The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Donald Poirier - One of the best experts on this subject based on the ideXlab platform.
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targeting cytochrome p450 cyp 1b1 enzyme with four series of a ring substituted Estrane derivatives design synthesis inhibitory activity and selectivity
Journal of Medicinal Chemistry, 2018Co-Authors: Raphael Dutour, René Maltais, Francisco Cortesbenitez, Donald PoirierAbstract:Cytochrome P450 (CYP) 1B1 is involved in the bioactivation of procarcinogens and drug resistance. To obtain selective CYP1B1 inhibitors over CYP1A1, we synthesized four series of Estrane derivatives: (1) 12 estrone (E1)- and 17β-estradiol (E2)-derivatives bearing a 3- or a 4-pyridinyl core at C2, C3, or C4, (2) eight Estrane derivatives with different sulfur groups at C3, (3) 19 E1- and E2-derivatives bearing distinct aryls at C2, and (4) five D-ring derivatives. E2-derivatives were more active than oxidized E1-analogues, thus highlighting the key role of 17β-OH for interaction with CYP1B1. 2-(4-Fluorophenyl)-E2 was the best CYP1B1 inhibitor (IC50 = 0.24 μM), with a selectivity index (SI) of 20 over CYP1A1. Furthermore, the addition of a C17α-ethynyl group as D-ring modification improved the selectivity index to 25 with only a slight loss of activity (IC50 = 0.37 μM). Our docking results showed that these compounds fit better into the CYP1B1 binding site than that of CYP1A1.
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Targeting Cytochrome P450 (CYP) 1B1 Enzyme with Four Series of A‑Ring Substituted Estrane Derivatives: Design, Synthesis, Inhibitory Activity, and Selectivity
2018Co-Authors: Raphael Dutour, René Maltais, Jenny Roy, Francisco Cortés-benítez, Donald PoirierAbstract:Cytochrome P450 (CYP) 1B1 is involved in the bioactivation of procarcinogens and drug resistance. To obtain selective CYP1B1 inhibitors over CYP1A1, we synthesized four series of Estrane derivatives: (1) 12 estrone (E1)- and 17β-estradiol (E2)-derivatives bearing a 3- or a 4-pyridinyl core at C2, C3, or C4, (2) eight Estrane derivatives with different sulfur groups at C3, (3) 19 E1- and E2-derivatives bearing distinct aryls at C2, and (4) five D-ring derivatives. E2-derivatives were more active than oxidized E1-analogues, thus highlighting the key role of 17β-OH for interaction with CYP1B1. 2-(4-Fluorophenyl)-E2 was the best CYP1B1 inhibitor (IC50 = 0.24 μM), with a selectivity index (SI) of 20 over CYP1A1. Furthermore, the addition of a C17α-ethynyl group as D-ring modification improved the selectivity index to 25 with only a slight loss of activity (IC50 = 0.37 μM). Our docking results showed that these compounds fit better into the CYP1B1 binding site than that of CYP1A1
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design of a mestranol 2 n piperazino substituted derivative showing potent and selective in vitro and in vivo activities in mcf 7 breast cancer models
ChemMedChem, 2017Co-Authors: Martin Perreault, René Maltais, Raphael Dutour, Jenny Roy, Donald PoirierAbstract:Anticancer structure–activity relationship studies on aminosteroid (5α-androstane) derivatives have emerged with a promising lead candidate: RM-133 (2β-[1-(quinoline-2-carbonyl)pyrrolidine-2-carbonyl]-N-piperazine-5α-androstane-3α,17β-diol), which possesses high in vitro and in vivo activities against several cancer cells, and selectivity over normal cells. However, the relatively weak metabolic stability of RM-133 has been a drawback to its progression toward clinical trials. We investigated the replacement of the androstane backbone by a more stable mestranol moiety. The resulting compound, called RM-581 ({4-[17α-ethynyl-17β-hydroxy-3-methoxyestra-1,3,5(10)-trien-2-yl]piperazin-1-yl}[(2S)-1-(quinolin-2-ylcarbonyl)pyrrolidin-2-yl]methanone), was synthesized efficiently in only five steps from commercially available estrone. In comparison with RM-133, RM-581 was found to be twice as metabolically stable, retains potent cytotoxic activity in breast cancer MCF-7 cell culture, and fully blocks tumor growth in a mouse xenograft model of breast cancer. Advantageously, the selectivity over normal cells has been increased with this Estrane version of RM-133. In fact, RM-581 showed a better selectivity index (15.3 vs. 3.0) for breast cancer MCF-7 cells over normal breast MCF-10A cells, and was found to be nontoxic toward primary human kidney proximal tubule cells at doses reaching 50 μm.
