Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 17 de 17
Filter
1.
Hypertens Pregnancy ; 42(1): 2285757, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38017693

ABSTRACT

OBJECTIVE: The aim of this study was to investigate the possible causal relationship between COVID-19 and the risk of pre-eclampsia/eclampsia using a Mendelian randomized (MR) design. METHODS: We estimated their genetic correlations and then performed two-sample Mendelian randomization analyses using pooled statistics from the COVID-19 susceptibility/hospitalization genome-wide association study and the pre-eclampsia/eclampsia datasets. The main analyses were performed using the inverse variance weighting method, supplemented by the weighted median method and the MR-Egger method. RESULTS: We identified a significant and positive genetic correlation between COVID-19 susceptibility and pre-eclampsia/eclampsia [OR = 1.23 (1.01-1.51), p = 0.043]. Meanwhile, hospitalization of COVID-19 was significantly associated with a higher risk of pre-eclampsia/eclampsia [OR = 1.15 (1.02-1.30), p = 0.024]. Consistently, hospitalization of COVID-19 were nominally associated with higher risk of pre-eclampsia [OR = 1.14, (1.01-1.30), p = 0.040]. The results were robust under all sensitivity analyses. CONCLUSION: These results suggest that COVID-19 may increase the risk of pre-eclampsia/eclampsia. Future development of preventive or therapeutic interventions should emphasize this to mitigate the complications of COVID-19. [Figure: see text].


Subject(s)
COVID-19 , Eclampsia , Pre-Eclampsia , Female , Pregnancy , Humans , Genome-Wide Association Study , Mendelian Randomization Analysis , Pre-Eclampsia/genetics
2.
Target Oncol ; 18(2): 269-285, 2023 03.
Article in English | MEDLINE | ID: mdl-36826464

ABSTRACT

BACKGROUND: Patients with triple-negative breast cancer (TNBC) expressing the androgen receptor (AR) respond poorly to neoadjuvant chemotherapy, although AR antagonists have shown promising clinical activity, suggesting these tumors are AR-dependent. cAMP responsive element binding protein (CREB)-binding protein (CBP) and p300 are transcriptional co-activators for the AR, a key driver of AR+ breast and prostate cancer, and may provide a novel therapeutic target in AR+ TNBC. OBJECTIVES: The aim of this study was to determine the therapeutic potential of FT-6876, a new CBP/p300 bromodomain inhibitor, in breast cancer models with a range of AR levels in vitro and in vivo. METHODS: Effects of FT-6876 on the CBP/p300 pathway were determined by combining chromatin immunoprecipitation (ChIP) with precision run-on sequencing (PRO-seq) complemented with H3K27 acetylation (Ac) and transcriptional profiling. The antiproliferative effect of FT-6876 was also measured in vitro and in vivo. RESULTS: We describe the discovery of FT-6876, a potent and selective CBP/p300 bromodomain inhibitor. The combination of ChIP and PRO-seq confirmed the reduction in H3K27Ac at specific promoter sites concurrent with a decrease in CBP/p300 on the chromatin and a reduction in nascent RNA and enhancer RNA. This was associated with a time- and concentration-dependent reduction in H3K37Ac associated with a decrease in AR and estrogen receptor (ER) target gene expression. This led to a time-dependent growth inhibition in AR+ models, correlated with AR expression. Tumor growth inhibition was also observed in AR+ tumor models of TNBC and ER+ breast cancer subtypes with consistent pharmacokinetics and pharmacodynamics. CONCLUSION: Our findings demonstrate FT-6876 as a promising new CBP/p300 bromodomain inhibitor, with efficacy in preclinical models of AR+ breast cancer.


