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result(s) for
"Gordon, Melanie B."
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Loss of Brca1 and Trp53 in adult mouse mammary ductal epithelium results in development of hormone receptor-positive or hormone receptor-negative tumors, depending on inactivation of Rb family proteins
by
Gordon, Melanie B.
,
Iacovelli, Anthony J.
,
Bassel, Laura
in
1-Phosphatidylinositol 3-kinase
,
Adenoviruses
,
Animals
2022
Background
Breast cancer is a heterogenous disease with several histological and molecular subtypes. Models that represent these subtypes are essential for translational research aimed at improving clinical strategy for targeted therapeutics.
Methods
Different combinations of genetic aberrations (
Brca1
and
Trp53
loss, and inhibition of proteins of the Rb family) were induced in the mammary gland by injection of adenovirus expressing Cre recombinase into the mammary ducts of adult genetically engineered mice. Mammary tumors with different genetic aberrations were classified into molecular subtypes based on expression of molecular markers and RNAseq analysis. In vitro potency assays and Western blots were used to examine their drug sensitivities.
Results
Induction of
Brca1
and
Trp53
loss in mammary ductal epithelium resulted in development of basal-like hormone receptor (HR)-negative mammary tumors. Inhibition of Rb and
Trp53
loss or the combination of Rb
, Trp53
and
Brca1
aberrations resulted in development of luminal ductal carcinoma positive for ER, PR, and Her2 expression. HR positivity in tumors with Rb
, Trp53
and
Brca1
aberrations indicated that functionality of the Rb pathway rather than
Brca1
status affected HR status in these models. Mammary tumor gene expression profiles recapitulated human basal-like or luminal B breast cancer signatures, but HR-positive luminal cancer models were endocrine resistant and exhibited upregulation of PI3K signaling and sensitivity to this pathway inhibition. Furthermore, both tumor subtypes were resistant to CDK4/6 inhibition.
Conclusions
Examination of molecular expression profiles and drug sensitivities of tumors indicate that these breast cancer models can be utilized as a translational platform for evaluation of targeted combinations to improve chemotherapeutic response in patients that no longer respond to hormone therapy or that are resistant to CDK4/6 inhibition.
Journal Article
New tools for studying microglia in the mouse and human CNS
by
Chang, Edward F.
,
Grant, Gerald A.
,
Zamanian, Jennifer L.
in
Aged
,
Animals
,
Antibodies, Monoclonal - immunology
2016
The specific function of microglia, the tissue resident macrophages of the brain and spinal cord, has been difficult to ascertain because of a lack of tools to distinguish microglia from other immune cells, thereby limiting specific immunostaining, purification, and manipulation. Because of their unique developmental origins and predicted functions, the distinction of microglia from other myeloid cells is critically important for understanding brain development and disease; better toolswould greatly facilitate studies of microglia function in the developing, adult, and injured CNS. Here, we identify transmembrane protein 119 (Tmem119), a cell-surface protein of unknown function, as a highly expressed microglia-specific marker in both mouse and human. We developed monoclonal antibodies to its intracellular and extracellular domains that enable the immunostaining of microglia in histological sections in healthy and diseased brains, as well as isolation of pure nonactivated microglia by FACS. Using our antibodies, we provide, to our knowledge, the first RNAseq profiles of highly pure mouse microglia during development and after an immune challenge. We used these to demonstrate that mouse microglia mature by the second postnatal week and to predict novel microglial functions. Together, we anticipate these resources will be valuable for the future study and understanding of microglia in health and disease.
Journal Article
Tenofovir alafenamide versus tenofovir disoproxil fumarate, coformulated with elvitegravir, cobicistat, and emtricitabine, for initial treatment of HIV-1 infection: two randomised, double-blind, phase 3, non-inferiority trials
by
Fordyce, Marshall W
,
Andrade-Villanueva, Jaime
,
Custodio, Joseph M
in
Acquired immune deficiency syndrome
,
Adenine - administration & dosage
,
Adenine - adverse effects
2015
Tenofovir disoproxil fumarate can cause renal and bone toxic effects related to high plasma tenofovir concentrations. Tenofovir alafenamide is a novel tenofovir prodrug with a 90% reduction in plasma tenofovir concentrations. Tenofovir alafenamide-containing regimens can have improved renal and bone safety compared with tenofovir disoproxil fumarate-containing regimens.
