M R Uskokovic

Rutgers, The State University of New Jersey, Newark, NJ, United States

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Publications (224)677.6 Total impact

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    ABSTRACT: Ductal carcinoma in situ (DCIS) is a non-malignant lesion of the breast with the potential to progress to invasive ductal carcinoma (IDC). The disappearance and breakdown of the myoepithelial cell layer and basement membrane in DCIS have been identified as major events in the development of breast cancer. The MCF10DCIS.com cell line is a well-established model which recapitulates the progression of breast cancer from DCIS to IDC. We have previously reported that a novel Gemini vitamin D analog, 1α,25-dihydroxy-20R-21(3-hydroxy-3-deuteromethyl-4,4,4-trideuterobutyl)-23-yne-26,27-hexafluoro-cholecalciferol (BXL0124) is a potent inhibitor of the growth of MCF10DCIS.com xenografted tumors without hypercalcemic toxicity. In the present study, we utilized the MCF10DCIS.com in vivo model to assess the effects of BXL0124 on breast cancer progression from weeks 1 to 4. Upon DCIS progression to IDC from weeks 3 to 4, tumors lost the myoepithelial cell layer and basement membrane as shown by immunofluorescence staining with smooth muscle actin (SMA) and laminin 5, respectively. Administration of BXL0124 maintained the critical myoepithelial cell layer as well as basement membrane, and animals treated with BXL0124 showed a 43% reduction in tumor volume by week 4. BXL0124 treatment decreased cell proliferation and maintained vitamin D receptor (VDR) levels in tumors. In addition, the BXL0124 treatment reduced the mRNA levels of matrix metalloproteinases (MMPs) starting at week 3, contributing to the inhibition of invasive transition. Our results suggest that the maintenance of DCIS plays a significant role in the cancer preventive action of the Gemini vitamin D BXL0124 during the progression of breast lesions.
    Cancer Prevention Research 04/2014; · 4.89 Impact Factor
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    ABSTRACT: The potency of 25-hydroxyvitamin D3 (25(OH)D3 ) is increased by several fold through its metabolism into 1α,25-dihydroxyvitamin D3 (1α,25(OH)2 D3 ) by cytochrome P450 27B1 (CYP27B1). Thus, the pivotal role of 1α-hydroxylation in the activation of vitamin D compounds is well known. Here, we examined the metabolism of 25-hydroxy-16-ene-23-yne-vitamin D3 (25(OH)-16-ene-23-yne-D3 ), a synthetic analog of 25(OH)D3 in a cell-free system and demonstrated that 25(OH)-16-ene-23-yne-D3 is neither activated by cytochrome CYP27B1 nor inactivated by cytochrome P450 24A1 (CYP24A1). These findings were also confirmed in immortalized normal human prostate epithelial cells (PZ-HPV-7) which are known to express both CYP27B1 and CYP24A1, indicating that the structural modifications featured in 25(OH)-16-ene-23-yne-D3 enable the analog to resist the actions of both CYP27B1 and CYP24A1. To provide intelligible structure-function information, we also performed molecular docking analysis between the analog and CYP27B1. Furthermore, 25(OH)-16-ene-23-yne-D3 was found to suppress the growth of PZ-HPV-7 cells with a potency equivalent to 1α,25(OH)2 D3 . The antiproliferative activity of 25(OH)-16-ene-23-yne-D3 was found to be vitamin D receptor (VDR)-dependent as it failed to inhibit the growth of mammary tumor cells derived from VDR-knockout mice. Furthermore, stable introduction of VDR into VDR-knockout cells restored the growth inhibition by 25(OH)-16-ene-23-yne-D3 . Thus, we identified 25-hydroxy-16-ene-23-yne-vitamin D3 as a novel non-1α-hydroxylated vitamin D analog which is equipotent to 1α,25(OH)2 D3 in its antiproliferative activity. We now propose that the low potency of the intrinsic VDR-mediated activities of 25(OH)D3 can be augmented to the level of 1α,25(OH)2 D3 without its activation through 1α-hydroxylation by CYP27B1, but by simply preventing its inactivation by CYP24A1. J. Cell. Biochem. 9999: XX-XX, 2014. © 2013 Wiley Periodicals, Inc.