Subject(s)
Receptors, Androgen , Triple Negative Breast Neoplasms , Male , Humans , Receptors, Androgen/metabolism , CREB-Binding Protein/genetics , CREB-Binding Protein/metabolism , Protein Binding , RNA/metabolism
3.
Nurs Open ; 8(5): 2686-2695, 2021 09.
Article in English | MEDLINE | ID: mdl-33760375

ABSTRACT

AIM: To analyse the application status of nursing assessment terminology for neurological conditions and determine whether the International Classification of Functioning, Disability, and Health (ICF) covers nursing assessment. DESIGN: A multi-centre cross-sectional study. METHODS: Four researchers extracted all nursing problems from the patients of three different hospitals and formed a pool of nursing terminology from the electronic nursing records, self-reports, family reports, medical examinations, and clinical records for all patients. The ICF Linking Rules were then used to map the nursing assessment terminology of neurological conditions with the ICF. RESULTS: Though 37.5% of nursing assessment terms were closely related to neurological diseases, this does not appear in the existing electronic nursing assessment records. The unrecorded rate of 9 (16.1%) terms ranged from 40%-50%, while the unrecorded rate of 8 (14.3%) terms was more than 80%. Overall, 96.4% of nursing assessment terms could be described by the corresponding categories of the ICF, with 37 (66.1%) of the "same" concepts, 9 (16.1%) "similar" concepts, 6 (10.7%) "narrower" concepts (the nursing assessment terms were more specific than the ICF categories), and 2 (3.6%) "broader" concepts (the nursing assessment were less specific than the ICF categories).


Subject(s)
International Classification of Functioning, Disability and Health , Standardized Nursing Terminology , Cross-Sectional Studies , Disability Evaluation , Humans , Nursing Assessment
4.
J Diabetes Investig ; 9(6): 1360-1369, 2018 Nov.
Article in English | MEDLINE | ID: mdl-29575786

ABSTRACT

AIMS/INTRODUCTION: To explore the association between lactation and type 2 diabetes incidence in women with prior gestational diabetes. MATERIALS AND METHODS: We searched PubMed, Embase and the Cochrane Library for cohort studies published through 12 June 2017 that evaluated the effect of lactation on the development of type 2 diabetes in women with prior gestational diabetes. A random effects model was used to estimate relative risks (RRs) with 95% confidence intervals (CIs). RESULTS: A total of 13 cohort studies were included in the meta-analysis. The pooled result suggested that compared with no lactation, lactation was significantly associated with a lower risk of type 2 diabetes (RR 0.66, 95% CI 0.48-0.90, I2  = 72.8%, P < 0.001). This relationship was prominent in a study carried out in the USA (RR 0.66, 95% CI 0.43-0.99), regardless of study design (prospective design RR 0.56, 95% CI 0.41-0.76; retrospective design RR 0.63, 95% CI 0.40-0.99), smaller sample size (RR 0.52, 95% CI 0.30-0.92, P = 0.024) and follow-up duration >1 years (RR 0.75, 95% CI 0.56-1.00), and the study used adjusted data (RR 0.69, 95% CI 0.50-0.94). Finally, by pooling data from three studies, we failed to show that compared with no lactation, long-term lactation (>1 to 3 months postpartum) was associated with the type 2 diabetes risk (RR 0.69, 95% CI 0.41-1.17). CONCLUSIONS: The present meta-analysis showed that lactation was associated with a lower risk of type 2 diabetes in women with prior gestational diabetes. Furthermore, no significant relationship between long-term lactation and type 2 diabetes risk was detected. The impact of long-term lactation and the risk of type 2 diabetes should be verified in further large-scale studies.


Subject(s)
Diabetes Mellitus, Type 2/epidemiology , Diabetes, Gestational/epidemiology , Disease Progression , Lactation , Cohort Studies , Diabetes Mellitus, Type 2/physiopathology , Diabetes, Gestational/physiopathology , Female , Humans , Pregnancy , Risk Factors
5.
Oncotarget ; 8(31): 51733-51747, 2017 Aug 01.
Article in English | MEDLINE | ID: mdl-28881682

