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Journal For Immunotherapy of Cancer Jan 2021Despite the remarkable benefits associated with the interventional treatment of melanomas (and other solid cancers) with immune checkpoint and Braf inhibitors (Brafi),...
BACKGROUND
Despite the remarkable benefits associated with the interventional treatment of melanomas (and other solid cancers) with immune checkpoint and Braf inhibitors (Brafi), most patients ultimately progress on therapy. The presence of multifocal/disseminated disease in patients increases their mortality risk. Hence, the development of novel strategies to effectively treat patients with melanomas that are resistant to anti-PD1 mAb (αPD1) and/or Brafi, particularly those with multifocal/disseminated disease remains a major unmet clinical need.
METHODS
Mice developing induced/spontaneous Braf/Pten melanomas were treated by cutaneous immunization with a DNA vaccine encoding the melanoma-associated antigen TRP2, with Brafi or αPD1 alone, or with a combination of these treatments. Tumor progression, tumor-infiltration by CD4 and CD8 T cells, and the development of TRP2-specific CD8 T cells were then monitored over time.
RESULTS
Vaccination led to durable antitumor immunity against PD1/Brafi-resistant melanomas in both single lesion and multifocal disease models, and it sensitized PD1-resistant melanomas to salvage therapy with αPD1. The therapeutic efficacy of the vaccine was associated with host skin-resident cells, the induction of a systemic, broadly reactive IFNγCD8 T cell repertoire, increased frequencies of CD8 TIL and reduced levels of PD1CD8 T cells. Extended survival was associated with improved TIL functionality, exemplified by the presence of enhanced levels of IFNγCD8 TIL and IL2CD4 TIL.
CONCLUSIONS
These data support the use of a novel genetic vaccine for the effective treatment of localized or multifocal melanoma refractory to conventional αPD1-based and/or Brafi-based (immune)therapy.
Topics: Animals; CD8-Positive T-Lymphocytes; Drug Resistance, Neoplasm; Drug Synergism; Female; Humans; Immune Checkpoint Inhibitors; Immunization; Intramolecular Oxidoreductases; Male; Melanoma; Mice; Mutation; PTEN Phosphohydrolase; Protein Kinase Inhibitors; Proto-Oncogene Proteins B-raf; Tamoxifen; Treatment Outcome; Vaccines, DNA; Xenograft Model Antitumor Assays
PubMed: 33408093
DOI: 10.1136/jitc-2020-001179 -
Anticancer Research Dec 2020Triple-negative breast cancer (TNBC) is a highly aggressive form of breast cancer (BC) and lacks targeted therapy and alternate therapeutic combinations. There is a...
BACKGROUND/AIM
Triple-negative breast cancer (TNBC) is a highly aggressive form of breast cancer (BC) and lacks targeted therapy and alternate therapeutic combinations. There is a necessity to increase disease-free survival in patients particularly within the first 5 years of diagnosis. 2,3-dichloro-5,8-dimethoxy-1,4-naphthoquinone (Z285), a novel 1,4 naphthoquinone analog, has been shown to have cytotoxic activity in BC cell lines and in combination with 4-hydroxytamoxifen (4-OHT). A known metabolite of tamoxifen, was postulated to decrease cell proliferation. Thus, this study investigates the use of Z285 and 4-OHT alone or in combination as a novel therapeutic alternative for TNBC.
MATERIALS AND METHODS
Cell proliferation assays were performed on MDA-MB-231, Hs578T, MCF7 and HCC1806 cell lines at varying time points with Z285 and 4-OHT alone and in combination. Furthermore, ROS activity was measured to determine the changes in oxidative stress caused by both drugs.
RESULTS
The results showed dose- and time-dependent decreases in proliferation for all cell lines when treated with Z285, 4-OHT and their combination. Combinatorial analysis performed at 72 h using Synergyfinder showed additive effects in MCF7, HCC1806 and Hs578T and an antagonistic response in MDA-MB-231. Z285 caused a significant increase in ROS production in three cell lines after 8 h, but HCC1806 showed no change in effect.
CONCLUSION
These promising results suggest the independent ability of each compound as a stand-alone chemotherapeutic agent, or in combinatorial therapy for the treatment of TNBC.