    Journal of Cellular Biochemistry 02/2014; · 3.06 Impact Factor
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    ABSTRACT: Human epidermal growth factor receptor 2 (HER2 or ErbB2), a member of ErbB receptor tyrosine kinases, is overexpressed in approximately 20 % of human breast cancer, and the ErbB2 signaling pathway is a critical therapeutic target for ErbB2-overexpressing breast cancer. We investigated the inhibitory effects of the Gemini vitamin D analog BXL0124, the synthetic triterpenoid CDDO-Im and the combination on the tumorigenesis of ErbB2-overexpressing breast cancer. MMTV-ErbB2/neu transgenic mice were treated with BXL0124, CDDO-Im or the combination from 3 months of age until the end of the experiment. Formation and growth of MMTV-ErbB2/neu mammary tumors were monitored every week, and all three treatments delayed the development of mammary tumors without significant toxicity. Decreased activation of ErbB2 as well as other ErbB receptors, ErbB1 and ErbB3, in MMTV-ErbB2/neu mammary tumors was shown by all treatments. Protein levels of downstream targets of the ErbB2 signaling pathway, including activated-Erk1/2, activated-Akt, c-Myc, CycD1 and Bcl2, were repressed by all three treatments, with the combination treatment exhibiting the strongest effects. To investigate therapeutic efficacy, the combination of BXL0124 and CDDO-Im was given to MMTV-ErbB2/neu mice after mammary tumors were established between 23-30 weeks of age. Short-term treatment with the combination did not show effects on tumor growth nor the ErbB2 signaling pathway. The present study demonstrates BXL0124, CDDO-Im and the combination as potential agents for prevention, but not treatment, against the tumorigenesis of ErbB2-overexpressing breast cancer.
    Cancer Prevention Research 07/2013; · 4.89 Impact Factor
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    ABSTRACT: We have synthesized thirty-nine 1,25-dihydroxyvitamin D3 [1,25(OH)2 D3 ] analogs having 2 side-chains attached to carbon-20 (Gemini) with various modifications and compared their anticancer activities. Five structure-function rules emerged to identify analogs with enhanced anti-cancer activity. One of these active analogs, BXL-01-0126 was more potent than 1,25(OH)2 D3 in mediating 50% clonal inhibition of cancer cell growth. Murine studies found that BXL-01-0126 and 1,25(OH)2 D3 had nearly the same potency to raise serum calcium levels. Taken together, BXL-01-0126 as compared to 1,25(OH)2 D3 has greater anticancer potency, but similar toxicity causing hypercalcemia. We focused on the effect of these compounds on the stimulation of expression of human cathelicidin antimicrobial peptide (CAMP) whose gene has a vitamin D response element in its promoter. Expression of CAMP mRNA and protein increased in a dose-response fashion after exposure of AML cells to the Gemini analog, BXL-01-126 in vitro. A xenograft model of AML was developed using U937 AML cells injected into NSG immunodeficient mice. Administration of vitamin D3 compounds to these mice resulted in substantial levels of CAMP in the systemic circulation. This suggests a unique prophylactic treatment at diagnosis or during induction chemotherapy for AML patients, to provide them with protection against various microbial infections through CAMP induction. © 2013 Wiley Periodicals, Inc.
    International Journal of Cancer 06/2013; · 6.20 Impact Factor
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    ABSTRACT: CD44, a transmembrane glycoprotein, is a major receptor for extracellular proteins involved in invasion and metastasis of human cancers. We have previously demonstrated that the novel Gemini vitamin D analog BXL0124 [1α,25-dihydroxy-20R-21(3-hydroxy-3-deuteromethyl-4,4,4-trideuterobutyl)-23-yne-26,27-hexafluro-cholecalciferol] repressed CD44 expression in MCF10DCIS.com basal-like human breast cancer cells and inhibited MCF10DCIS xenograft tumor growth. In the present study, we investigated potential factors downstream of CD44 and the biological role of CD44 repression by BXL0124 in MCF10DCIS cells. The treatment with Gemini vitamin D BXL0124 decreased CD44 protein level, suppressed STAT3 signaling, and inhibited invasion and proliferation of MCF10DCIS cells. The interaction between CD44 and STAT3 was determined by co-immunoprecipitation. CD44 forms a complex with STAT3 and Janus kinase 2 (JAK2) to activate STAT3 signaling, which was inhibited by BXL0124 in MCF10DCIS cells. The role of CD44 in STAT3 signaling and invasion of MCF10DCIS cells was further determined by the knockdown of CD44 using small hairpin RNA in vitro and in vivo. MCF10DCIS cell invasion was markedly decreased by the knockdown of CD44 in vitro. The knockdown of CD44 also significantly decreased mRNA expression levels of invasion markers, matrix metalloproteinases (MMPs) and urokinase plasminogen activator (uPA), in MCF10DCIS cells. In MCF10DCIS xenograft tumors, CD44 knockdown decreased tumor size and weight as well as invasion markers. The present study identifies STAT3 as an important signaling molecule interacting with CD44 and demonstrates the essential role of CD44-STAT3 signaling in breast cancer invasion. It also suggests that repression of CD44-STAT3 signaling is a key molecular mechanism in the inhibition of breast cancer invasion by the Gemini vitamin D analog BXL0124.
