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1.
Cell ; 160(6): 1125-34, 2015 Mar 12.
Article in English | MEDLINE | ID: mdl-25768908

ABSTRACT

Circular RNAs (circRNAs), formed by non-sequential back-splicing of pre-mRNA transcripts, are a widespread form of non-coding RNA in animal cells. However, it is unclear whether the majority of circRNAs represent splicing by-products without function or are produced in a regulated manner to carry out specific cellular functions. We show that hundreds of circRNAs are regulated during human epithelial-mesenchymal transition (EMT) and find that the production of over one-third of abundant circRNAs is dynamically regulated by the alternative splicing factor, Quaking (QKI), which itself is regulated during EMT. Furthermore, by modulating QKI levels, we show the effect on circRNA abundance is dependent on intronic QKI binding motifs. Critically, the addition of QKI motifs is sufficient to induce de novo circRNA formation from transcripts that are normally linearly spliced. These findings demonstrate circRNAs are both purposefully synthesized and regulated by cell-type specific mechanisms, suggesting they play specific biological roles in EMT.


Subject(s)
Epithelial-Mesenchymal Transition , RNA-Binding Proteins/metabolism , RNA/metabolism , Cell Line , Exons , Humans , Introns , RNA Splicing , RNA, Circular
2.
RNA Biol ; 21(1): 1-11, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38112323

ABSTRACT

Epithelial-mesenchymal transition (EMT) plays important roles in tumour progression and is orchestrated by dynamic changes in gene expression. While it is well established that post-transcriptional regulation plays a significant role in EMT, the extent of alternative polyadenylation (APA) during EMT has not yet been explored. Using 3' end anchored RNA sequencing, we mapped the alternative polyadenylation (APA) landscape following Transforming Growth Factor (TGF)-ß-mediated induction of EMT in human mammary epithelial cells and found APA generally causes 3'UTR lengthening during this cell state transition. Investigation of potential mediators of APA indicated the RNA-binding protein Quaking (QKI), a splicing factor induced during EMT, regulates a subset of events including the length of its own transcript. Analysis of QKI crosslinked immunoprecipitation (CLIP)-sequencing data identified the binding of QKI within 3' untranslated regions (UTRs) was enriched near cleavage and polyadenylation sites. Following QKI knockdown, APA of many transcripts is altered to produce predominantly shorter 3'UTRs associated with reduced gene expression. These findings reveal the changes in APA that occur during EMT and identify a potential role for QKI in this process.


Subject(s)
Gene Expression Regulation , Polyadenylation , Humans , Epithelial-Mesenchymal Transition/genetics , Base Sequence , RNA-Binding Proteins/genetics , 3' Untranslated Regions
3.
EMBO J ; 37(13)2018 07 02.
Article in English | MEDLINE | ID: mdl-29871889

ABSTRACT

Members of the miR-200 family are critical gatekeepers of the epithelial state, restraining expression of pro-mesenchymal genes that drive epithelial-mesenchymal transition (EMT) and contribute to metastatic cancer progression. Here, we show that miR-200c and another epithelial-enriched miRNA, miR-375, exert widespread control of alternative splicing in cancer cells by suppressing the RNA-binding protein Quaking (QKI). During EMT, QKI-5 directly binds to and regulates hundreds of alternative splicing targets and exerts pleiotropic effects, such as increasing cell migration and invasion and restraining tumour growth, without appreciably affecting mRNA levels. QKI-5 is both necessary and sufficient to direct EMT-associated alternative splicing changes, and this splicing signature is broadly conserved across many epithelial-derived cancer types. Importantly, several actin cytoskeleton-associated genes are directly targeted by both QKI and miR-200c, revealing coordinated control of alternative splicing and mRNA abundance during EMT These findings demonstrate the existence of a miR-200/miR-375/QKI axis that impacts cancer-associated epithelial cell plasticity through widespread control of alternative splicing.