Topics: Apoptosis; Cell Line, Tumor; Cell Survival; Drug Synergism; Female; Humans; Inhibitory Concentration 50; Naphthoquinones; Reactive Oxygen Species; Tamoxifen; Triple Negative Breast Neoplasms
PubMed: 33288557
DOI: 10.21873/anticanres.14687 -
Molecular Oncology Apr 2021Low steady-state levels of active tamoxifen metabolites have been associated with inferior treatment outcomes. In this retrospective analysis of 406 estrogen... (Observational Study)
Observational Study
Low steady-state levels of active tamoxifen metabolites have been associated with inferior treatment outcomes. In this retrospective analysis of 406 estrogen receptor-positive breast cancer (BC) patients receiving adjuvant tamoxifen as initial treatment, we have associated our previously reported thresholds for the two active metabolites, Z-endoxifen and Z-4-hydroxy-tamoxifen (Z-4OHtam), with treatment outcomes in an independent cohort of BC patients. Among all patients, metabolite levels did not affect survival. However, in the premenopausal subgroup receiving tamoxifen alone (n = 191) we confirmed an inferior BC -specific survival in patients with the previously described serum concentration threshold of Z-4OHtam ≤ 3.26 nm (HR = 2.37, 95% CI = 1.02-5.48, P = 0.039). The 'dose-response' survival trend in patients categorized to ordinal concentration cut-points of Z-4OHtamoxifen (≤ 3.26, 3.27-8.13, > 8.13 nm) was also replicated (P-trend log-rank = 0.048). Z-endoxifen was not associated with outcome. This is the first study to confirm the association between a published active tamoxifen metabolite threshold and BC outcome in an independent patient cohort. Premenopausal patients receiving 5-year of tamoxifen alone may benefit from therapeutic drug monitoring to ensure tamoxifen effectiveness.
Topics: Adult; Antineoplastic Agents, Hormonal; Breast Neoplasms; Female; Humans; Middle Aged; Norway; Premenopause; Retrospective Studies; Tamoxifen; Treatment Outcome
PubMed: 33252186
DOI: 10.1002/1878-0261.12865 -
ELife Nov 2020Fragile X syndrome (FXS) is an X chromosome-linked disease associated with severe intellectual disabilities. Previous studies using the knockout (KO) mouse, an FXS...
Fragile X syndrome (FXS) is an X chromosome-linked disease associated with severe intellectual disabilities. Previous studies using the knockout (KO) mouse, an FXS mouse model, have attributed behavioral deficits to synaptic dysfunctions. However, how functional deficits at neural network level lead to abnormal behavioral learning remains unexplored. Here, we show that the efficacy of hippocampal engram reactivation is reduced in KO mice performing contextual fear memory recall. Experiencing an enriched environment (EE) prior to learning improved the engram reactivation efficacy and rescued memory recall in the KO mice. In addition, chemogenetically inhibiting EE-engaged neurons in CA1 reverses the rescue effect of EE on memory recall. Thus, our results suggest that inappropriate engram reactivation underlies cognitive deficits in FXS, and enriched environment may rescue cognitive deficits by improving network activation accuracy.
Topics: Animals; Behavior, Animal; Estrogen Antagonists; Fear; Fragile X Mental Retardation Protein; Fragile X Syndrome; Gene Expression Regulation; Male; Memory; Mice; Mice, Knockout; Neurons; Tamoxifen
PubMed: 33215988
DOI: 10.7554/eLife.61882 -
European Journal of Drug Metabolism and... Jan 2021Previous studies have revealed that sulfation, as mediated by the estrogen-sulfating cytosolic sulfotransferase (SULT) SULT1E1, is involved in the metabolism of...
BACKGROUND AND OBJECTIVES
Previous studies have revealed that sulfation, as mediated by the estrogen-sulfating cytosolic sulfotransferase (SULT) SULT1E1, is involved in the metabolism of 17β-estradiol (E2), 4-hydroxytamoxifen (4OH-tamoxifen), and diethylstilbestrol in humans. It is an interesting question whether the genetic polymorphisms of SULT1E1, the gene that encodes the SULT1E1 enzyme, may impact on the metabolism of E2 and these two drug compounds through sulfation.