In these two controlled, double-blind phase 3 studies, we recruited treatment-naive HIV-infected patients with an estimated creatinine clearance of 50 mL per min or higher from 178 outpatient centres in 16 countries. Patients were randomly assigned (1:1) to receive once-daily oral tablets containing 150 mg elvitegravir, 150 mg cobicistat, 200 mg emtricitabine, and 10 mg tenofovir alafenamide (E/C/F/tenofovir alafenamide) or 300 mg tenofovir disoproxil fumarate (E/C/F/tenofovir disoproxil fumarate) with matching placebo. Randomisation was done by a computer-generated allocation sequence (block size 4) and was stratified by HIV-1 RNA, CD4 count, and region (USA or ex-USA). Investigators, patients, study staff, and those assessing outcomes were masked to treatment group. All participants who received one dose of study drug were included in the primary intention-to-treat efficacy and safety analyses. The main outcomes were the proportion of patients with plasma HIV-1 RNA less than 50 copies per mL at week 48 as defined by the the US Food and Drug Adminstration (FDA) snapshot algorithm (pre-specified non-inferiority margin of 12%) and pre-specified renal and bone endpoints at 48 weeks. These studies are registered with ClinicalTrials.gov, numbers NCT01780506 and NCT01797445.
We recruited patients from Jan 22, 2013, to Nov 4, 2013 (2175 screened and 1744 randomly assigned), and gave treatment to 1733 patients (866 given E/C/F/tenofovir alafenamide and 867 given E/C/F/tenofovir disoproxil fumarate). E/C/F/tenofovir alafenamide was non-inferior to E/C/F/tenofovir disoproxil fumarate, with 800 (92%) of 866 patients in the tenofovir alafenamide group and 784 (90%) of 867 patients in the tenofovir disoproxil fumarate group having plasma HIV-1 RNA less than 50 copies per mL (adjusted difference 2·0%, 95% CI −0·7 to 4·7). Patients given E/C/F/tenofovir alafenamide had significantly smaller mean serum creatinine increases than those given E/C/F/tenofovir disoproxil fumarate (0·08 vs 0·12 mg/dL; p<0·0001), significantly less proteinuria (median % change −3 vs 20; p<0·0001), and a significantly smaller decrease in bone mineral density at spine (mean % change −1·30 vs –2·86; p<0·0001) and hip (−0·66 vs –2·95; p<0·0001) at 48 weeks.
Through 48 weeks, more than 90% of patients given E/C/F/tenofovir alafenamide or E/C/F/tenofovir disoproxil fumarate had virological success. Renal and bone effects were significantly reduced in patients given E/C/F/tenofovir alafenamide. Although these studies do not have the power to assess clinical safety events such as renal failure and fractures, our data suggest that E/C/F/tenofovir alafenamide will have a favourable long-term renal and bone safety profile.
Gilead Sciences.
Journal Article
Inhibitors of histone acetyltransferases KAT6A/B induce senescence and arrest tumour growth
2018
Acetylation of histones by lysine acetyltransferases (KATs) is essential for chromatin organization and function
1
. Among the genes coding for the MYST family of KATs (KAT5–KAT8) are the oncogenes
KAT6A
(also known as
MOZ
) and
KAT6B
(also known as
MORF
and
QKF
)
2
,
3
.
KAT6A
has essential roles in normal haematopoietic stem cells
4
–
6
and is the target of recurrent chromosomal translocations, causing acute myeloid leukaemia
7
,
8
. Similarly, chromosomal translocations in
KAT6B
have been identified in diverse cancers
8
. KAT6A suppresses cellular senescence through the regulation of suppressors of the
CDKN2A
locus
9
,
10
, a function that requires its KAT activity
10
. Loss of one allele of
KAT6A
extends the median survival of mice with MYC
-
induced lymphoma from 105 to 413 days
11
. These findings suggest that inhibition of KAT6A and KAT6B may provide a therapeutic benefit in cancer. Here we present highly potent, selective inhibitors of KAT6A and KAT6B, denoted WM-8014 and WM-1119. Biochemical and structural studies demonstrate that these compounds are reversible competitors of acetyl coenzyme A and inhibit MYST-catalysed histone acetylation. WM-8014 and WM-1119 induce cell cycle exit and cellular senescence without causing DNA damage. Senescence is INK4A/ARF-dependent and is accompanied by changes in gene expression that are typical of loss of KAT6A function. WM-8014 potentiates oncogene-induced senescence in vitro and in a zebrafish model of hepatocellular carcinoma. WM-1119, which has increased bioavailability, arrests the progression of lymphoma in mice. We anticipate that this class of inhibitors will help to accelerate the development of therapeutics that target gene transcription regulated by histone acetylation.
