulted in the enhancement, while transfection of dominant-negative (dn) Nrf2 produced suppression of differentiation induced by the 1,25D/CA combination and, surprisingly, by 1,25D alone. These opposite effects were associated with a corresponding increase or decrease in vitamin D receptor and retinoid X receptor-α protein levels, and in vitamin D responsive element transactivation. Cells transfected with wtNrf2 and dnNrf2 also displayed opposing changes in the levels of the AP-1 family proteins (c-Jun and ATF2) and AP-1 transcriptional activity. Pretreatment with AP-1 decoy oligodeoxynucleotide markedly attenuated the differentiation in wtNrf2-transfected cells, suggesting that the pro-differentiation action of Nrf2 is mediated by functional AP-1. Our findings suggest that the Nrf2/ARE pathway plays an important part in the cooperative induction of myeloid leukemia cell differentiation by 1,25D and a plant polyphenol.
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Affiliation(s)
- Irene Bobilev
- Department of Clinical Biochemistry, Faculty of Health Sciences, Ben-Gurion University of the Negev, Petakh Tikva, Israel
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Age-related changes in the epithelial and stromal compartments of the mammary gland in normocalcemic mice lacking the vitamin D3 receptor. PLoS One 2011; 6:e16479. [PMID: 21298063 PMCID: PMC3027678 DOI: 10.1371/journal.pone.0016479] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Accepted: 12/29/2010] [Indexed: 12/31/2022] Open
Abstract
The vitamin D3 receptor (VDR) serves as a negative growth regulator during mammary gland development via suppression of branching morphogenesis during puberty and modulation of differentiation and apoptosis during pregnancy, lactation and involution. To assess the role of the VDR in the aging mammary gland, we utilized 12, 14, and 16 month old VDR knockout (KO) and wild type (WT) mice for assessment of integrity of the epithelial and stromal compartments, steroid hormone levels and signaling pathways. Our data indicate that VDR ablation is associated with ductal ectasia of the primary mammary ducts, loss of secondary and tertiary ductal branches and atrophy of the mammary fat pad. In association with loss of the white adipose tissue compartment, smooth muscle actin staining is increased in glands from VDR KO mice, suggesting a change in the stromal microenviroment. Activation of caspase-3 and increased Bax expression in mammary tissue of VDR KO mice suggests that enhanced apoptosis may contribute to loss of ductal branching. These morphological changes in the glands of VDR KO mice are associated with ovarian failure and reduced serum 17β-estradiol. VDR KO mice also exhibit progressive loss of adipose tissue stores, hypoleptinemia and increased metabolic rate with age. These developmental studies indicate that, under normocalcemic conditions, loss of VDR signaling is associated with age-related estrogen deficiency, disruption of epithelial ductal branching, abnormal energy expenditure and atrophy of the mammary adipose compartment.
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Sharan C, Halder SK, Thota C, Jaleel T, Nair S, Al-Hendy A. Vitamin D inhibits proliferation of human uterine leiomyoma cells via catechol-O-methyltransferase. Fertil Steril 2010; 95:247-53. [PMID: 20736132 DOI: 10.1016/j.fertnstert.2010.07.1041] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Revised: 06/12/2010] [Accepted: 07/05/2010] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To evaluate the effects and mechanisms of action of vitamin D on human uterine leiomyoma (HuLM) cell proliferation in vitro. DESIGN Laboratory study. SETTING University hospitals. PATIENTS(S) Not applicable. INTERVENTIONS(S) Not applicable. MAIN OUTCOME MEASURE(S) HuLM cells were treated with 1,25-dihydroxyvitamin D3 (vitamin D), and cell proliferation was assayed by the methylthiazolyl tetrazolium technique. proliferating cell nuclear antigen (PCNA), BCL-2, BCL-w, cyclin-dependent kinase (CDK) 1, and catechol-O-methyltransferase (COMT) protein levels were analyzed by Western blotting. COMT mRNA and enzyme activity were assayed by quantitative reverse-transcription polymerase chain reaction (RT-PCR) and high-performance liquid chromatography analysis, respectively. The role of COMT was evaluated in stable HuLM cells by silencing COMT expression. RESULT(S) Vitamin D inhibited the growth of HuLM cells by 47±0.03% at 1 μM and by 38±0.02% at 0.1 μM compared with control cells at 120 hours of treatment. Vitamin D inhibited extracellular signal-regulated kinase activation and down-regulated the expression of BCL-2, BCL-w, CDK1, and PCNA. Western blot, RT-PCR, and enzyme assay of COMT demonstrated inhibitory effects of vitamin D on COMT expression and enzyme activity. Silencing endogenous COMT expression abolished vitamin D-mediated inhibition of HuLM cell proliferation. CONCLUSION(S) Vitamin D inhibits growth of HuLM cells through the down-regulation of PCNA, CDK1, and BCL-2 and suppresses COMT expression and activity in HuLM cells. Thus, hypovitaminosis D appears to be a risk factor for uterine fibroids.
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Affiliation(s)
- Chakradhari Sharan
- Center for Women's Health Research, Department of Obstetrics and Gynecology, Meharry Medical College, Nashville, Tennessee, USA
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Krishnan AV, Swami S, Feldman D. Vitamin D and breast cancer: inhibition of estrogen synthesis and signaling. J Steroid Biochem Mol Biol 2010; 121:343-8. [PMID: 20156557 DOI: 10.1016/j.jsbmb.2010.02.009] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2009] [Accepted: 02/08/2010] [Indexed: 11/18/2022]
Abstract
Calcitriol (1,25-dihydroxyvitamin D3), the hormonally active metabolite of vitamin D, inhibits the growth and induces the differentiation of many malignant cells including breast cancer (BCa) cells. Calcitriol exerts its anti-proliferative activity in BCa cells by inducing cell cycle arrest and stimulating apoptosis. Calcitriol also inhibits invasion, metastasis and tumor angiogenesis in experimental models of BCa. Our recent studies show additional newly discovered pathways of calcitriol action to inhibit the growth of BCa cells. Calcitriol suppresses COX-2 expression and increases that of 15-PGDH thereby reducing the levels and biological activity of prostaglandins (PGs). Calcitriol decreases the expression of aromatase, the enzyme that catalyzes estrogen synthesis selectively in BCa cells and the breast adipose tissue surrounding BCa, by a direct repression of aromatase transcription via promoter II as well as an indirect effect due to the reduction in the levels and biological activity of PGE2, which is a major stimulator of aromatase transcription through promoter II in BCa. Calcitriol down-regulates the expression of estrogen receptor alpha and thereby attenuates estrogen signaling in BCa cells including the proliferative stimulus provided by estrogens. We hypothesize that the inhibition of estrogen synthesis and signaling by calcitriol and its anti-inflammatory actions will play an important role in the use of calcitriol for the prevention and/or treatment of BCa.
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Affiliation(s)
- Aruna V Krishnan
- Division of Endocrinology, Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, United States
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Zhang Z, Kovalenko P, Cui M, Desmet M, Clinton SK, Fleet JC. Constitutive activation of the mitogen-activated protein kinase pathway impairs vitamin D signaling in human prostate epithelial cells. J Cell Physiol 2010; 224:433-42. [PMID: 20432439 DOI: 10.1002/jcp.22139] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We studied the effect of prolonged activation of mitogen-activated protein kinase (MAPK) signaling on 1,25 dihydroxyvitamin D (1,25(OH)(2)D(3)) action in the immortalized human prostate epithelial cell line RWPE1 and its Ki-Ras transformed clone RWPE2. 1,25(OH)(2)D(3)-treatment caused growth arrest and induced gene expression in both cell lines but the response was blunted in RWPE2 cells. Vitamin D receptor (VDR) levels were lower in RWPE2 cells but VDR over-expression did not increase vitamin-D-mediated gene transcription in either cell line. In contrast, MAPK inhibition restored normal vitamin D transcriptional responses in RWPE2 cells and MAPK activation with constitutively active MEK1R4F reduced vitamin-D-regulated transcription in RWPE1 cells. 1,25(OH)(2)D(3)-mediated transcription depends upon the VDR and its heterodimeric partner the retinoid X receptor (RXR) so we studied whether changes in the VDR-RXR transcription complex occur in response to MAPK activation. Mutation of putative phosphorylation sites in the activation function 1 (AF-1) domain (S32A, T82A) of RXRalpha restored 1,25(OH)(2)D(3)-mediated transactivation in RWPE2 cells. Mammalian two-hybrid and co-immunoprecipitation assays revealed a vitamin-D-independent interaction between steroid receptor co-activator-1 (SRC-1) and RXRalpha that was reduced by MAPK activation and was restored in RWPE2 cells by mutating S32 and T82 in the RXRalpha AF-1 domain. Our data show that a common contributor to cancer development, prolonged activation of MAPK signaling, impairs 1,25(OH)(2)D(3)-mediated transcription in prostate epithelial cells. This is due in part to the phosphorylation of critical amino acids in the RXRalpha AF-1 domain and impaired co-activator recruitment.
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Affiliation(s)
- Zhentao Zhang
- Department of Foods and Nutrition, Purdue University, West Lafayette, Indiana 47907-2059, USA
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Levendusky MC, Basle J, Chang S, Mandalaywala NV, Voigt JM, Dearborn RE. Expression and regulation of vitamin D3 upregulated protein 1 (VDUP1) is conserved in mammalian and insect brain. J Comp Neurol 2010; 517:581-600. [PMID: 19824090 DOI: 10.1002/cne.22195] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Originally characterized as a cell-cycle inhibitor induced by vitamin D(3), the tumor suppressor vitamin-D(3) upregulated protein 1 (VDUP1) has increasingly been shown to play major physiological roles in cell differentiation and glucose metabolism. Here we show evolutionarily conserved expression patterns of VDUP1 in Drosophila and rat nervous systems, including subcellular localization--cytoplasmic enrichment in neurons and nuclear expression in glia. These anatomical correlates suggested conservation of VDUP1 regulation, which was investigated both functionally and through promoter studies. Characterization of orthologous vdup1 cis-regulatory regions identified evolutionarily conserved sequence blocks (CSBs) with similarities to neural enhancers, including basic helix-loop-helix (bHLH) transcription factor Neurogenin/Math/atonal and Mash/achaete-scute family members. E-boxes (CANNTG), the binding sites for bHLH proteins, were associated with these CSBs as well, including E-boxes known to mediate glucose-dependent upregulation of VDUP1 in nonneuronal cells. Hyperglycemia-induced upregulation of VDUP1 was observed in brain tumor cells and in the Drosophila nervous system, which resulted in developmental arrest. Taken together, these data demonstrate evolutionary conservation of VDUP1 regulation and function, and suggest an expanding role for VDUP1 in nervous system development.