Subject(s)
Alternative Splicing/physiology , Cell Plasticity/physiology , Epithelial-Mesenchymal Transition/physiology , MicroRNAs/physiology , RNA-Binding Proteins/physiology , Animals , Cell Line, Tumor , Cell Movement , Dogs , Humans , Madin Darby Canine Kidney Cells , Mice, SCID
4.
Arch Biochem Biophys ; 677: 108169, 2019 11 30.
Article in English | MEDLINE | ID: mdl-31697914

ABSTRACT

Pyruvate carboxylase (PC) is a biotin-containing enzyme that converts pyruvate to oxaloacetate. We have previously shown that PC is overexpressed in highly invasive cancer cell lines where it supports biosynthesis during rapid cell growth. Here, we show that miR-143-3p suppresses the expression of PC in MDA-MB-231 cells by targeting its conserved binding site in the 3'-untranslated region (UTR) of human PC mRNA. Incorporation of the PC 3'UTR into a luciferase reporter gene inhibited expression of luciferase by 50% while mutation of the miR-143-3p binding site abrogated this inhibitory effect in MDA-MB-231 cells but not in low aggressive MCF-7 cell line. Transfection of miR-143-3p mimic or overexpression of miR-143-3p using tetracycline-inducible system in MDA-MB-231 cells down-regulated expression of both endogenous PC mRNA and protein by 40% and 50% respectively, confirming the regulatory role of miR-143-3p in PC expression. Induction of miR-143-3p expression at low and high levels lowered proliferation, metabolic activity and migration of MDA-MB-231 cells, in a dose-dependent manner. Re-expression of PC in MDA-MB-231 cells which were induced to express miR-143-3p partially restored migration but not proliferation, indicating that miR-143-3p regulates proliferation and migration through multiple pathways.


Subject(s)
Cell Movement/physiology , Cell Proliferation/physiology , Gene Expression Regulation, Neoplastic/physiology , MicroRNAs/metabolism , Pyruvate Carboxylase/metabolism , 3' Untranslated Regions , Base Sequence , Binding Sites , Cell Line, Tumor , Computational Biology , Down-Regulation , Humans , Pyruvate Carboxylase/genetics , RNA, Messenger/chemistry , RNA, Messenger/metabolism
5.
Gynecol Oncol ; 149(1): 49-52, 2018 04.
Article in English | MEDLINE | ID: mdl-29605050

ABSTRACT

BACKGROUND: Population-based studies of women with epithelial ovarian cancer suggest that black women have worse survival compared to white women. The primary objective of this study was to determine if, at a National Cancer Institute (NCI)-Designated Comprehensive Cancer Center (CCC) serving a diverse racial and socioeconomic population, race is independently associated with differences in survival. METHODS: A retrospective review of women with EOC diagnosed between 2004-2009 undergoing treatment with follow-up at our institution was performed. Records were reviewed for demographics, comorbidities (as defined by the Charlson Comorbidity Index (CCI)), tumor characteristics, treatment, progression-free (PFS), and overall survival (OS). Survival was calculated using the Kaplan-Meier method and compared with the log-rank test. Multivariate survival analysis was performed with Cox (proportional hazards) model. RESULTS: 367 patients met inclusion criteria. 54 (15%) were black and 308 (84%) were white. Compared to white women, black women had higher BMI, lower rates of optimal surgical cytoreduction, lower rates of intraperitoneal chemotherapy, and higher CCI scores. The median PFS for black and white women were 9.7 and 14.6months, respectively (p=0.033). The median overall survival was 21.7months for black women and 42.6months for white women (p<0.001). On multivariate analysis, black race independently correlated with a worse overall survival (HR 1.61, 95% CI 1.06-2.43). CONCLUSION: In this cohort, racial disparities may be due to higher medical comorbidities and lower rates of optimal surgical cytoreduction. After accounting for these differences, race remained an independent predictor of worse overall survival.


Subject(s)
Black People/statistics & numerical data , Neoplasms, Glandular and Epithelial/ethnology , Neoplasms, Glandular and Epithelial/therapy , Ovarian Neoplasms/ethnology , Ovarian Neoplasms/therapy , White People/statistics & numerical data , Carcinoma, Ovarian Epithelial , Cohort Studies , Comorbidity , Disease-Free Survival , Female , Healthcare Disparities/ethnology , Healthcare Disparities/statistics & numerical data , Humans , Middle Aged , Neoplasms, Glandular and Epithelial/mortality , Neoplasms, Glandular and Epithelial/pathology , Ovarian Neoplasms/mortality , Ovarian Neoplasms/pathology , Retrospective Studies , Socioeconomic Factors , Survival Rate , United States/epidemiology
6.
Ann Pharmacother ; 50(7): 525-33, 2016 07.
Article in English | MEDLINE | ID: mdl-27066988