Selective inhibitors of KAT6A and KAT6B inhibit MYST-catalysed histone acetylation, induce cell cycle exit and cellular senescence without causing DNA damage, and arrest lymphoma progression in mouse models.
Journal Article
Inflammasome Activation in Response to the Yersinia Type III Secretion System Requires Hyperinjection of Translocon Proteins YopB and YopD
by
Snyder, Annelise G.
,
Wynosky-Dolfi, Meghan A.
,
Philip, Naomi H.
in
Animals
,
Apoptosis
,
Bacterial Outer Membrane Proteins - metabolism
2015
Type III secretion systems (T3SS) translocate effector proteins into target cells in order to disrupt or modulate host cell signaling pathways and establish replicative niches. However, recognition of T3SS activity by cytosolic pattern recognition receptors (PRRs) of the nucleotide-binding domain leucine rich repeat (NLR) family, either through detection of translocated products or membrane disruption, induces assembly of multiprotein complexes known as inflammasomes. Macrophages infected with Yersinia pseudotuberculosis strains lacking all known effectors or lacking the translocation regulator YopK induce rapid activation of both the canonical NLRP3 and noncanonical caspase-11 inflammasomes. While this inflammasome activation requires a functional T3SS, the precise signal that triggers inflammasome activation in response to Yersinia T3SS activity remains unclear. Effectorless strains of Yersinia as well as Δ yopK strains translocate elevated levels of T3SS substrates into infected cells. To dissect the contribution of pore formation and translocation to inflammasome activation, we took advantage of variants of YopD and LcrH that separate these functions of the T3SS. Notably, YopD variants that abrogated translocation but not pore-forming activity failed to induce inflammasome activation. Furthermore, analysis of individual infected cells revealed that inflammasome activation at the single-cell level correlated with translocated levels of YopB and YopD themselves. Intriguingly, LcrH mutants that are fully competent for effector translocation but produce and translocate lower levels of YopB and YopD also fail to trigger inflammasome activation. Our findings therefore suggest that hypertranslocation of YopD and YopB is linked to inflammasome activation in response to the Yersinia T3SS. IMPORTANCE The innate immune response is critical to effective clearance of pathogens. Recognition of conserved virulence structures and activities by innate immune receptors such as NLRs constitute one of the first steps in mounting the innate immune response. However, pathogens such as Yersinia actively evade or subvert components of host defense, such as inflammasomes. The T3SS-secreted protein YopK is an essential virulence factor that limits translocation of other Yops, thereby limiting T3SS-induced inflammasome activation. However, what triggers inflammasome activation in cells infected by YopK-deficient Yersinia is not clear. Our findings indicate that hypertranslocation of pore complex proteins promotes inflammasome activation and that YopK prevents inflammasome activation by the T3SS by limiting translocation of YopD and YopB themselves. The innate immune response is critical to effective clearance of pathogens. Recognition of conserved virulence structures and activities by innate immune receptors such as NLRs constitute one of the first steps in mounting the innate immune response. However, pathogens such as Yersinia actively evade or subvert components of host defense, such as inflammasomes. The T3SS-secreted protein YopK is an essential virulence factor that limits translocation of other Yops, thereby limiting T3SS-induced inflammasome activation. However, what triggers inflammasome activation in cells infected by YopK-deficient Yersinia is not clear. Our findings indicate that hypertranslocation of pore complex proteins promotes inflammasome activation and that YopK prevents inflammasome activation by the T3SS by limiting translocation of YopD and YopB themselves.
