RESUMO
Triple-negative breast cancer (TNBC) is an aggressive cancer subtype for which effective therapies are unavailable. TNBC has a high frequency of tumor protein p53 (Tp53/p53)- and phosphatase and tensin homolog (PTEN) deficiencies, and combined p53- and PTEN-deficiency is associated with poor prognosis and poor response to anticancer therapies. In this study, we discovered that combined p53- and PTEN-deficiency in TNBC activates expression of the transcription factor mesenchyme homeobox 1 (MEOX1). We found that MEOX1 is expressed only in TNBC cells with frequent deficiencies in p53 and PTEN, and that its expression is undetectable in luminal A, luminal B, and HER2+ subtypes, as well as in normal breast cells with wild-type (WT) p53 and PTEN. Notably, siRNA knockdown of both p53 and PTEN activated MEOX1 expression in breast cancer cells, whereas individual knockdowns of either p53 or PTEN had only minimal effects on MEOX1 expression. MEOX1 knockdown abolished cell proliferation of p53- and PTEN-deficient TNBC in vitro and inhibited tumor growth in vivo, but had no effect on the proliferation of luminal and HER2+ cancer cells and normal breast cells. RNA-Seq and immunoblotting analyses showed that MEOX1 knockdown decreased expression of tyrosine kinase 2 (TYK2), signal transducer and activator of transcription 5B (STAT5B), and STAT6 in p53- and PTEN-deficient TNBC cells. These results reveal the effects of combined p53- and PTEN-deficiency on MEOX1 expression and TNBC cell proliferation, suggesting that MEOX1 may serve as a potential therapeutic target for managing p53- and PTEN-deficient TNBC.
Assuntos
Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Proteínas de Homeodomínio/biossíntese , PTEN Fosfo-Hidrolase/deficiência , Fatores de Transcrição/biossíntese , Proteína Supressora de Tumor p53/deficiência , Animais , Feminino , Proteínas de Homeodomínio/genética , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , PTEN Fosfo-Hidrolase/metabolismo , Fator de Transcrição STAT5/biossíntese , Fator de Transcrição STAT5/genética , Fator de Transcrição STAT6/biossíntese , Fator de Transcrição STAT6/genética , TYK2 Quinase/biossíntese , TYK2 Quinase/genética , Fatores de Transcrição/genética , Neoplasias de Mama Triplo Negativas , Proteína Supressora de Tumor p53/metabolismoRESUMO
The transcription factor BCL11A has recently been reported to be a driving force in triple-negative breast cancer (TNBC), contributing to the maintenance of a chemoresistant breast cancer stem cell (BCSC) population. Although BCL11A was shown to suppress γ-globin and p21 and to induce MDM2 expression in the hematopoietic system, its downstream targets in TNBC are still unclear. For its role in transcriptional repression, BCL11A was found to interact with several corepressor complexes; however, the mechanisms underlying these interactions remain unknown. Here, we reveal that BCL11A interacts with histone methyltransferase (PRC2) and histone deacetylase (NuRD and SIN3A) complexes through their common subunit, RBBP4/7. In fluorescence polarization assays, we show that BCL11A competes with histone H3 for binding to the negatively charged top face of RBBP4. To define that interaction, we solved the crystal structure of RBBP4 in complex with an N-terminal peptide of BCL11A (residues 2-16, BCL11A(2-16)). The crystal structure identifies novel interactions between BCL11A and the side of the ß-propeller of RBBP4 that are not seen with histone H3. We next show that BCL11A(2-16) pulls down RBBP4, RBBP7, and other components of PRC2, NuRD, and SIN3A from the cell lysate of the TNBC cell line SUM149. Furthermore, we demonstrate the therapeutic potential of targeting the RBBP4-BCL11A binding by showing that a BCL11A peptide can decrease aldehyde dehydrogenase-positive BCSCs and mammosphere formation capacity in SUM149. Together, our findings have uncovered a previously unidentified mechanism that BCL11A may use to recruit epigenetic complexes to regulate transcription and promote tumorigenesis.