ABSTRACT

BACKGROUND: Few studies have compared the risk of recurrent falls across various antidepressant agents-using detailed dosage and duration data-among community-dwelling older adults, including those who have a history of a fall/fracture. OBJECTIVE: To examine the association of antidepressant use with recurrent falls, including among those with a history of falls/fractures, in community-dwelling elders. METHODS: This was a longitudinal analysis of 2948 participants with data collected via interview at year 1 from the Health, Aging and Body Composition study and followed through year 7 (1997-2004). Any antidepressant medication use was self-reported at years 1, 2, 3, 5, and 6 and further categorized as (1) selective serotonin reuptake inhibitors (SSRIs), (2) tricyclic antidepressants, and (3) others. Dosage and duration were examined. The outcome was recurrent falls (≥2) in the ensuing 12-month period following each medication data collection. RESULTS: Using multivariable generalized estimating equations models, we observed a 48% greater likelihood of recurrent falls in antidepressant users compared with nonusers (adjusted odds ratio [AOR] = 1.48; 95% CI = 1.12-1.96). Increased likelihood was also found among those taking SSRIs (AOR = 1.62; 95% CI = 1.15-2.28), with short duration of use (AOR = 1.47; 95% CI = 1.04-2.00), and taking moderate dosages (AOR = 1.59; 95% CI = 1.15-2.18), all compared with no antidepressant use. Stratified analysis revealed an increased likelihood among users with a baseline history of falls/fractures compared with nonusers (AOR = 1.83; 95% CI = 1.28-2.63). CONCLUSION: Antidepressant use overall, SSRI use, short duration of use, and moderate dosage were associated with recurrent falls. Those with a history of falls/fractures also had an increased likelihood of recurrent falls.


Subject(s)
Accidental Falls/statistics & numerical data , Aging , Antidepressive Agents/therapeutic use , Fractures, Bone/epidemiology , Selective Serotonin Reuptake Inhibitors/therapeutic use , Adult , Aged , Aged, 80 and over , Aging/drug effects , Antidepressive Agents/administration & dosage , Antidepressive Agents/adverse effects , Dose-Response Relationship, Drug , Drug Utilization , Female , Humans , Longitudinal Studies , Male , Multivariate Analysis , Odds Ratio , Recurrence , Risk , Self Report , Selective Serotonin Reuptake Inhibitors/administration & dosage , Selective Serotonin Reuptake Inhibitors/adverse effects , United States
7.
Am J Phys Anthropol ; 161(4): 685-697, 2016 12.
Article in English | MEDLINE | ID: mdl-27553783

ABSTRACT

OBJECTIVES: The shorter-term overview from feces provides scope to investigate dietary fluctuations. We assess the correlation of stable isotopic fecal values with recorded seasonal diet of 10 adult chimpanzees (P. t. schweinfurthii) of the Kanyawara community (Kibale National Park, Uganda) and whether fecal nitrogen levels (%N) indicate a change in crude protein intake. MATERIALS AND METHODS: We recorded food eaten by each ape and collected both concurrent fecal samples (N = 115) and plant foods eaten by this community (N = 64). We compared fecal δ13 C and δ15 N values (also %N) with: (a) plant values; (b) feeding data; and (c) food-items found macroscopically in the fecal samples. Interspecies and intraspecies differences in plant and fecal isotope values (and %N) as well as seasonality in diet were determined using parametric and nonparametric tests. RESULTS: No difference in plant δ13 C and δ15 N values was found at intraspecies or interspecies level. Fecal isotope values reflected a diet of C3 plants from evergreen forest vegetation. Seasonal differences in δ13 C and δ15 N corresponded with aspects of feeding and fecal macroscopic data, but only at community level. A change in crude protein intake was not indicated from %N content. DISCUSSION: This study further validates the use of staple isotope analyses of primate feces to provide a dietary overview, revealing seasonal differences at community level; however, conclusive results may be limited for individuals when using short sampling periods. Further study of variables that influence fecal %N content is also suggested to interpret crude protein intake.


Subject(s)
Carbon Isotopes/analysis , Feces/chemistry , Feeding Behavior/physiology , Nitrogen Isotopes/analysis , Pan troglodytes/metabolism , Animals , Anthropology, Physical , Diet , Ecology , Female , Male , Plants/chemistry , Seasons , Uganda
8.
Am Heart J ; 170(3): 498-505.e2, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26385033