ABSTRACT

Because cancer stem cells (CSCs) have been implicated in chemo-resistance, metastasis and tumor recurrence, therapeutic targeting of CSCs holds promise to address these clinical challenges to cancer treatment. VS-4718 and VS-6063 are potent inhibitors of focal adhesion kinase (FAK), a non-receptor tyrosine kinase that mediates cell signals transmitted by integrins and growth factor receptors. We report here that inhibition of FAK kinase activity by VS-4718 or VS-6063 preferentially targets CSCs, as demonstrated by a panel of orthogonal CSC assays in cell line models and surgically resected primary breast tumor specimens cultured ex vivo. Oral administration of VS-4718 or VS-6063 to mice bearing xenograft models of triple-negative breast cancer (TNBC) significantly reduced the proportion of CSCs in the tumors, as evidenced by a reduced tumor-initiating capability upon re-implantation in limiting dilutions of cells prepared from these tumors. In contrast, the cytotoxic chemotherapeutic agents, paclitaxel and carboplatin, enriched for CSCs, consistent with previous reports that these cytotoxic agents preferentially target non-CSCs. Importantly, VS-4718 and VS-6063 attenuated the chemotherapy-induced enrichment of CSCs in vitro and delayed tumor regrowth following cessation of chemotherapy. An intriguing crosstalk between FAK and the Wnt/ß-catenin pathway was revealed wherein FAK inhibition blocks ß-catenin activation by reducing tyrosine 654 phosphorylation of ß-catenin. Furthermore, a constitutively active mutant form of ß-catenin reversed the preferential targeting of CSCs by FAK inhibition, suggesting that this targeting is mediated, at least in part, through attenuating ß-catenin activation. The preferential targeting of cancer stem cells by FAK inhibitors provides a rationale for the clinical development of FAK inhibitors aimed to increase durable responses for cancer patients.

6.
Int J Cancer ; 139(9): 2116-26, 2016 11 01.
Article in English | MEDLINE | ID: mdl-27376928

ABSTRACT

Pancreatic cancer, the fourth leading cause of cancer death in the United States, has a negative prognosis because metastasis occurs before symptoms manifest. Leiodermatolide, a polyketide macrolide with antimitotic activity isolated from a deep water sponge of the genus Leiodermatium, exhibits potent and selective cytotoxicity toward the pancreatic cancer cell lines AsPC-1, PANC-1, BxPC-3, and MIA PaCa-2, and potent cytotoxicity against skin, breast and colon cancer cell lines. Induction of apoptosis by leiodermatolide was confirmed in the AsPC-1, BxPC-3 and MIA PaCa-2 cells. Leiodermatolide induces cell cycle arrest but has no effects on in vitro polymerization or depolymerization of tubulin alone, while it enhances polymerization of tubulin containing microtubule associated proteins (MAPs). Observations through confocal microscopy show that leiodermatolide, at low concentrations, causes minimal effects on polymerization or depolymerization of the microtubule network in interphase cells, but disruption of spindle formation in mitotic cells. At higher concentrations, depolymerization of the microtubule network is observed. Visualization of the growing microtubule in HeLa cells expressing GFP-tagged plus end binding protein EB-1 showed that leiodermatolide stopped the polymerization of tubulin. These results suggest that leiodermatolide may affect tubulin dynamics without directly interacting with tubulin and hint at a unique mechanism of action. In a mouse model of metastatic pancreatic cancer, leiodermatolide exhibited significant tumor reduction when compared to gemcitabine and controls. The antitumor activities of leiodermatolide, as well as the proven utility of antimitotic compounds against cancer, make leiodermatolide an interesting compound with potential chemotherapeutic effects that may merit further research.


