Jenny Roy

Comparison of the effects of EM-652 (SCH57068), tamoxifen, toremifene, droloxifene, idoxifene, GW-5638 and raloxifene on the growth of human ZR-75-1 breast tumors in nude mice.

EM‐652 exerts pure antiestrogenic activity in the mammary gland and endometrium, while tamoxifen, the antiestrogen most widely used for the treatment of breast cancer, exerts mixed antiestrogenic–estrogenic activity in these tissues. Our objective was to compare the agonistic and antagonistic effects of EM‐652 with tamoxifen and 5 other antiestrogens on the growth of ZR‐75‐1 human breast xenografts in ovariectomized nude mice. During the 23 weeks of treatment at a daily oral dose of 50 μg, EM‐652 was the only compound that decreased tumor size relative to pretreatment values, whereas the 6 other antiestrogens only decreased to various extents the progression rate stimulated by estrone. Under estrone stimulation, all groups of animals had more than 60% of their tumors in the progression category except for the EM‐652–treated group, where only 7% of the tumors progressed. In the absence of estrone stimulation, progression was seen in 60%, 33%, 21% and 12% of tumors in the tamoxifen‐, idoxifene‐, toremifene‐ and raloxifene‐treated groups, respectively, while only 4% of tumors progressed in the EM‐652–treated group. The agonistic and antagonistic actions of each antiestrogen were also measured on endometrial epithelial cell thickness. Our present findings indicate that EM‐652, in addition to being the most potent antiestrogen on human breast tumor growth, has no agonistic effect in breast and endometrial tissues. Since previous data have shown benefits of EM‐652 on bone density and lipid profile, this compound could be an ideal candidate for chemoprevention of breast and uterine cancers, while protecting against osteoporosis and cardiovascular disease.

Copper(II) and uranyl(II) complexes with acylthiosemicarbazide: synthesis, characterization, antibacterial activity and effects on the growth of promyelocytic leukemia cells HL-60.

New chelates of N(1)-[4-(4-X-phenylsulfonyl)benzoyl]-N(4)-butyl-thiosemicarbazide (X=H, Cl, Br) with Cu(2+) and UO(2)(2+) have been prepared and characterized by analytical and physico-chemical techniques such as magnetic susceptibility measurements, elemental and thermal analyses, electronic, ESR and IR spectral studies. Room temperature ESR spectra of Cu(II) complexes yield {g} values characteristic of distorted octahedral and pseudo-tetrahedral geometry. Infrared spectra indicate that complexes contain six-coordinate uranium atom with the ligand atoms arranged in an equatorial plane around the linear uranyl group. Effects of these complexes on the growth of human promyelocytic leukemia cells HL-60 and their antibacterial activity (against Staphylococcus epidermidis ATCC 14990, Bacillus subtilis ATCC 6633, Bacillus cereus ATCC 14579, Pseudomonas aeruginosa ATCC 9027 and Escherichia coli ATCC 11775 strains) were studied comparatively with that of free ligands.

Impact of estradiol structural modifications (18-methyl and/or 17-hydroxy inversion of configuration) on the in vitro and in vivo estrogenic activity

It is well recognized that the majority of breast cancers are initially hormone-dependent and that 17β-estradiol (17β-E2) plays a crucial role in their development and progression. For this reason, using a compound able to block a specific enzyme involved in the last steps of the biosynthesis of 17β-E2 remains a rational way to treat estrogen-dependent diseases such as breast cancer. The present study describes the biological in vitro and in vivo evaluation of a structural modification (inversion of C18-methyl group at position 13 from β to α face) of 17β-E2 (1) and 17α-estradiol (17α-E2; 2). The two epimers 18-epi-17β-E2 (3) and 18-epi-17α-E2 (4) were obtained in two chemical steps by inversion of the C18-methyl of estrone using 1,2-phenylendiamine in refluxing acetic acid and reduction of ketone at position C17 with LiAlH(4). The new E2 isomers were tested on estrogen-sensitive cell lines (MCF-7 and T-47D), on estrogen-sensitive tissues (uterus and vagina of mice) and on estrogen receptor (ER) to determine their estrogenic potency relatively to natural estrogen 17β-E2 (1). The results show that 18-epi-17β-E2 (3) possesses the lower affinity for ER (RBA = 1.2%), the lower estrogenicity on estrogen-sensitive cells (1000 folds less estrogenic than 17β-E2 in MCF-7) and no uterotrophic (estrogenic) activity when tested on mice. In fact, we observed the following order of estrogenicity: 18-epi-17β-E2 (3)<18-epi-17α-E2 (4) << 17α-E2 (2)17β-E2 (1). These results suggest that the inversion of C18-methyl of natural 17β-E2 scaffold could be a useful strategy to decrease the estrogenicity of E2 derivatives used as enzyme inhibitors in the context of a treatment of estrogen-dependent diseases.