ABSTRACT

UNLABELLED: Obesity is a well-recognized risk factor for atrial fibrillation (AF), yet adiposity measures other than body mass index (BMI) have had limited assessment in relation to AF risk. We examined the associations of adiposity measures with AF in a biracial cohort of older adults. Given established racial differences in obesity and AF, we assessed for differences by black and white race in relating adiposity and AF. METHODS: We analyzed data from 2,717 participants of the Health, Aging, and Body Composition Study. Adiposity measures were BMI, abdominal circumference, subcutaneous and visceral fat area, and total and percent fat mass. We determined the associations between the adiposity measures and 10-year incidence of AF using Cox proportional hazards models and assessed for their racial differences in these estimates. RESULTS: In multivariable-adjusted models, 1-SD increases in BMI, abdominal circumference, and total fat mass were associated with a 13% to 16% increased AF risk (hazard ratio [HR] 1.14, 95% CI 1.02-1.28; HR 1.16, 95% CI 1.04-1.28; and HR 1.13, 95% CI 1.002-1.27). Subcutaneous and visceral fat areas were not significantly associated with incident AF. We did not identify racial differences in the associations between the adiposity measures and AF. CONCLUSION: Body mass index, abdominal circumference, and total fat mass are associated with risk of AF for 10years among white and black older adults. Obesity is one of a limited number of modifiable risk factors for AF; future studies are essential to evaluate how obesity reduction can modify the incidence of AF.


Subject(s)
Aging , Atrial Fibrillation/ethnology , Obesity/complications , Racial Groups , Aged , Atrial Fibrillation/etiology , Atrial Fibrillation/physiopathology , Body Composition , Body Fat Distribution , Female , Follow-Up Studies , Humans , Incidence , Male , Obesity/ethnology , Prospective Studies , Risk Factors , Sex Factors , Time Factors , United States/epidemiology
9.
J Pharmacol Exp Ther ; 353(2): 340-50, 2015 May.
Article in English | MEDLINE | ID: mdl-25736418

ABSTRACT

In normal physiologic responses to injury and infection, inflammatory cells enter tissue and sites of inflammation through a chemotactic process regulated by several families of proteins, including inflammatory chemokines, a family of small inducible cytokines. In neutrophils, chemokines chemokine (CXC motif) ligand 1 (CXCL1) and CXCL8 are potent chemoattractants and activate G protein-coupled receptors CXC chemokine receptor 1 (CXCR1) and CXCR2. Several small-molecule antagonists of CXCR2 have been developed to inhibit the inflammatory responses mediated by this receptor. Here, we present the data describing the pharmacology of AZD5069 [N-(2-(2,3-difluorobenzylthio)-6-((2R,3S)-3,4-dihydroxybutan-2-yloxy)[2,4,5,6-(13)C4, 1,3-(15)N2]pyrimidin-4-yl)azetidine-1-sulfonamide,[(15)N2,(13)C4]N-(2-(2,3-difluoro-6-[3H]-benzylthio)-6-((2R,3S)-3,4-dihydroxybutan-2-yloxy)pyrimidin-4-yl)azetidine-1-sulfonamide], a novel antagonist of CXCR2. AZD5069 was shown to inhibit binding of radiolabeled CXCL8 to human CXCR2 with a pIC50 value of 9.1. Furthermore, AZD5069 inhibited neutrophil chemotaxis, with a pA2 of approximately 9.6, and adhesion molecule expression, with a pA2 of 6.9, in response to CXCL1. AZD5069 was a slowly reversible antagonist of CXCR2 with effects of time and temperature evident on the pharmacology and binding kinetics. With short incubation times, AZD5069 appeared to have an antagonist profile with insurmountable antagonism of calcium response curves. This behavior was also observed in vivo in an acute lipopolysaccharide-induced lung inflammation model. Altogether, the data presented here show that AZD5069 represents a novel, potent, and selective CXCR2 antagonist with potential as a therapeutic agent in inflammatory conditions.


Subject(s)
Pyrimidines/pharmacology , Receptors, Interleukin-8B/antagonists & inhibitors , Sulfonamides/pharmacology , Animals , CD11b Antigen/metabolism , Calcium/metabolism , Chemotaxis/drug effects , Gene Expression Regulation/drug effects , HEK293 Cells , Humans , Interleukin-8/metabolism , Kinetics , Lipopolysaccharides/adverse effects , Lung/drug effects , Lung/immunology , Lung/metabolism , Male , Neutrophil Infiltration/drug effects , Neutrophils/drug effects , Neutrophils/metabolism , Pyrimidines/therapeutic use , Rats , Receptors, Interleukin-8B/metabolism , Substrate Specificity , Sulfonamides/therapeutic use , Temperature
10.
Bioorg Med Chem Lett ; 25(7): 1616-20, 2015 Apr 01.
Article in English | MEDLINE | ID: mdl-25708618

ABSTRACT

Antagonism of the chemokine receptor CXCR2 has been proposed as a strategy for the treatment of inflammatory diseases such as arthritis, chronic obstructive pulmonary disease and asthma. Earlier series of bicyclic CXCR2 antagonists discovered at AstraZeneca were shown to have low solubility and poor oral bioavailability. In this Letter we describe the design, synthesis and characterisation of a new series of monocyclic CXCR2 antagonists with improved solubility and good pharmacokinetic profiles.