Journal Article
MPX-004 and MPX-007: New Pharmacological Tools to Study the Physiology of NMDA Receptors Containing the GluN2A Subunit
2016
GluN2A is the most abundant of the GluN2 NMDA receptor subunits in the mammalian CNS. Physiological and genetic evidence implicate GluN2A-containing receptors in susceptibility to autism, schizophrenia, childhood epilepsy and neurodevelopmental disorders such as Rett Syndrome. However, GluN2A-selective pharmacological probes to explore the therapeutic potential of targeting these receptors have been lacking. Here we disclose a novel series of pyrazine-containing GluN2A antagonists exemplified by MPX-004 (5-(((3-chloro-4-fluorophenyl)sulfonamido)methyl)-N-((2-methylthiazol-5-yl)methyl)pyrazine-2-carboxamide) and MPX-007 (5-(((3-fluoro-4-fluorophenyl)sulfonamido)methyl)-N-((2-methylthiazol-5-yl)methyl)methylpyrazine-2-carboxamide). MPX-004 and MPX-007 inhibit GluN2A-containing NMDA receptors expressed in HEK cells with IC50s of 79 nM and 27 nM, respectively. In contrast, at concentrations that completely inhibited GluN2A activity these compounds have no inhibitory effect on GluN2B or GluN2D receptor-mediated responses in similar HEK cell-based assays. Potency and selectivity were confirmed in electrophysiology assays in Xenopus oocytes expressing GluN2A-D receptor subtypes. Maximal concentrations of MPX-004 and MPX-007 inhibited ~30% of the whole-cell current in rat pyramidal neurons in primary culture and MPX-004 inhibited ~60% of the total NMDA receptor-mediated EPSP in rat hippocampal slices. GluN2A-selectivity at native receptors was confirmed by the finding that MPX-004 had no inhibitory effect on NMDA receptor mediated synaptic currents in cortical slices from GRIN2A knock out mice. Thus, MPX-004 and MPX-007 offer highly selective pharmacological tools to probe GluN2A physiology and involvement in neuropsychiatric and developmental disorders.
Journal Article
Developmental care pathway for hospitalised infants with CHD: on behalf of the Cardiac Newborn Neuroprotective Network, a Special Interest Group of the Cardiac Neurodevelopmental Outcome Collaborative
2023
Infants and children born with CHD are at significant risk for neurodevelopmental delays and abnormalities. Individualised developmental care is widely recognised as best practice to support early neurodevelopment for medically fragile infants born premature or requiring surgical intervention after birth. However, wide variability in clinical practice is consistently demonstrated in units caring for infants with CHD. The Cardiac Newborn Neuroprotective Network, a Special Interest Group of the Cardiac Neurodevelopmental Outcome Collaborative, formed a working group of experts to create an evidence-based developmental care pathway to guide clinical practice in hospital settings caring for infants with CHD. The clinical pathway, “Developmental Care Pathway for Hospitalized Infants with Congenital Heart Disease,” includes recommendations for standardised developmental assessment, parent mental health screening, and the implementation of a daily developmental care bundle, which incorporates individualised assessments and interventions tailored to meet the needs of this unique infant population and their families. Hospitals caring for infants with CHD are encouraged to adopt this developmental care pathway and track metrics and outcomes using a quality improvement framework.
Journal Article
The Resistance Exercise in Already Active Diabetic Individuals (READI) Randomized Clinical Trial
by
Goldfield, Gary S
,
Donovan, Lois
,
Gougeon, Réjeanne
in
Aerobics
,
Apolipoproteins
,
Blood glucose
2023
Abstract
Context
Resistance exercise training (strength training) and aerobic exercise training are both recommended for people with type 1 diabetes, but it is unknown whether adding resistance exercise provides incremental benefits in people with this condition who already perform aerobic exercise regularly.
Objective
This work aimed to evaluate the incremental effect of resistance training on glycated hemoglobin A1c (HbA1c), fitness, body composition, and cardiometabolic risk factors in aerobically active people with type 1 diabetes.
Methods
The Resistance Exercise in Already-active Diabetic Individuals (READI) trial (NCT00410436) was a 4-center, randomized, parallel-group trial. After a 5-week run-in period with diabetes management optimization, 131 aerobically active individuals with type 1 diabetes were randomly assigned to resistance exercise (n = 71, intervention—INT) or control (n = 60, CON) for 22 additional weeks. Both groups maintained their aerobic activities and were provided dietary counseling throughout. Exercise training was 3 times per week at community-based facilities. The primary outcome was HbA1c, and secondary outcomes included fitness (peak oxygen consumption, muscle strength), body composition (anthropometrics, dual-energy x-ray absorptiometry, computed tomography), and cardiometabolic risk markers (lipids, apolipoproteins). Assessors were blinded to group allocation.
Results
There were no significant differences in HbA1c change between INT and CON. Declines in HbA1c (INT: 7.75 ± 0.10% [61.2 ± 1.1 mmol/mol] to 7.55 ± 0.10% [59 ± 1.1 mmol/mol]; CON: 7.70 ± 0.11% [60.7 ± 1.2 mmol/mol] to 7.57 ± 0.11% [59.6 ± 1.3 mmol/mol]; intergroup difference in change −0.07 [95% CI, −0.31 to 0.18]). Waist circumference decreased more in INT than CON after 6 months (P = .02). Muscular strength increased more in INT than in CON (P < .001). There were no intergroup differences in hypoglycemia or any other variables.