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Affiliation(s)
- Mark C Levendusky
- Department of Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, Albany, New York 12208, USA
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Abstract
The possible biological role played by Clusterin (CLU) has been puzzling researchers for a long time since its first discovery and characterization. CLU has been often described as an "enigmatic" gene, a clear indication that too many aspects of this issue have been obscure or difficult to interpret for long. The good news is that this is certainly no longer true. Since the beginning, CLU was believed to play important roles in nearly all most important biological phenomena. The diversity, sometime the contradictions, of its biological action is now likely explained by the existence of different protein products all generated by the same single copy CLU gene. The relatively recent discovery that CLU can be retained inside the cell and targeted to many intracellular sites and organelles, including the nucleus, provided us a very different view from that solely deriving from its possible role in the outer cellular environment. In particular, nuclear localization of CLU (nCLU) was found to trigger cell death in many systems. In this chapter, a critical review of previous work will enable us to reinterpret old data and observations in the attempt to progressively unravelling the CLU "enigma" by considering its localization inside and outside the cell. The final picture would supposedly reconciliate different or alternative hypothesis. Starting with an "historical" approach demonstrating that nCLU was right under our eyes since the beginning, up to the more recent contributions we will describe which stimuli would inhibit secretion and maturation of CLU leading at least one protein product to target the nucleus and kill the cell. A better understanding of this complex issue is not an easy work, considering the thoughtfulness in reviewing the existing literature and the known controversial reports. We hope that the information contained in this article will be useful for the reader to enlighten this field.
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Affiliation(s)
- Saverio Bettuzzi
- Dipartimento di Medicina Sperimentale, Sezione di Biochimica, Biochimica Clinica e Biochimica dell'Esercizio Fisico, Parma, Italy
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Nowak D, Stewart D, Koeffler HP. Differentiation therapy of leukemia: 3 decades of development. Blood 2009; 113:3655-65. [PMID: 19221035 PMCID: PMC2943835 DOI: 10.1182/blood-2009-01-198911] [Citation(s) in RCA: 252] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2009] [Accepted: 02/09/2009] [Indexed: 12/27/2022] Open
Abstract
A characteristic feature of leukemia cells is a blockade of differentiation at a distinct stage in cellular maturation. In the 1970s and 1980s, studies demonstrating the capabilities of certain chemicals to induce differentiation of hematopoietic cell lines fostered the concept of treating leukemia by forcing malignant cells to undergo terminal differentiation instead of killing them through cytotoxicity. The first promising reports on this notion prompted a review article on this subject by us 25 years ago. In this review, we revisit this interesting field of study and report the progress achieved in the course of nearly 3 decades. The best proof of principle for differentiation therapy has been the treatment of acute promyelocytic leukemia with all-trans retinoic acid. Attempts to emulate this success with other nuclear hormone ligands such as vitamin D compounds and PPARgamma agonists or different classes of substances such as hematopoietic cytokines or compounds affecting the epigenetic landscape have not been successful on a broad scale. However, a multitude of studies demonstrating partial progress and improvements and, finally, the new powerful possibilities of forward and reverse engineering of differentiation pathways by manipulation of transcription factors support the continued enthusiasm for differentiation therapy of leukemia in the future.
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Affiliation(s)
- Daniel Nowak
- Division of Hematology and Oncology, Cedars Sinai Medical Center, University of California Los Angeles (UCLA) School of Medicine, CA 90048, USA.
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Actualité sur les effets de la vitamine D et l’évaluation du statut vitaminique D. ANNALES D'ENDOCRINOLOGIE 2008; 69:501-10. [DOI: 10.1016/j.ando.2008.07.010] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2008] [Accepted: 07/08/2008] [Indexed: 12/27/2022]
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Bouillon R, Carmeliet G, Verlinden L, van Etten E, Verstuyf A, Luderer HF, Lieben L, Mathieu C, Demay M. Vitamin D and human health: lessons from vitamin D receptor null mice. Endocr Rev 2008; 29:726-76. [PMID: 18694980 PMCID: PMC2583388 DOI: 10.1210/er.2008-0004] [Citation(s) in RCA: 1137] [Impact Index Per Article: 71.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2008] [Accepted: 07/08/2008] [Indexed: 02/06/2023]
Abstract
The vitamin D endocrine system is essential for calcium and bone homeostasis. The precise mode of action and the full spectrum of activities of the vitamin D hormone, 1,25-dihydroxyvitamin D [1,25-(OH)(2)D], can now be better evaluated by critical analysis of mice with engineered deletion of the vitamin D receptor (VDR). Absence of a functional VDR or the key activating enzyme, 25-OHD-1alpha-hydroxylase (CYP27B1), in mice creates a bone and growth plate phenotype that mimics humans with the same congenital disease or severe vitamin D deficiency. The intestine is the key target for the VDR because high calcium intake, or selective VDR rescue in the intestine, restores a normal bone and growth plate phenotype. The VDR is nearly ubiquitously expressed, and almost all cells respond to 1,25-(OH)(2)D exposure; about 3% of the mouse or human genome is regulated, directly and/or indirectly, by the vitamin D endocrine system, suggesting a more widespread function. VDR-deficient mice, but not vitamin D- or 1alpha-hydroxylase-deficient mice, and man develop total alopecia, indicating that the function of the VDR and its ligand is not fully overlapping. The immune system of VDR- or vitamin D-deficient mice is grossly normal but shows increased sensitivity to autoimmune diseases such as inflammatory bowel disease or type 1 diabetes after exposure to predisposing factors. VDR-deficient mice do not have a spontaneous increase in cancer but are more prone to oncogene- or chemocarcinogen-induced tumors. They also develop high renin hypertension, cardiac hypertrophy, and increased thrombogenicity. Vitamin D deficiency in humans is associated with increased prevalence of diseases, as predicted by the VDR null phenotype. Prospective vitamin D supplementation studies with multiple noncalcemic endpoints are needed to define the benefits of an optimal vitamin D status.
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Affiliation(s)
- Roger Bouillon
- Katholieke Universiteit Leuven, Laboratory of Experimental Medicine and Endocrinology, Herestraat 49, O&N 1 bus 902, 3000 Leuven, Belgium.
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Abstract
Since the discovery of the vitamin D receptor (VDR) in mammary cells, the role of the vitamin D signaling pathway in normal glandular function and in breast cancer has been extensively explored. In vitro studies have shown that the VDR ligand, 1,25-dihydroxyvitamin D (1,25D), modulates key proteins involved in signaling proliferation, differentiation, and survival of normal mammary epithelial cells. Similar anti-proliferative and pro-differentiating effects of 1,25D have been observed in VDR-positive breast cancer cells, indicating that transformation per se does not abolish vitamin D signaling. However, many transformed breast cancer lose sensitivity to 1,25D secondary to alterations in vitamin D metabolizing enzymes or downregulation of VDR function. Over the years, our laboratory has focused on three general areas: (1) defining mechanisms of vitamin D-mediated apoptosis in breast cancer cells, (2) examining changes in the vitamin D signaling pathway during transformation, including the development of vitamin D resistance, and (3) using mouse models to study the impact of the VDR on growth regulatory pathways in the context of development and tumorigenesis in vivo. Recent developments include detection of megalin-mediated uptake of vitamin D-binding protein (DBP) and identification of CYP27B1 and CYP24 metabolizing enzymes in mammary cells, demonstration of precocious mammary gland development in VDR-null mice, and identification of novel pathways triggered by 1,25D during apoptosis. Our preclinical studies have been complemented by emerging data from other groups suggesting that human breast cancer may be influenced by VDR genotype and vitamin D status. Collectively, these studies have reinforced the need to further define the regulation and function of the vitamin D pathway in cells in relation to prevention and treatment of breast cancer.
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Valrance ME, Brunet AH, Welsh J. Vitamin D receptor-dependent inhibition of mammary tumor growth by EB1089 and ultraviolet radiation in vivo. Endocrinology 2007; 148:4887-94. [PMID: 17628009 DOI: 10.1210/en.2007-0267] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
1,25-Dihydroxyvitamin D(3) (1,25D), the biologically active form of vitamin D(3), exerts antiproliferative and proapoptotic effects in multiple transformed cell types, and thus, the vitamin D signaling pathway represents a potential anticancer target. Although chronic treatment with 1,25D induces hypercalcemia, synthetic vitamin D analogs have been developed that inhibit tumor growth in vivo with minimal elevation of serum calcium. Furthermore, vitamin D is synthesized in skin exposed to UV light, and this route of vitamin D elevation is not associated with hypercalcemia. In this study, we examined whether enhancement of vitamin D status via exogenous (EB1089, a 1,25D analog) or endogenous (UV exposure) approaches could exert antitumor effects without hypercalcemia. We used mammary xenografts with differential vitamin D receptor (VDR) expression to examine whether the antitumor effects of either therapy are receptor mediated. We present evidence that both EB1089 and UV exposure inhibit tumor growth via induction of growth arrest and apoptosis. These antitumor effects were observed only in xenografts containing VDR-positive tumor cells; heterogeneous tumors containing VDR-negative tumor cells and VDR-positive stromal and endothelial cells were unresponsive to both therapies. No evidence for antiangiogenic effects of EB1089 were detected in this model system. Neither EB1089 nor UV was associated with overt toxicity, but keratinocyte proliferation was increased in UV-exposed skin. These data provide proof of principle that UV exposure modulates tumor growth via elevation of vitamin D signaling and that therapeutic approaches designed to target the vitamin D pathway will be effective only if tumor cells express functional VDR.
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Affiliation(s)
- Meggan E Valrance
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
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Deeb KK, Trump DL, Johnson CS. Vitamin D signalling pathways in cancer: potential for anticancer therapeutics. Nat Rev Cancer 2007; 7:684-700. [PMID: 17721433 DOI: 10.1038/nrc2196] [Citation(s) in RCA: 985] [Impact Index Per Article: 57.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Epidemiological studies indicate that vitamin D insufficiency could have an aetiological role in various human cancers. Preclinical research indicates that the active metabolite of vitamin D, 1alpha,25(OH)2D3, also known as calcitriol, or vitamin D analogues might have potential as anticancer agents because their administration has antiproliferative effects, can activate apoptotic pathways and inhibit angiogenesis. In addition, 1alpha,25(OH)2D3 potentiates the anticancer effects of many cytotoxic and antiproliferative anticancer agents. Here, we outline the epidemiological, preclinical and clinical studies that support the development of 1alpha,25(OH)2D3 and vitamin D analogues as preventative and therapeutic anticancer agents.
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Affiliation(s)
- Kristin K Deeb
- Department of Pharmacology, Roswell Park Cancer Institute, Buffalo, New York, USA
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Abstract
Epidemiologic data have demonstrated that breast cancer incidence is inversely correlated with indices of vitamin D status, including ultraviolet exposure, which enhances epidermal vitamin D synthesis. The vitamin D receptor (VDR) is expressed in mammary epithelial cells, suggesting that vitamin D may directly influence sensitivity of the gland to transformation. Consistent with this concept, in vitro studies have demonstrated that the VDR ligand, 1,25-dihydroxyvitamin D (1, 25D), exerts negative growth regulatory effects on mammary epithelial cells that contribute to maintenance of the differentiated phenotype. Furthermore, deletion of the VDR gene in mice alters the balance between proliferation and apoptosis in the mammary gland, which ultimately enhances its susceptibility to carcinogenesis. In addition, dietary supplementation with vitamin D, or chronic treatment with synthetic VDR agonists, reduces the incidence of carcinogen-induced mammary tumors in rodents. Collectively, these observations have reinforced the need to further define the human requirement for vitamin D and the molecular actions of the VDR in relation to prevention of breast cancer.