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synthesis and steroid sulphatase inhibitory activity of c19 and c21 steroidal derivatives bearing a benzyl inhibiting group
European Journal of Medicinal Chemistry, 2001Co-Authors: Liviu C Ciobanu, Roch P Boivin, Van Luuthe, Donald PoirierAbstract:Abstract Two series of compounds, benzyl alkylated at position 17α and 20 of androstane and pregnane, respectively, were synthesised and tested for steroid sulphatase inhibition. We compared the ability of the compounds to inhibit steroid sulphatase obtained from two different sources (homogenates of transfected HEK-293 cells and Jeg-3 cells) and with two types of substrate (DHEAS or E 1 S). The inhibitory activity of 17α-benzyl-5α-androstane-3β,17β-diol ( 7 ), 17α-benzyl-5-androstene-3β,17β-diol ( 9 ), 17α-benzyl-4,17β-dihydroxy-4-androsten-3-one ( 15 ) and 20-benzyl-5-pregnene-3β,20α-diol ( 16 ) has proven to be superior to that of danazol, the first steroid sulphatase inhibitor to be reported, but still lower than that of the potent inhibitor estrone-3- O -sulphamate. The inhibitory activity of compound 7 was as potent as that of its previously reported Estrane analogue, 17α-benzyl estradiol. Benzyl alkylated compounds with no OH group on the A-ring (with a 4-OCH 3 , 4-Cl, or 4-H and their precursor epoxides), as well as a series of basic steroids without a benzyl group (ADT, epi-ADT, 3α-diol, 3β-diol, DHEA, Δ 5 -diol, DHT, T, Preg and Prog), did not show steroid sulphatase inhibition. We have thus demonstrated that the steroid sulphatase inhibitory effect of a benzyl group, previously observed for an Estrane nucleus, can be extended to certain androstane and pregnane nuclei bearing a 3β-OH or a 4-OH group. Inhibitors 7 , 9 , 15 and 16 did not induce any proliferative effect on androgen-sensitive Shionogi cells. However, when tested on oestrogen-sensitive ZR-75-1 cells, a proliferative effect was observed for 7 and 9 , but not for 15 and 16 .
Ikumi Tamai - One of the best experts on this subject based on the ideXlab platform.
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predominant contribution of organic anion transporting polypeptide oatp b oatp2b1 to apical uptake of estrone 3 sulfate by human intestinal caco 2 cells
Drug Metabolism and Disposition, 2006Co-Authors: Yoshimichi Sai, Ikumi Tamai, Yosuke Kaneko, Satsuki Ito, Keisuke Mitsuoka, Yukio Kato, Per Artursson, Akira TsujiAbstract:Human organic anion transporting polypeptide OATP-B (OATP2B1) is a pH-sensitive transporter expressed in the apical membranes of small intestinal epithelial cells. In this study, we have examined the contribution of OATP-B to the uptake of [3H]estrone-3-sulfate in Caco-2 cells in comparison with those of its homologs OATP-D (OATP3A1) and OATP-E (OATP4A1). Immunocytochemical study revealed that OATP-B is expressed in the apical membranes of Caco-2 cells. The uptake of [3H]estrone-3-sulfate by Caco-2 cells was Na+-independent and inhibited by several organic anions. It showed biphasic saturation kinetics with Km values of 1.81 microM and 1.40 mM. The uptake of [3H]estrone-3-sulfate by human embryonic kidney (HEK) 293 cells stably expressing OATP-B (HEK293/OATP-B) was also Na+-independent and inhibited by several organic anions. The Km value for estrone-3-sulfate uptake by OATP-B (1.56 microM) was close to that for the high-affinity component observed in Caco-2 cells. The mRNA expression level of OATP-B was higher than that of OATP-D or OATP-E in Caco-2 cells and in human jejunum biopsies from healthy volunteers. The values of [3H]estrone-3-sulfate uptake normalized to OATP-B mRNA expression were similar in Caco-2 cells and HEK293/OATP-B cells. The specific activity of OATP-B per mRNA expression was much higher than that of OATP-D and OATP-E. [3H]Estrone-3-sulfate uptake by membrane vesicles prepared from HEK293/OATP-B cells exhibited an overshoot phenomenon in the presence of an inwardly directed H+ gradient, suggesting that an H+ gradient is the driving force of estrone-3-sulfate transport by OATP-B. These results suggest that OATP-B is predominantly responsible for the apical uptake of estrone-3-sulfate in Caco-2 cells.