Conclusion
Adding resistance training did not affect glycemia, but it increased strength and reduced waist circumference, in aerobically active individuals with type 1 diabetes.
Journal Article
Adaptive multi-interventional trial platform to improve patient care for fibrotic interstitial lung diseases
by
Bryce, Peter
,
Crisan-Dabija, Radu
,
Lewis, Roger
in
Adaptive Clinical Trials as Topic
,
Clinical outcomes
,
Clinical trials
2024
BackgroundFibrotic interstitial lung diseases (fILDs) are a heterogeneous group of lung diseases associated with significant morbidity and mortality. Despite a large increase in the number of clinical trials in the last 10 years, current regulatory-approved management approaches are limited to two therapies that prevent the progression of fibrosis. The drug development pipeline is long and there is an urgent need to accelerate this process. This manuscript introduces the concept and design of an innovative research approach to drug development in fILD: a global Randomised Embedded Multifactorial Adaptive Platform in fILD (REMAP-ILD).MethodsDescription of the REMAP-ILD concept and design: the specific terminology, design characteristics (multifactorial, adaptive features, statistical approach), target population, interventions, outcomes, mission and values, and organisational structure.ResultsThe target population will be adult patients with fILD, and the primary outcome will be a disease progression model incorporating forced vital capacity and mortality over 12 months. Responsive adaptive randomisation, prespecified thresholds for success and futility will be used to assess the effectiveness and safety of interventions. REMAP-ILD embraces the core values of diversity, equity, and inclusion for patients and researchers, and prioritises an open-science approach to data sharing and dissemination of results.ConclusionBy using an innovative and efficient adaptive multi-interventional trial platform design, we aim to accelerate and improve care for patients with fILD. Through worldwide collaboration, novel analytical methodology and pragmatic trial delivery, REMAP-ILD aims to overcome major limitations associated with conventional randomised controlled trial approaches to rapidly improve the care of people living with fILD.
Journal Article
Cognitive Behavioural Therapy to Optimize Post-Operative Recovery (COPE): a randomized controlled feasibility trial in extremity fracture patients
by
MacRae, Sarah
,
Sprague, Sheila
,
Bzovsky, Sofia
in
Behavioral health care
,
Biomedicine
,
Care and treatment
2025
Background
Outcomes following surgery to operatively manage extremity fractures are variable, and up to two-thirds of patients report chronic post-surgical pain. Preliminary evidence suggests that psychotherapy directed at improving coping skills and reducing somatic vigilance may improve outcomes among fracture patients. The objective of this pilot study was to test the feasibility and acceptability of a randomized controlled trial comparing an online cognitive behavioural therapy (CBT) program versus usual care in patients with an operatively managed open or closed extremity fracture.
Methods
We conducted a single-centre internal pilot study over a 10-month period in patients with at least one operatively managed open or closed fracture of the appendicular skeleton. Participants were randomized to an online CBT program or usual care and followed for 12 months. The goals of our pilot study were to determine an acceptable rate of recruitment, the degree to which participants randomized to CBT were compliant with treatment, the site investigator’s ability to adhere to study protocol and data collection procedures, and our ability to achieve high follow-up rates. Feasibility criteria were evaluated using a graded “traffic light” approach, in which “green light” indicates moving forward with the definitive trial, “yellow light” indicates proceeding with modifications to the protocol and trial procedures, and “red light” indicates a definitive trial is not feasible without significant protocol and trial procedure modifications.
Results
We enrolled 94 participants over 10 months, which resulted in a “yellow light” for recruitment. Participant compliance with completion of the online CBT program received a “yellow light”, with 60% of participants who were randomized to CBT completing all seven modules. However, 40% of participants in the CBT-arm withdrew from the program, resulting in a “red light”. Adherence with the study protocol activities at baseline was relatively high (88%) which resulted in a “yellow light”. Follow-up was 85% (80 of 94) at 12 months, resulting in a “yellow light”.
Conclusions
These results suggest feasibility of a definitive, multi-centre trial to compare CBT versus usual care in the management of persistent post-operative pain in fracture patients despite the pilot phase identifying some challenges with enrollment timelines, compliance with the CBT program, and participant follow-up. For the definitive trial, we will expand participant recruitment to additional centres and implement strategies to optimize participant engagement and compliance with the CBT program and follow-up.
Trial registration
ClincialTrials.gov (NCT04274530). Registered February 18, 2020,
https://classic.clinicaltrials.gov/ct2/show/NCT04274530
.
Journal Article