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Affiliation(s)
- JoEllen Welsh
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA.
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68
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Petrioli R, Pascucci A, Francini E, Marsili S, Sciandivasci A, De Rubertis G, Barbanti G, Manganelli A, Salvestrini F, Francini G. Weekly high-dose calcitriol and docetaxel in patients with metastatic hormone-refractory prostate cancer previously exposed to docetaxel. BJU Int 2007; 100:775-9. [PMID: 17535276 DOI: 10.1111/j.1464-410x.2007.07019.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To evaluate the activity and tolerability of weekly high-dose calcitriol and docetaxel in patients with metastatic hormone-refractory prostate cancer (HRPC) previously exposed to docetaxel, as patients who progress after docetaxel treatment might be considered for second-line chemotherapy, but with no standard salvage therapy available we hypothesised that high-dose calcitriol might restore sensitivity to chemotherapy. PATIENTS AND METHODS The study comprised 26 patients who had progressed after first-line treatment with docetaxel-based chemotherapy had failed. Treatment cycles consisted of calcitriol (32 microg orally as 0.5 microg tablets) on day 1 and docetaxel (30 mg/m(2) intravenous) on day 2, administered for six consecutive weeks followed by a 2-week rest interval for a maximum of 24 cycles. RESULTS There was a response in prostate-specific antigen (PSA) level in eight patients (31%); seven (27%) had a stable PSA level for >/= 12 weeks. The median time to PSA progression was 4.2 months and the median survival was 9.3 months. The regimen was generally well tolerated; there was grade 2 hypercalcaemia, probably related to calcitriol, in one patient after six treatment cycles. CONCLUSION Weekly high-dose calcitriol and docetaxel seems to be an effective and well-tolerated treatment option for patients with metastatic HRPC previously exposed to docetaxel-based chemotherapy.
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Affiliation(s)
- Roberto Petrioli
- Department of Human Pathology and Oncology, Medical Oncology Section, University of Siena, Siena, Italy.
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69
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Russo IH, Russo J. Primary prevention of breast cancer by hormone-induced differentiation. Recent Results Cancer Res 2007; 174:111-30. [PMID: 17302191 DOI: 10.1007/978-3-540-37696-5_11] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Breast cancer is a fatal disease whose incidence is gradually increasing in most industrialized countries and in all ethnic groups. Primary prevention is the ultimate goal for the control of this disease. The knowledge that breast cancer risk is reduced by early full-term pregnancy and that additional pregnancies increase the rate of protection has provided novel tools for designing cancer prevention strategies. The protective effect of pregnancy has been experimentally reproduced in virgin rats by treatment with the placental hormone human chorionic gonadotropin (hCG). HCG prevents the initiation and inhibits the progression of chemically induced mammary carcinomas by inducing differentiation of the mammary gland, inhibiting cell proliferation, and increasing apoptosis. It also induces the synthesis of inhibin, a tumor suppressor factor, downregulates the level of expression of the estrogen receptor alpha (ER-alpha) by methylation of CpG islands, imprinting a permanent genomic signature that characterizes the refractory condition of the mammary gland to undergo malignant transformation. The genomic signature induced by hCG is identical to that induced by pregnancy and is specific for this hormone. Comparison of the mammary gland's genomic profile of virgin Sprague-Dawley rats treated daily with hCG for 21 days with that of rats receiving 17beta-estradiol (E2) and progesterone (Pg) (E2 + Pg) revealed that in hCG-treated rats 194 genes were significantly up-modulated (> 2.5 log2-folds) (p < 0.01) and commonly expressed, whereas these genes were not expressed in the E2 + Pg group. The genomic signature induced by hCG and pregnancy included activators or repressors of transcription genes, apoptosis, growth factors, cell division control, DNA repair, tumor suppressor, and cell-surface antigen genes. Our data indicate that hCG, like pregnancy, induces permanent genomic changes that are not reproduced by steroid hormones and in addition regulates gene expression through epigenetic mechanisms that are differentiation-dependent processes, leading us to conclude that hormonally induced differentiation offers enormous promise for the primary prevention of breast cancer.
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Affiliation(s)
- Irma H Russo
- Breast Cancer Research Laboratory, Fox Chase Cancer Center, Philadelphia, PA 19111, USA
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70
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Byrne B, Welsh J. Identification of novel mediators of Vitamin D signaling and 1,25(OH)2D3 resistance in mammary cells. J Steroid Biochem Mol Biol 2007; 103:703-7. [PMID: 17254776 PMCID: PMC1885398 DOI: 10.1016/j.jsbmb.2006.12.061] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2006] [Indexed: 11/22/2022]
Abstract
Since the discovery of the Vitamin D receptor (VDR) in mammary cells, the role of the Vitamin D signaling pathway in normal glandular function and in breast cancer has been extensively explored. In vitro studies have demonstrated that the VDR ligand, 1,25(OH)(2)D(3), modulates key proteins involved in signaling proliferation, differentiation and survival of normal mammary epithelial cells. Anti-proliferative and pro-differentiating effects of 1,25(OH)(2)D(3) have also been observed in VDR positive breast cancer cells, indicating that transformation per se does not abolish Vitamin D signaling. However, many breast cancer cell lines are less sensitive to 1,25(OH)(2)D(3) than normal mammary epithelial cells. Reduced sensitivity to 1,25(OH)(2)D(3) has been linked to alterations in Vitamin D metabolizing enzymes as well as down regulation of VDR expression or function. In this report, we describe results from a proteomics screening approach used to search for proteins involved in dictating sensitivity or resistance to Vitamin D mediated apoptosis in breast cancer cells. Several proteins not previously linked to 1,25(OH)(2)D(3) signaling were identified with this approach, and a distinct subset of proteins was linked to 1,25(OH)(2)D(3) resistance. Follow-up studies to determine the relevance of these proteins to Vitamin D signaling in general are in progress.
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Affiliation(s)
- Belinda Byrne
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
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71
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Zhang S, Zhang D, Zhu Y, Guo H, Zhao X, Sun B. Clusterin expression and univariate analysis of overall survival in human breast cancer. Technol Cancer Res Treat 2007; 5:573-8. [PMID: 17121433 DOI: 10.1177/153303460600500604] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The aim of this research is to investigate the significance of clusterin (CLU) expression as a risk factor for breast cancer through tissue microarray technology and univariate analysis of overall survival. Formalin-fixed, paraffin-embedded tissues from 158 cases of breast cancer and 31 cases of normal adjacent tissues assembled into a tissue microarray. Cytoplasmic CLU expression in tumor tissues was measured by immunochemistry. Survival analysis was used to investigate the relationship between CLU expression and prognosis, tumor volume, pathological classification, and recurrence. Survival time of patients with CLU expression, lymph node metastasis, and limited post-surgery chemotherapy (<6 cycles of treatment) was significantly shorter than that of patients with no detectable CLU expression (P=0.000), without lymph node metastasis (P=0.000) and more comprehensive post-surgery chemotherapy (>/=6 cycles of treatment) (P=0.035). CLU expression in tumor cells was higher than in normal adjacent breast epithelial cells (P=0.03). The CLU expression staining coefficient of cancer tissues with lymph node metastasis was higher than those without lymph node metastasis (P=0.000). Cytoplasmic CLU expression was found to be a prognostic factor for human breast cancer.
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Affiliation(s)
- Shiwu Zhang
- Department of Pathology, Tianjin Cancer Hospital, Tianjin Medical University, Tianjin 300060, China.
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72
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Alagbala AA, Johnson CS, Trump DL, Posner GH, Foster BA. Antitumor effects of two less-calcemic vitamin D analogs (Paricalcitol and QW-1624F2-2) in squamous cell carcinoma cells. Oncology 2007; 70:483-92. [PMID: 17237623 DOI: 10.1159/000098813] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2006] [Accepted: 09/25/2006] [Indexed: 01/03/2023]
Abstract
The active metabolite of vitamin D(3) (1alpha,25-dihydroxyvitamin D(3), calcitriol) has potent antitumor activities in vitro and in vivo in multiple cancers. Concerns about induction of hypercalcemia by calcitriol and the desire for more potent agents have prompted development of less-calcemic vitamin D analogs. These studies demonstrate that two vitamin D analogs, 19-nor-1alpha,25-dihydroxyvitamin D(2) (paricalcitol) and 1alpha-hydroxymethyl-16-ene-24,24-difluoro-25-hydroxy-26,27-bis-homovitamin D(3) (QW-1624F(2)-2, QW), have anticancer effects in the calcitriol-responsive squamous cell carcinoma (SCC) cell line. Paricalcitol (GI50 = 0.7 nM) and QW (GI50 = 0.001 nM) inhibited SCC cell growth; however, QW was more potent. Paricalcitol (10 nM) and QW (10 nM) induced G0/G1 cell cycle arrest and inhibited DNA synthesis by approximately 95%. The vitamin D analogs modulated cell cycle regulators, including decreasing mRNA and protein levels of p21(Waf1/Cip1) (p21) and cyclin-dependent kinase 2 (cdk2), and increasing p27(Kip1) (p27) protein expression. Vitamin D analogs induced apoptosis, caspase-3 cleavage and increased expression of pro-apoptotic MEKK-1. Phosphorylation of Akt, MEK and ERK1/2 that promote cell growth and survival were inhibited by vitamin D analogs. The anticancer effects of paricalcitol and QW are comparable to the effect of calcitriol. These less-calcemic vitamin D analogs are as effective as calcitriol in vitro and are promising for prevention and treatment of cancer and other diseases.
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Affiliation(s)
- Adebusola A Alagbala
- Department of Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, N.Y., USA
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73
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Cochrane DR, Wang Z, Muramaki M, Gleave ME, Nelson CC. Differential regulation of clusterin and its isoforms by androgens in prostate cells. J Biol Chem 2006; 282:2278-87. [PMID: 17148459 DOI: 10.1074/jbc.m608162200] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Clusterin mRNA levels were shown to increase dramatically in rat ventral prostate following castration, and clusterin was therefore originally thought to be repressed by androgens. It was later discovered that the increased clusterin levels are most likely due to castration-induced apoptosis of the prostatic epithelium rather than direct action of the androgen receptor (AR). In the studies presented here, LNCaP cells in culture and rat prostate organ culture were treated with androgens. Clusterin mRNA and protein are shown to increase with androgen treatment in a time- and dose-dependent manner. This induction of clusterin requires AR and can be inhibited by casodex, an AR antagonist. We have found that the first intron of the clusterin gene contains putative androgen response elements. The intronic region is shown to be bound by AR in chromatin immunoprecipitation assays and is transactivated by AR in reporter assays. Two isoforms of clusterin result from alternate transcriptional start sites. Both isoforms are cytoprotective; however, Isoform 1 has the capacity to produce a splice variant that is apoptotic. Real time PCR was used to determine the response of the two isoforms to androgens. Intriguingly, these results illustrated that Isoform 2 was up-regulated, whereas Isoform 1 was down-regulated by androgens. Isoform 2 was also increased as the LNCaP xenograft tumor progressed to androgen-independence, whereas Isoform 1 was unaltered. This androgen regulation of clusterin may underline the cytoprotective role of androgens in normal prostate physiology as well as play an antiapoptotic role in prostate cancer progression.