Subject(s)
Amides/pharmacology , Drug Discovery , Pyrimidines/pharmacology , Receptors, Interleukin-8B/antagonists & inhibitors , Amides/chemical synthesis , Amides/chemistry , Animals , Biological Availability , Dose-Response Relationship, Drug , Humans , Molecular Conformation , Pyrimidines/chemical synthesis , Pyrimidines/chemistry , Rats , Solubility , Structure-Activity Relationship
11.
Am J Primatol ; 76(8): 757-73, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24573696

ABSTRACT

Most primate populations remain unobservable; therefore, researchers depend on the analyses of indirect evidence encountered at a study-site in order to understand their behavioral ecology. Diet can be determined through the analyses of scats or feeding remains encountered on-site. This allows aspects of their dietary repertoire to be established, which has implications both for conservation efforts (by locating food resources), and for understanding the evolution of hominin diet (if used as referential models). Macroscopic inspection of fecal samples is a common method applied to ascertain a primate population's diet. However, new approaches are required to identify food-items unrecognizable at this level. We applied a dry ash extraction method to fecal samples (N=50) collected from 10 adult chimpanzees in Kanyawara, Kibale National Park, Uganda and also to plant parts (N=66) from 34 species known to be included in the diet of this community of apes. We recovered phytoliths in 26 of the 34 plant species. Fifteen phytolith morphotypes were only detected in 14 plant species (termed "distinct" phytoliths). We used these distinct phytoliths to identify plant foods (i.e., that they were associated with) in fecal samples. We then validated findings by checking if the 10 chimpanzees had eaten parts of these plants ∼24 hr prior to fecal sample collection; six plant species associated with five distinct phytoliths had been eaten. Finally, we compared plant foods identified in fecal samples from phytolith analyses with plants that had been identified from macroscopic inspection of the same fecal samples. Findings from phytolith analyses corroborate with those from macroscopic inspection by expanding the total number of plant species identified per fecal sample (i.e., we identified certain plant parts that remained unrecognizable at macroscopic level). This study highlights the potential of phytolith analyses of feces to increase our knowledgebase of the dietary repertoire of primate populations.


Subject(s)
Diet , Feces , Pan troglodytes , Animals , Feeding Behavior , Female , Male , Plants/chemistry , Uganda
12.
Am J Primatol ; 76(6): 539-50, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24482001

ABSTRACT

Macroscopic inspection of feces has been used to investigate primate diet. The limitations of this method to identify food-items to species level have long been recognized, but ascertaining aspects of diet (e.g., folivory) are achievable by quantifying food-items in feces. Quantification methods applied include rating food-items using a scale of abundance, estimating their percentage volume, and weighing food-items. However, verification as to whether or not composition data differ, depending on which quantification method is used during macroscopic inspection, has not been done. We analyzed feces collected from ten adult chimpanzees (Pan troglodytes schweinfurthii) of the Kanyawara community in Kibale National Park, Uganda. We compare dietary composition totals obtained from using different quantification methods and ascertain if sieve mesh size influences totals calculated. Finally, this study validates findings from direct observation of feeding by the same individuals from whom the fecal samples had been collected. Contrasting diet composition totals obtained by using different quantification methods and sieve mesh sizes can influence folivory and frugivory estimates. However, our findings were based on the assumption that fibrous matter contained pith and leaf fragments only, which remains to be verified. We advocate macroscopic inspection of feces can be a valuable tool to provide a generalized overview of dietary composition for primate populations. As most populations remain unhabituated, scrutinizing and validating indirect measures are important if they are to be applied to further understand inter- and intra-species dietary variation.