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suppression of cell proliferation by inhibition of estrone 3 sulfate transporter in estrogen dependent breast cancer cells
Pharmaceutical Research, 2005Co-Authors: Takashi Nozawa, Masato Suzuki, Hikaru Yabuuchi, Masanori Irokawa, Akira Tsuji, Ikumi TamaiAbstract:Purpose. The aim of the study is to suppress the progress of estrogen-dependent breast cancer by inhibiting the membrane transporter, which mediates the internalization of estrone-3-sulfate as estrogen precursor in the cancer cells. Methods. The uptake of estrone-3-sulfate by estrogen-dependent breast cancer MCF-7 cells was measured, and inhibitory study using various organic anions on estrone-3-sulfate uptake by MCF-7 cells was conducted. The effects of the inhibitor on the transcription of reporter gene and cell proliferation induced by estrone-3-sulfate were examined. Results. The uptake of estrone-3-sulfate by MCF-7 cells was saturable with Km value of 2.32 2M. The uptake was Na + -independent and was inhibited by several anionic compounds such as bromosulfophthalein. Bromosulfophthalein also significantly inhibited the transcription of reporter gene via estrogen response element and cell proliferation induced by estrone-3-sulfate. However, the transcriptional activation or cell proliferation induced by estrone was not inhibited by bromosulfophthalein. Reverse transcriptionY polymerase chain reaction analysis revealed the expression of mRNA of organic anion transporting polypeptide (OATP)-D and OATP-E as possible candidates to transport estrone-3-sulfate. Conclusions. The uptake of estrone-3-sulfate is mediated by Na + -independent transporter(s). Inhibitor of estrone-3-sulfate transporter suppressed the transcription and cell proliferation induced by estrone-3sulfate in MCF-7 cells. The results provide the basis of a novel strategy for breast cancer treatment by focusing on the transporter responsible for the uptake of estrone-3-sulfate.
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suppression of cell proliferation by inhibition of estrone 3 sulfate transporter in estrogen dependent breast cancer cells
Pharmaceutical Research, 2005Co-Authors: Takashi Nozawa, Masato Suzuki, Hikaru Yabuuchi, Masanori Irokawa, Akira Tsuji, Ikumi TamaiAbstract:The aim of the study is to suppress the progress of estrogen-dependent breast cancer by inhibiting the membrane transporter, which mediates the internalization of estrone-3-sulfate as estrogen precursor in the cancer cells. The uptake of estrone-3-sulfate by estrogen-dependent breast cancer MCF-7 cells was measured, and inhibitory study using various organic anions on estrone-3-sulfate uptake by MCF-7 cells was conducted. The effects of the inhibitor on the transcription of reporter gene and cell proliferation induced by estrone-3-sulfate were examined. The uptake of estrone-3-sulfate by MCF-7 cells was saturable with Km value of 2.32 μM. The uptake was Na+-independent and was inhibited by several anionic compounds such as bromosulfophthalein. Bromosulfophthalein also significantly inhibited the transcription of reporter gene via estrogen response element and cell proliferation induced by estrone-3-sulfate. However, the transcriptional activation or cell proliferation induced by estrone was not inhibited by bromosulfophthalein. Reverse transcription–polymerase chain reaction analysis revealed the expression of mRNA of organic anion transporting polypeptide (OATP)-D and OATP-E as possible candidates to transport estrone-3-sulfate. The uptake of estrone-3-sulfate is mediated by Na+-independent transporter(s). Inhibitor of estrone-3-sulfate transporter suppressed the transcription and cell proliferation induced by estrone-3-sulfate in MCF-7 cells. The results provide the basis of a novel strategy for breast cancer treatment by focusing on the transporter responsible for the uptake of estrone-3-sulfate.