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Affiliation(s)
- Dawn R Cochrane
- Department of Genetics, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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74
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Toyama T, Zhang Z, Iwase H, Yamashita H, Ando Y, Hamaguchi M, Mizutani M, Kondo N, Fujita T, Fujii Y, Iwata H. Low expression of the snail gene is a good prognostic factor in node-negative invasive ductal carcinomas. Jpn J Clin Oncol 2006; 36:357-63. [PMID: 16766568 DOI: 10.1093/jjco/hyl038] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND While Snail is a zinc-finger transcription factor that triggers the epithelial-mesenchymal transition, it has also been reported to be indirectly regulated by estrogen receptor alpha (ERalpha) and to be involved in the transcriptional repression of the aromatase gene. The aim of the present study was to examine the role of Snail expression in node-negative invasive ductal carcinomas. METHODS We analyzed Snail mRNA expression levels in 86 node-negative invasive ductal carcinomas by real-time quantitative RT-PCR and studied whether Snail mRNA expression correlates with clinicopathological factors. RESULTS No correlation was found between Snail mRNA expression and ERalpha protein expression levels. However, we observed that none of the 34 patients showing low Snail mRNA expression developed distant metastasis while 6 of 52 (12%) showing high expression of Snail mRNA did. The level of Snail mRNA expression was not found to be significantly correlated with clinicopathological factors. No inverse correlation was found between the Snail and aromatase mRNA expression levels in our series. CONCLUSION Our data show that low expression of Snail mRNA is a good prognostic factor in node-negative invasive ductal carcinomas. Snail expression is suggested to be involved in distant metastasis in node-negative invasive ductal carcinomas.
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Affiliation(s)
- Tatsuya Toyama
- Department of Breast Oncology, Aichi Cancer Center Hospital, Japan.
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75
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Colangelo LA, Chiu BCH, Lopez P, Scholtens D, Willis LC, Hendrick RE, Gapstur SM. A pilot study of vitamin D, calcium, and percent breast density in Hispanic women. Nutr Res 2006. [DOI: 10.1016/j.nutres.2005.11.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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76
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Byrne BM, Welsh J. Altered thioredoxin subcellular localization and redox status in MCF-7 cells following 1,25-dihydroxyvitamin D3 treatment. J Steroid Biochem Mol Biol 2005; 97:57-64. [PMID: 16061374 DOI: 10.1016/j.jsbmb.2005.06.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
1,25-Dihydroxyvitamin D(3) (1,25D) induces apoptosis in MCF-7 cells via the intrinsic pathway involving bax translocation to mitochondria, cytochrome c release and reactive oxygen species (ROS) generation. Vitamin D up-regulated protein 1 (VDUP1), an apoptotic regulatory gene induced by 1,25D in HL-60 cells, is a negative regulator of thioredoxin (Trx1), a redox protein which neutralizes ROS and protects against oxidative stress induced apoptosis. Due to the involvement of oxidative stress in 1,25D mediated apoptosis, we analyzed whether VDUP1 or Trx1 are altered by 1,25D in MCF-7 cells. In contrast to HL-60 cells, VDUP1 mRNA was not up-regulated by 1,25D in MCF-7 cells, indicating that transcriptional up-regulation of this gene is not required for 1,25D mediated apoptosis. 1,25D did not affect the expression or activity of Trx1 in MCF-7 cells, however, Trx1 activity was higher in MCF-7 cells selected for resistance to 1,25D mediated apoptosis. In untreated MCF-7 cells, Trx1 was present only in the cytosol, and the majority was in the oxidized state. In 1,25D treated MCF-7 cells, Trx1 was present in both cytosol and nucleus, and the nuclear Trx1 pool was in the reduced state. Nuclear localization of Trx1 in 1,25D treated MCF-7 cells was confirmed by immunofluorescent microscopy. Although redox status is known to alter the ability of Trx1 to bind apoptosis signal regulating kinase 1 (ASK1), no changes in ASK1 transcript or protein levels were observed in 1,25D treated MCF-7 cells. Collectively, these studies indicate that although VDUP1 and ASK1 are not altered by 1,25D, changes in redox status and sub-cellular distribution of Trx1 occurs during 1,25D mediated apoptosis of MCF-7 cells.
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Affiliation(s)
- Belinda M Byrne
- Department of Biological Sciences, 214 Galvin Life Sciences Building, University of Notre Dame, Notre Dame, IN 46556, USA
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77
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Le Corre L, Chalabi N, Delort L, Bignon YJ, Bernard-Gallon DJ. Resveratrol and breast cancer chemoprevention: molecular mechanisms. Mol Nutr Food Res 2005; 49:462-71. [PMID: 15786518 DOI: 10.1002/mnfr.200400094] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Despite years of intensive research, breast cancer remains a major cause of death among women. New strategies to combat breast cancer are being developed, one of the most exciting of which is the use of chemopreventive agents. Resveratrol (RES) is a polyphenolic compound found in plants that seems to have a wide spectrum of biological activity. RES has been shown to afford protection against several types of cancer. This review summarizes the chemopreventive effects of RES at the three major stages of breast carcinogenesis: initiation, promotion, and progression. It has anti-oxidant and anti-inflammatory properties, and may induce apoptosis as well as modulate cell cycle and estrogen receptor function in breast cancer cell lines. Although RES has shown remarkable promise as a potent chemopreventive agent in breast cancer, further studies are needed to etablish its usefulness.
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Affiliation(s)
- Ludovic Le Corre
- Laboratoire d'Oncologie Moléculaire, CBRV, Centre Jean Perrin, Clermont-Ferrand, France
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78
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Milliken EL, Zhang X, Flask C, Duerk JL, MacDonald PN, Keri RA. EB1089, a vitamin D receptor agonist, reduces proliferation and decreases tumor growth rate in a mouse model of hormone-induced mammary cancer. Cancer Lett 2005; 229:205-15. [PMID: 16115727 PMCID: PMC1615916 DOI: 10.1016/j.canlet.2005.06.044] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2005] [Revised: 05/22/2005] [Accepted: 06/01/2005] [Indexed: 10/25/2022]
Abstract
1,25-Dihydroxyvitamin D3 and several of its analogs, such as EB1089, induce growth arrest and apoptosis of breast cancer cells in culture. EB1089 has also been shown to limit growth of xenografts in nude mice and carcinogen-induced mammary tumors in rats. Coupled with the fact that the vitamin D receptor is highly expressed in a large proportion of breast tumors, these data suggest that it may be a broad spectrum therapeutic target. We utilized a transgenic model of hormone-induced mammary cancer, the LH-overexpressing mouse, to assess, for the first time, the efficacy of EB1089 in a spontaneous tumor model. Similar to human breast cancers, the pre-neoplastic mammary glands and mammary tumors in these mice express high levels of vitamin D receptor. Treatment with EB1089 decreased proliferation of mammary epithelial cells in pre-neoplastic glands by 35%. Moreover, half of hormone-induced mammary tumors treated with EB1089 demonstrated a decreased rate of growth, with a subset of these tumors even regressing, suggesting that 1,25-dihydroxyvitamin D3 analogs may be effective chemopreventive and chemotherapeutic agents for breast cancer.
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Affiliation(s)
- Erin L. Milliken
- Department of Pharmacology, Case Western Reserve University School of Medicine, 2109 Adelbert Road, Cleveland, OH 44106, USA
| | - Xiaoxue Zhang
- Department of Pharmacology, Case Western Reserve University School of Medicine, 2109 Adelbert Road, Cleveland, OH 44106, USA
| | - Chris Flask
- Department of Biomedical Engineering, University Hospitals of Cleveland, 11100 Euclid Avenue, Cleveland, OH 44106, USA
| | - Jeffrey L. Duerk
- Department of Biomedical Engineering, University Hospitals of Cleveland, 11100 Euclid Avenue, Cleveland, OH 44106, USA
| | - Paul N. MacDonald
- Department of Pharmacology, Case Western Reserve University School of Medicine, 2109 Adelbert Road, Cleveland, OH 44106, USA
| | - Ruth A. Keri
- Department of Pharmacology, Case Western Reserve University School of Medicine, 2109 Adelbert Road, Cleveland, OH 44106, USA
- Division of General Medical Sciences-Oncology, Case Western Reserve University School of Medicine, 2109 Adelbert Road, Cleveland, OH 44106, USA
- * Corresponding author. Tel.: + 1 216 368 3495; fax: + 1 216 368 3395. E-mail address: (R.A. Keri)
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79
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Rajapakse R, Mousli M, Pfaff AW, Uring-Lambert B, Marcellin L, Bronner C, Jeanblanc M, Villard O, Letscher-Bru V, Klein JP, Candolfi E. 1,25-Dihydroxyvitamin D3 induces splenocyte apoptosis and enhances BALB/c mice sensitivity to toxoplasmosis. J Steroid Biochem Mol Biol 2005; 96:179-85. [PMID: 15939587 DOI: 10.1016/j.jsbmb.2005.03.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2004] [Accepted: 03/10/2005] [Indexed: 01/09/2023]
Abstract
The hormonal form of Vitamin D, 1,25-dihydroxyvitamin D3, is well known for its immunosuppressive, anti-proliferative and pro-apoptotic activities. In the present work, we studied the effect of 1,25-dihydroxyvitamin D3 on Toxoplasma gondii-infected mice. We observed that 1,25-dihydroxyvitamin D3 reduces the survival rate of infected mice by up to 37% at day 10 post-infection compared to untreated infected mice (P < 0.0001). IFN-gamma and IL-12p40 levels were significantly reduced by 1,25-dihydroxyvitamin D3 in infected mice sera indicating an inhibition of Th-1-type cytokines. CD4+ T lymphocyte and splenocyte counts were also reduced following 1,25-dihydroxyvitamin D3 treatment and a marked induction of apoptosis, accompanied with down-regulation of the anti-apoptotic proteins Bcl-2 and Bcl-X(L), was observed. The above results indicate that 1,25-dihydroxyvitamin D3 induces splenocyte apoptosis and enhances host susceptibility to toxoplasmosis.
