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Science Advances Jun 2019Cellular senescence is a stress response program characterized by a robust cell cycle arrest and the induction of a proinflammatory senescence-associated secretory...
Cellular senescence is a stress response program characterized by a robust cell cycle arrest and the induction of a proinflammatory senescence-associated secretory phenotype (SASP) that is triggered through an unknown mechanism. Here, we show that, during oncogene-induced senescence (OIS), the Toll-like receptor 2 (TLR2) and its partner TLR10 are key mediators of senescence in vitro and in murine models. TLR2 promotes cell cycle arrest by regulating the tumor suppressors p53-p21, p16, and p15 and regulates the SASP through the induction of the acute-phase serum amyloids A1 and A2 (A-SAAs) that, in turn, function as the damage-associated molecular patterns (DAMPs) signaling through TLR2 in OIS. Last, we found evidence that the cGAS-STING cytosolic DNA sensing pathway primes TLR2 and A-SAAs expression in OIS. In summary, we report that innate immune sensing of senescence-associated DAMPs by TLR2 controls the SASP and reinforces the cell cycle arrest program in OIS.
Topics: Alarmins; Animals; Cellular Senescence; Fibroblasts; Humans; Immunity, Innate; Membrane Proteins; Mice; Mice, Inbred C57BL; Mice, Knockout; NF-kappa B; Nucleotidyltransferases; RNA Interference; RNA, Small Interfering; Serum Amyloid A Protein; Signal Transduction; Tamoxifen; Toll-Like Receptor 10; Toll-Like Receptor 2; p38 Mitogen-Activated Protein Kinases; ras Proteins
PubMed: 31183403
DOI: 10.1126/sciadv.aaw0254 -
Breast Cancer Research and Treatment Nov 2018Tamoxifen has a wide inter-variability. Recently, two SNPs in the 3'-untranslated region (UTR) of the SULT1A1 gene, rs6839 and rs1042157, have been associated with...
PURPOSE
Tamoxifen has a wide inter-variability. Recently, two SNPs in the 3'-untranslated region (UTR) of the SULT1A1 gene, rs6839 and rs1042157, have been associated with decreased SULT1A1 activity. The aim of this study is to investigate the role of the rs6839 and rs1042157 on tamoxifen metabolism and relapse-free survival (RFS) in women diagnosed with early-breast cancer receiving tamoxifen.
METHODS
Samples from 667 patients collected in the CYPTAM study (NTR1509) were used for genotyping (CYP2D6, SULT1A1 rs6839 and rs1042157) and measurements of tamoxifen and metabolites. Patients were categorized in three groups depending on the decreased SULT1A1 activity due to rs6839 and rs1042157: low activity group (rs6839 (GG) and rs1042157 (TT)); high activity group (rs6839 (AA) and rs1042157 (CC)); and medium activity group (all the other combinations of rs6839 and rs1042157). Associations between SULT1A1 phenotypes and clinical outcome (RFS) were explored.
RESULTS
In the low SULT1A1 activity group, higher endoxifen and 4-hydroxy-tamoxifen concentrations were found, compared to the medium and high activity group (endoxifen: 31.23 vs. 30.51 vs. 27.00, p value: 0.016; 4-hydroxy-tamoxifen: 5.55 vs. 5.27 vs. 4.94, p value:0.05). In terms of relapse, the low activity group had a borderline better outcome compared to the medium and high SULT1A1 activity group (adjusted Hazard ratio: 0.297; 95% CI 0.088-1.000; p value: 0.05).
CONCLUSION
Our results suggested that rs6839 and rs1042157 SNPs have a minor effect on the concentrations and metabolic ratios of tamoxifen and its metabolites, and RFS in women receiving adjuvant tamoxifen.
Topics: 3' Untranslated Regions; Adult; Aged; Arylsulfotransferase; Breast Neoplasms; Cytochrome P-450 CYP2D6; Disease-Free Survival; Female; Genetic Association Studies; Genotype; Humans; Middle Aged; Polymorphism, Single Nucleotide; Tamoxifen; Treatment Outcome
PubMed: 30120701
DOI: 10.1007/s10549-018-4923-7 -
Laboratory Investigation; a Journal of... Mar 2016Postnatal inflammatory lymphangiogenesis presumably requires precise regulatory processes to properly assemble proliferating lymphatic endothelial cells (LECs). The...