Assuntos
Proteínas de Transporte/metabolismo , Proteínas Nucleares/metabolismo , Proteína 4 de Ligação ao Retinoblastoma/metabolismo , Proteína 7 de Ligação ao Retinoblastoma/metabolismo , Carcinogênese , Proteínas de Transporte/química , Linhagem Celular , Cristalografia por Raios X , Epigenômica , Histona Desacetilases/metabolismo , Histona Metiltransferases/metabolismo , Humanos , Proteínas Nucleares/química , Ligação Proteica , Proteínas Repressoras , Proteína 4 de Ligação ao Retinoblastoma/química , Proteína 7 de Ligação ao Retinoblastoma/química , Fatores de Transcrição/metabolismo , Neoplasias de Mama Triplo Negativas/patologiaRESUMO
In light of the need for Extramural Hospital Information System (HIS) access through mobile devices outside the hospital, this research analyzes situational information security threats, including the circumstances in which a mobile device may get lost and personal data may be stolen. Moreover, the system needs to be implemented in accordance with the regulations. Based on the security threat analysis, it is proposed to use a security control module to provide a security-enabled HIS proxy module, two-way authentication module, and One-Time Password (OTP). The sending module and cryptographic technology computing module with Micro SD encryption card form a set of HIS extension system, which includes the SMS OTP method to simultaneously verify the two-way authentication mechanism of a user and the device that the user owns.
Assuntos
Telefone Celular , Segurança Computacional , Registros de Saúde Pessoal , Sistemas de Informação Hospitalar , Algoritmos , Confidencialidade , Humanos , TelemedicinaRESUMO
The first mock jury study in Taiwan, in which 279 community members watched a videotaped trial, investigated how jurors' estimates of the relative undesirability of wrongful conviction versus wrongful acquittal predicted individual decisions and how decision rules affected outcomes. The percentage of jurors who viewed wrongful conviction as more undesirable increased from 50.9% to 60.9% after deliberation and jurors' postdeliberation acquittal rate (71.7%) was higher than predeliberation acquittal rate (58.8%). Jurors' estimates of the undesirability of wrongful conviction were not correlated with their predeliberation votes but became positively correlated with their postdeliberation decisions. The unanimous rule facilitated jurors' change of vote, predominantly from conviction to acquittal, than the simple majority rule. Jurors reaching a verdict under the unanimous rule viewed deliberation and the verdict more positively. This study indicates that deliberation can ameliorate the problem of most Taiwanese citizens not viewing wrongful conviction as more undesirable than wrongful acquittal. It also suggests that Taiwan should adopt a unanimous rule for its proposed lay participation system.
Assuntos
Direito Penal , Tomada de Decisões , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Taiwan , Adulto JovemRESUMO
CDK4/6 inhibitors (CDK4/6i) have improved survival of patients with estrogen receptor-positive (ER+) breast cancer. However, patients treated with CDK4/6i eventually develop drug resistance and progress. RB1 loss-of-function alterations confer resistance to CDK4/6i, but the optimal therapy for these patients is unclear. Through a genome-wide CRISPR screen, we identify protein arginine methyltransferase 5 (PRMT5) as a molecular vulnerability in ER+/RB1-knockout breast cancer cells. Inhibition of PRMT5 blocks the G1-to-S transition in the cell cycle independent of RB, leading to growth arrest in RB1-knockout cells. Proteomics analysis uncovers fused in sarcoma (FUS) as a downstream effector of PRMT5. Inhibition of PRMT5 results in dissociation of FUS from RNA polymerase II, leading to hyperphosphorylation of serine 2 in RNA polymerase II, intron retention, and subsequent downregulation of proteins involved in DNA synthesis. Furthermore, treatment with the PRMT5 inhibitor pemrametostat and a selective ER degrader fulvestrant synergistically inhibits growth of ER+/RB-deficient cell-derived and patient-derived xenografts. These findings highlight dual ER and PRMT5 blockade as a potential therapeutic strategy to overcome resistance to CDK4/6i in ER+/RB-deficient breast cancer.
Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , RNA Polimerase II , Quinase 4 Dependente de Ciclina/metabolismo , Proteínas Inibidoras de Quinase Dependente de Ciclina , Quinase 6 Dependente de Ciclina/genética , Quinase 6 Dependente de Ciclina/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/genética , Proteína-Arginina N-Metiltransferases/genética , Proteína-Arginina N-Metiltransferases/metabolismoRESUMO
CDK4/6 inhibitors (CDK4/6i) have improved survival of patients with estrogen receptor-positive (ER+) breast cancer. However, patients treated with CDK4/6i eventually develop drug resistance and progress. RB1 loss-of-function alterations confer acquired resistance to CDK4/6i, but the optimal therapy for these patients is unclear. Using a genome-wide CRISPR screen, we identified protein arginine methyltransferase 5 (PRMT5) as a molecular vulnerability in ER+/RB1-knockout (RBKO) breast cancer cells. PRMT5 inhibition blocked cell cycle G1-to-S transition independent of RB, thus arresting growth of RBKO cells. Proteomics analysis uncovered fused in sarcoma (FUS) as a downstream effector of PRMT5. Pharmacological inhibition of PRMT5 resulted in dissociation of FUS from RNA polymerase II (Pol II), Ser2 Pol II hyperphosphorylation, and intron retention in genes that promote DNA synthesis. Treatment with the PRMT5i inhibitor pemrametostat and fulvestrant synergistically inhibited growth of ER+/RB-deficient patient-derived xenografts, suggesting dual ER and PRMT5 blockade as a novel therapeutic strategy to treat ER+/RB-deficient breast cancer.
RESUMO
The consumption of Chinese herbal medicines (CHMs) is increasing exponentially. Many patients utilize CHMs concomitantly with prescription drugs in great frequency. Herb-drug interaction has hence become an important focus of study. Transporter-mediated herb-drug interactions have the potential to seriously influence drug efficacy and toxicity. Since organic anion transporter 1 (OAT1) is crucial in renal active secretion and drug-drug interactions, the possibility of modulation of OAT1-mediated drug transport should be seriously concerned. Sixty-three clinically used CHMs were evaluated in the study. An hOAT1-overexpressing cell line was used for the in vitro CHMs screening, and the effective candidates were administered to Wistar rats to access renal hemodynamics. The regulation of OAT1 mRNA expression was also examined for further evidence of CHMs affecting OAT1-mediated transport. Among all the 63 CHMs, formulae Gui Zhi Fu Ling Wan (GZ) and Chia Wei Hsiao Yao San (CW) exhibited significant inhibitions on hOAT1-mediated [(3)H]-PAH uptake in vitro and PAH clearance and net secretion in vivo. Moreover, GZ showed concentration-dependent manners both in vitro and in vivo, and the decrease of rOAT1 mRNA expression indicated that GZ not only inhibited function of OAT1 but also suppressed expression of OAT1.
RESUMO
The MYC oncogene is frequently amplified in triple-negative breast cancer (TNBC). Here, we show that MYC suppression induces immune-related hallmark gene set expression and tumor-infiltrating T cells in MYC-hyperactivated TNBCs. Mechanistically, MYC repressed stimulator of interferon genes (STING) expression via direct binding to the STING1 enhancer region, resulting in downregulation of the T-cell chemokines CCL5, CXCL10, and CXCL11. In primary and metastatic TNBC cohorts, tumors with high MYC expression or activity exhibited low STING expression. Using a CRISPR-mediated enhancer perturbation approach, we demonstrated that MYC-driven immune evasion is mediated by STING repression. STING repression induced resistance to PD-L1 blockade in mouse models of TNBC. Finally, a small-molecule inhibitor of MYC combined with PD-L1 blockade elicited a durable response in immune-cold TNBC with high MYC expression, suggesting a strategy to restore PD-L1 inhibitor sensitivity in MYC-overexpressing TNBC.