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Affiliation(s)
- Rohan Rajapakse
- Institut National de la Santé Et de la Recherche Médicale UMR-S 392, Institut de Parasitologie et de Pathologie Tropicale, Faculté de Médicine, 3 rue de Koeberlé, 67000 Strasbourg, France
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80
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Swamy N, Chen TC, Peleg S, Dhawan P, Christakos S, Stewart LV, Weigel NL, Mehta RG, Holick MF, Ray R. Inhibition of proliferation and induction of apoptosis by 25-hydroxyvitamin D3-3beta-(2)-Bromoacetate, a nontoxic and vitamin D receptor-alkylating analog of 25-hydroxyvitamin D3 in prostate cancer cells. Clin Cancer Res 2005; 10:8018-27. [PMID: 15585637 DOI: 10.1158/1078-0432.ccr-04-0881] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The 25-hydroxyvitamin D(3) (25-OH-D(3)) is a nontoxic and low-affinity vitamin D receptor (VDR)-binding metabolic precursor of 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)]. We hypothesized that covalent attachment of a 25-OH-D(3) analog to the hormone-binding pocket of VDR might convert the latter into transcriptionally active holo-form, making 25-OH-D(3) biologically active. Furthermore, it might be possible to translate the nontoxic nature of 25-OH-D(3) into its analog. We showed earlier that 25-hydroxyvitamin D(3)-3-bromoacetate (25-OH-D(3)-3-BE) alkylated the hormone-binding pocket of VDR. In this communication we describe that 10(-6) mol/L of 25-OH-D(3)-3-BE inhibited the growth of keratinocytes, LNCaP, and LAPC-4 androgen-sensitive and PC-3 and DU145 androgen-refractory prostate cancer cells, and PZ-HPV-7 immortalized normal prostate cells with similar or stronger efficacy as 1,25(OH)(2)D(3). But its effect was strongest in LNCaP, PC-3, LAPC-4, and DU145 cells. Furthermore, 25-OH-D(3)-3-BE was toxic to these prostate cancer cells and caused these cells to undergo apoptosis as shown by DNA-fragmentation and caspase-activation assays. In a reporter assay with COS-7 cells, transfected with a 1alpha,25-dihydroxyvitamin D(3)-24-hydroxylase (24-OHase)-construct and VDR-expression vector, 25-OH-D(3)-3-BE induced 24-OHase promoter activity. In a "pull down assay" with PC-3 cells, 25-OH-D(3)-3-BE induced strong interaction between VDR and general transcription factors, retinoid X receptor, and GRIP-1. Collectively, these results strongly suggested that the cellular effects of 25-OH-D(3)-3-BE were manifested via 1,25(OH)(2)D(3)/VDR signaling pathway. A toxicity study in CD-1 mice showed that 166 microg/kg of 25-OH-D(3)-3-BE did not raise serum-calcium beyond vehicle control. Collectively, these results strongly suggested that 25-OH-D(3)-3-BE has a strong potential as a therapeutic agent for androgen-sensitive and androgen-refractory prostate cancer.
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Affiliation(s)
- Narasimha Swamy
- Endocrinology, Diabetes and Nutrition, Department of Medicine, Boston University School of Medicine, 85 East Newton Street, Boston, MA 02118, USA.
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81
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Li F, Ling X, Huang H, Brattain L, Apontes P, Wu J, Binderup L, Brattain MG. Differential regulation of survivin expression and apoptosis by vitamin D3 compounds in two isogenic MCF-7 breast cancer cell sublines. Oncogene 2005; 24:1385-95. [PMID: 15608672 PMCID: PMC2820410 DOI: 10.1038/sj.onc.1208330] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2004] [Revised: 10/07/2004] [Accepted: 10/29/2004] [Indexed: 11/09/2022]
Abstract
Although both the antiapoptotic function of survivin and vitamin D3 (VD3)-mediated cell growth inhibition and apoptosis have been extensively studied, it is not known whether survivin plays a role in VD3 compound-mediated cell growth inhibition and apoptosis induction. Using an isogenic model of MCF-7 breast adenocarcinoma cells (MCF-7E and MCF-7L sublines that are sensitive and resistant to VD3 compounds), we found that VD3 compounds effectively downregulated survivin in VD3-sensitive MCF-7E cells, which was associated with VD3-induced apoptosis. In contrast, VD3 compounds failed to downregulate survivin in VD3-resistant MCF-7L cells, which showed resistant to VD3-induced apoptosis. However, inhibition of survivin expression by small interfering RNA (siRNA) induced cell death per se and further sensitized VD3-induced apoptosis in MCF-7L cells, indicating that the inability of these cells to respond to VD3 is due to the failure to downregulate survivin. Forced expression of survivin not only blocked VD3-mediated G1 cell accumulation but also increased S and G2/M cell populations. VD3 treatment rapidly triggered the activation of p38 MAPK signaling in MCF-7E cells but not in MCF-7L cells. Moreover, inhibition of p38 activation diminished VD3-mediated survivin inhibition and partially rescued VD3-induced cell death. We further showed that VD3 increased the expression of TGF(beta)1 and TGF(beta) receptor 2, and that blocking the function of TGF(beta) receptor 2 diminished VD3 compound-mediated survivin downregulation. Thus, we propose that the VD3 compound-induced growth inhibition and apoptosis induction are at least partially dependent on survivin downregulation via VD3-induced TGFbeta signaling and the activation of p38 MAPK pathway. Targeting survivin through these pathways may lead to novel applications for cancer therapeutics.
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Affiliation(s)
- Fengzhi Li
- Department of Pharmacology and Therapeutics, Grace Cancer Drug Center, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.
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82
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Zinser GM, Welsh J. Vitamin D receptor status alters mammary gland morphology and tumorigenesis in MMTV-neu mice. Carcinogenesis 2004; 25:2361-72. [PMID: 15333467 DOI: 10.1093/carcin/bgh271] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The vitamin D(3) receptor (VDR) is a ligand-dependent transcription factor implicated in regulation of cell cycle, differentiation and apoptosis of both normal and transformed cells derived from mammary gland. In these studies we examined whether VDR status altered mammary gland morphology or transformation in the well-characterized MMTV-neu transgenic model of breast cancer. We demonstrate that VDR protein is highly expressed in neu-positive epithelial cells of preneoplastic lesions, established tumors and lung metastases from MMTV-neu mice. Furthermore, MMTV-neu mice lacking VDR exhibit abnormal mammary ductal morphology characterized by dilated, distended ducts containing dysplastic epithelial cells. From 12 months of age on, MMTV-neu mice lacking VDR also experience body weight loss, atrophy of the mammary fat pad, estrogen deficiency and reduced survival. The limited survival of MMTV-neu mice lacking VDR precluded an accurate assessment of the impact of complete VDR ablation on tumor development. MMTV-neu mice heterozygous for VDR, however, did not exhibit body weight loss, mammary gland atrophy or compromised survival. Compared with MMTV-neu mice with two copies of the VDR gene, haploinsufficiency of VDR shortened the latency and increased the incidence of mammary tumor formation. Tumor histology and expression/subcellular localization of the neu transgene were not altered by VDR haploinsufficiency despite a significant decrease in tumor VDR expression. Collectively, these studies suggest that VDR gene dosage impacts on age-related changes in ductal morphology and oncogene-induced tumorigenesis of the mammary gland in vivo.
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MESH Headings
- Age Distribution
- Animals
- Cell Transformation, Neoplastic
- Female
- Gene Dosage
- Immunoenzyme Techniques
- Lung Neoplasms/metabolism
- Lung Neoplasms/pathology
- Lung Neoplasms/secondary
- Mammary Glands, Animal/drug effects
- Mammary Glands, Animal/growth & development
- Mammary Glands, Animal/pathology
- Mammary Neoplasms, Experimental/etiology
- Mammary Tumor Virus, Mouse/genetics
- Mice
- Mice, Knockout
- Mice, Transgenic
- Receptors, Calcitriol/genetics
- Receptors, Calcitriol/physiology
- Reverse Transcriptase Polymerase Chain Reaction
- Subcellular Fractions
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Affiliation(s)
- Glendon M Zinser
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
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83
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Zinser GM, Welsh J. Effect of Vitamin D3 receptor ablation on murine mammary gland development and tumorigenesis. J Steroid Biochem Mol Biol 2004; 89-90:433-6. [PMID: 15225815 DOI: 10.1016/j.jsbmb.2004.03.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Glendon M Zinser
- Department of Biological Sciences, University of Notre Dame, Galvin Life Science Building, Notre Dame, IN 46556, USA.
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84
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Valrance ME, Welsh J. Breast cancer cell regulation by high-dose Vitamin D compounds in the absence of nuclear vitamin D receptor. J Steroid Biochem Mol Biol 2004; 89-90:221-5. [PMID: 15225775 DOI: 10.1016/j.jsbmb.2004.03.082] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
1alpha,25-dihydroxyvitamin D(3) (1,25D(3)) inhibits growth and induces apoptosis in breast cancer cells in vivo and in vitro. To examine the role of the Vitamin D receptor (VDR) in mediating the actions of 1,25D(3) at nanomolar and micromolar concentrations, mammary epithelial tumor cell lines generated in wild type (WT) and VDR knockout (VDRKO) mice were utilized. WT cells express VDR and are growth inhibited by 1,25D(3) and synthetic analogs EB1089 and CB1093 at 1nM concentrations, while VDRKO cells do not express VDR and are insensitive to Vitamin D compounds at concentrations up to 100nM. In the current studies, we have confirmed and extended these previous observations. At nanomolar concentrations of 1,25D(3) and all analogs tested, including EB1089, CB1093, MC1288, and KH1230, WT cells are growth inhibited and exhibit apoptotic morphology, while VDRKO cells show no growth inhibition or apoptosis. At concentrations of 1-10microM, however, 1,25D(3) and synthetic analogs induce growth inhibition and apoptotic morphology in both WT and VDRKO cell lines. These data indicate that nanomolar concentrations of 1,25D(3) and analogs mediate growth regulatory effects via mechanisms requiring the nuclear VDR, but that micromolar concentrations of Vitamin D compounds can exert non VDR-mediated effects.
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Affiliation(s)
- Meggan E Valrance
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
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85
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Li P, Li C, Zhao X, Zhang X, Nicosia SV, Bai W. p27(Kip1) stabilization and G(1) arrest by 1,25-dihydroxyvitamin D(3) in ovarian cancer cells mediated through down-regulation of cyclin E/cyclin-dependent kinase 2 and Skp1-Cullin-F-box protein/Skp2 ubiquitin ligase. J Biol Chem 2004; 279:25260-7. [PMID: 15075339 DOI: 10.1074/jbc.m311052200] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
p27(Kip1) (p27) is a tumor suppressor whose stability is controlled by proteasome-mediated degradation, a process directed in part by cyclin-dependent kinase 2 (CDK2)-mediated phosphorylation of p27 at Thr(187) and its subsequent interaction with the Skp1-Cullin-F-box protein/Skp2 (Skp2) ubiquitin ligase. The present study shows that 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) arrests ovarian cancer cells in G(1) by stabilizing the p27 protein. 1,25(OH)(2)D(3) initiates a chain of events by decreasing the amounts of cyclin E and cyclin E-associated CDK2 activity. As a result, p27 phosphorylation at Thr(187) and consequently the interaction with Skp2 are decreased. 1,25(OH)(2)D(3) also increases p27 stability by decreasing the abundance of Skp2. It is the combined effect of 1,25(OH)(2)D(3) on both the CDK2-dependent phosphorylation of p27, and thus its affinity for Skp2, and Skp2 expression that dramatically increases the stability of the p27 protein. Similar to its effects in ovarian cancer cells, 1,25(OH)(2)D(3) induces p27 accumulation in wild type mouse embryo fibroblasts and arrests wild type but not p27-null mouse embryo fibroblasts in G(1). Stable expression of Skp2 in OVCAR3 cells diminishes the G(1) arrest and decreases the growth response to 1,25(OH)(2)D(3). Taken together, the results of this study identify p27 as the key mediator of 1,25(OH)(2)D(3)-induced growth suppression in G(1) and show that the hormone achieves this by decreasing the activity of CDK2 and reducing the abundance of Skp2, which act together to degrade p27.