    PLoS ONE 01/2013; 8(1):e54020. · 3.53 Impact Factor
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    ABSTRACT: CD44 is a multifunctional transmembrane protein involved in cell proliferation, angiogenesis, invasion, and metastasis. CD44 is identified as a cancer stem cell marker, and the CD44-positive breast cancer cells are enriched in residual breast cancer cell populations after conventional therapies, suggesting that CD44 may be an important target for cancer prevention and therapy. Therefore, we investigated for the inhibitory effect of a novel Gemini vitamin D analog, 1α,25-dihydroxy-20R-21(3-hydroxy-3-deuteromethyl-4,4,4-trideuterobutyl)-23-yne-26,27-hexafluoro-cholecalciferol (BXL0124), on mammary tumor growth and CD44 expression in MCF10DCIS.com human breast cancer in vitro and in vivo. MCF10DCIS.com cells were injected into mammary fat pads in immunodeficient mice, and BXL0124 was then administered intraperitoneally (0.1 μg/kg body weight) or orally (0.03 or 0.1 μg/kg body weight) 6 days a week for 5 weeks. At necropsy, mammary tumors and blood were collected for evaluating tumor growth, CD44 expression, and serum calcium level. BXL0124 suppressed mammary tumor growth and markedly decreased the expression of CD44 protein in MCF10DCIS xenograft tumors without causing hypercalcemic toxicity. BXL0124 also inhibited the expression of CD44 protein and mRNA as well as the transcriptional activity of the CD44 promoter in cultured MCF10DCIS.com cells. The repression of CD44 expression induced by BXL0124 was blocked by siRNA vitamin D receptor (VDR), indicating that the regulation of CD44 expression by BXL0124 is a VDR-dependent event. The novel Gemini vitamin D analog, BXL0124, represses CD44 expression in MCF10DCIS.com cells in vitro and in xenograft tumors, suggesting an inhibitory role of a Gemini vitamin D derivative on breast cancer stem cells.
    Molecular pharmacology 03/2011; 79(3):360-7. · 4.53 Impact Factor
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    ABSTRACT: We examined the metabolism of two synthetic analogs of 1α,25-dihydroxyvitamin D₃ (1), namely 1α,25-dihydroxy-16-ene-23-yne-vitamin D₃ (2) and 1α,25-dihydroxy-16-ene-23-yne-26,27-dimethyl-vitamin D₃ (4) using rat cytochrome P450 24A1 (CYP24A1) in a reconstituted system. We noted that 2 is metabolized into a single metabolite identified as C26-hydroxy-2 while 4 is metabolized into two metabolites, identified as C26-hydroxy-4 and C26a-hydroxy-4. The structural modification of adding methyl groups to the side chain of 1 as in 4 is also featured in another analog, 1α,25-dihydroxy-22,24-diene-24,26,27-trihomo-vitamin D₃ (6). In a previous study, 6 was shown to be metabolized exactly like 4, however, the enzyme responsible for its metabolism was found to be not CYP24A1. To gain a better insight into the structural determinants for substrate recognition of different analogs, we performed an in silico docking analysis using the crystal structure of rat CYP24A1 that had been solved for the substrate-free open form. Whereas analogs 2 and 4 docked similar to 1, 6 showed altered interactions for both the A-ring and side chain, despite prototypical recognition of the CD-ring. These findings hint that CYP24A1 metabolizes selectively different analogs of 1, based on their ability to generate discrete recognition cues required to close the enzyme and trigger the catalytic mechanism.