Assuntos
Proteínas de Membrana/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Neoplasias de Mama Triplo Negativas , Animais , Antígeno B7-H1 , Linhagem Celular Tumoral , Repressão Epigenética , Humanos , Inibidores de Checkpoint Imunológico/farmacologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Evasão da Resposta Imune , Camundongos , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/patologiaRESUMO
BACKGROUND AND OBJECTIVES: An accurate estimate of the loss of lifetime employment duration resulting from kidney failure can facilitate comprehensive evaluation of societal financial burdens. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: All patients undergoing incident dialysis in Taiwan during 2000-2017 were identified using the National Health Insurance Research Database. The corresponding age-, sex-, and calendar year-matched general population served as the referents. The survival functions and the employment states of the index cohort (patients on dialysis) and their referents for each age strata were first calculated, and then extrapolated until age 65 years, where the sum of the product of the survival function and the employment states was the lifetime employment duration. The difference in lifetime employment duration between the index and referent cohort was the loss of lifetime employment duration. Extrapolation of survival function and relative employment-to-population ratios were estimated by the restricted cubic spline models and the quadratic/linear models, respectively. RESULTS: A total of 83,358 patients with kidney failure were identified. Men had a higher rate of employment than women in each age strata. The expected loss of lifetime employment duration for men with kidney failure was 11.8, 7.6, 5.7, 3.8, 2.3, 1.0, and 0.2 years for those aged 25-34, 35-40, 41-45, 46-50, 51-55, 56-60, and 61-64 years, respectively; and the corresponding data for women was 10.5, 10.1, 7.9, 5.6, 3.3, 1.5, and 0.3 years, respectively. The values for loss of lifetime employment duration divided by loss of life expectancy were all >70% for women and >88% for men across the different age strata. The sensitivity analyses indicated that the results were robust. CONCLUSIONS: The loss of lifetime employment duration in patients undergoing dialysis mainly originates from loss of life expectancy.
Assuntos
Emprego/estatística & dados numéricos , Falência Renal Crônica/terapia , Expectativa de Vida , Diálise Renal , Adulto , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Taiwan , Fatores de TempoRESUMO
PURPOSE: FGFR1 overexpression has been associated with endocrine resistance in ER+ breast cancer. We found FGFR1 localized in the nucleus of breast cancer cells in primary tumors resistant to estrogen suppression. We investigated a role of nuclear FGFR1 on gene transcription and antiestrogen resistance. EXPERIMENTAL DESIGN: Tumors from patients treated with letrozole were subjected to Ki67 and FGFR1 IHC. MCF7 cells were transduced with FGFR1(SP-)(NLS) to promote nuclear FGFR1 overexpression. FGFR1 genomic activity in ER+/FGFR1-amplified breast cancer cells ± FOXA1 siRNA or ± the FGFR tyrosine kinase inhibitor (TKI) erdafitinib was examined by chromatin immunoprecipitation sequencing (ChIP-seq) and RNA sequencing (RNA-seq). The nuclear and chromatin-bound FGFR1 interactome was investigated by mass spectrometry (MS). RESULTS: High nuclear FGFR1 expression in ER+ primary tumors positively correlated with post-letrozole Ki67 values. Nuclear FGFR1 overexpression influenced gene transcription and promoted resistance to estrogen suppression and to fulvestrant in vivo. A gene expression signature induced by nuclear FGFR1 correlated with shorter survival in the METABRIC cohort of patients treated with antiestrogens. ChIP-Seq revealed FGFR1 occupancy at transcription start sites, overlapping with active transcription histone marks. MS analysis of the nuclear FGFR1 interactome identified phosphorylated RNA-Polymerase II and FOXA1, with FOXA1 RNAi impairing FGFR1 recruitment to chromatin. Treatment with erdafitinib did not impair nuclear FGFR1 translocation and genomic activity. CONCLUSIONS: These data suggest nuclear FGFR1 contributes to endocrine resistance by modulating gene transcription in ER+ breast cancer. Nuclear FGFR1 activity was unaffected by FGFR TKIs, thus supporting the development of treatment strategies to inhibit nuclear FGFR1 in ER+/FGFR1 overexpressing breast cancer.