Postnatal inflammatory lymphangiogenesis presumably requires precise regulatory processes to properly assemble proliferating lymphatic endothelial cells (LECs). The specific mechanisms that regulate the assembly of LECs during new lymphatic vessel synthesis are unclear. Dynamic endothelial shuffling and rearrangement has been proposed as a mechanism of blood vessel growth. We developed genetic lineage-tracing strategies using an inductive transgenic technology to track the fate of entire tandem dimer tomato-positive (tdT) lymphatic vessels or small, in some cases clonal, populations of LECs. We coupled this platform with a suture-induced mouse model of corneal lymphangiogenesis and used different analytic microscopy techniques including serial live imaging to study the spatial properties of proliferating tdT(+) LEC progenies. LEC precursors and their progeny expanded from the corneal limbal lymphatic vessel and were assembled contiguously to comprise a subunit within a new lymphatic vessel. VE-cadherin blockade induced morphologic abnormalities in newly synthesized lymphatic vessels, but did not disrupt the tdT(+) lymphatic endothelial lineage assembly. Analysis of this static and dynamic data based largely on direct in vivo observations supports a model of lymphatic endothelial lineage assemblage during corneal inflammatory lymphangiogenesis.
Topics: Animals; Antigens, CD; Cadherins; Cell Lineage; Cornea; Endothelial Cells; Endothelium, Corneal; Humans; Lymphangiogenesis; Mice; Mice, Inbred C57BL; Tamoxifen; Vesicular Transport Proteins
PubMed: 26658452
DOI: 10.1038/labinvest.2015.147 -
Hippocampus Jul 2018Recent genetic tools have allowed researchers to visualize and manipulate memory traces (i.e., engrams) in small brain regions. However, the ultimate goal is to...
Recent genetic tools have allowed researchers to visualize and manipulate memory traces (i.e., engrams) in small brain regions. However, the ultimate goal is to visualize memory traces across the entire brain in order to better understand how memories are stored in neural networks and how multiple memories may coexist. Intact tissue clearing and imaging is a new and rapidly growing area of focus that could accomplish this task. Here, we utilized the leading protocols for whole-brain clearing and applied them to the ArcCreER mice, a murine line that allows for the indelible labeling of memory traces. We found that CLARITY and PACT greatly distorted the tissue, and iDISCO quenched enhanced yellow fluorescent protein (EYFP) fluorescence and hindered immunolabeling. Alternative clearing solutions, such as tert-Butanol, circumvented these harmful effects, but still did not permit whole-brain immunolabeling. CUBIC and CUBIC with Reagent-1A produced improved antibody penetration and preserved EYFP fluorescence, but also did not allow for whole-brain memory trace visualization. Modification of CUBIC with Reagent-1A resulted in EYFP fluorescence preservation and immunolabeling of the immediate early gene (IEG) Arc in deep brain areas; however, optimized memory trace labeling still required tissue slicing into mm-thick tissue sections. In summary, our data show that CUBIC with Reagent-1A* is the ideal method for reproducible clearing and immunolabeling for the visualization of memory traces in mm-thick tissue sections from ArcCreER mice.
Topics: AIDS-Related Complex; Animals; Brain; Channelrhodopsins; Conditioning, Operant; Estrogen Antagonists; Fear; Immunohistochemistry; Indicators and Reagents; Luminescent Proteins; Memory; Mice; Mice, Transgenic; Microscopy, Confocal; Receptors, Estrogen; Tamoxifen
PubMed: 29663578
DOI: 10.1002/hipo.22951 -
PloS One 2016Tamoxifen (Tam) is a selective estrogen receptor (ER) modulator (SERM) that is an essential drug to treat ER-positive breast cancer. Aside from known actions at ERs,...