    Archives of Biochemistry and Biophysics 02/2011; 509(1):33-43. · 3.37 Impact Factor
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    ABSTRACT: Derivatives of vitamin D(3) containing a second side-chain emanating at C-20 are known as gemini and act as vitamin D receptor agonists. Recently, two of these, namely Gemini-0072 and the epimeric Gemini-0097, were selected for further studies in view of their high biological activities and lack of hypercalcemic effects. We now show that the two analogs recruit coactivator SRC-1 better than the parental gemini and act as VDR superagonists. The crystal structures of complexes of zVDR with Gemini-0072 and Gemini-0097 indicate that these ligands induce an extra cavity within the ligand-binding pocket similar to gemini and that their superagonistic activity is due to an increased stabilization of helix H12.
    Medicinal Chemistry Communication 01/2011; 2(5):424-429. · 2.72 Impact Factor
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    ABSTRACT: Numerous synthetic vitamin D analogs have been studied for their effects on the prevention and treatment of breast cancer. However, the inhibitory effects of naturally occurring 1alpha,25-dihydroxyvitamin D3 or its synthetic analogs on ErbB2 overexpressing mammary tumorigenesis have not been reported. Gemini vitamin D analogs are novel synthetic vitamin D derivatives with a unique structure of two six-carbon chains at C-20. We have previously shown that Gemini vitamin D analogs significantly inhibited carcinogen-induced estrogen receptor (ER)-positive mammary tumorigenesis and reduced ER-negative MCF10DCIS.com xenograft tumor growth without hypercalcemic toxicity. In the present study, we have determined the inhibitory effect of a potent Gemini vitamin D analog BXL0124 (1alpha,25-dihydroxy-20R-21(3-hydroxy-3-deuteromethyl-4,4,4-trideuterobutyl)-23-yne-26,27-hexafluoro-cholecalciferol) on the ErbB2/Her-2/neu overexpressing mammary tumorigenesis. The Gemini BXL0124 inhibits ErbB2-positive mammary tumor growth and down-regulates the phosphorylation of ErbB2, ERK and AKT in tumors of MMTV-ErbB2/neu transgenic mice. These effects of Gemini BXL0124 in vivo were confirmed by using the ErbB2 overexpressing tumor cells derived from the mammary tumors of MMTV-ErbB2/neu mice. In conclusion, the Gemini vitamin D analog BXL0124 inhibits the growth of ErbB2 overexpressing mammary tumors through regulating the ErbB2/AKT/ERK signaling pathways, suggesting that Gemini vitamin D analog may be considered for translational studies.
    The Journal of steroid biochemistry and molecular biology 03/2010; 121(1-2):408-12. · 3.98 Impact Factor
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    ABSTRACT: ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
    ChemInform 01/2010; 27(20).
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    ABSTRACT: ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
    ChemInform 01/2010; 26(50).
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    ABSTRACT: Induction of terminal differentiation is a conceptually attractive approach for the therapy of neoplastic diseases. Although vitamin D derivatives (deltanoids) can induce differentiation of AML cells in vitro, so far deltanoids have not been successfully brought to the clinic, due to the likelihood of life-threatening hypercalcemia. Here, we incubated freshly obtained blood cells from patients with AML with a plant antioxidant (PAOx), silibinin (SIL), alone or together with a deltanoid. Twenty patients with AML (all subtypes except M3) were available for this study, and in 14 (70%), SIL (60 µM) either induced differentiation ex vivo, or enhanced differentiation induced by deltanoids, or both. Interestingly, SIL acting alone induced differentiation only in cases in which chromosome aberrations could not be detected. In eleven samples sufficient material was available for a limited analysis of the underlying events. Quantitative RT-PCR showed that differentiation markers were upregulated at the mRNA level by both SIL and deltanoids, suggesting that intracellular signaling pathways upstream of transcription factors (TFs) were activated by these agents. Western analysis for proteins which function as TFs in deltanoid-induced monocytic differentiation, such as members of Jun and C/EBP families, surprisingly demonstrated that SIL upregulated all these TFs in the cases tested. This suggests that although the presence of SIL may not always be sufficient to induce differentiation, it can serve as a differentiation enabling factor for blasts obtained from a large proportion of patients with AML. Thus, SIL/deltanoid combinations warrant further consideration as preventive/therapeutic regimens in human leukaemia.