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involvement of estrone 3 sulfate transporters in proliferation of hormone dependent breast cancer cells
Journal of Pharmacology and Experimental Therapeutics, 2004Co-Authors: Takashi Nozawa, Masato Suzuki, Hikaru Yabuuchi, Akira Tsuji, Koichi Takahashi, Tomoji Maeda, Ikumi TamaiAbstract:Although circulating estrone-3-sulfate is a major precursor of biologically active estrogen, permeation across the plasma membrane is unlikely to occur by diffusion because of the high hydrophilicity of the molecule. The object of this study was to clarify the involvement of specific transporter(s) in the supply of estrone-3-sulfate to human breast cancer-derived T-47D cells, which grow in an estrogen-dependent manner. The proliferation of T-47D cells was increased by the addition of estrone-3-sulfate, or estradiol, to the cultivation medium. The initial uptake rate of estrone-3-sulfate kinetically exhibited a single saturable component, with Km and Vmax values of 7.6 microM and 172 pmol/mg of protein/min, respectively. The replacement of extracellular Na+ with Li+, K+, or N-methylglucamine+ had no effect on the uptake of [3H]estrone-3-sulfate. The uptake was strongly inhibited by sulfate conjugates of steroid hormones, but not by estradiol-17beta-glucuronide. Taurocholate and sulfobromophthalein inhibited the uptake, whereas other tested anionic and cationic compounds did not. The expression of organic anion transporting polypeptides, OATP-D and OATP-E, which are candidate transporters of estrone-3-sulfate, was detected by reverse transcription-polymerase chain reaction analysis, although their actual involvement in the uptake of estrogen remains to be clarified. In conclusion, the uptake of estrone-3-sulfate by T-47D cells was mediated by a carrier-mediated transport mechanism, suggesting that the estrogen precursor is actively imported by estrogen-dependent breast cancer cells.
Takashi Nozawa - One of the best experts on this subject based on the ideXlab platform.
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suppression of cell proliferation by inhibition of estrone 3 sulfate transporter in estrogen dependent breast cancer cells
Pharmaceutical Research, 2005Co-Authors: Takashi Nozawa, Masato Suzuki, Hikaru Yabuuchi, Masanori Irokawa, Akira Tsuji, Ikumi TamaiAbstract:Purpose. The aim of the study is to suppress the progress of estrogen-dependent breast cancer by inhibiting the membrane transporter, which mediates the internalization of estrone-3-sulfate as estrogen precursor in the cancer cells. Methods. The uptake of estrone-3-sulfate by estrogen-dependent breast cancer MCF-7 cells was measured, and inhibitory study using various organic anions on estrone-3-sulfate uptake by MCF-7 cells was conducted. The effects of the inhibitor on the transcription of reporter gene and cell proliferation induced by estrone-3-sulfate were examined. Results. The uptake of estrone-3-sulfate by MCF-7 cells was saturable with Km value of 2.32 2M. The uptake was Na + -independent and was inhibited by several anionic compounds such as bromosulfophthalein. Bromosulfophthalein also significantly inhibited the transcription of reporter gene via estrogen response element and cell proliferation induced by estrone-3-sulfate. However, the transcriptional activation or cell proliferation induced by estrone was not inhibited by bromosulfophthalein. Reverse transcriptionY polymerase chain reaction analysis revealed the expression of mRNA of organic anion transporting polypeptide (OATP)-D and OATP-E as possible candidates to transport estrone-3-sulfate. Conclusions. The uptake of estrone-3-sulfate is mediated by Na + -independent transporter(s). Inhibitor of estrone-3-sulfate transporter suppressed the transcription and cell proliferation induced by estrone-3sulfate in MCF-7 cells. The results provide the basis of a novel strategy for breast cancer treatment by focusing on the transporter responsible for the uptake of estrone-3-sulfate.