Subject(s)
Diet , Feces , Pan troglodytes , Animals , Ethology/methods , Feeding Behavior , Female , Food , Male
13.
Mol Biol Cell ; 35(2): ar17, 2024 Feb 01.
Article in English | MEDLINE | ID: mdl-38019605

ABSTRACT

The RNA-binding protein Quaking (QKI) has widespread effects on mRNA regulation including alternative splicing, stability, translation, and localization of target mRNAs. Recently, QKI was found to be induced during epithelial-mesenchymal transition (EMT), where it promotes a mesenchymal alternative splicing signature that contributes to the mesenchymal phenotype. QKI is itself alternatively spliced to produce three major isoforms, QKI-5, QKI-6, and QKI-7. While QKI-5 is primarily localized to the nucleus where it controls mesenchymal splicing during EMT, the functions of the two predominantly cytoplasmic isoforms, QKI-6 and QKI-7, in this context remain uncharacterized. Here we used CRISPR-mediated depletion of QKI in a human mammary epithelial cell model of EMT and studied the effects of expressing the QKI isoforms in isolation and in combination. QKI-5 was required to induce mesenchymal morphology, while combined expression of QKI-5 with either QKI-6 or QKI-7 further enhanced mesenchymal morphology and cell migration. In addition, we found that QKI-6 and QKI-7 can partially localize to the nucleus and contribute to alternative splicing of QKI target genes. These findings indicate that the QKI isoforms function in a dynamic and cooperative manner to promote the mesenchymal phenotype.


Subject(s)
Alternative Splicing , RNA Splicing , Humans , Protein Isoforms/metabolism , Phenotype , RNA, Messenger/genetics , RNA, Messenger/metabolism
14.
J Physiol Biochem ; 79(1): 223-234, 2023 Feb.
Article in English | MEDLINE | ID: mdl-34865180

ABSTRACT

Pancreatic ductal adenocarcinoma (PDAC) is characterised by a pro-inflammatory stroma and multi-faceted microenvironment that promotes and maintains tumorigenesis. However, the models used to test new and emerging therapies for PDAC have not increased in complexity to keep pace with our understanding of the human disease. Promising therapies that pass pre-clinical testing often fail in pancreatic cancer clinical trials. The objective of this study was to investigate whether changes in the drug-dosing regimen or the addition of cancer-associated fibroblasts (CAFs) to current existing models can impact the efficacy of chemotherapy drugs used in the clinic. Here, we reveal that gemcitabine and paclitaxel markedly reduce the viability of pancreatic cell lines, but not CAFs, when cultured in 2D. Following the use of an in vitro drug pulsing experiment, PDAC cell lines showed sensitivity to gemcitabine and paclitaxel. However, CAFs were less sensitive to pulsing with gemcitabine compared to their response to paclitaxel. We also identify that a 3D co-culture model of MIA PaCa-2 or PANC-1 with CAFs showed an increased chemoresistance to gemcitabine when compared to standard 2D mono-cultures a difference to paclitaxel which showed no measurable difference between the 2D and 3D models, suggesting a complex interaction between the drug in study and the cell type used. Changes to standard 2D mono-culture-based assays and implementation of 3D co-culture assays lend complexity to established models and could provide tools for identifying therapies that will match clinically the success observed with in vitro models, thereby aiding in the discovery of novel therapies.


Subject(s)
Cancer-Associated Fibroblasts , Carcinoma, Pancreatic Ductal , Pancreatic Neoplasms , Humans , Deoxycytidine/metabolism , Deoxycytidine/therapeutic use , Cancer-Associated Fibroblasts/metabolism , Cancer-Associated Fibroblasts/pathology , Drug Evaluation, Preclinical , Cell Line, Tumor , Early Detection of Cancer , Pancreatic Neoplasms/metabolism , Gemcitabine , Carcinoma, Pancreatic Ductal/metabolism , Paclitaxel/metabolism , Paclitaxel/therapeutic use , Tumor Microenvironment , Pancreatic Neoplasms
15.
Bioorg Med Chem Lett ; 22(1): 532-6, 2012 Jan 01.
Article in English | MEDLINE | ID: mdl-22094028

ABSTRACT

Optimisation of a series of pyrazole inhibitors of the human FPR1 receptor has been achieved. The use of an in vitro media loss assay was utilised to identify sub-series with more robust DMPK profiles. These were subsequently improved to generate analogues with attractive overall profiles.