A New Nonestrogenic Steroidal Inhibitor of 17β-Hydroxysteroid Dehydrogenase Type I Blocks the Estrogen-Dependent Breast Cancer Tumor Growth Induced by Estrone

17β-Hydroxysteroid dehydrogenase type 1 (17β-HSD1) converts estrone (E1) into estradiol (E2) and is expressed in many steroidogenic tissues and breast cancer cell lines. Because the potent estrogen E2 stimulates the growth and development of hormone-dependent diseases, inhibition of the final step of E2 synthesis is considered a promising strategy for the treatment of breast cancer. On the basis of our previous study identifying 16β-(m-carbamoylbenzyl)-E2 (CC-156) as a lead compound for the inhibition of 17β-HSD1, we conducted a number of structural modifications to reduce its undesired residual estrogenic activity. The steroid derivative PBRM [3-(2-bromoethyl)-16β-(m-carbamoylbenzyl)-17β-hydroxy-1,3,5(10)-estratriene] emerged as a potent inhibitor of 17β-HSD1 with an IC50 value of 68 nmol/L for the transformation of E1 into E2. When tested in the estrogen-sensitive breast cancer cell line T-47D and in mice, PBRM showed no estrogenic activity in the range of concentrations tested. Furthermore, with the purpose of evaluating the bioavailability of PBRM and CC-156 injected subcutaneously (2.3 mg/kg), we measured their plasmatic concentrations as a function of time, calculated the area under the curve (AUC0–12h) and showed a significant improvement for PBRM (772 ng*h/mL) compared with CC-156 (445 ng*h/mL). We next tested the in vivo efficiency of PBRM on the T-47D xenograft tumor model in female ovariectomized athymic nude mice. After a treatment with PBRM, tumor sizes in mice stimulated with exogenous E1 were completely reduced at the control group level (without E1 treatment). As a conclusion, PBRM is a promising nonestrogenic inhibitor of 17β-HSD1 for the treatment of estrogen-dependent diseases such as breast cancer. Mol Cancer Ther; 11(10); 2096–104. ©2012 AACR.

In vitro antileukemia, antibacterial and antifungal activities of some 3d metal complexes: Chemical synthesis and structure – activity relationships

The present paper describes the synthesis, characterization and in vitro biological evaluation screening of different classes (ammoniacates, dioximates, carboxylates, semi- and thiosemicarbazidates) of Co(II), Co(III), Cu(II), Ni(II), Mn(II), Zn(II) and Fe(III) complexes. Schiff bases were obtained from the reaction of some salicyl aldehydes with, respectively, furoylhydrazine, benzoylhydrazine, semicarbazide, thiosemicarbazide and S-methylthiosemicarbazide to give tridentate ligands containing ONO, ONS or ONN as donor atoms. The synthetic metal complexes are of various geometrical and electronic structures, thermodynamic and thermal stabilities, and magnetic and conductance properties. All complexes, except those of Cu, are octahedral. Some Cu, Co and Mn compounds have a dimeric or a polymeric structure. The composition and structure of complexes were analysed by elemental analysis, IR and 1H NMR and 13C NMR spectroscopies, and magnetochemical, thermoanalytical and molar conductance measurements. All ligands and metal complexes were tested as inhibitors of human leukemia (HL-60) cells growth, and the most potent, the Cu(II) complexes, have been also tested for their in vitro antibacterial and antifungal activities. Structure-activity relationships were carried out.

Chemical synthesis of 2β-amino-5α-androstane-3α,17β-diol N-derivatives and their antiproliferative effect on HL-60 human leukemia cells

Even though few steroids are used for the treatment of leukemia, 2beta-(4-methylpiperazinyl)-5alpha-androstane-3alpha,17beta-diol (1) was recently reported for its ability to inhibit the proliferation of human leukemia HL-60 cells. With an efficient procedure that we had developed for the aminolysis of hindered steroidal epoxides, we synthesized a series of 2beta-amino-5alpha-androstane-3alpha,17beta-diol N-derivatives structurally similar to 1. Hence, the opening of 2,3alpha-epoxy-5alpha-androstan-17beta-diol with primary and secondary amines allowed the synthesis of aminosteroids with diverse length, ramification, and functionalization of the 2beta-side chain. Sixty-four steroid derivatives were tested for their capacity to inhibit the proliferation of HL-60 cells; thus obtaining first structure-activity relationship results. Ten aminosteroids with long alkyl chains (7-16 carbons) or bulky groups (diphenyl or adamantyl) have shown antiproliferative activity over 78% at 10microM and superior to that of the lead compound. The 3,3-diphenylpropylamino, 4-nonylpiperazinyl and octylamino derivatives of 5alpha-androstane-3alpha,17beta-diol inhibited the HL-60 cell growth with IC(50) of 3.1, 4.2 and 6.4microM, respectively. They were also found to induce the HL-60 cell differentiation.