Assuntos
Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Resistencia a Medicamentos Antineoplásicos/genética , Moduladores de Receptor Estrogênico/uso terapêutico , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/fisiologia , Transcrição Gênica/fisiologia , Neoplasias da Mama/química , Núcleo Celular , Feminino , Humanos , Receptores de Estrogênio/análise , Células Tumorais CultivadasRESUMO
Activating mutations in HER2 (ERBB2) drive the growth of a subset of breast and other cancers and tend to co-occur with HER3 (ERBB3) missense mutations. The HER2 tyrosine kinase inhibitor neratinib has shown clinical activity against HER2-mutant tumors. To characterize the role of HER3 mutations in HER2-mutant tumors, we integrate computational structural modeling with biochemical and cell biological analyses. Computational modeling predicts that the frequent HER3E928G kinase domain mutation enhances the affinity of HER2/HER3 and reduces binding of HER2 to its inhibitor neratinib. Co-expression of mutant HER2/HER3 enhances HER2/HER3 co-immunoprecipitation and ligand-independent activation of HER2/HER3 and PI3K/AKT, resulting in enhanced growth, invasiveness, and resistance to HER2-targeted therapies, which can be reversed by combined treatment with PI3Kα inhibitors. Our results provide a mechanistic rationale for the evolutionary selection of co-occurring HER2/HER3 mutations and the recent clinical observations that HER3 mutations are associated with a poor response to neratinib in HER2-mutant cancers.
Assuntos
Neoplasias da Mama/genética , Mutação com Ganho de Função , Quinolinas/farmacologia , Receptor ErbB-2/genética , Receptor ErbB-3/genética , Aminopiridinas/administração & dosagem , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Humanos , Camundongos Nus , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Morfolinas/administração & dosagem , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase/administração & dosagem , Multimerização Proteica , Quinolinas/administração & dosagem , Quinolinas/química , Quinolinas/metabolismo , Receptor ErbB-2/antagonistas & inibidores , Receptor ErbB-2/química , Receptor ErbB-2/metabolismo , Receptor ErbB-3/química , Receptor ErbB-3/metabolismo , Trastuzumab/farmacologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
An efficient stereoselective synthesis of alpha-(2-->9)-tetrasialic acid was achieved using tri-O-chloroacetyl-derivatized sialyl donor and a triol sialyl acceptor. Both the acceptor and the donor were also protected with a cyclic 5-N-4-O-carbonyl protecting group. The donor is highly reactive and enabled alpha-selective sialylation with various primary, secondary, and tertiary acceptors under in situ activation conditions (NIS/TfOH, -78 degrees C, acetonitrile/dichloromethane). The trans-fused oxazolidinone ring and O-chloroacetyl protecting groups were easily removed under mild reaction conditions to provide the fully deprotected alpha(2-->9)-tetrasialic acid.
RESUMO
The first liquid chromatography-tandem mass spectrometry method was developed and validated for the simultaneous quantification of p-aminohippuric acid and inulin, both typical biomarkers of kidney function. 5-(Hydroxymethyl)furfural, generated from inulin by acid and heat preparation, was used as an inulin substitute for the quantification. Acetaminophen was used as the internal standard. Solid-phase extraction was carried out with 5% methanol as the washing solution to optimize the retention of the analytes and to avoid obstruction of the orifice plate of the mass spectrometer caused by any unreacted inulin residue remaining from the sample preparation process. Chromatography separation was performed on a Symmetry C(18) column and a mobile phase composed of 2 mM ammonium formate and 0.1% formic acid in water (solvent A) and 2 mM ammonium formate and 0.1% formic acid in acetonitrile (solvent B) (30:70, v/v). Detection was performed with a triple-quadrupole tandem mass spectrometer using positive ion mode electrospray ionization in the multiple reaction monitoring mode. The selected transitions were m/z 195.2 â 120.2, 127.1 â 109.1, and 152.1 â 110.0 for p-aminohippuric acid, inulin [measured as 5-(hydroxymethyl)furfural], and acetaminophen, respectively. The linearity ranged from 10 to 140 µg/mL and from 100 to 1,400 µg/mL for p-aminohippurric acid and inulin (r > 0.99), respectively. The precisions and accuracies were all within 12 and 11% for the lower limit of quantification and quality control samples, respectively. This application was proven to be reliable and accurate and was successfully applied to a renal function study.