Subject(s)
Pyrazoles/chemical synthesis , Pyrazoles/pharmacology , Receptors, Formyl Peptide/antagonists & inhibitors , Animals , Chemistry, Pharmaceutical/methods , Chemistry, Physical/methods , Drug Design , Hepatocytes/cytology , Humans , Inhibitory Concentration 50 , Male , Microsomes, Liver/metabolism , Models, Chemical , Rats , Rats, Sprague-Dawley , Receptors, Formyl Peptide/chemistry
16.
Pharmacol Ther ; 238: 108179, 2022 10.
Article in English | MEDLINE | ID: mdl-35358569

ABSTRACT

Gastrointestinal cancers are responsible for more cancer deaths than any other system of the body. This review summarises how Wnt pathway dysregulation contributes to the development of the most common gastrointestinal cancers, with a particular focus on the nature and frequency of upstream pathway aberrations. Tumors with upstream aberrations maintain a dependency on the presence of functional Wnt ligand, and are predicted to be tractable to inhibitors of Porcupine, an enzyme that plays a key role in Wnt secretion. We summarise available pre-clinical efficacy data from Porcupine inhibitors in vitro and in vivo, as well as potential toxicities and the data from early phase clinical trials. We appraise the rationale for biomarker-defined targeted approaches, as well as outlining future opportunities for combination with other therapeutics.


Subject(s)
Gastrointestinal Neoplasms , Wnt Signaling Pathway , Acyltransferases/metabolism , Gastrointestinal Neoplasms/drug therapy , Humans , Ligands , Membrane Proteins/metabolism
17.
Cancer Res Commun ; 2(9): 914-928, 2022 09.
Article in English | MEDLINE | ID: mdl-36922934

ABSTRACT

Wnt signaling is implicated in the etiology of gastrointestinal tract cancers. Targeting Wnt signaling is challenging due to on-target toxicity concerns and lack of druggable pathway components. We describe the discovery and characterization of RXC004, a potent and selective inhibitor of the membrane-bound o-acyl transferase Porcupine, essential for Wnt ligand secretion. Absorption, distribution, metabolism, and excretion and safety pharmacology studies were conducted with RXC004 in vitro, and pharmacokinetic exposure assessed in vivo. RXC004 effects on proliferation and tumor metabolism were explored in genetically defined colorectal and pancreatic cancer models in vitro and in vivo. RXC004 effects on immune evasion were assessed in B16F10 immune "cold" and CT26 immune "hot" murine syngeneic models, and in human cell cocultures. RXC004 showed a promising pharmacokinetic profile, inhibited Wnt ligand palmitoylation, secretion, and pathway activation, and demonstrated potent antiproliferative effects in Wnt ligand-dependent (RNF43-mutant or RSPO3-fusion) colorectal and pancreatic cell lines. Reduced tumor growth and increased cancer cell differentiation were observed in SNU-1411 (RSPO3-fusion), AsPC1 and HPAF-II (both RNF43-mutant) xenograft models, with a therapeutic window versus Wnt homeostatic functions. Additional effects of RXC004 on tumor cell metabolism were confirmed in vitro and in vivo by glucose uptake and 18fluorodeoxyglucose-PET, respectively. RXC004 stimulated host tumor immunity; reducing resident myeloid-derived suppressor cells within B16F10 tumors and synergizing with anti-programmed cell death protein-1 (PD-1) to increase CD8+/regulatory T cell ratios within CT26 tumors. Moreover, RXC004 reversed the immunosuppressive effects of HPAF-II cells cocultured with human peripheral blood mononuclear cells, confirming the multiple anticancer mechanisms of this compound, which has progressed into phase II clinical trials. Significance: Wnt pathway dysregulation drives many gastrointestinal cancers; however, there are no approved therapies that target the pathway. RXC004 has demonstrated the potential to block both tumor growth and tumor immune evasion in a genetically defined, clinically actionable subpopulation of Wnt ligand-dependent gastrointestinal cancers. The clinical utility of RXC004, and other Porcupine inhibitors, in such Wnt ligand-dependent cancers is currently being assessed in patient trials.


Subject(s)
Colorectal Neoplasms , Pancreatic Neoplasms , Humans , Mice , Animals , Wnt Signaling Pathway , Ligands , Immune Evasion , Leukocytes, Mononuclear/metabolism , Pancreatic Neoplasms/drug therapy , Enzyme Inhibitors/pharmacology , Colorectal Neoplasms/drug therapy
18.
Front Bioeng Biotechnol ; 10: 975786, 2022.
Article in English | MEDLINE | ID: mdl-36394032