Tamoxifen (Tam) is a selective estrogen receptor (ER) modulator (SERM) that is an essential drug to treat ER-positive breast cancer. Aside from known actions at ERs, recent studies have suggested that some SERMs like Tam also exhibit novel activity at cannabinoid subtype 1 and 2 receptors (CB1R and CB2Rs). Interestingly, cis- (E-Tam) and trans- (Z-Tam) isomers of Tam exhibit over a 100-fold difference in affinity for ERs. Therefore, the current study assessed individual isomers of Tam and subsequent cytochrome P450 metabolic products, 4-hydroxytamoxifen (4OHT) and 4-hydroxy-N-desmethyl tamoxifen (End) for affinity and activity at CBRs. Results showed that Z-4OHT, but not Z-Tam or Z-End, exhibits higher affinity for both CB1 and CB2Rs relative to the E-isomer. Furthermore, Z- and E-isomers of Tam and 4OHT show slightly higher affinity for CB2Rs, while both End isomers are relatively CB1R-selective. When functional activity was assessed by G-protein activation and regulation of the downstream effector adenylyl cyclase, all isomers examined act as full CB1 and CB2R inverse agonists. Interestingly, Z-Tam appears to be more efficacious than the full inverse agonist AM630 at CB2Rs, while both Z-Tam and Z-End exhibit characteristics of insurmountable antagonism at CB1 and CB2Rs, respectively. Collectively, these results suggest that the SERMs Tam, 4OHT and End elicit ER-independent actions via CBRs in an isomer-specific manner. As such, this novel structural scaffold might be used to develop therapeutically useful drugs for treatment of a variety of diseases mediated via CBRs.
Topics: Adenylyl Cyclases; Animals; Binding, Competitive; Breast Neoplasms; CHO Cells; Cannabinoid Receptor Agonists; Cannabinoid Receptor Antagonists; Colforsin; Cricetinae; Cricetulus; Cyclic AMP; Cyclohexanols; Female; GTP-Binding Proteins; Guanosine 5'-O-(3-Thiotriphosphate); Humans; Indoles; Isomerism; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Selective Estrogen Receptor Modulators; Tamoxifen
PubMed: 27936172
DOI: 10.1371/journal.pone.0167240 -
Journal of B.U.ON. : Official Journal... 2015To investigate the effect of quercetin on the reversal of tamoxifen resistance in breast cancer cells, and explore the underlying mechanism.
PURPOSE
To investigate the effect of quercetin on the reversal of tamoxifen resistance in breast cancer cells, and explore the underlying mechanism.
METHODS
We established a tamoxifen-resistant breast cancer cell line (MCF-7Ca/TAM-R), and exposed it to different concentrations of quercetin (experimental group 1: 10 μM, group 2: 25 μM, and group 3: 50μM). Each group was further subdivided into 2 subgroups: 1) simultaneous administration of quercetin and 4-hydroxytamoxifen (OHT); 2) sequential administration of quercetin (12-h induction) followed by OHT. No drug exposure and OHT alone were used as controls. We determined cell survival, apoptosis, and expression of ERα (estrogen receptor α) and Her-2 (human epidermal growth factor receptor 2).
RESULTS
With increasing dosage of quercetin, significant decrease in proliferation and increase in apoptosis was observed. Low concentrations of quercetin (10 μM) had no effects. We found no significant difference between simultaneous and sequential mode of drug administration. Further, with increasing dosage of quercetin, we observed a gradual reduction in Her-2 expression and upregulation of ERα. Again, no difference in Her-2 and ERα protein levels between simultaneous and sequential drug administration was noticed.
CONCLUSIONS
Proliferation inhibition and apoptosis in MCF-7Ca/TAM-R cells increase with increasing dosage of quercetin. This suggests that quercetin can reverse tamoxifen resistance in breast cancer cells. The underlying mechanism likely involves upregulation of ERα combined with downregulation of Her-2. However, this effect is independent of whether quercetin and tamoxifen are administered simultaneously or sequentially.
Topics: Antineoplastic Agents, Hormonal; Apoptosis; Breast Neoplasms; Cell Proliferation; Cell Survival; Dose-Response Relationship, Drug; Drug Resistance, Neoplasm; Estrogen Antagonists; Estrogen Receptor alpha; Female; Humans; MCF-7 Cells; Quercetin; Receptor, ErbB-2; Signal Transduction; Tamoxifen; Time Factors
PubMed: 26214621
DOI: No ID Found -
Scientific Reports Apr 2018Inducible DNA recombination of floxed alleles in vivo by liver metabolites of tamoxifen (TAM) is an important tool to study gene functions. Here, we describe protocols...