    Hematological Oncology 10/2009; 28(3):124-32. · 2.04 Impact Factor
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    ABSTRACT: Calcitriol is implicated in many cellular functions including cellular growth and differentiation, thus explaining its antitumor effects. It was shown that gemini, the calcitriol derivative containing two side chain at C20, is also active in gene transcription with enhanced antitumor activity. We have now further optimized both the A-ring and the two side chains. The chemical structures of the resulting 18 geminis were correlated with biological activities. Those containing the 1alpha-fluoro A-ring are the least active. Those featuring 23-yne and 23(E) side-chains are generally more active in human breast cancer cell growth inhibition and human leukemia cell differentiation induction than their 23(Z) counterparts. On the basis of these evaluations, we selected as lead compound a 20(R) gemini, related to calcitriol in terms of it is A-ring, where one side chain was modified by introduction of a 23-yne function and replacement of the geminal methyl groups with trifluoromethyl groups, the other created by extension of C21 with a 3-hydroxy-3-trideuteromethyl-4,4,4-trideutero-butyl moiety.
    Journal of Medicinal Chemistry 09/2009; 52(17):5505-19. · 5.61 Impact Factor
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    ABSTRACT: 1alpha,25(OH)(2)-16-ene-20-cyclopropyl-vitamin D(3) (13) is several fold more potent than the natural hormone 1alpha,25-dihydroxyvitamin D(3) (1) as an anti-inflammatory agent. Here, we have further analyzed the anti-inflammatory properties of 13, confirming it as the most potent analogue tested within this family. We then determined the structures of all the natural metabolites of 13, including the 24-oxo metabolite 14, and carried out its synthesis. A comparison of 13 with 14 showed a similar induction of the primary VDR target genes CYP24A1 and CAMP and comparable anti-inflammatory properties as revealed by a similar inhibition of TNF-alpha, IL-12/23p40, IL-6, and IFN-gamma production. Interestingly, 14 displays a 3-fold lower calcemic activity in vivo compared to 13. Collectively, these findings indicate that the strong potency of 13 can be explained by the accumulation of its stable 24-oxo metabolite, which shows immunoregulatory and anti-inflammatory properties superimposable to those exerted by 13 itself.
    Journal of Medicinal Chemistry 04/2009; 52(8):2204-13. · 5.61 Impact Factor
  • Hubert Maehr, Milan R. Uskokovic, Carl P. Schaffner
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    ABSTRACT: The synthesis of dimethyl (diazomethyl)phosphonate, a useful reagent for the homologation of aldehydes to alkynes, is described as a one-pot process and comprises the generation of the azide transfer agent, diazotransfer to dimethyl (2-oxopropyl)phosphonate, and methanolysis, followed by a simple extraction protocol. Previously described syntheses for this bulk product are much more elaborate. The homologation of aldehydes to alkynes can also be extended to a single-step process by adding the aldehyde directly to the reaction mixture prior to isolation of the reagent. The homologation process using dimethyl (diazomethyl)phosphonate was shown to proceed also in nonprotic solvents with mild bases, emphasizing the importance of a facile access to the reagent. The oxidation of alcohols to the required aldehydes was performed by a TEMPO-mediated process using chloramine-T as electron acceptor.
    Synthetic Communications 01/2009; 39(2):299-310. · 1.06 Impact Factor
  • Hubert Maehr, Milan R. Uskokovic, Carl P. Schaffner
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    ABSTRACT: ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
    ChemInform 01/2009; 40(27).