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suppression of cell proliferation by inhibition of estrone 3 sulfate transporter in estrogen dependent breast cancer cells
Pharmaceutical Research, 2005Co-Authors: Takashi Nozawa, Masato Suzuki, Hikaru Yabuuchi, Masanori Irokawa, Akira Tsuji, Ikumi TamaiAbstract:The aim of the study is to suppress the progress of estrogen-dependent breast cancer by inhibiting the membrane transporter, which mediates the internalization of estrone-3-sulfate as estrogen precursor in the cancer cells. The uptake of estrone-3-sulfate by estrogen-dependent breast cancer MCF-7 cells was measured, and inhibitory study using various organic anions on estrone-3-sulfate uptake by MCF-7 cells was conducted. The effects of the inhibitor on the transcription of reporter gene and cell proliferation induced by estrone-3-sulfate were examined. The uptake of estrone-3-sulfate by MCF-7 cells was saturable with Km value of 2.32 μM. The uptake was Na+-independent and was inhibited by several anionic compounds such as bromosulfophthalein. Bromosulfophthalein also significantly inhibited the transcription of reporter gene via estrogen response element and cell proliferation induced by estrone-3-sulfate. However, the transcriptional activation or cell proliferation induced by estrone was not inhibited by bromosulfophthalein. Reverse transcription–polymerase chain reaction analysis revealed the expression of mRNA of organic anion transporting polypeptide (OATP)-D and OATP-E as possible candidates to transport estrone-3-sulfate. The uptake of estrone-3-sulfate is mediated by Na+-independent transporter(s). Inhibitor of estrone-3-sulfate transporter suppressed the transcription and cell proliferation induced by estrone-3-sulfate in MCF-7 cells. The results provide the basis of a novel strategy for breast cancer treatment by focusing on the transporter responsible for the uptake of estrone-3-sulfate.
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involvement of estrone 3 sulfate transporters in proliferation of hormone dependent breast cancer cells
Journal of Pharmacology and Experimental Therapeutics, 2004Co-Authors: Takashi Nozawa, Masato Suzuki, Hikaru Yabuuchi, Akira Tsuji, Koichi Takahashi, Tomoji Maeda, Ikumi TamaiAbstract:Although circulating estrone-3-sulfate is a major precursor of biologically active estrogen, permeation across the plasma membrane is unlikely to occur by diffusion because of the high hydrophilicity of the molecule. The object of this study was to clarify the involvement of specific transporter(s) in the supply of estrone-3-sulfate to human breast cancer-derived T-47D cells, which grow in an estrogen-dependent manner. The proliferation of T-47D cells was increased by the addition of estrone-3-sulfate, or estradiol, to the cultivation medium. The initial uptake rate of estrone-3-sulfate kinetically exhibited a single saturable component, with Km and Vmax values of 7.6 microM and 172 pmol/mg of protein/min, respectively. The replacement of extracellular Na+ with Li+, K+, or N-methylglucamine+ had no effect on the uptake of [3H]estrone-3-sulfate. The uptake was strongly inhibited by sulfate conjugates of steroid hormones, but not by estradiol-17beta-glucuronide. Taurocholate and sulfobromophthalein inhibited the uptake, whereas other tested anionic and cationic compounds did not. The expression of organic anion transporting polypeptides, OATP-D and OATP-E, which are candidate transporters of estrone-3-sulfate, was detected by reverse transcription-polymerase chain reaction analysis, although their actual involvement in the uptake of estrogen remains to be clarified. In conclusion, the uptake of estrone-3-sulfate by T-47D cells was mediated by a carrier-mediated transport mechanism, suggesting that the estrogen precursor is actively imported by estrogen-dependent breast cancer cells.
Raphael Dutour - One of the best experts on this subject based on the ideXlab platform.