Inducible DNA recombination of floxed alleles in vivo by liver metabolites of tamoxifen (TAM) is an important tool to study gene functions. Here, we describe protocols for optimal DNA recombination in astrocytes, based on the GLAST-Cre/loxP system. In addition, we demonstrate that quantification of genomic recombination allows to determine the proportion of cell types in various brain regions. We analyzed the presence and clearance of TAM and its metabolites (N-desmethyl-tamoxifen, 4-hydroxytamoxifen and endoxifen) in brain and serum of mice by liquid chromatographic-high resolution-tandem mass spectrometry (LC-HR-MS/MS) and assessed optimal injection protocols by quantitative RT-PCR of several floxed target genes (p2ry1, gria1, gabbr1 and Rosa26-tdTomato locus). Maximal recombination could be achieved in cortex and cerebellum by single daily injections for five and three consecutive days, respectively. Furthermore, quantifying the loss of floxed alleles predicted the percentage of GLAST-positive cells (astroglia) per brain region. We found that astrocytes contributed 20 to 30% of the total cell number in cortex, hippocampus, brainstem and optic nerve, while in the cerebellum Bergmann glia, velate astrocytes and white matter astrocytes accounted only for 8% of all cells.
Topics: Alleles; Animals; Astrocytes; Brain; Cerebellum; Chromatography, Liquid; DNA; Liver; Mice; RNA, Untranslated; Receptors, AMPA; Receptors, GABA-B; Receptors, Purinergic P2Y1; Recombination, Genetic; Tamoxifen; Tandem Mass Spectrometry
PubMed: 29651133
DOI: 10.1038/s41598-018-24085-9 -
Frontiers in Immunology 2021Cell swelling and membrane blebbing are characteristic of pyroptosis. In the present study, we explored the role of intracellular tension activity in the deformation of...
Cell swelling and membrane blebbing are characteristic of pyroptosis. In the present study, we explored the role of intracellular tension activity in the deformation of pyroptotic astrocytes. Protein nanoparticle-induced osmotic pressure (PN-OP) was found to be involved in cell swelling and membrane blebbing in pyroptotic astrocytes, and was associated closely with inflammasome production and cytoskeleton depolymerization. However, accumulation of protein nanoparticles seemed not to be absolutely required for pyroptotic permeabilization in response to cytoskeleton depolymerization. Gasdermin D activation was observed to be involved in modification of typical pyroptotic features through inflammasome-induced OP upregulation and calcium increment. Blockage of nonselective ion pores can inhibit permeabilization, but not inflammasome production and ion influx in pyroptotic astrocytes. The results suggested that the inflammasomes, as protein nanoparticles, are involved in PN-OP upregulation and control the typical features of pyroptotic astrocytes.
Topics: Animals; Astrocytes; Calcium Signaling; Caspase 1; Cell Line, Tumor; Cell Membrane; Cell Size; Cytoskeleton; Disease Models, Animal; Humans; Inflammasomes; Intracellular Signaling Peptides and Proteins; Lipopolysaccharides; Male; Mechanotransduction, Cellular; Mice, Inbred C57BL; NLR Family, Pyrin Domain-Containing 3 Protein; Nigericin; Osmotic Pressure; Phosphate-Binding Proteins; Polyethylene Glycols; Pyroptosis; Sepsis; Stress, Mechanical; Tamoxifen; Mice
PubMed: 34305921
DOI: 10.3389/fimmu.2021.688674 -
Arteriosclerosis, Thrombosis, and... Apr 2017Platelets, which are mainly known for their role in hemostasis, are now known to play a crucial role in metastasis. Tamoxifen is a selective estrogen receptor modulator...
OBJECTIVE
Platelets, which are mainly known for their role in hemostasis, are now known to play a crucial role in metastasis. Tamoxifen is a selective estrogen receptor modulator that is widely used for the treatment of breast cancer. Tamoxifen and its metabolites have been shown to directly impact platelet function, suggesting that this drug has additional mechanisms of action. The purpose of this study was to determine whether tamoxifen exerts antitumor effects through direct platelet inhibition.