Subject(s)
Antineoplastic Agents/administration & dosage , Macrolides/administration & dosage , Microtubules/drug effects , Pancreatic Neoplasms/drug therapy , Tubulin Modulators/administration & dosage , Animals , Antineoplastic Agents/pharmacology , Apoptosis , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Gene Expression Regulation, Neoplastic/drug effects , HeLa Cells , Humans , Macrolides/pharmacology , Mice , Microtubule-Associated Proteins/metabolism , Neoplasm Metastasis , Pancreatic Neoplasms/metabolism , Tubulin Modulators/pharmacology , Xenograft Model Antitumor Assays
7.
Cancer Biol Ther ; 16(4): 589-601, 2015.
Article in English | MEDLINE | ID: mdl-25729885

ABSTRACT

Natural compound schweinfurthins are of considerable interest for novel therapy development because of their selective anti-proliferative activity against human cancer cells. We previously reported the isolation of highly active schweinfurthins E-H, and in the present study, mechanisms of the potent and selective anti-proliferation were investigated. We found that schweinfurthins preferentially inhibited the proliferation of PTEN deficient cancer cells by indirect inhibition of AKT phosphorylation. Mechanistically, schweinfurthins and their analogs arrested trans-Golgi-network trafficking, an intracellular vesicular trafficking system, resulting in the induction of endoplasmic reticulum stress and the suppression of both lipid raft-mediated PI3K activation and mTOR/RheB complex formation, which collectively led to an effective inhibition of mTOR/AKT signaling. The trans-Golgi-network traffic arresting effect of schweinfurthins was associated with their in vitro binding activity to oxysterol-binding proteins that are known to regulate intracellular vesicular trafficking. Moreover, schweinfurthins were found to be highly toxic toward PTEN-deficient B cell lymphoma cells, and displayed 2 orders of magnitude lower activity toward normal human peripheral blood mononuclear cells and primary fibroblasts in vitro. These results revealed a previously unrecognized role of schweinfurthins in regulating trans-Golgi-network trafficking, and linked mechanistically this cellular effect with mTOR/AKT signaling and with cancer cell survival and growth. Our findings suggest the schweinfurthin class of compounds as a novel approach to modulate oncogenic mTOR/AKT signaling for cancer treatment.


Subject(s)
Cell Proliferation/drug effects , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction/drug effects , Small Molecule Libraries/pharmacology , Stilbenes/pharmacology , TOR Serine-Threonine Kinases/metabolism , trans-Golgi Network/drug effects , Cell Line , Cell Line, Tumor , Cell Survival/drug effects , Fibroblasts/drug effects , Fibroblasts/metabolism , Humans , Leukocytes, Mononuclear/drug effects , Leukocytes, Mononuclear/metabolism , Lymphoma, B-Cell/metabolism , PTEN Phosphohydrolase/metabolism , Phosphatidylinositol 3-Kinases/metabolism
8.
Cancer Res ; 75(2): 446-55, 2015 Jan 15.
Article in English | MEDLINE | ID: mdl-25432176

ABSTRACT

Cancer stem cells (CSC) have been implicated in disease recurrence, metastasis, and therapeutic resistance, but effective targeting strategies for these cells are still wanting. VS-5584 is a potent and selective dual inhibitor of mTORC1/2 and class I PI 3-kinases. Here, we report that VS-5584 is up to 30-fold more potent in inhibiting the proliferation and survival of CSC compared with non-CSC in solid tumor cell populations. VS-5584 preferentially diminished CSC levels in multiple mouse xenograft models of human cancer, as evidenced by marked reduction of tumor-initiating capacity in limiting dilution assays. Likewise, VS-5584 treatment ex vivo preferentially reduced CSC in surgically resected breast and ovarian patient tumors. In contrast, chemotherapeutics such as paclitaxel and cisplatin were less effective in targeting CSC than bulk tumor cells. Mechanistic investigations revealed that preferential targeting of CSC required inhibition of multiple components of the PI3K-mTOR pathway: coordinate RNAi-mediated silencing of PI3Kα, PI3Kß, and mTOR phenocopied the effect of VS-5584, exhibiting the strongest preferential targeting of CSC, while silencing of individual PI3K isoforms or mTOR failed to replicate the effect of VS-5584. Consistent with CSC ablation, VS-5584 delayed tumor regrowth following chemotherapy in xenograft models of small-cell lung cancer. Taken together, the preferential targeting of CSC prompts a new paradigm for clinical testing of VS-5584: clinical trials designed with CSC-directed endpoints may facilitate demonstration of the therapeutic benefit of VS-5584. We suggest that combining VS-5584 with classic chemotherapy that debulks tumors may engender a more effective strategy to achieve durable remissions in patients with cancer.