Assuntos
Inulina/sangue , Espectrometria de Massas em Tandem/métodos , Ácido p-Aminoipúrico/sangue , Animais , Cromatografia Líquida/métodos , Rim/metabolismo , Testes de Função Renal , Masculino , Ratos , Ratos Wistar , Sensibilidade e Especificidade , Extração em Fase Sólida/métodosRESUMO
The 17q23 amplicon is associated with poor outcome in ER+ breast cancers, but the causal genes to endocrine resistance in this amplicon are unclear. Here, we interrogate transcriptome data from primary breast tumors and find that among genes in 17q23, PRR11 is a key gene associated with a poor response to therapeutic estrogen suppression. PRR11 promotes estrogen-independent proliferation and confers endocrine resistance in ER+ breast cancers. Mechanistically, the proline-rich motif-mediated interaction of PRR11 with the p85α regulatory subunit of PI3K suppresses p85 homodimerization, thus enhancing insulin-stimulated binding of p110-p85α heterodimers to IRS1 and activation of PI3K. PRR11-amplified breast cancer cells rely on PIK3CA and are highly sensitive to PI3K inhibitors, suggesting that PRR11 amplification confers PI3K dependence. Finally, genetic and pharmacological inhibition of PI3K suppresses PRR11-mediated, estrogen-independent growth. These data suggest ER+/PRR11-amplified breast cancers as a novel subgroup of tumors that may benefit from treatment with PI3K inhibitors and antiestrogens.
Assuntos
Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Moduladores de Receptor Estrogênico/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas/genética , Proteínas/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células , Classe I de Fosfatidilinositol 3-Quinases/metabolismo , Modelos Animais de Doenças , Resistencia a Medicamentos Antineoplásicos , Antagonistas de Estrogênios/farmacologia , Moduladores de Receptor Estrogênico/uso terapêutico , Estrogênios , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Insulina , Camundongos Nus , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
A sensitive and selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination of triazolam and its metabolites, alpha-hydroxytriazolam (alpha-OHTRZ) and 4-hydroxytriazolam (4-OHTRZ), was developed and validated. Triazolam-D4 was used as the internal standard (IS). This analysis was carried out on a Thermo C(18) column and the mobile phase was composed of acetonitrile:H(2)O:formic acid (35:65:0.2, v/v/v). Detection was performed on a triple-quadrupole tandem mass spectrometer using positive ion mode electrospray ionization (ESI) and quantification was performed by multiple reaction monitoring (MRM) mode. The MS/MS ion transitions monitored were m/z 343.1-->308.3, 359.0-->308.3, 359.0-->111.2 and 347.0-->312.0 for triazolam, alpha-OHTRZ, 4-OHTRZ and triazolam-D4, respectively. LLOQ of the analytical method was 0.05 ng/mL for triazolam and 0.1 ng/mL for alpha-OHTRZ and 4-OHTRZ. The within- and between-run precisions were less than 15.26% and accuracy was -8.08% to 13.33%. The method proved to be accurate and specific, and was applied to the pharmacokinetic study of triazolam in healthy Chinese volunteers.
Assuntos
Ansiolíticos/sangue , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas em Tandem/métodos , Triazolam/sangue , Ansiolíticos/farmacocinética , Humanos , Padrões de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Triazolam/farmacocinéticaRESUMO
Targeting cancer stem cells (CSCs) is a key strategy to prevent cancers from developing drug resistance and metastasis. Mitochondria have been reported to be a vulnerability of CSCs by multiple studies. Here, we report that doxycycline, functioning as an inhibitor of mitochondrial biogenesis, can effectively target breast cancer stem cells (BCSCs). Our results revealed that doxycycline significantly decreased the frequency of aldehyde dehydrogenasepositive (ALDH+) BCSCs as well as mammosphere formation efficiency in HER2+ and triplenegative breast cancer (TNBC) subtypes. Doxycycline also ameliorated paclitaxelinduced enrichment of ALDH+ BCSCs in TNBC. Mechanistically, we showed that doxycycline decreased the level of reactive oxygen species and their downstream p38 MAPK pathway. In agreement with the key role for p38 in maintaining BCSCs, a specific inhibitor targeting this MAPK pathway significantly decreased the number of ALDH+ cells. Doxycycline is a FDAapproved drug with minor and limited sideeffects. Given doxycycline's low toxicity and strong effect on BCSC inhibition, we report that doxycycline should be safe to be used concomitantly with chemotherapy drugs to eradicate both CSCs and bulk tumor cells.
