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1.
Semin Cell Dev Biol ; 156: 1-10, 2024 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-37977107

RESUMO

The emergence of therapeutic resistance remains a formidable barrier to durable responses by cancer patients and is a major cause of cancer-related deaths. It is increasingly recognized that non-genetic mechanisms of acquired resistance are important in many cancers. These mechanisms of resistance rely on inherent cellular plasticity where cancer cells can switch between multiple phenotypic states without genetic alterations, providing a dynamic, reversible resistance landscape. Such mechanisms underlie the generation of drug-tolerant persister (DTP) cells, a subpopulation of tumour cells that contributes to heterogeneity within tumours and that supports therapeutic resistance. In this review, we provide an overview of the major features of DTP cells, focusing on phenotypic and metabolic plasticity as two key drivers of tolerance and persistence. We discuss the link between DTP cell plasticity and the potential vulnerability of these cells to ferroptosis. We also discuss the relationship between DTP cells and cells that survive the induction of apoptosis, a process termed anastasis, and discuss the properties of such cells in the context of increased metastatic potential and sensitivity to cell death mechanisms such as ferroptosis.


Assuntos
Resistencia a Medicamentos Antineoplásicos , Neoplasias , Humanos , Resistencia a Medicamentos Antineoplásicos/genética , Plasticidade Celular , Neoplasias/patologia , Apoptose , Morte Celular
2.
Nat Immunol ; 15(10): 957-64, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25194422

RESUMO

Despite the increasing knowledge of the molecular events that induce the glycolysis pathway in effector T cells, very little is known about the transcriptional mechanisms that dampen the glycolysis program in quiescent cell populations such as memory T cells. Here we found that the transcription factor Bcl-6 directly repressed genes encoding molecules involved in the glycolysis pathway, including Slc2a1, Slc2a3, Pkm and Hk2, in type 1 helper T cells (TH1 cells) exposed to low concentrations of interleukin 2 (IL-2). Thus, Bcl-6 had a role opposing the IL-2-sensitive glycolytic transcriptional program that the transcription factors c-Myc and HIF-1α promote in effector T cells. Additionally, the TH1 lineage-specifying factor T-bet functionally antagonized the Bcl-6-dependent repression of genes encoding molecules in the glycolysis pathway, which links the molecular balance of these two factors to regulation of the metabolic gene program.


Assuntos
Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Proteínas de Ligação a DNA/genética , Glicólise/genética , Redes e Vias Metabólicas/genética , Animais , Western Blotting , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linhagem Celular Tumoral , Células Cultivadas , Proteínas de Ligação a DNA/metabolismo , Expressão Gênica/efeitos dos fármacos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Interleucina-2/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Proto-Oncogênicas c-bcl-6 , Reação em Cadeia da Polimerase Via Transcriptase Reversa
3.
Proc Natl Acad Sci U S A ; 116(39): 19571-19578, 2019 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-31501339

RESUMO

Most living birds exhibit cranial kinesis-movement between the rostrum and braincase-in which force is transferred through the palatal and jugal bars. The palate alone distinguishes the Paleognathae from the Neognathae, with cranial kinesis more developed in neognaths. Most previous palatal studies were based on 2D data and rarely incorporated data from stem birds despite great interest in their kinetic abilities. Here we reconstruct the vomer of the Early Cretaceous stem bird Sapeornis and the troodontid Sinovenator, taxa spanning the dinosaur-bird transition. A 3D shape analysis including these paravians and an extensive sampling of neornithines reveals their strong similarity to paleognaths and indicates that morphological differences in the vomer between paleognaths and neognaths are intimately related to their different kinetic abilities. These results suggest the skull of Mesozoic paravians lacked the kinetic abilities observed in neognaths, a conclusion also supported by our identification of an ectopterygoid in Sapeornis here. We conclude that cranial kinesis evolved relatively late, likely an innovation of the Neognathae, and is linked to the transformation of the vomer. This transformation increased palatal mobility, enabling the evolution of a diversity of kinetic mechanisms and ultimately contributing to the extraordinary evolutionary success of this clade.