Subject(s)
Breast Neoplasms/drug therapy , Morpholines/pharmacology , Neoplastic Stem Cells/drug effects , Neoplastic Stem Cells/enzymology , Ovarian Neoplasms/drug therapy , Phosphoinositide-3 Kinase Inhibitors , Protein Kinase Inhibitors/pharmacology , Purines/pharmacology , TOR Serine-Threonine Kinases/antagonists & inhibitors , Animals , Breast Neoplasms/enzymology , Breast Neoplasms/pathology , Female , Humans , MCF-7 Cells , Mice , Mice, Inbred NOD , Mice, SCID , Ovarian Neoplasms/enzymology , Ovarian Neoplasms/pathology , Phosphatidylinositol 3-Kinases/metabolism , Random Allocation , TOR Serine-Threonine Kinases/metabolism , Xenograft Model Antitumor Assays
9.
Blood ; 124(17): 2675-86, 2014 Oct 23.
Article in English | MEDLINE | ID: mdl-25217697

ABSTRACT

Proline-rich tyrosine kinase 2 (Pyk2) is a member of the focal adhesion kinase family that has been recently linked to tumor development. However, its role in modulating multiple myeloma (MM) biology and disease progression remains unexplored. We first demonstrated that patients with MM present with higher expression of Pyk2 compared with healthy individuals. By using loss-of-function approaches, we found that Pyk2 inhibition led to reduction of MM tumor growth in vivo as well as decreased cell proliferation, cell-cycle progression, and adhesion ability in vitro. In turn, overexpression of Pyk2 promoted the malignant phenotype, substantiated by enhanced tumor growth and reduced survival. Mechanistically, inhibition of Pyk2 reduced activation of Wnt/ß-catenin signaling by destabilizing ß-catenin, leading to downregulation of c-Myc and Cyclin D1. Furthermore, treatment of MM cells with the FAK/Pyk2 inhibitor VS-4718 effectively inhibited MM cell growth both in vitro and in vivo. Collectively, our findings describe the tumor-promoting role of Pyk2 in MM, thus providing molecular evidence for a novel tyrosine kinase inhibitor as a new therapeutic option in MM.


Subject(s)
Aminopyridines/pharmacology , Focal Adhesion Kinase 2/antagonists & inhibitors , Multiple Myeloma/prevention & control , Protein Kinase Inhibitors/pharmacology , Xenograft Model Antitumor Assays , Animals , Cell Adhesion/drug effects , Cell Adhesion/genetics , Cell Cycle/drug effects , Cell Cycle/genetics , Cell Line, Tumor , Cell Proliferation/drug effects , Cells, Cultured , Disease Progression , Female , Focal Adhesion Kinase 2/genetics , Focal Adhesion Kinase 2/metabolism , Gene Expression Regulation, Enzymologic/drug effects , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism , HEK293 Cells , Humans , Immunoblotting , Luminescent Measurements , Mice, SCID , Multiple Myeloma/genetics , Multiple Myeloma/metabolism , RNA Interference , Reverse Transcriptase Polymerase Chain Reaction , Survival Analysis , Tumor Burden/drug effects , Tumor Burden/genetics , Wnt Signaling Pathway/drug effects , beta Catenin/metabolism
10.
Sci Transl Med ; 6(237): 237ra68, 2014 May 21.
Article in English | MEDLINE | ID: mdl-24848258