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Affiliation(s)
- Pengfei Li
- Department of Pathology, University of South Florida College of Medicine and Programs of Molecular Oncology and Drug Discovery, Tampa, FL 33612, USA
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86
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Abstract
Abstract
1,25-Dihydroxyvitamin D (calcitriol), the most active metabolite of vitamin D, has significant antineoplastic activity in preclinical models. Several mechanisms of activity have been proposed. These include inhibition of proliferation associated with cell cycle arrest and, in some models, differentiation, reduction in invasiveness and angiogenesis, and induction of apoptosis. Proposed mechanisms differ between tumor models and experimental conditions, and no unifying hypothesis about the mechanism of antineoplastic activity has emerged. Synergistic and/or additive effects with cytotoxic chemotherapy, radiation, and other cancer drugs have been reported. Significantly supraphysiological concentrations of calcitriol are required for antineoplastic effects. Such concentrations are not achievable in patients when calcitriol is dosed daily due to predictable hypercalcemia and hypercalcuria; however, phase I trials have demonstrated that intermittent dosing allows substantial dose escalation and has produced potentially therapeutic peak calcitriol concentrations. Recently, a phase II study reported encouraging levels of activity for the combination of high-dose calcitriol and docetaxel administered on a weekly schedule in patients with androgen-independent prostate cancer. This regimen is now under study in a placebo-controlled randomized trial in androgen-independent prostate cancer and in phase II studies in several other tumor types. Further work is needed to elucidate the molecular mechanisms of antineoplastic activity and optimal clinical applications of calcitriol in cancer.
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Affiliation(s)
- Tomasz M. Beer
- Division of Hematology and Medical Oncology, Oregon Health and Science University, Portland, OR
| | - Anne Myrthue
- Division of Hematology and Medical Oncology, Oregon Health and Science University, Portland, OR
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87
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Morris MJ, Smaletz O, Solit D, Kelly WK, Slovin S, Flombaum C, Curley T, Delacruz A, Schwartz L, Fleisher M, Zhu A, Diani M, Fallon M, Scher HI. High-dose calcitriol, zoledronate, and dexamethasone for the treatment of progressive prostate carcinoma. Cancer 2004; 100:1868-75. [PMID: 15112267 DOI: 10.1002/cncr.20185] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND Preclinical and clinical data have suggested that high-dose calcitriol (1,25-dihydroxycholecalciferol) has activity against prostate carcinoma. Pulse-dosed calcitriol and dexamethasone may maximize tolerability and efficacy. The authors examined the toxicity of pulse-dosed calcitriol with zoledronate and with the addition of dexamethasone at the time of disease progression. METHODS Patients with progressive prostate carcinoma were eligible for the current study. In cohorts of 3-6 patients, calcitriol was administered for 3 consecutive days per week, starting at a dose of 4 microg per day. Doses were escalated to 30 microg per day. Intravenous zoledronate (4 mg) was administered monthly. Dexamethasone could be added to the regimen at disease progression. Toxicities, markers of bone turnover, plasma calcitriol levels, and clinical outcomes were recorded. RESULTS Thirty-one patients were treated in cohorts that were defined by the calcitriol dose administered (4, 6, 8, 10, 14, 20, 24, or 30 microg). Seven patients received dexamethasone. Three patients had their doses reduced due to calcium-related laboratory findings. Patients tolerated therapy well, even in the 30 microg cohort; therefore, a maximum tolerated dose was not defined. Peak plasma levels observed in the 24 microg and 30 microg cohorts ranged from 391 to 968 pg/mL. Minimal antitumor effects were observed. CONCLUSIONS Calcitriol was well tolerated at doses up to and including 30 microg 3 times per week in combination with intravenous zoledronate 4 mg monthly, with or without dexamethasone, in patients with progressive prostate carcinoma. Peak plasma levels in the 24 microg and 30 microg cohorts were greater than the levels associated with antitumor effects preclinically. Due to the cumbersome dosing schedule and the lack of significant activity observed, Phase II trials of this regimen are not planned.
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Affiliation(s)
- Michael J Morris
- Genitourinary Oncology Service, Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA.
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88
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Jiang F, Li P, Fornace AJ, Nicosia SV, Bai W. G2/M arrest by 1,25-dihydroxyvitamin D3 in ovarian cancer cells mediated through the induction of GADD45 via an exonic enhancer. J Biol Chem 2003; 278:48030-40. [PMID: 14506229 DOI: 10.1074/jbc.m308430200] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
1,25-Dihydroxyvitamin D3 suppresses the growth of multiple human cancer cell lines by inhibiting cell cycle progression and inducing cell death. The present study showed that 1,25-dihydroxyvitamin D3 causes cell cycle arrest at the G2/M transition through p53-independent induction of GADD45 in ovarian cancer cells. Detailed analyses have established GADD45 as a primary target gene for 1,25-dihydroxyvitamin D3. A DR3-type vitamin D response element was identified in the fourth exon of GADD45 that forms a complex with the vitamin D receptor.retinoid X receptor heterodimer in electrophoresis mobility shift assays and mediates the dose-dependent induction of luciferase activity by 1,25-dihydroxyvitamin D3 in reporter assays. Chromatin immunoprecipitation assays have shown that the vitamin D receptor is recruited in a ligand-dependent manner to the exonic enhancer but not to the GADD45 promoter regions. In ovarian cancer cells expressing GADD45 antisense cDNA or GADD45-null mouse embryo fibroblasts, 1,25-dihydroxyvitamin D3 failed to induce G2/M arrest. Taken together, these results identify GADD45 as an important mediator for the tumor-suppressing activity of 1,25-dihydroxyvitamin D3 in human ovarian cancer cells.
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MESH Headings
- 3' Untranslated Regions
- Blotting, Northern
- Calcitriol/pharmacology
- Cell Death
- Cell Line, Tumor
- Chromatin/metabolism
- DNA Mutational Analysis
- DNA, Complementary/metabolism
- Dimerization
- Dose-Response Relationship, Drug
- Enhancer Elements, Genetic
- Exons
- Female
- Flow Cytometry
- G2 Phase
- Genes, Reporter
- Genome
- HeLa Cells
- Humans
- Immunoblotting
- Intracellular Signaling Peptides and Proteins
- Introns
- Ligands
- Luciferases/metabolism
- Mitosis
- Models, Biological
- Models, Genetic
- Mutagenesis, Site-Directed
- Oligonucleotides, Antisense/chemistry
- Oligonucleotides, Antisense/metabolism
- Ovarian Neoplasms/metabolism
- Plasmids/metabolism
- Precipitin Tests
- Protein Binding
- Proteins/genetics
- Proteins/metabolism
- RNA, Messenger/metabolism
- Receptors, Calcitriol/metabolism
- Time Factors
- Transcription, Genetic
- Transfection
- Up-Regulation
- GADD45 Proteins
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Affiliation(s)
- Feng Jiang
- Department of Pathology, University of South Florida College of Medicine and the Program of Molecular Oncology, H. Lee Moffitt Cancer Center, Tampa, Florida 33612-4799, USA
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89
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Ryhänen S, Jääskeläinen T, Mahonen A, Mäenpää PH. Inhibition of MG-63 cell cycle progression by synthetic vitamin D3 analogs mediated by p27, Cdk2, cyclin E, and the retinoblastoma protein. Biochem Pharmacol 2003; 66:495-504. [PMID: 12907249 DOI: 10.1016/s0006-2952(03)00283-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Progression through eukaryotic cell division cycle is regulated by synergistic activities of both positive and negative regulatory factors. The active form of vitamin D(3) (1alpha,25(OH)(2)D(3), 1,25D) and a number of its synthetic analogs have been shown to arrest cells in the G(1) phase of the cell cycle. In the present study, 1alpha,25(OH)(2)D(3) and the analogs KH1060, EB1089, and CB1093 were used to study the mechanism of the cell cycle arrest and to compare the effectiveness of these compounds in human MG-63 osteosarcoma cells. The 20-epi analogs KH1060 and CB1093, as well as the 20-normal analog EB1089, were found to be more potent than 1alpha,25(OH)(2)D(3) in inhibiting cell proliferation and arresting the MG-63 cells in the G(1) phase. These analogs were more active than 1alpha,25(OH)(2)D(3) in increasing the cyclin dependent kinase inhibitor p27 protein levels (approximately 2.3-2.5-fold compared to 1alpha,25(OH)(2)D(3)) by both increasing its formation and decreasing its degradation rate. The increased p27 formation was accompanied by stabilization of binding of nuclear proteins to the Sp1+NF-Y responsive promoter region of the p27 gene. The increase in p27 protein levels and the simultaneous decrease in cyclin E protein levels was accompanied by decreased Cdk2 kinase activity, retinoblastoma (Rb) protein hypophosphorylation and, finally, cell cycle arrest in the G(1) phase. In summary, the analogs KH1060, EB1089, and CB1093 keep Rb protein in its growth-suppressing, hypophosphorylated form and prevent cell cycle progression through the restriction point. Therefore, these synthetic vitamin D(3) analogs may be potential candidates for treating diseases, where cell cycle regulation is needed.
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Affiliation(s)
- Sanna Ryhänen
- Department of Biochemistry, University of Kuopio, Kuopio, Finland.
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90
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Swamy N, Persons KS, Chen TC, Ray R. 1alpha,25-Dihydroxyvitamin D3-3beta-(2)-bromoacetate, an affinity labeling derivative of 1alpha,25-dihydroxyvitamin D3 displays strong antiproliferative and cytotoxic behavior in prostate cancer cells. J Cell Biochem 2003; 89:909-16. [PMID: 12874825 DOI: 10.1002/jcb.10585] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
In this report we describe that 1,25(OH)(2)D(3)-3-BE, a VDR-affinity labeling analog of 1,25(OH)(2)D(3), showed strong and dose-dependent growth-inhibitory effect in several epithelial cells, i.e., keratinocytes (primary cells), MCF-7 breast cancer, PC-3, and LNCaP prostate cancer and PZ-HPV-7 immortalized normal prostate cell-lines. Furthermore, 10(-6) M of 1,25(OH)(2)D(3)-3-BE induced apoptosis specifically in LNCaP and PC-3 cells; and the effect was much less pronounced at lower doses. We also showed that the effect (of 1,25(OH)(2)D(3)-3-BE) was not due to probable degradation (hydrolysis) of 1,25(OH)(2)D(3)-3-BE or random interaction of this molecule with cellular proteins. Tissue- or cell-specific action of 1,25(OH)(2)D(3) and its mimics is not common due to the ubiquitous nature of VDR. Furthermore, variable effects of 1,25(OH)(2)D(3) and its analogs in various cell-lines potentially limits their application as anticancer agents. We showed that 1,25(OH)(2)D(3)-3-BE displayed similar growth-inhibitory and cytotoxic activities towards androgen sensitive LNCaP and androgen-independent PC-3 cell-lines. Therefore, these results raise the possibility that 1,25(OH)(2)D(3)-3-BE or similar VDR-cross linking analogs of 1,25(OH)(2)D(3) might be considered for further development as potential candidates for prostate cancer.