Assuntos
Aves/anatomia & histologia , Crânio/anatomia & histologia , Vômer/fisiologia , Adaptação Biológica/fisiologia , Animais , Evolução Biológica , Dinossauros/anatomia & histologia , Fósseis , Cinese , Filogenia
4.
Gastroenterology ; 157(3): 823-837, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31078621

RESUMO

BACKGROUND & AIMS: Most pancreatic ductal adenocarcinomas (PDACs) express an activated form of KRAS, become hypoxic and dysplastic, and are refractory to chemo and radiation therapies. To survive in the hypoxic environment, PDAC cells upregulate enzymes and transporters involved in pH regulation, including the extracellular facing carbonic anhydrase 9 (CA9). We evaluated the effect of blocking CA9, in combination with administration of gemcitabine, in mouse models of pancreatic cancer. METHODS: We knocked down expression of KRAS in human (PK-8 and PK-1) PDAC cells with small hairpin RNAs. Human and mouse (KrasG12D/Pdx1-Cre/Tp53/RosaYFP) PDAC cells were incubated with inhibitors of MEK (trametinib) or extracellular signal-regulated kinase (ERK), and some cells were cultured under hypoxic conditions. We measured levels and stability of the hypoxia-inducible factor 1 subunit alpha (HIF1A), endothelial PAS domain 1 protein (EPAS1, also called HIF2A), CA9, solute carrier family 16 member 4 (SLC16A4, also called MCT4), and SLC2A1 (also called GLUT1) by immunoblot analyses. We analyzed intracellular pH (pHi) and extracellular metabolic flux. We knocked down expression of CA9 in PDAC cells, or inhibited CA9 with SLC-0111, incubated them with gemcitabine, and assessed pHi, metabolic flux, and cytotoxicity under normoxic and hypoxic conditions. Cells were also injected into either immune-compromised or immune-competent mice and growth of xenograft tumors was assessed. Tumor fragments derived from patients with PDAC were surgically ligated to the pancreas of mice and the growth of tumors was assessed. We performed tissue microarray analyses of 205 human PDAC samples to measure levels of CA9 and associated expression of genes that regulate hypoxia with outcomes of patients using the Cancer Genome Atlas database. RESULTS: Under hypoxic conditions, PDAC cells had increased levels of HIF1A and HIF2A, upregulated expression of CA9, and activated glycolysis. Knockdown of KRAS in PDAC cells, or incubation with trametinib, reduced the posttranscriptional stabilization of HIF1A and HIF2A, upregulation of CA9, pHi, and glycolysis in response to hypoxia. CA9 was expressed by 66% of PDAC samples analyzed; high expression of genes associated with metabolic adaptation to hypoxia, including CA9, correlated with significantly reduced survival times of patients. Knockdown or pharmacologic inhibition of CA9 in PDAC cells significantly reduced pHi in cells under hypoxic conditions, decreased gemcitabine-induced glycolysis, and increased their sensitivity to gemcitabine. PDAC cells with knockdown of CA9 formed smaller xenograft tumors in mice, and injection of gemcitabine inhibited tumor growth and significantly increased survival times of mice. In mice with xenograft tumors grown from human PDAC cells, oral administration of SLC-0111 and injection of gemcitabine increased intratumor acidosis and increased cell death. These tumors, and tumors grown from PDAC patient-derived tumor fragments, grew more slowly than xenograft tumors in mice given control agents, resulting in longer survival times. In KrasG12D/Pdx1-Cre/Tp53/RosaYFP genetically modified mice, oral administration of SLC-0111 and injection of gemcitabine reduced numbers of B cells in tumors. CONCLUSIONS: In response to hypoxia, PDAC cells that express activated KRAS increase expression of CA9, via stabilization of HIF1A and HIF2A, to regulate pH and glycolysis. Disruption of this pathway slows growth of PDAC xenograft tumors in mice and might be developed for treatment of pancreatic cancer.


Assuntos
Antígenos de Neoplasias/metabolismo , Anidrase Carbônica IX/metabolismo , Carcinoma Ductal Pancreático/enzimologia , Neoplasias Pancreáticas/enzimologia , Proteínas Proto-Oncogênicas p21(ras)/genética , Microambiente Tumoral , Animais , Antígenos de Neoplasias/genética , Antimetabólitos Antineoplásicos/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Anidrase Carbônica IX/antagonistas & inibidores , Anidrase Carbônica IX/genética , Inibidores da Anidrase Carbônica/farmacologia , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Hipóxia Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Desoxicitidina/análogos & derivados , Desoxicitidina/farmacologia , Feminino , Regulação Neoplásica da Expressão Gênica , Predisposição Genética para Doença , Glicólise/efeitos dos fármacos , Humanos , Concentração de Íons de Hidrogênio , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos SCID , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Fenótipo , Compostos de Fenilureia/farmacologia , Transdução de Sinais , Sulfonamidas/farmacologia , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto , Gencitabina
5.
Mol Pharm ; 15(10): 4529-4537, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30118239