ABSTRACT

The goal of targeted therapy is to match a selective drug with a genetic lesion that predicts for drug sensitivity. In a diverse panel of cancer cell lines, we found that the cells most sensitive to focal adhesion kinase (FAK) inhibition lack expression of the neurofibromatosis type 2 (NF2) tumor suppressor gene product, Merlin. Merlin expression is often lost in malignant pleural mesothelioma (MPM), an asbestos-induced aggressive cancer with limited treatment options. Our data demonstrate that low Merlin expression predicts for increased sensitivity of MPM cells to a FAK inhibitor, VS-4718, in vitro and in tumor xenograft models. Disruption of MPM cell-cell or cell-extracellular matrix (ECM) contacts with blocking antibodies suggests that weak cell-cell adhesions in Merlin-negative MPM cells underlie their greater dependence on cell-ECM-induced FAK signaling. This provides one explanation of why Merlin-negative cells are vulnerable to FAK inhibitor treatment. Furthermore, we validated aldehyde dehydrogenase as a marker of cancer stem cells (CSCs) in MPM, a cell population thought to mediate tumor relapse after chemotherapy. Whereas pemetrexed and cisplatin, standard-of-care agents for MPM, enrich for CSCs, FAK inhibitor treatment preferentially eliminates these cells. These preclinical results provide the rationale for a clinical trial in MPM patients using a FAK inhibitor as a single agent after first-line chemotherapy. With this design, the FAK inhibitor could potentially induce a more durable clinical response through reduction of CSCs along with a strong antitumor effect. Furthermore, our data suggest that patients with Merlin-negative tumors may especially benefit from FAK inhibitor treatment.


Subject(s)
Antineoplastic Agents/pharmacology , Focal Adhesion Kinase 1/antagonists & inhibitors , Lung Neoplasms/drug therapy , Mesothelioma/drug therapy , Neurofibromin 2/deficiency , Protein Kinase Inhibitors/pharmacology , Aldehyde Dehydrogenase/metabolism , Animals , Apoptosis/drug effects , Cell Adhesion/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Focal Adhesion Kinase 1/genetics , Focal Adhesion Kinase 1/metabolism , Humans , Lung Neoplasms/enzymology , Lung Neoplasms/genetics , Lung Neoplasms/pathology , Mesothelioma/enzymology , Mesothelioma/genetics , Mesothelioma/pathology , Mesothelioma, Malignant , Mice , Molecular Targeted Therapy , Neoplastic Stem Cells/drug effects , Neoplastic Stem Cells/enzymology , Neurofibromin 2/genetics , RNA Interference , Signal Transduction/drug effects , Time Factors , Transfection , Tumor Burden/drug effects , Xenograft Model Antitumor Assays
11.
Chem Commun (Camb) ; 48(96): 11766-8, 2012 Dec 14.
Article in English | MEDLINE | ID: mdl-23114612

ABSTRACT

Rlyso, a highly selective and sensitive pH sensor, can stain lysosomes with a novel lysosome-locating group, methylcarbitol. Rlyso was successfully used to detect lysosomal pH changes during apoptosis or induced by chloroquine while avoiding the "alkalizing effect" on lysosomes of current lysosomal probes with nitrogen-containing sidechains.


Subject(s)
Ethylene Glycols/chemistry , Fluorescent Dyes/chemistry , Lysosomes/chemistry , Animals , Antineoplastic Agents, Hormonal/pharmacology , Apoptosis/drug effects , Cell Line, Tumor , Chloroquine/pharmacology , Dexamethasone/pharmacology , Humans , Hydrogen-Ion Concentration/drug effects , Mice , Microscopy, Fluorescence , Spectrometry, Fluorescence
12.
Anticancer Res ; 31(9): 2773-9, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21868519

ABSTRACT

The marine natural product (+)-spongistatin 1 is an extremely potent growth inhibitory agent having activity against a wide variety of cancer cell lines, while exhibiting low cytotoxicity against quiescent human fibroblasts. Consistent with a microtubule-targeting mechanism of action, (+)-spongistatin 1 causes mitotic arrest in DU145 human prostate cancer cells. More importantly, (+)-spongistatin 1 exhibits significant in vivo antitumor activity in the LOX-IMVI human melanoma xenograft model. (+)-Spongistatin 1 is, thus, an important class of microtubule targeting anticancer agent that warrants further investigation.