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targeting cytochrome p450 cyp 1b1 enzyme with four series of a ring substituted Estrane derivatives design synthesis inhibitory activity and selectivity
Journal of Medicinal Chemistry, 2018Co-Authors: Raphael Dutour, René Maltais, Francisco Cortesbenitez, Donald PoirierAbstract:Cytochrome P450 (CYP) 1B1 is involved in the bioactivation of procarcinogens and drug resistance. To obtain selective CYP1B1 inhibitors over CYP1A1, we synthesized four series of Estrane derivatives: (1) 12 estrone (E1)- and 17β-estradiol (E2)-derivatives bearing a 3- or a 4-pyridinyl core at C2, C3, or C4, (2) eight Estrane derivatives with different sulfur groups at C3, (3) 19 E1- and E2-derivatives bearing distinct aryls at C2, and (4) five D-ring derivatives. E2-derivatives were more active than oxidized E1-analogues, thus highlighting the key role of 17β-OH for interaction with CYP1B1. 2-(4-Fluorophenyl)-E2 was the best CYP1B1 inhibitor (IC50 = 0.24 μM), with a selectivity index (SI) of 20 over CYP1A1. Furthermore, the addition of a C17α-ethynyl group as D-ring modification improved the selectivity index to 25 with only a slight loss of activity (IC50 = 0.37 μM). Our docking results showed that these compounds fit better into the CYP1B1 binding site than that of CYP1A1.
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Targeting Cytochrome P450 (CYP) 1B1 Enzyme with Four Series of A‑Ring Substituted Estrane Derivatives: Design, Synthesis, Inhibitory Activity, and Selectivity
2018Co-Authors: Raphael Dutour, René Maltais, Jenny Roy, Francisco Cortés-benítez, Donald PoirierAbstract:Cytochrome P450 (CYP) 1B1 is involved in the bioactivation of procarcinogens and drug resistance. To obtain selective CYP1B1 inhibitors over CYP1A1, we synthesized four series of Estrane derivatives: (1) 12 estrone (E1)- and 17β-estradiol (E2)-derivatives bearing a 3- or a 4-pyridinyl core at C2, C3, or C4, (2) eight Estrane derivatives with different sulfur groups at C3, (3) 19 E1- and E2-derivatives bearing distinct aryls at C2, and (4) five D-ring derivatives. E2-derivatives were more active than oxidized E1-analogues, thus highlighting the key role of 17β-OH for interaction with CYP1B1. 2-(4-Fluorophenyl)-E2 was the best CYP1B1 inhibitor (IC50 = 0.24 μM), with a selectivity index (SI) of 20 over CYP1A1. Furthermore, the addition of a C17α-ethynyl group as D-ring modification improved the selectivity index to 25 with only a slight loss of activity (IC50 = 0.37 μM). Our docking results showed that these compounds fit better into the CYP1B1 binding site than that of CYP1A1
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design of a mestranol 2 n piperazino substituted derivative showing potent and selective in vitro and in vivo activities in mcf 7 breast cancer models
ChemMedChem, 2017Co-Authors: Martin Perreault, René Maltais, Raphael Dutour, Jenny Roy, Donald PoirierAbstract:Anticancer structure–activity relationship studies on aminosteroid (5α-androstane) derivatives have emerged with a promising lead candidate: RM-133 (2β-[1-(quinoline-2-carbonyl)pyrrolidine-2-carbonyl]-N-piperazine-5α-androstane-3α,17β-diol), which possesses high in vitro and in vivo activities against several cancer cells, and selectivity over normal cells. However, the relatively weak metabolic stability of RM-133 has been a drawback to its progression toward clinical trials. We investigated the replacement of the androstane backbone by a more stable mestranol moiety. The resulting compound, called RM-581 ({4-[17α-ethynyl-17β-hydroxy-3-methoxyestra-1,3,5(10)-trien-2-yl]piperazin-1-yl}[(2S)-1-(quinolin-2-ylcarbonyl)pyrrolidin-2-yl]methanone), was synthesized efficiently in only five steps from commercially available estrone. In comparison with RM-133, RM-581 was found to be twice as metabolically stable, retains potent cytotoxic activity in breast cancer MCF-7 cell culture, and fully blocks tumor growth in a mouse xenograft model of breast cancer. Advantageously, the selectivity over normal cells has been increased with this Estrane version of RM-133. In fact, RM-581 showed a better selectivity index (15.3 vs. 3.0) for breast cancer MCF-7 cells over normal breast MCF-10A cells, and was found to be nontoxic toward primary human kidney proximal tubule cells at doses reaching 50 μm.