Assuntos
Aldeído Desidrogenase/metabolismo , Neoplasias da Mama/metabolismo , Doxiciclina/farmacologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Células MCF-7 , Células-Tronco Neoplásicas/metabolismo , Espécies Reativas de Oxigênio/metabolismoRESUMO
Triple-negative breast cancer (TNBC) is the most difficult subtype of breast cancer to treat due to a paucity of effective targeted therapies. Many studies have reported that breast cancer stem cells (BCSCs) are enriched in TNBC and are responsible for chemoresistance and metastasis. In this study, we identify LRP8 as a novel positive regulator of BCSCs in TNBC. LRP8 is highly expressed in TNBC compared to other breast cancer subtypes and its genomic locus is amplified in 24% of TNBC tumors. Knockdown of LRP8 in TNBC cell lines inhibits Wnt/ß-catenin signaling, decreases BCSCs, and suppresses tumorigenic potential in xenograft models. LRP8 knockdown also induces a more differentiated, luminal-epithelial phenotype and thus sensitizes the TNBC cells to chemotherapy. Together, our study highlights LRP8 as a novel therapeutic target for TNBC as inhibition of LRP8 can attenuate Wnt/ß-catenin signaling to suppress BCSCs.
Assuntos
Neoplasias da Mama/genética , Proteínas Relacionadas a Receptor de LDL/genética , Células-Tronco Neoplásicas/metabolismo , Interferência de RNA , Neoplasias de Mama Triplo Negativas/genética , Animais , Neoplasias da Mama/metabolismo , Neoplasias da Mama/terapia , Linhagem Celular Tumoral , Feminino , Células HEK293 , Humanos , Estimativa de Kaplan-Meier , Proteínas Relacionadas a Receptor de LDL/metabolismo , Camundongos Endogâmicos NOD , Camundongos SCID , Terapêutica com RNAi/métodos , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/terapia , Carga Tumoral/genética , Via de Sinalização Wnt/genética , Ensaios Antitumorais Modelo de Xenoenxerto/métodos , beta Catenina/genéticaRESUMO
Numb chin syndrome (NCS) is a multifactorial neuropathic disorder associated with paresthesia to the chin, lip, and oral mucosa, particularly arising as a sequela to various dental-related procedures or infections in the mandible. Timely elucidation of the underlying etiology is of paramount importance as the presentation of NCS could serve as a harbinger of malignancy or metastatic disease. This report describes an unusual case of NCS developing synchronously with a vertical root fracture and odontogenic infection in a mandibular first molar. Clinicians should consider the inclusion of a vertical root fracture as plausible cofactor for the development of NCS.
Assuntos
Queixo , Necrose da Polpa Dentária/diagnóstico por imagem , Necrose da Polpa Dentária/cirurgia , Hipestesia/etiologia , Fraturas dos Dentes/diagnóstico por imagem , Fraturas dos Dentes/cirurgia , Raiz Dentária/lesões , Diagnóstico Diferencial , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Medição da Dor , Radiografia Panorâmica , Síndrome , Tomografia Computadorizada por Raios X , Extração DentáriaRESUMO
Vanadyl triflate has been identified as a mild and efficient catalyst for the chemoselective O-isopropylidenation of functionalized carbohydrates with acetone and acetone equivalents. The current protocol is compatible with a diverse array of protecting groups and the products can be readily isolated by simple aqueous wash.
Assuntos
Acetona/química , Carboidratos/química , Mesilatos/química , Vanadatos/química , Catálise , Glicosídeos/síntese química , Glicosídeos/química , Espectroscopia de Ressonância Magnética , Estrutura MolecularRESUMO
An enzymatic one-pot three-step glycosylation strategy was developed for the synthesis of sLex moiety of truncated PSGL-1 glycopeptide with and without sulfation. The method provided an efficient way to afford complex glycopeptides in a semi-preparative scale without further complicated and time-consuming purification process in each glycosylation step.