METHODS
In this study, five missense coding single nucleotide polymorphisms of the SULT1E1 gene were selected to investigate the sulfating activity of the coded SULT1E1 allozymes toward E2, 4OH-tamoxifen, and diethylstilbestrol. Corresponding cDNAs were generated by site-directed mutagenesis, and recombinant SULT1E1 allozymes were bacterially expressed, affinity-purified, and characterized using enzymatic assays.
RESULTS
Purified SULT1E1 allozymes were shown to display differential sulfating activities toward E2, 4OH-tamoxifen, and diethylstilbestrol. Kinetic analysis revealed further distinct K (reflecting substrate affinity) and V (reflecting catalytic activity) values of the five SULT1E1 allozymes with E2, 4OH-tamoxifen, and diethylstilbestrol as substrates.
CONCLUSIONS
Taken together, these findings highlighted the significant differences in E2-, as well as the drug-sulfating activities of SULT1E1 allozymes, which may have implications in the differential metabolism of E2, 4OH-tamoxifen, and diethylstilbestrol in individuals with different SULT1E1 genotypes.
Topics: Diethylstilbestrol; Dose-Response Relationship, Drug; Estradiol; Estrogen Antagonists; Estrogens; Estrogens, Non-Steroidal; Humans; Isoenzymes; Polymorphism, Single Nucleotide; Protein Structure, Secondary; Sulfotransferases; Tamoxifen
PubMed: 33064293
DOI: 10.1007/s13318-020-00653-1 -
Experimental Hematology Sep 2020Hematopoietic stem cells (HSCs) are multipotent cells that form the entire blood system and have the potential to cure several pathogenic conditions directly or...
Hematopoietic stem cells (HSCs) are multipotent cells that form the entire blood system and have the potential to cure several pathogenic conditions directly or indirectly arising from defects within the HSC compartment. Pluripotent stem cells (PSCs) or induced pluripotent stem cells (iPSCs) can give rise to all embryonic cell types; however, efficient in vitro differentiation of HSCs from PSCs remains challenging. HoxB4 is a key regulator orchestrating the differentiation of PSCs into all cells types across the mesodermal lineage, including HSCs. Moreover, the ectopic expression of HoxB4 enhances the in vitro generation and expansion of HSCs. However, several aspects of HoxB4 biology including its regulatory functions are not fully understood. Here, we describe the role of HoxB4 in indirectly inhibiting the emergence of mature CD45 HSCs from iPSCs in vitro. Forced activation of HoxB4 permitted long-term maintenance of functional hematopoietic stem and progenitor cells (HSPCs), which efficiently reconstituted hematopoiesis upon transplantation. Our method enables an easy and scalable in vitro platform for the generation of HSCs from iPSCs, which will ultimately lead to a better understanding of HSC biology and facilitate preparation of the roadma for producing an unrestricted supply of HSCs for several curative therapies.
Topics: Animals; Cell Differentiation; Cell Proliferation; Cellular Reprogramming; Gene Expression Regulation; Hematopoiesis; Hematopoietic Stem Cell Transplantation; Hematopoietic Stem Cells; Homeodomain Proteins; Humans; Induced Pluripotent Stem Cells; Leukocyte Common Antigens; Mice; Mice, Inbred C57BL; Mice, Transgenic; Mutant Chimeric Proteins; Primary Cell Culture; Receptors, Estrogen; Stem Cell Factor; Tamoxifen; Thrombopoietin; Transcription Factors; Whole-Body Irradiation
PubMed: 32795499
DOI: 10.1016/j.exphem.2020.08.003 -
ChemMedChem Aug 2020In the search for new and effective treatments of breast and prostate cancer, a series of hybrid compounds based on tamoxifen, estrogens, and artemisinin were...
In the search for new and effective treatments of breast and prostate cancer, a series of hybrid compounds based on tamoxifen, estrogens, and artemisinin were successfully synthesized and analyzed for their in vitro activities against human prostate (PC-3) and breast cancer (MCF-7) cell lines. Most of the hybrid compounds exhibit a strong anticancer activity against both cancer cell lines - for example, EC (PC-3) down to 1.07 μM, and EC (MCF-7) down to 2.08 μM - thus showing higher activities than their parent compounds 4-hydroxytamoxifen (afimoxifene, 7; EC =75.1 (PC-3) and 19.3 μM (MCF-7)), dihydroartemisinin (2; EC =263.6 (PC-3) and 49.3 μM (MCF-7)), and artesunic acid (3; EC =195.1 (PC-3) and 32.0 μM (MCF-7)). The most potent compounds were the estrogen-artemisinin hybrids 27 and 28 (EC =1.18 and 1.07 μM, respectively) against prostate cancer, and hybrid 23 (EC =2.08 μM) against breast cancer. These findings demonstrate the high potential of hybridization of artemisinin and estrogens to further improve their anticancer activities and to produce synergistic effects between linked pharmacophores.