Subject(s)
Macrolides/pharmacology , Tubulin Modulators/pharmacology , ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism , Animals , Cell Line, Tumor , Drug Screening Assays, Antitumor , Humans , In Vitro Techniques , Macrolides/chemistry , Macrolides/metabolism , Mice , Microscopy, Fluorescence , Stereoisomerism , Tubulin Modulators/chemistry , Tubulin Modulators/metabolism
13.
J Am Chem Soc ; 133(35): 14042-53, 2011 Sep 07.
Article in English | MEDLINE | ID: mdl-21761891

ABSTRACT

The design, synthesis, and biological evaluation of two diminutive forms of (+)-spongistatin 1, in conjunction with the development of a potentially general design strategy to simplify highly flexible macrocyclic molecules while maintaining biological activity, have been achieved. Examination of the solution conformations of (+)-spongistatin 1 revealed a common conformational preference along the western perimeter comprising the ABEF rings. Exploiting the hypothesis that the small-molecule recognition/binding domains are likely to comprise the conformationally less mobile portions of a ligand led to the design of analogues, incorporating tethers (blue) in place of the CD and the ABCD components of the (+)-spongistatin 1 macrolide, such that the conformation of the retained (+)-spongistatin 1 skeleton would mimic the assigned solution conformations of the natural product. The observed nanomolar cytotoxicity and microtubule destabilizing activity of the ABEF analogue provide support for both the assigned solution conformation of (+)-spongistatin 1 and the validity of the design strategy.


Subject(s)
Macrolides/chemistry , Macrolides/pharmacology , Tubulin Modulators/chemistry , Tubulin Modulators/pharmacology , Animals , Cell Line, Tumor , Cell Proliferation/drug effects , Drug Design , Humans , Macrolides/chemical synthesis , Mice , Models, Molecular , Neoplasms/drug therapy , Tubulin Modulators/chemical synthesis
14.
Org Lett ; 12(8): 1792-5, 2010 Apr 16.
Article in English | MEDLINE | ID: mdl-20297810

ABSTRACT

The design, synthesis, and biological evaluation of two potential (+)-spongistatin 1 analogues have been achieved. The analogues, incorporating tethers (red) in place of the ABCD and the CD components of the (+)-spongistatin 1 macrolide, were designed such that the conformations of the retained skeleton (blue) would mimic the assigned major solution conformation of the natural product The nanomolar cytotoxicity observed for the ABEF analogue provides strong support for the assigned solution conformation.


Subject(s)
Drug Design , Macrolides/chemistry , Macrolides/pharmacology , Cell Line, Tumor , Cell Proliferation/drug effects , Humans , Inhibitory Concentration 50 , Macrolides/chemical synthesis , Structure-Activity Relationship
15.
Mol Cancer Ther ; 8(5): 1250-60, 2009 May.
Article in English | MEDLINE | ID: mdl-19417157

ABSTRACT

We report here that des-methyl, des-amino pateamine A (DMDA-PatA), a structurally simplified analogue of the marine natural product pateamine A, has potent antiproliferative activity against a wide variety of human cancer cell lines while showing relatively low cytotoxicity against nonproliferating, quiescent human fibroblasts. DMDA-PatA retains almost full in vitro potency in P-glycoprotein-overexpressing MES-SA/Dx5-Rx1 human uterine sarcoma cells that are significantly resistant to paclitaxel, suggesting that DMDA-PatA is not a substrate for P-glycoprotein-mediated drug efflux. Treatment of proliferating cells with DMDA-PatA leads to rapid shutdown of DNA synthesis in the S phase of the cell cycle. Cell-free studies show that DMDA-PatA directly inhibits DNA polymerases α and γ in vitro albeit at concentrations considerably higher than those that inhibit cell proliferation. DMDA-PatA shows potent anticancer activity in several human cancer xenograft models in nude mice, including significant regressions observed in the LOX and MDA-MB-435 melanoma models. DMDA-PatA thus represents a promising natural product-based anticancer agent that warrants further investigation.