Akira Tsuji - One of the best experts on this subject based on the ideXlab platform.
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predominant contribution of organic anion transporting polypeptide oatp b oatp2b1 to apical uptake of estrone 3 sulfate by human intestinal caco 2 cells
Drug Metabolism and Disposition, 2006Co-Authors: Yoshimichi Sai, Ikumi Tamai, Yosuke Kaneko, Satsuki Ito, Keisuke Mitsuoka, Yukio Kato, Per Artursson, Akira TsujiAbstract:Human organic anion transporting polypeptide OATP-B (OATP2B1) is a pH-sensitive transporter expressed in the apical membranes of small intestinal epithelial cells. In this study, we have examined the contribution of OATP-B to the uptake of [3H]estrone-3-sulfate in Caco-2 cells in comparison with those of its homologs OATP-D (OATP3A1) and OATP-E (OATP4A1). Immunocytochemical study revealed that OATP-B is expressed in the apical membranes of Caco-2 cells. The uptake of [3H]estrone-3-sulfate by Caco-2 cells was Na+-independent and inhibited by several organic anions. It showed biphasic saturation kinetics with Km values of 1.81 microM and 1.40 mM. The uptake of [3H]estrone-3-sulfate by human embryonic kidney (HEK) 293 cells stably expressing OATP-B (HEK293/OATP-B) was also Na+-independent and inhibited by several organic anions. The Km value for estrone-3-sulfate uptake by OATP-B (1.56 microM) was close to that for the high-affinity component observed in Caco-2 cells. The mRNA expression level of OATP-B was higher than that of OATP-D or OATP-E in Caco-2 cells and in human jejunum biopsies from healthy volunteers. The values of [3H]estrone-3-sulfate uptake normalized to OATP-B mRNA expression were similar in Caco-2 cells and HEK293/OATP-B cells. The specific activity of OATP-B per mRNA expression was much higher than that of OATP-D and OATP-E. [3H]Estrone-3-sulfate uptake by membrane vesicles prepared from HEK293/OATP-B cells exhibited an overshoot phenomenon in the presence of an inwardly directed H+ gradient, suggesting that an H+ gradient is the driving force of estrone-3-sulfate transport by OATP-B. These results suggest that OATP-B is predominantly responsible for the apical uptake of estrone-3-sulfate in Caco-2 cells.
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suppression of cell proliferation by inhibition of estrone 3 sulfate transporter in estrogen dependent breast cancer cells
Pharmaceutical Research, 2005Co-Authors: Takashi Nozawa, Masato Suzuki, Hikaru Yabuuchi, Masanori Irokawa, Akira Tsuji, Ikumi TamaiAbstract:Purpose. The aim of the study is to suppress the progress of estrogen-dependent breast cancer by inhibiting the membrane transporter, which mediates the internalization of estrone-3-sulfate as estrogen precursor in the cancer cells. Methods. The uptake of estrone-3-sulfate by estrogen-dependent breast cancer MCF-7 cells was measured, and inhibitory study using various organic anions on estrone-3-sulfate uptake by MCF-7 cells was conducted. The effects of the inhibitor on the transcription of reporter gene and cell proliferation induced by estrone-3-sulfate were examined. Results. The uptake of estrone-3-sulfate by MCF-7 cells was saturable with Km value of 2.32 2M. The uptake was Na + -independent and was inhibited by several anionic compounds such as bromosulfophthalein. Bromosulfophthalein also significantly inhibited the transcription of reporter gene via estrogen response element and cell proliferation induced by estrone-3-sulfate. However, the transcriptional activation or cell proliferation induced by estrone was not inhibited by bromosulfophthalein. Reverse transcriptionY polymerase chain reaction analysis revealed the expression of mRNA of organic anion transporting polypeptide (OATP)-D and OATP-E as possible candidates to transport estrone-3-sulfate. Conclusions. The uptake of estrone-3-sulfate is mediated by Na + -independent transporter(s). Inhibitor of estrone-3-sulfate transporter suppressed the transcription and cell proliferation induced by estrone-3sulfate in MCF-7 cells. The results provide the basis of a novel strategy for breast cancer treatment by focusing on the transporter responsible for the uptake of estrone-3-sulfate.