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Affiliation(s)
- Narasimha Swamy
- Section in Endocrinology, Diabetes and Metabolism, Department of Medicine, Boston University School of Medicine, 85 East Newton Street, Boston, MA 02118, USA
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91
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O'Sullivan J, Whyte L, Drake J, Tenniswood M. Alterations in the post-translational modification and intracellular trafficking of clusterin in MCF-7 cells during apoptosis. Cell Death Differ 2003; 10:914-27. [PMID: 12867999 DOI: 10.1038/sj.cdd.4401254] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Clusterin is a heterodimeric, disulfide-linked 70-80 kDa glycoprotein that is induced during regression of most, if not all, hormone-dependent epithelial tissues. These studies describe the biogenesis and intracellular trafficking of clusterin in MCF-7 cells before and after the initiation of apoptosis with antiestrogens and TNF alpha. Under physiological conditions, clusterin is modified in the endoplasmic reticulum (ER), and proteolytically cleaved in the Golgi to generate discrete alpha and beta chains prior to secretion. Treatment with TNFalpha or the antiestrogen, ICI 182,780, induces apoptosis in MCF-7 cells and leads to substantial changes in the activity of Golgi-resident enzymes, significantly altering the biogenesis of clusterin. This leads to the appearance of a 50-53 kDa uncleaved, nonglycosylated, disulfide-linked isoform of clusterin that accumulates in the nucleus. While clusterin contains a cryptic SV-40-like nuclear localization signal, mutation of this sequence does not affect the nuclear accumulation of the disulfide-linked nuclear isoform. Confocal microscopy demonstrates that the nuclear accumulation of clusterin is coincident with DNA fragmentation. These data suggest that, at least in secretory epithelial cells, retrograde transport from the Golgi to the ER of a nonglycosylated, uncleaved isoform and the subsequent translocation of clusterin to the nucleus occur in dying cells.
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Affiliation(s)
- J O'Sullivan
- Department of Biological Sciences, University of Notre Dame, Notre Dame IN 46556, USA
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92
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Leskov KS, Klokov DY, Li J, Kinsella TJ, Boothman DA. Synthesis and functional analyses of nuclear clusterin, a cell death protein. J Biol Chem 2003; 278:11590-600. [PMID: 12551933 DOI: 10.1074/jbc.m209233200] [Citation(s) in RCA: 304] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Nuclear clusterin (nCLU) is an ionizing radiation (IR)-inducible protein that binds Ku70, and triggers apoptosis when overexpressed in MCF-7 cells. We demonstrate that endogenous nCLU synthesis is a product of alternative splicing. Reverse transcriptase-PCR analyses revealed that exon II, containing the first AUG and encoding the endoplasmic reticulum-targeting peptide, was omitted. Exons I and III are spliced together placing a downstream AUG in exon III as the first available translation start site. This shorter mRNA produces the 49-kDa precursor nCLU protein. Ku70 binding activity was localized to the C-terminal coiled-coil domain of nCLU. Leucine residues 357, 358, and 361 of nCLU were necessary for Ku70-nCLU interaction. The N- and C-terminal coiled-coil domains of nCLU interacted with each other, suggesting that the protein could dimerize or fold. Mutation analyses indicate that the C-terminal NLS was functional in nCLU with the same contribution from N-terminal NLS. The C-terminal coiled-coil domain of nCLU was the minimal region required for Ku binding and apoptosis. MCF-7 cells show nuclear as well as cytoplasmic expression of GFP-nCLU in apoptotic cells. Cytosolic aggregation of GFP-nCLU was found in viable cells. These results indicate that an inactive precursor of nCLU exists in the cytoplasm of non-irradiated MCF-7 cells, translocates into the nucleus following IR, and induces apoptosis.
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Affiliation(s)
- Konstantin S Leskov
- Department of Radiation Oncology, Laboratory of Molecular Stress Responses, Ireland Comprehensive Cancer Center and Case Western Reserve University School of Medicine, Cleveland, Ohio 44106-4942, USA
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93
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Zinser GM, McEleney K, Welsh J. Characterization of mammary tumor cell lines from wild type and vitamin D3 receptor knockout mice. Mol Cell Endocrinol 2003; 200:67-80. [PMID: 12644300 DOI: 10.1016/s0303-7207(02)00416-1] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
1,25-Dihydroxyvitamin D(3) (1,25D(3)), the active metabolite of vitamin D(3), inhibits breast cancer cell growth in vivo and in vitro. To examine mechanisms of 1,25D(3) induced growth arrest and apoptosis, cell lines were established from DMBA induced mammary tumors derived from vitamin D(3) receptor knockout (VDRKO) and wild type (WT) mice. Two VDRKO (KO240, KO288) and two WT (WT145, WT276) cell lines were selected and characterized. All four cell lines express cytokeratins indicative of an epithelial origin, as well as vimentin, which is expressed in many transformed cell lines. The tumorigenicity of the cells was confirmed in vivo as all four cell lines form estrogen responsive tumors in nude mice. Both WT cell lines express the VDR protein and are sensitive to growth inhibition by 1,25D(3) at doses as low as 1 nM. Flow cytometric analysis indicated that 1,25D(3) induces G(0)/G(1) arrest and apoptosis in the WT cell lines. In contrast, both cell lines established from tumors that developed in VDRKO mice lack VDR mRNA and protein. Cells from WT mice exhibit 1,25D(3) inducible transcriptional activity, as measured by reporter gene assays, but cells from VDRKO mice do not. Cells from VDRKO mice are also completely resistant to 1,25D(3) mediated growth arrest and apoptosis over the range of 0.01-100 nM 1,25D(3). VDRKO cells are also resistant to the synthetic vitamin D(3) analogs EB1089 and CB1093 that are more potent growth inhibitors than 1,25D(3) in WT cells. This data conclusively demonstrate that the induction of cell cycle arrest and apoptosis in breast cancer cells by 1,25D(3), EB1089 and CB1093 is dependent on the nuclear VDR. Cells lacking VDR remain sensitive to growth arrest mediated by 9-cis retinoic acid, a ligand for the retinoid x receptor which can heterodimerize with the VDR. Sensitivity to apoptosis induced by the DNA damaging agent etoposide is not altered in VDRKO cells, indicating that VDR ablation does not impair apoptotic pathways in general. All four cell lines display equal sensitivity to tamoxifen induced growth arrest. These estrogen responsive, transformed cell lines which differentially express the VDR provide a novel model system for identification of the mechanisms by which 1,25D(3) regulates proliferation and apoptosis in breast cancer cells.
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Affiliation(s)
- Glendon M Zinser
- Department of Biological Sciences, University of Notre Dame, IN 46556, USA
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94
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Flanagan L, Packman K, Juba B, O'Neill S, Tenniswood M, Welsh J. Efficacy of Vitamin D compounds to modulate estrogen receptor negative breast cancer growth and invasion. J Steroid Biochem Mol Biol 2003; 84:181-92. [PMID: 12711002 DOI: 10.1016/s0960-0760(03)00028-1] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In estrogen receptor (ER) positive breast cancer cells such as MCF-7 cells, the anti-tumor effects of 1,25(OH)(2)D(3) (1,25D(3)) may be secondary to disruption of estrogen mediated survival signals. If so, then sensitivity to 1,25D(3) mediated growth arrest could be reduced in estrogen independent breast cancer cells. The aim of these studies was to determine the effects of 1,25D(3) and EB1089 on the ER negative, invasive human breast cancer cell line SUM-159PT. 1,25D(3) and EB1089 reduced SUM-159PT cell growth subsequent to elevation of p27 and p21 levels. 1,25D(3) mediated apoptosis of SUM-159PT cells was associated with an enrichment of membrane bound bax, a redistribution of cytochome c from the mitochondria to the cytosol and PARP cleavage. 1,25D(3) and EB1089 also inhibited SUM-159PT cell invasion through an 8 microM Matrigel membrane. In pre-clinical studies, EB1089 dramatically reduced the growth of SUM-159PT xenografts in nude mice. The decreased size of tumors from EB1089 treated mice was associated with decreased proliferation and increased DNA fragmentation. Our data support the concept that Vitamin D(3) compounds trigger apoptosis by mechanisms independent of estrogen signaling. These studies indicate that Vitamin D(3) based therapeutics may be beneficial, alone or in conjunction with other agents, for the treatment of estrogen independent breast cancer.
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Affiliation(s)
- Louise Flanagan
- Department of Biological Sciences, University of Notre Dame, 126 Galvin Life Sciences Building, IN 46556, USA
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95
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Wietzke JA, Welsh J. Phytoestrogen regulation of a Vitamin D3 receptor promoter and 1,25-dihydroxyvitamin D3 actions in human breast cancer cells. J Steroid Biochem Mol Biol 2003; 84:149-57. [PMID: 12710998 DOI: 10.1016/s0960-0760(03)00024-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)), a steroid hormone derived from Vitamin D(3), is a negative growth regulator of breast cancer cells, and Vitamin D(3) analogs represent a novel treatment approach for human cancer. Elucidation of Vitamin D(3) receptor (VDR) regulation may reveal strategies to sensitize cancer cells to the effects of 1,25-dihydroxyvitamin D(3) and Vitamin D(3) analogs. We have previously characterized an estrogen responsive promoter region (800 bp upstream of exon 1c) in the human VDR gene, and the present studies examined regulation of this VDR promoter region by two phytoestrogens, resveratrol (present in red wine) and genistein (present in soy). We transiently transfected a VDR promoter luciferase construct into the estrogen receptor (ER) positive human breast cancer cell lines T47D and MCF-7, and treated with 0.4-4 microM resveratrol or 5-500 nM genistein. Both phytoestrogens up-regulated the transcription of the VDR promoter, as measured by reporter gene activity, approximately two-fold compared to vehicle treated cells. Co-treatment with the anti-estrogen tamoxifen (TAM) in T47D cells and transfection in an estrogen receptor negative breast cancer cell line demonstrated that the effects of phytoestrogens on the VDR promoter are dependent on estrogen receptor. Resveratrol and genistein also increased VDR protein expression as detected by Western blotting. Treatment with resveratrol had no effect on cell number or cell cycle profile, while treatment with genistein increased cell number. Because resveratrol could up-regulate VDR without increasing breast cancer cell growth, we hypothesized that resveratrol mediated increase in VDR expression would sensitize breast cancer cells to the effects of 1,25-dihydroxyvitamin D(3) and Vitamin D(3) analogs. In support of this hypothesis, both T47D and MCF-7 cells pre-treated with resveratrol exhibited increased VDR mediated transactivation of a Vitamin D(3) responsive promoter compared to cells pre-treated with vehicle. In addition, co-treatment with resveratrol enhanced the growth inhibitory effects of 1,25-dihydroxyvitamin D(3) and the Vitamin D(3) analog EB1089. These data support the concept that dietary factors, such as phytoestrogens, may impact on breast cancer cell sensitivity to Vitamin D(3) analogs through regulation of the VDR promoter.