Topics: Antineoplastic Agents; Artemisinins; Breast Neoplasms; Cell Proliferation; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Estrogens; Female; Humans; MCF-7 Cells; Male; Molecular Structure; PC-3 Cells; Prostatic Neoplasms; Structure-Activity Relationship; Tamoxifen
PubMed: 32374071
DOI: 10.1002/cmdc.202000174 -
Scientific Reports Feb 2020Hepatitis C virus (HCV) is the main cause of chronic hepatitis and probably liver cirrhosis. Dasabuvir (DSV) is a direct-acting antiviral agent with efficiency in...
Hepatitis C virus (HCV) is the main cause of chronic hepatitis and probably liver cirrhosis. Dasabuvir (DSV) is a direct-acting antiviral agent with efficiency in managing HCV. The anti-viral activity of the anti-estrogen drug tamoxifen (TAM) suggested the synergistic effect of DSV and TAM for blocking the replication of HCV. However, being substrates and inhibitors of efflux transporters (TAM inhibits P-gp, DSV inhibits P-gp and BCRP), there is a possibility for a pharmacokinetic (PK) drug-drug interaction. In this work, a new UPLC-MS/MS method was developed and validated for the simultaneous determination of TAM, its active metabolite 4-hydroxy tamoxifen (TOH), and DSV in rat plasma. The method was applied to investigate the PK interaction between DSV and TAM/TOH following the co-administration of DSV and TAM to Wistar rats. Chromatographic analysis was performed on Waters BEH C18 column using a mobile phase of acetonitrile/water containing 0.1% formic acid (80: 20, v/v). The method allowed the determination of concentration ranges 20-1000, 0.1-500, 0.5-500 ng/mL for DSV, TAM, and TOH, respectively. Unexpectedly, results revealed the absence of PK interactions between DSV and TAM/TOH, compared with their single administration, suggesting the safety of co-administering DSV/TAM as an anti-viral combination without the need of dosage adjustment.
Topics: 2-Naphthylamine; Animals; Chromatography, High Pressure Liquid; Drug Interactions; Hepatitis C, Chronic; Rats; Rats, Wistar; Sulfonamides; Tamoxifen; Tandem Mass Spectrometry; Uracil
PubMed: 32103133
DOI: 10.1038/s41598-020-60613-2 -
International Journal of Molecular... Jan 2020Alpha-fetoprotein (AFP) is a major embryo- and tumor-associated protein capable of binding and transporting a variety of hydrophobic ligands, including estrogens. AFP...
Alpha-fetoprotein (AFP) is a major embryo- and tumor-associated protein capable of binding and transporting a variety of hydrophobic ligands, including estrogens. AFP has been shown to inhibit estrogen receptor (ER)-positive tumor growth, which can be attributed to its estrogen-binding ability. Despite AFP having long been investigated, its three-dimensional (3D) structure has not been experimentally resolved and molecular mechanisms underlying AFP-ligand interaction remains obscure. In our study, we constructed a homology-based 3D model of human AFP (HAFP) with the purpose of molecular docking of ERα ligands, three agonists (17β-estradiol, estrone and diethylstilbestrol), and three antagonists (tamoxifen, afimoxifene and endoxifen) into the obtained structure. Based on the ligand-docked scoring functions, we identified three putative estrogen- and antiestrogen-binding sites with different ligand binding affinities. Two high-affinity binding sites were located (i) in a tunnel formed within HAFP subdomains IB and IIA and (ii) on the opposite side of the molecule in a groove originating from a cavity formed between domains I and III, while (iii) the third low-affinity binding site was found at the bottom of the cavity. Here, 100 ns molecular dynamics (MD) simulation allowed us to study their geometries and showed that HAFP-estrogen interactions were caused by van der Waals forces, while both hydrophobic and electrostatic interactions were almost equally involved in HAFP-antiestrogen binding. Molecular mechanics/Generalized Born surface area (MM/GBSA) rescoring method exploited for estimation of binding free energies (ΔG) showed that antiestrogens have higher affinities to HAFP as compared to estrogens. We performed in silico point substitutions of amino acid residues to confirm their roles in HAFP-ligand interactions and showed that Thr132, Leu138, His170, Phe172, Ser217, Gln221, His266, His316, Lys453, and Asp478 residues, along with two disulfide bonds (Cys224-Cys270 and Cys269-Cys277), have key roles in both HAFP-estrogen and HAFP-antiestrogen binding. Data obtained in our study contribute to understanding mechanisms underlying protein-ligand interactions and anticancer therapy strategies based on ERα-binding ligands.