Subject(s)
Antineoplastic Agents/pharmacology , Epoxy Compounds/pharmacology , Macrolides/pharmacology , Thiazoles/pharmacology , ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/therapeutic use , Cell Cycle/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Drug Resistance, Neoplasm/drug effects , Epoxy Compounds/chemistry , Epoxy Compounds/therapeutic use , Female , Humans , Macrolides/chemistry , Macrolides/therapeutic use , Mice , Mice, Nude , Mice, SCID , Neoplasms/drug therapy , Neoplasms/pathology , Thiazoles/chemistry , Thiazoles/therapeutic use , Xenograft Model Antitumor Assays
16.
Org Lett ; 11(6): 1417-20, 2009 Mar 19.
Article in English | MEDLINE | ID: mdl-19228042

ABSTRACT

The first total synthesis of ipomoeassin F was carried out using a convergent approach that relied upon the use of Schmidt glycosidation technology for the coupling of two suitably protected monosaccharide fragments. After two steps, ring-closing metathesis was used to form the macrocyclic ring, and seven more steps then furnished ipomoeassin F. In vitro inhibitory activity against a four-panel cell line showed low nanomolar inhibitory activity.


Subject(s)
Antineoplastic Agents, Phytogenic/chemical synthesis , Biological Products/chemical synthesis , Glycoconjugates/chemical synthesis , Antineoplastic Agents, Phytogenic/chemistry , Antineoplastic Agents, Phytogenic/pharmacology , Biological Products/chemistry , Biological Products/pharmacology , Drug Screening Assays, Antitumor , Glycoconjugates/chemistry , Glycoconjugates/pharmacology , Glycosylation , Humans , Ipomoea/chemistry , Molecular Structure
17.
J Biol Chem ; 279(51): 53015-22, 2004 Dec 17.
Article in English | MEDLINE | ID: mdl-15471885

ABSTRACT

The p53 tumor suppressor is a key mediator of the cellular response to stress. Phosphorylation induced by multiple stress-activated kinases has been proposed to be essential for p53 stabilization, interaction with transcriptional co-activators, and activation of p53 target genes. However, genetic studies suggest that stress-activated phosphorylation may not be essential for p53 activation. We therefore investigated the role of p53 phosphorylation on six key serine residues (Ser(6), Ser(15), Ser(20), Ser(37), Ser(46), and Ser(392)) for p53 activation using nutlin-3, a recently developed small molecule MDM2 antagonist. We show here that nutlin does not induce the phosphorylation of p53. Comparison of the activity of unphosphorylated and phosphorylated p53 induced by the genotoxic drugs doxorubicin and etoposide in HCT116 and RKO cells revealed no difference in their sequence-specific DNA binding and ability to transactivate p53 target genes and to induce p53-dependent apoptosis. We conclude that p53 phosphorylation on six major serine sites is not required for activation of p53 target genes or biological responses in vivo.


Subject(s)
Apoptosis , Transcriptional Activation , Tumor Suppressor Protein p53/metabolism , Annexin A5/pharmacology , Antibiotics, Antineoplastic/pharmacology , Antineoplastic Agents, Phytogenic/pharmacology , Blotting, Western , Cell Line, Tumor , Coloring Agents/pharmacology , DNA/chemistry , Dose-Response Relationship, Drug , Doxorubicin/pharmacology , Enzyme-Linked Immunosorbent Assay , Etoposide/pharmacology , Humans , Imidazoles/metabolism , Kinetics , Nuclear Proteins/metabolism , Phosphorylation , Piperazines/metabolism , Polymerase Chain Reaction , Protein Binding , Proto-Oncogene Proteins/metabolism , Proto-Oncogene Proteins c-mdm2 , Serine/chemistry
SELECTION OF CITATIONS
SEARCH DETAIL