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    ABSTRACT: Differentiation therapy with the hormonal form of vitamin D, 1alpha,25-dihydroxyvitamin D(3) (1,25D(3)), is a promising approach to treatment of acute myeloid leukemia (AML); however, 1,25D(3) induces hypercalcemia at pharmacologically active doses. We investigated the in vitro and in vivoantileukemic efficacy of combined treatment with non-toxic doses of a low-calcemic 1,25D(3) analogue, 1,25-dihydroxy-21(3-hydroxy-3-methyl-butyl)-19-nor-cholecalciferol (19-nor-Gemini; Ro27-5646), and rosemary plant agents in a mouse model of AML. Proliferation and differentiation of WEHI-3B D- (WEHI) murine myelomonocytic leukemia cellsin vitro were determined by standard assays. Reactive oxygen species, glutathione and protein expression levels were measured by flow cytometry, enzymatic assay and Western blotting, respectively. Systemic AML was developed by intravenous injection of WEHI cells in syngeneic Balb/c mice. 19-nor-Gemini had a higher potency than its parent compounds, Gemini (Ro27-2310) and 1,25D(3), in the induction of differentiation (EC(50) = 0.059 +/- 0.011, 0.275 +/- 0.093 and 0.652 +/- 0.085 nM, respectively) and growth arrest (IC(50) = 0.072 +/- 0.018, 0.165 +/- 0.061 and 0.895 +/- 0.144 nM, respectively) in WEHI cells in vitro, and lower in vivo toxicity. Combined treatment of leukemia-bearing mice with 19-nor-Gemini (injected intraperitoneally) and standardized rosemary extract (mixed with food) resulted in a synergistic increase in survival (from 42.2 +/- 2.5 days in untreated mice to 66.5 +/- 4.2 days, n = 3) and normalization of white blood cell and differential counts. This was consistent with strong cooperative antiproliferative and differentiation effects of low concentrations of 19-nor-Gemini or 1,25D(3) combined with rosemary extract or its major polyphenolic component, carnosic acid, as well as with the antioxidant action of rosemary agents and vitamin D derivatives in WEHI cell cultures. Combined effectiveness of 1,25D(3) analogues and rosemary agents against mouse AML warrants further exploration of this therapeutic approach in translational models of human leukemia.
    Oncology 11/2008; 75(3-4):203-14. · 2.17 Impact Factor
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    ABSTRACT: Numerous preclinical, epidemiologic, and clinical studies have suggested the benefits of vitamin D and its analogues for the prevention and treatment of cancer. However, the hypercalcemic effects have limited the use of 1alpha,25(OH)(2)D(3), the hormonally active form of vitamin D. To identify vitamin D analogues with better efficacy and low toxicity, we have tested >60 novel Gemini vitamin D analogues with a unique structure of two side chains for growth inhibition of breast cancer cells. Our initial studies found that some Gemini analogues are 5-15 times more active than 1alpha,25(OH)(2)D(3) in growth inhibition assay. In vivo experiments were designed to study the inhibitory effect of selected Gemini vitamin D analogues against mammary carcinogenesis by using (a) an N-methyl-N-nitrosourea-induced estrogen receptor (ER)-positive mammary tumor model and (b) an MCF10DCIS.com xenograft model of ER-negative mammary tumors. Among vitamin D analogues we tested, Gemini 0072 [1alpha,25-dihydroxy-20S-21(3-trideuteromethyl-3-hydroxy-4,4,4-trideuterobutyl)-23-yne-26,27-hexafluoro-19-nor-cholecalciferol] and Gemini 0097 [1alpha,25-dihydroxy-20R-21(3-trideuteromethyl-3-hydroxy-4,4,4-trideuterobutyl)-23-yne-26,27-hexafluoro-19-nor-cholecalciferol] administration inhibited by 60% the NMU-induced mammary tumor burden compared with the NMU-treated control group, but these compounds were devoid of hypercalcemia toxicity. In an ER-negative xenograft model, Gemini 0097 significantly suppressed tumor growth without hypercalcemia toxicity. We found that the inhibitory effect of Gemini 0097 was associated with an increased level of cyclin-dependent kinase inhibitor p21 and the insulin-like growth factor binding protein 3 in both ER-positive and ER-negative mammary tumors. Our results suggest that Gemini vitamin D analogues may be potent agents for the prevention and treatment of both ER-positive and ER-negative breast cancer without hypercalcemia toxicity.
    Cancer Prevention Research 11/2008; 1(6):476-84. · 4.89 Impact Factor
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    ABSTRACT: The active form of vitamin D(3), 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)], modulates proliferation and induces differentiation of many cancer cells. A new class of analogs of vitamin D(3) has been synthesized, having two side-chains attached to carbon-20 (Gemini) and deuterium substituted on one side-chain. We have examined six of these analogs for their ability to inhibit growth of myeloid leukemia (HL-60), prostate (LNCaP, PC-3, DU145), lung (H520), colon (HT-29), and breast (MCF-7) cancer cell lines. Dose-response clonogenic studies showed that all six analogs had greater antiproliferative activities against cancer cells than 1,25(OH)(2)D(3). Although they had similar potency, the most active of these analogs was BXL-01-0120. BXL-01-0120 was 529-fold more potent than 1,25(OH)(2)D(3) in causing 50% clonal growth inhibition (ED(50)) of HL-60 cells. Pulse-exposure studies demonstrated that exposure to BXL-01-120 (10(-9)M, 48h) resulted in 85% clonal inhibition of HL-60 growth. BXL-01-0120 (10(-11)M, 4 days) induced the differentiation marker, CD11b. Also, morphologically differentiation was more prominent compared to 1,25(OH)(2)D(3). Annexin V assay showed that BXL-01-0120 (10(-10)M, 4 days) induced significantly (p<0.05) more apoptosis than 1,25(OH)(2)D(3). In summary, these analogs have a unique structure resulting in extremely potent inhibition of clonal proliferation of various types of cancer cells, especially HL-60 cells.