A Novel Pure SERM Achieves Complete Regression of the Majority of Human Breast Cancer Tumors in Nude Mice

AbstractBackground. The objective was to determine if EM-652, a novel selective estrogen receptor modulator (SERM) having highly potent and pure antiestrogenic activity in the mammary gland could cause complete regression of the majority of human breast cancer xenografts in nude mice. Methods. Human breast cancer ZR-75-1 xenografts were used as model in nude mice. Results. EM-652 not only prevented estrogen-induced tumor growth but it reduced tumor size to 20% of the pretreatment value. Complete disappearance of the tumors was observed in 65% (106/163) of tumors. No tumor progressed. Most importantly, 93% of the tumors which had become undetectable under EM-652 treatment did not reappear when exposed to estrogen challenge for 12 weeks, thus achieving an overall 61% cure rate. Conclusions. The present data demonstrate that EM-652 is strongly cytotoxic or tumorocidal and not only cytostatic or tumorostatic in estrogen-sensitive breast cancer, thus changing the paradigm of a tumorostatic role of estrogen blockade established with tamoxifen. These findings support the use of such a compound for more efficient breast cancer prevention and therapy.

A novel aminosteroid of the 5α-androstane-3α,17β-diol family induces cell cycle arrest and apoptosis in human promyelocytic leukemia HL-60 cells.

SummaryRM, a novel aminosteroid synthesized by our research group, shows a broad spectrum of antitumor activity against nine cancer cell lines and limited toxicity against two normal cell lines. However, its related mechanism of action has not yet been elucidated. In this study, we investigated the cellular and molecular events underlying the cytotoxicity of RM in human acute promyelocytic leukemia HL-60 cells. RM was found to induce a G0/G1 cell cycle block of HL-60 cells but not terminal myeloid differentiation. Interestingly, typical apoptotic morphological changes were exhibited by HL-60 cells treated with RM stained with Hoechst 33342 and examined by fluorescence microscopy. Apoptotic death assay using annexin-V/propidium iodide dual staining flow cytometry demonstrated a dose-dependent apoptotic effect of RM on HL-60 cells. In addition, RM induced the cleavage of caspase-3, caspase-8 and PARP, but not the cleavage of caspase-9. Our findings suggest that RM reduces HL-60 cells survival through a caspase-dependent death receptor pathway.

Chemical synthesis, NMR analysis and evaluation on a cancer xenograft model (HL-60) of the aminosteroid derivative RM-133

The aminosteroid derivative RM-133 has been reported to be a promising pro-apoptotic agent showing activity on various cancer cell lines. Following the development of solid-phase synthesis that generated a series of libraries of aminosteroid derivatives, we now report the development of a convenient liquid phase chemical synthesis of RM-133, the most promising candidate, in order to obtain sufficient quantities to proceed with the first preclinical assays. A simple and convergent six-step synthesis was designed and allowed the preparation of a gram-quantity scale of RM-133. This aminosteroid derivative was also fully characterized by NMR experiments which revealed an interesting mixture of conformers. Finally, the in vivo potency of RM-133 was evaluated on a xenograft model in nude mice with HL-60 tumors, which has resulted in the blocking of tumor progression by 57%.

Inhibition of dehydroepiandosterone sulfate action in androgen-sensitive tissues by EM-1913, an inhibitor of steroid sulfatase.

Steroid sulfatase (STS) plays an important role in the formation of estrogens and androgens by allowing the conversion of inactive circulating sulfated steroids into active hormones. These steroids support the development and growth of a number of hormone-dependent cancers, including prostate cancer. Here, we tested a non-estrogenic and non-androgenic inhibitor of steroid STS, namely EM-1913, with special attention to its potential use in the treatment of prostate cancer. After determining the required dosage of dehydroepiandrosterone sulfate (DHEAS) needed to stimulate the ventral prostate and seminal vesicles in castrated rats, we measured that EM-1913 partially (26%) and almost entirely blocked (81%) the stimulating effect of DHEAS on ventral prostates and seminal vesicles, respectively. In addition, the homogenization of these two tissues allowed us to confirm that they were completely deprived of STS activity following a treatment with EM-1913. This effect is also reflected in blood, since the plasma level of DHEAS was increased in animals treated with EM-1913, whereas the levels of dehydroepiandrosterone (DHEA) and dihydrotestosterone (DHT), two DHEAS metabolites, meanwhile decreased. From these results, we concluded that STS inhibitor EM-1913 is a good candidate for additional preclinical studies.