Topics: Amino Acid Sequence; Amino Acid Substitution; Binding Sites; Estradiol; Estrogen Receptor Modulators; Estrogen Receptor alpha; Estrogens; Female; Humans; Ligands; Models, Molecular; Molecular Docking Simulation; Molecular Dynamics Simulation; Mutagenesis; Sequence Alignment; alpha-Fetoproteins
PubMed: 32019136
DOI: 10.3390/ijms21030893 -
BMC Pharmacology & Toxicology Dec 2019Tamoxifen is considered a prodrug of its active metabolite endoxifen, which is dependent on the CYP2D6 and CYP3A enzymes. Tamoxifen pharmacokinetic variability...
BACKGROUND
Tamoxifen is considered a prodrug of its active metabolite endoxifen, which is dependent on the CYP2D6 and CYP3A enzymes. Tamoxifen pharmacokinetic variability influences endoxifen exposure and, consequently, its clinical outcome. This study investigated the impact of hormonal status on the pharmacokinetics of tamoxifen and its metabolites in TAM-treated breast cancer patients.
METHODS
TAM-treated breast cancer patients (n = 40) previously believed to have CYP3A activity within the normal range based on oral midazolam and phenotyped as CYP2D6 normal metabolizers using oral metoprolol were divided into two groups according to premenopausal (n = 20; aged 35-50 years) or postmenopausal (n = 20; aged 60-79 years) status. All patients were treated with 20 mg/day tamoxifen for at least three months. Serial plasma samples were collected within the 24 h dose interval for analysis of unchanged tamoxifen, endoxifen, 4-hydroxytamoxifen and N-desmethyltamoxifen quantified by LC-MS/MS. CYP activities were assessed using midazolam apparent clearance (CYP3A) and the metoprolol/alfa-hydroxymetoprolol plasma metabolic ratio (CYP2D6). CYP3A4, CYP3A5 and CYP2D6 SNPs and copy number variation were investigated using TaqMan assays.
RESULTS
Postmenopausal status increased steady-state plasma concentrations (Css) of tamoxifen (116.95 vs 201.23 ng/mL), endoxifen (8.01 vs 18.87 ng/mL), N-desmethyltamoxifen (485.16 vs 843.88 ng/mL) and 4-hydroxytamoxifen (2.67 vs 4.11 ng/mL). The final regression models included hormonal status as the only predictor for Css of tamoxifen [β-coef ± SE, p-value (75.03 ± 17.71, p = 0.0001)] and 4-hydroxytamoxifen (1.7822 ± 0.4385, p = 0.0002), while endoxifen Css included hormonal status (8.578 ± 3.402, p = 0.02) and race (11.945 ± 2.836, p = 0.007). For N-desmethyltamoxifen Css, the final model was correlated with hormonal status (286.259 ± 76.766, p = 0.0007) and weight (- 8.585 ± 3.060, p = 0.008).
CONCLUSION
The premenopausal status was associated with decreased endoxifen plasma concentrations by 135% compared to postmenopausal status. Thus, the endoxifen plasma concentrations should be monitored mainly in the premenopausal period to maintain plasma levels above the efficacy threshold value.
TRIAL REGISTRATION
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Topics: Adult; Aged; Breast Neoplasms; Cytochrome P-450 CYP2D6; Cytochrome P-450 CYP3A; Female; Humans; Middle Aged; Polymorphism, Single Nucleotide; Postmenopause; Premenopause; Tamoxifen
PubMed: 31852530
DOI: 10.1186/s40360-019-0358-y