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suppression of cell proliferation by inhibition of estrone 3 sulfate transporter in estrogen dependent breast cancer cells
Pharmaceutical Research, 2005Co-Authors: Takashi Nozawa, Masato Suzuki, Hikaru Yabuuchi, Masanori Irokawa, Akira Tsuji, Ikumi TamaiAbstract:The aim of the study is to suppress the progress of estrogen-dependent breast cancer by inhibiting the membrane transporter, which mediates the internalization of estrone-3-sulfate as estrogen precursor in the cancer cells. The uptake of estrone-3-sulfate by estrogen-dependent breast cancer MCF-7 cells was measured, and inhibitory study using various organic anions on estrone-3-sulfate uptake by MCF-7 cells was conducted. The effects of the inhibitor on the transcription of reporter gene and cell proliferation induced by estrone-3-sulfate were examined. The uptake of estrone-3-sulfate by MCF-7 cells was saturable with Km value of 2.32 μM. The uptake was Na+-independent and was inhibited by several anionic compounds such as bromosulfophthalein. Bromosulfophthalein also significantly inhibited the transcription of reporter gene via estrogen response element and cell proliferation induced by estrone-3-sulfate. However, the transcriptional activation or cell proliferation induced by estrone was not inhibited by bromosulfophthalein. Reverse transcription–polymerase chain reaction analysis revealed the expression of mRNA of organic anion transporting polypeptide (OATP)-D and OATP-E as possible candidates to transport estrone-3-sulfate. The uptake of estrone-3-sulfate is mediated by Na+-independent transporter(s). Inhibitor of estrone-3-sulfate transporter suppressed the transcription and cell proliferation induced by estrone-3-sulfate in MCF-7 cells. The results provide the basis of a novel strategy for breast cancer treatment by focusing on the transporter responsible for the uptake of estrone-3-sulfate.
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involvement of estrone 3 sulfate transporters in proliferation of hormone dependent breast cancer cells
Journal of Pharmacology and Experimental Therapeutics, 2004Co-Authors: Takashi Nozawa, Masato Suzuki, Hikaru Yabuuchi, Akira Tsuji, Koichi Takahashi, Tomoji Maeda, Ikumi TamaiAbstract:Although circulating estrone-3-sulfate is a major precursor of biologically active estrogen, permeation across the plasma membrane is unlikely to occur by diffusion because of the high hydrophilicity of the molecule. The object of this study was to clarify the involvement of specific transporter(s) in the supply of estrone-3-sulfate to human breast cancer-derived T-47D cells, which grow in an estrogen-dependent manner. The proliferation of T-47D cells was increased by the addition of estrone-3-sulfate, or estradiol, to the cultivation medium. The initial uptake rate of estrone-3-sulfate kinetically exhibited a single saturable component, with Km and Vmax values of 7.6 microM and 172 pmol/mg of protein/min, respectively. The replacement of extracellular Na+ with Li+, K+, or N-methylglucamine+ had no effect on the uptake of [3H]estrone-3-sulfate. The uptake was strongly inhibited by sulfate conjugates of steroid hormones, but not by estradiol-17beta-glucuronide. Taurocholate and sulfobromophthalein inhibited the uptake, whereas other tested anionic and cationic compounds did not. The expression of organic anion transporting polypeptides, OATP-D and OATP-E, which are candidate transporters of estrone-3-sulfate, was detected by reverse transcription-polymerase chain reaction analysis, although their actual involvement in the uptake of estrogen remains to be clarified. In conclusion, the uptake of estrone-3-sulfate by T-47D cells was mediated by a carrier-mediated transport mechanism, suggesting that the estrogen precursor is actively imported by estrogen-dependent breast cancer cells.