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MESH Headings
- Antineoplastic Agents/pharmacology
- Antineoplastic Agents, Hormonal/pharmacology
- Antineoplastic Agents, Phytogenic/pharmacology
- Blotting, Western
- Breast Neoplasms/metabolism
- Breast Neoplasms/pathology
- Calcitriol/metabolism
- Cell Cycle
- Dose-Response Relationship, Drug
- Estrogens, Non-Steroidal/metabolism
- Flow Cytometry
- Genes, Reporter
- Genistein/pharmacology
- Humans
- Isoflavones
- Phytoestrogens
- Plant Preparations
- Promoter Regions, Genetic
- Protein Binding
- Protein Structure, Tertiary
- Receptors, Calcitriol/genetics
- Resveratrol
- Stilbenes/pharmacology
- Tamoxifen/pharmacology
- Time Factors
- Transcription, Genetic
- Transcriptional Activation
- Transfection
- Tumor Cells, Cultured
- Up-Regulation
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Affiliation(s)
- Jennifer A Wietzke
- Department of Biological Sciences, University of Notre Dame, IN 46556, USA
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96
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Polek TC, Stewart LV, Ryu EJ, Cohen MB, Allegretto EA, Weigel NL. p53 Is required for 1,25-dihydroxyvitamin D3-induced G0 arrest but is not required for G1 accumulation or apoptosis of LNCaP prostate cancer cells. Endocrinology 2003; 144:50-60. [PMID: 12488329 DOI: 10.1210/en.2001-210109] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
1,25-Dihydroxyvitamin D(3) [1,25-(OH)(2)D(3)] is an effective agent for inhibiting the growth of prostate cancer cells including LNCaP and PC-3 cell lines. However, the extent of growth inhibition in these cell lines differs because LNCaP cells are much more responsive than PC-3 cells. Previous studies in LNCaP cells have shown that 1,25-(OH)(2)D(3) treatment results in G(0)/G(1) cell cycle accumulation, loss of Ki67 expression, and induction of apoptosis. One difference between the two cell lines is that PC-3 cells lack functional p53, a protein that plays roles both in cell cycle regulation and induction of apoptosis. In this study, the role of p53 in 1,25-(OH)(2)D(3) action was examined using the p53-negative PC-3 cells and a line of LNCaP cells, called LN-56, in which p53 function was shut off using a dominant negative p53 fragment. We found that treatment with 1,25-(OH)(2)D(3) extensively inhibits growth of LN-56 prostate cancer cells lacking p53, but in contrast to the parental LNCaP cells, the LN-56 cells recover rapidly. Moreover, in prostate cancer cells, the synergism between 1,25-(OH)(2)D(3) and 9-cis retinoic acid appears to be dependent on the presence of functional p53; however, 1,25-(OH)(2)D(3)-mediated induction of G(1) cell cycle accumulation and induction of apoptosis is not.
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Affiliation(s)
- Tara C Polek
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
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97
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Welsh J, Wietzke JA, Zinser GM, Smyczek S, Romu S, Tribble E, Welsh JC, Byrne B, Narvaez CJ. Impact of the Vitamin D3 receptor on growth-regulatory pathways in mammary gland and breast cancer. J Steroid Biochem Mol Biol 2002; 83:85-92. [PMID: 12650704 DOI: 10.1016/s0960-0760(02)00277-7] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
1,25-Dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) interacts with the Vitamin D(3) receptor (VDR) to modulate proliferation and apoptosis in a variety of cell types, including breast cancer cells. In this review, we discuss three issues related to the role of the VDR in growth control: first, whether mammary glands lacking VDR exhibit abnormal growth; second, whether the VDR is essential for induction of apoptosis by 1,25(OH)(2)D(3); and third, whether VDR up-regulation can sensitize cells to 1,25(OH)(2)D(3). Studies from our laboratory have demonstrated that mammary glands from VDR knockout (VDR KO) mice exhibit accelerated growth and branching during puberty, pregnancy and lactation as compared to wild-type (WT) mice. In addition, involution after weaning, a process driven by epithelial cell apoptosis, proceeds at a slower rate in VDR KO mice compared to WT mice. Using cells isolated from VDR KO and WT mice, we report that both normal and transformed mammary cells derived from WT mice are growth inhibited by 1,25(OH)(2)D(3), however, cells derived from VDR KO mice are completely unresponsive to 1,25(OH)(2)D(3). In human breast cancer cells, we have identified a variety of agents, including steroid hormones, phytoestrogens and growth factors, that up-regulate VDR expression and enhance sensitivity to 1,25(OH)(2)D(3)-mediated growth inhibition. Collectively, these studies support a role for 1,25(OH)(2)D(3) and the VDR in negative growth regulation of both normal mammary gland and breast cancer cells.
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Affiliation(s)
- JoEllen Welsh
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA.
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98
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Johnson CS, Hershberger PA, Bernardi RJ, Mcguire TF, Trump DL. Vitamin D receptor: a potential target for intervention. Urology 2002; 60:123-30; discussion 130-1. [PMID: 12231068 DOI: 10.1016/s0090-4295(02)01591-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Epidemiologic data suggest that low exposure to vitamin D or 1alpha,25-dihydroxycholecalciferol (calcitriol) increases the risk of prostate cancer. Calcitriol, a central factor in bone and mineral metabolism, is also a potent antiproliferative agent in a wide variety of malignant cell types. We have demonstrated that calcitriol has significant antitumor activity in vitro and in vivo in prostate and squamous cell carcinoma model systems. Calcitriol, in these models, induces a significant G0/G1 arrest and modulates p21(Waf1/Cip1) and p27(Kip1), the cyclin-dependent kinase inhibitors. Calcitriol induces poly (adenosine diphosphate-ribose) polymerase cleavage, increases bax/bcl-2 ratio, reduces levels of phosphorylated mitogen-activated protein kinases (P-MAPKs; also known as extracellular signal-related kinase [ERK] 1/2) and phosphorylated Akt, induces caspase-dependent mitogen-activated protein kinase kinase (MEK) cleavage and upregulation of MEK kinase-1, all potential markers of the apoptotic pathway. We also have demonstrated that dexamethasone (dex) potentiates the antitumor effect of calcitriol through effects on the vitamin D receptor and decreases calcitriol-induced hypercalcemia. We initiated phase 1 and phase 2 trials of calcitriol, either alone or in combination with carboplatin, paclitaxel, or dex. Data from these studies indicate that high-dose calcitriol is feasible on an intermittent schedule, the maximum tolerated dose (MTD) is unclear, and dex or paclitaxel appear to ameliorate hypercalcemia. Studies continue to define the MTD of calcitriol on this intermittent schedule, either alone or with other agents, and to evaluate the mechanisms of calcitriol effects in prostate cancer models.
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Affiliation(s)
- Candace S Johnson
- Department of Pharmacology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA.
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99
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Abstract
Postnatal mammary gland morphogenesis is achieved through coordination of signaling networks in both the epithelial and stromal cells of the developing gland. While the major proliferative hormones driving pubertal mammary gland development are estrogen and progesterone, studies in transgenic and knockout mice have successfully identified other steroid and peptide hormones that impact on mammary gland development. The vitamin D3 receptor (VDR), whose ligand 1,25-dihydroxyvitamin D3 is the biologically active form of vitamin D3, has been implicated in control of differentiation, cell cycle and apoptosis of mammary cells in culture, but little is known about the physiological relevance of the vitamin D3 endocrine system in the developing gland. In these studies, we report the expression of the VDR in epithelial cells of the terminal end bud and subtending ducts, in stromal cells and in a subset of lymphocytes within the lymph node. In the terminal end bud, a distinct gradient of VDR expression is observed, with weak VDR staining in proliferative populations and strong VDR staining in differentiated populations. The role of the VDR in ductal morphogenesis was examined in Vdr knockout mice fed high dietary Ca2+ which normalizes fertility, serum estrogen and neonatal growth. Our results indicate that mammary glands from virgin Vdr knockout mice are heavier and exhibit enhanced growth, as evidenced by higher numbers of terminal end buds, greater ductal outgrowth and enhanced secondary branch points, compared with glands from age- and weight-matched wild-type mice. In addition, glands from Vdr knockout mice exhibit enhanced growth in response to exogenous estrogen and progesterone, both in vivo and in organ culture, compared with glands from wild-type mice. Our data provide the first in vivo evidence that 1,25-dihydroxyvitamin D3 and the VDR impact on ductal elongation and branching morphogenesis during pubertal development of the mammary gland. Collectively, these results suggest that the vitamin D3 signaling pathway participates in negative growth regulation of the mammary gland.
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Affiliation(s)
- Glendon Zinser
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
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100
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Im HJ, Craig TA, Pittelkow MR, Kumar R. Characterization of a novel hexameric repeat DNA sequence in the promoter of the immediate early gene, IEX-1, that mediates 1alpha,25-dihydroxyvitamin D(3)-associated IEX-1 gene repression. Oncogene 2002; 21:3706-14. [PMID: 12032839 DOI: 10.1038/sj.onc.1205450] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2001] [Revised: 02/15/2002] [Accepted: 02/21/2002] [Indexed: 11/09/2022]
Abstract
1alpha,25-Dihydroxyvitamin D(3)(1alpha,25(OH)(2)D(3)), the active metabolite of vitamin D(3), mediates anti-proliferative effects in cells by regulating the expression of 1alpha,25(OH)(2)D(3)-responsive genes. The expression of the proliferation-promoting Immediate Early gene X-1 (IEX-1) is reduced by 1alpha,25(OH)(2)D(3) through unknown mechanisms. Here we report the presence of a novel inhibitory hexameric repeat DNA response element in the promoter of the human IEX-1 gene that mediates 1alpha,25(OH)(2)D(3)-associated IEX-1 gene repression. To localize a vitamin D sensitive DNA response element we transfected the keratinocyte-like cell line, HaCaT, (referred as HaCaT) with a series of plasmids containing full-length and truncated IEX-1 promoter elements fused to the luciferase reporter gene in the absence or presence of 1alpha,25(OH)(2)D(3), and we performed electrophoretic gel mobility assays in the presence of receptors for 1alpha,25(OH)(2)D(3) (vitamin D receptor, VDR) and 9-cis-retinoic acid (RXRalpha). We mapped a negative response element between nt -405 and -391(15 bp) of theIEX-1 promoter (5'-TGAACC AGG GAGTCA-3') that mediates transcriptional inhibition in response to 1alpha,25(OH)(2)D(3) and which requires expression of both nuclear receptors for 1alpha,25(OH)(2)D(3) and 9-cis-retinoic acid. Our data indicate that the physiological repression of IEX-1 gene expression by 1alpha,25(OH)(2)D(3) is directly mediated by nuclear VDR/RXRalpha heterodimers through a specific transcriptional element.
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Affiliation(s)
- Hee-Jeong Im
- Department of Internal Medicine, Mayo Clinic and Foundation, 200 First Street, SW, Rochester, Minnesota, MN 55905, USA
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