APPROACH AND RESULTS
This study found that pretreatment with tamoxifen leads to a significant inhibition of platelet activation. Platelets exposed to tamoxifen released significantly lower amounts of proangiogenic regulator vascular endothelial growth factor. In vitro angiogenesis assays confirmed that tamoxifen pretreatment led to diminished capillary tube formation and decreased endothelial migration. Tamoxifen and its metabolite, 4-hydroxytamoxifen, also significantly inhibited the ability of platelets to promote metastasis in vitro. Using a membrane-based array, we identified several proteins associated with angiogenesis metastasis that were lower in activated releasate from tamoxifen-treated platelets, including angiogenin, chemokine (C-X-C motif) ligand 1, chemokine (C-C motif) ligand 5, epidermal growth factor, chemokine (C-X-C motif) ligand 5, platelet-derived growth factor dimeric isoform BB, whereas antiangiogenic angiopoietin-1 was elevated. Platelets isolated from patients on tamoxifen maintenance therapy were also found to have decreased activation responses, diminished vascular endothelial growth factor release, and lower angiogenic and metastatic potential.
CONCLUSIONS
We demonstrate that tamoxifen and its metabolite 4-hydroxytamoxifen directly alter platelet function leading to decreased angiogenic and metastatic potential. Furthermore, this study supports the idea of utilizing targeted platelet therapies to inhibit the platelet's role in angiogenesis and malignancy.
Topics: Angiogenesis Inhibitors; Blood Platelets; Breast Neoplasms; Cell Movement; Cell Proliferation; Coculture Techniques; Female; Human Umbilical Vein Endothelial Cells; Humans; MCF-7 Cells; Neoplasm Metastasis; Neovascularization, Physiologic; Platelet Activation; Platelet Aggregation Inhibitors; Signal Transduction; Tamoxifen; Vascular Endothelial Growth Factor A
PubMed: 28153880
DOI: 10.1161/ATVBAHA.116.308791 -
Cells Sep 2021Cancer cells have an increased need for glucose and, despite aerobic conditions, obtain their energy through aerobic oxidation and lactate fermentation, instead of...
Cancer cells have an increased need for glucose and, despite aerobic conditions, obtain their energy through aerobic oxidation and lactate fermentation, instead of aerobic oxidation alone. Glutamine is an essential amino acid in the human body. Glutaminolysis and glycolysis are crucial for cancer cell survival. In the therapy of estrogen receptor α (ERα)-positive breast cancer (BC), the focus lies on hormone sensitivity targeting therapy with selective estrogen receptor modulators (SERMs) such as 4-hydroxytamoxifen (4-OHT), although this therapy is partially limited by the development of resistance. Therefore, further targets for therapy improvement of ERα-positive BC with secondary 4-OHT resistance are needed. Hence, increased glucose requirement and upregulated glutaminolysis in BC cells could be used. We have established sublines of ERα-positive MCF7 and T47D BC cells, which were developed to be resistant to 4-OHT. Further, glycolysis inhibitor 2-Deoxy-D-Glucose (2-DG) and glutaminase inhibitor CB-839 were analyzed. Co-treatments using 4-OHT and CB-839, 2-DG and CB-839, or 4-OHT, 2-DG and CB-839, respectively, showed significantly stronger inhibitory effects on viability compared to single treatments. It could be shown that tamoxifen-resistant BC cell lines, compared to the non-resistant cell lines, exhibited a stronger reducing effect on cell viability under co-treatments. In addition, the tamoxifen-resistant BC cell lines showed increased expression of proto-oncogene c-Myc compared to the parental cell lines. This could be reduced depending on the treatment. Suppression of c-Myc expression using specific siRNA completely abolished resistance to 4OH-tamoxifen. In summary, our data suggest that combined treatments affecting the metabolism of BC are suitable depending on the cellularity and resistance status. In addition, the anti-metabolic treatments affected the expression of the proto-oncogene c-Myc, a key player in the regulation of cancer cell metabolism.
Topics: Antimetabolites; Apoptosis; Benzeneacetamides; Breast Neoplasms; Cell Proliferation; Deoxyglucose; Drug Resistance, Neoplasm; Drug Therapy, Combination; Estrogen Antagonists; Female; Glutaminase; Glycolysis; Humans; Proto-Oncogene Mas; Proto-Oncogene Proteins c-myc; Tamoxifen; Thiadiazoles; Tumor Cells, Cultured
PubMed: 34572047
DOI: 10.3390/cells10092398