ABSTRACT

For more than 60 years, efforts to develop mating-based mosquito control technologies have largely failed to produce solutions that are both effective and scalable, keeping them out of reach of most governments and communities in disease-impacted regions globally. High pest suppression levels in trials have yet to fully translate into broad and effective Aedes aegypti control solutions. Two primary challenges to date-the need for complex sex-sorting to prevent female releases, and cumbersome processes for rearing and releasing male adult mosquitoes-present significant barriers for existing methods. As the host range of Aedes aegypti continues to advance into new geographies due to increasing globalisation and climate change, traditional chemical-based approaches are under mounting pressure from both more stringent regulatory processes and the ongoing development of insecticide resistance. It is no exaggeration to state that new tools, which are equal parts effective and scalable, are needed now more than ever. This paper describes the development and field evaluation of a new self-sexing strain of Aedes aegypti that has been designed to combine targeted vector suppression, operational simplicity, and cost-effectiveness for use in disease-prone regions. This conditional, self-limiting trait uses the sex-determination gene doublesex linked to the tetracycline-off genetic switch to cause complete female lethality in early larval development. With no female progeny survival, sex sorting is no longer required, eliminating the need for large-scale mosquito production facilities or physical sex-separation. In deployment operations, this translates to the ability to generate multiple generations of suppression for each mosquito released, while being entirely self-limiting. To evaluate these potential benefits, a field trial was carried out in densely-populated urban, dengue-prone neighbourhoods in Brazil, wherein the strain was able to suppress wild mosquito populations by up to 96%, demonstrating the utility of this self-sexing approach for biological vector control. In doing so, it has shown that such strains offer the critical components necessary to make these tools highly accessible, and thus they harbour the potential to transition mating-based approaches to effective and sustainable vector control tools that are within reach of governments and at-risk communities who may have only limited resources.

19.
Cancers (Basel) ; 13(21)2021 Nov 04.
Article in English | MEDLINE | ID: mdl-34771706

ABSTRACT

Urine-based biomarkers have shown suitable diagnostic potential for prostate cancer (PCa) detection. Yet, until now, prostatic massage remains required prior to urine sampling. Here, we test a potential diagnostic approach using voided urine collected without prior digital rectal examination (DRE). In this study, we evaluated the diagnostic performance of a microfluidic-based platform that combines the principle of photodynamic diagnostic with immunocapture for the detection of PCa cells. The functionality and sensitivity of this platform were validated using both cultured cells and PCa patient urine samples. Quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) demonstrated this platform had a detection limit of fewer than 10 cells per 60 µL and successfully validated the presence of a PCa biomarker in the urine of cancer patients without prior DRE. This biosensing platform exhibits a sensitivity of 72.4% and a specificity of 71.4%, in suitable agreement with qRT-PCR data. The results of this study constitute a stepping stone in the future development of noninvasive prostate cancer diagnostic technologies that do not require DRE.

20.
PLoS One ; 15(2): e0229519, 2020.
Article in English | MEDLINE | ID: mdl-32097438

ABSTRACT

BACKGROUND: Measures of cardiac ventricular electrophysiology have been associated with cognitive performance in cross-sectional studies. We sought to evaluate the association of worsening ventricular repolarization in midlife, as measured by incident prolonged QT interval, with cognitive decline in late life. METHODS: Midlife QT interval was assessed by electrocardiography during three study visits from 1965/68 to 1971/74 in a cohort of Japanese American men aged 46-68 at Exam 1 from the Honolulu Heart Study. We defined incident prolonged QT as the QT interval in the upper quartile at Exam 2 or 3 after QT interval in lower three quartiles at Exam 1. Cognitive performance was assessed at least once using the Cognitive Abilities Screening Instrument (CASI), scored using item response theory (CASI-IRT), during four subsequent visits from 1991/93 to 1999/2000 among 2,511 of the 4,737 men in the Honolulu-Asia Aging Study otherwise eligible for inclusion in analyses. We used marginal structural modeling to determine the association of incident prolonged QT with cognitive decline, using weighting to account for confounding and attrition. RESULTS: Incident prolonged QT interval in midlife was not associated with late-life CASI-IRT at cognitive baseline (estimated difference in CASI-IRT: 0.04; 95% CI: -0.28, 0.35; p = 0.81), or change in CASI-IRT over time (estimated difference in annual change in CASI-IRT: -0.002; 95%CI: -0.013, 0.010; p = 0.79). Findings were consistent across sensitivity analyses. CONCLUSIONS: Although many midlife cardiovascular risk factors and cardiac structure and function measures are associated with late-life cognitive decline, incident prolonged QT interval in midlife was not associated with late-life cognitive performance or cognitive decline.


Subject(s)
Cognition/physiology , Heart Rate/physiology , Myocardial Contraction/physiology , Aged , Aging , Asian , Cardiac Electrophysiology/methods , Cognition Disorders/physiopathology , Cognitive Dysfunction/complications , Cohort Studies , Cross-Sectional Studies , Humans , Hypertension/complications , Longitudinal Studies , Male , Middle Aged , Risk Factors , United States
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