    The Journal of Steroid Biochemistry and Molecular Biology 09/2008; 112(1-3):151-6. · 3.98 Impact Factor
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    ABSTRACT: Differentiation of mammalian cells is accompanied by reduced rates of proliferation and an exit from the cell cycle. Human leukemic cells HL60 present a widely used model of neoplastic cell differentiation, and acquire the monocytic phenotype when exposed to analogs of vitamin D3 (VD3). The maturation process is accompanied by two blocks in the cell cycle: an arrest in the G1/G0 phase, and a recently described G2+ M block. In this study we have analyzed the traverse of the cell cycle phases of the well-differentiating HL60-G cells exposed to one of ten analogs of VD3, and compared the cell cycle effects of each compound with its potency as a differentiation-inducing agent. We found that in general there was a good correlation between the effects of these compounds on the cell cycle and on differentiation, but the best cell cycle predictor of differentiation potency was the extent of accumulation of the cells in the G2 compartment. All analogs induced a marked decrease in the mitotic index, and polynucleation of HL60 cells was produced, especially by compounds which were effective as inducers of differentiation. Time course studies showed that induction of differentiation was accompanied by a transient increase of the proportion of cells in the G2+ M compartment, but preceded the G1 to S, and the G2 compartment blocks. These studies indicate that complex changes in the cell cycle traverse accompany, but do not precede, the acquisition of the monocytic phenotype by HL60 cells.
    Cell Proliferation 04/2008; 27(11):643 - 654. · 2.27 Impact Factor

Publication Stats

3k Citations
677.60 Total Impact Points

Institutions

  • 2006–2013
    • Rutgers, The State University of New Jersey
      • Department of Chemical Biology
      Newark, NJ, United States
    • University of Birmingham
      Birmingham, England, United Kingdom
  • 1991–2013
    • Cedars-Sinai Medical Center
      • • Division of Hematology and Oncology
      • • Department of Medicine
      Los Angeles, CA, United States
  • 1990–2010
    • University of California, Riverside
      • Division of Biomedical Sciences
      Riverside, California, United States
  • 1993–2009
    • Rutgers New Jersey Medical School
      • Department of Pathology and Laboratory Medicine
      Newark, NJ, United States
  • 2008
    • University of Leeds
      Leeds, England, United Kingdom
  • 2005–2007
    • Boston University
      • • Department of Physiology and Biophysics
      • • Department of Medicine
      Boston, MA, United States
    • Washington University in St. Louis
      San Luis, Missouri, United States
  • 1999–2006
    • Brown University
      • • School of Engineering
      • • Department of Chemistry
      Providence, Rhode Island, United States
  • 2004–2005
    • Roche
      Bâle, Basel-City, Switzerland
  • 2003–2004
    • Queen Elizabeth Hospital Birmingham
      Birmingham, England, United Kingdom
  • 1990–2002
    • University of California, Los Angeles
      • • Division of Hematology and Medical Oncology
      • • Department of Medicine
      Los Angeles, California, United States
  • 2001
    • Shinshu University
      • Department of Pediatrics
      Shonai, Nagano, Japan
  • 1992–2001
    • Alpert Medical School - Brown University
      Providence, Rhode Island, United States
    • Wayne State University
      • Department of Chemistry
      Detroit, Michigan, United States
  • 2000
    • University of Michigan
      Ann Arbor, Michigan, United States
  • 1996
    • American University Washington D.C.
      Washington, Washington, D.C., United States
  • 1994
    • Dong-Pusan College
      Tsau-liang-hai, Busan, South Korea
  • 1987
    • Iowa State University
      • Department of Animal Science
      Ames, IA, United States