RESUMO

A critical part of the clinical development path for a therapeutic antibody involves evaluating the physical and chemical stability of candidate molecules throughout the manufacturing process. In particular, the risks of chemical liabilities that can impact antigen binding, such as deamidation, oxidation, and isomerization in the antibody CDR sequences, need to be controlled through formulation development or eliminated by replacing the amino acid motif displaying the chemical instability. Commonly, the antibody CDR sequence contains multiple sequence motifs (potential hotspots) for chemical instability. However, only a subset of these motifs results in actual chemical modification, and thus, experimental assessment of the extent of instability is necessary to identify positions for potential sequence engineering. Ideally, this information should be available prior to antibody humanization at the stage of parental rodent antibody identification. Early knowledge of liabilities allows for ranking of clones or the mitigation of liabilities by concurrent engineering with the antibody humanization process instead of time-consuming sequential activities. However, concurrent engineering of chemical liabilities and humanization requires translatability of the chemical modifications from the rodent parental antibody to the humanized. We experimentally compared the stability of all sequence motifs by mass spectrometric peptide mapping between the rodent parental antibody and the final humanized antibody and observed a linear correlation. These results have enabled a streamlined developability assessment process for therapeutic antibodies from lead discovery to clinical development.


Assuntos
Anticorpos/imunologia , Sequência de Aminoácidos , Animais , Cromatografia Líquida , Desaminação , Concentração de Íons de Hidrogênio , Isomerismo , Metionina/química , Camundongos , Oxirredução , Espectrometria de Massas em Tandem , Triptofano/química
6.
Dev Psychobiol ; 60(8): 975-988, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30098006

RESUMO

The neonate distress cry, which displays a similar acoustic structure across a range of mammalian species, is highly effective in attracting, even compelling, parental care. However, if this cry is defective, as found in human and rodent neonates with poor neurobehavioral function, is the signal less enticing? Using playback recordings of a ewe's own co-twins as stimuli in a two choice test, we compared the preference of each sheep dam for acoustic features of lamb distress calls to assess the impact of signal quality on maternal response. The results of this study indicate that lamb vocalizations with acoustic parameters reflecting poor vocal fold engagement and arousal were less likely to be preferred by their dam. Additionally, these calls were associated with delayed vocal initiation and poor infant survival behavior suggestive of subtle cognitive deficit; and support the possibility that, as in deer and rodents, ovine vocalizations within a specific fundamental frequency range may well be a trigger for optimal maternal behavior. This research has important implications for understanding failed maternal-young interactions in ungulate and other species, and for verifying standardization of infant stimuli used in maternal behavior studies.


Assuntos
Animais Recém-Nascidos/fisiologia , Percepção Auditiva/fisiologia , Comportamento Materno/fisiologia , Ovinos/fisiologia , Vocalização Animal/fisiologia , Voz/fisiologia , Animais , Feminino
7.
J Virol ; 88(17): 9842-63, 2014 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-24942570

RESUMO

UNLABELLED: Rotaviruses (RVs) are 11-segmented, double-stranded RNA viruses that cause severe gastroenteritis in children. In addition to an error-prone genome replication mechanism, RVs can increase their genetic diversity by reassorting genes during host coinfection. Such exchanges allow RVs to acquire advantageous genes and adapt in the face of selective pressures. However, reassortment may also impose fitness costs if it unlinks genes/proteins that have accumulated compensatory, coadaptive mutations and that operate best when kept together. To better understand human RV evolutionary dynamics, we analyzed the genome sequences of 135 strains (genotype G1/G3/G4-P[8]-I1-C1-R1-A1-N1-T1-E1-H1) that were collected at a single location in Washington, DC, during the years 1974 to 1991. Intragenotypic phylogenetic trees were constructed for each viral gene using the nucleotide sequences, thereby defining novel allele level gene constellations (GCs) and illuminating putative reassortment events. The results showed that RVs with distinct GCs cocirculated during the vast majority of the collection years and that some of these GCs persisted in the community unchanged by reassortment. To investigate the influence of protein coadaptation on GC maintenance, we performed a mutual information-based analysis of the concatenated amino acid sequences and identified an extensive covariance network. Unexpectedly, amino acid covariation was highest between VP4 and VP2, which are structural components of the RV virion that are not thought to directly interact. These results suggest that GCs may be influenced by the selective constraints placed on functionally coadapted, albeit noninteracting, viral proteins. This work raises important questions about mutation-reassortment interplay and its impact on human RV evolution. IMPORTANCE: Rotaviruses are devastating human pathogens that cause severe diarrhea and kill >450,000 children each year. The virus can evolve by accumulating mutations and by acquiring new genes from other strains via a process called reassortment. However, little is known about the relationship between mutation accumulation and gene reassortment for rotaviruses and how it impacts viral evolution. In this study, we analyzed the genome sequences of human strains found in clinical fecal specimens that were collected at a single hospital over an 18-year time span. We found that many rotaviruses did not reassort their genes but instead maintained them as specific sets (i.e., constellations). By analyzing the encoded proteins, we discovered concurrent amino acid changes among them, which suggests that they are functionally coadapted to operate best when kept together. This study increases our understanding of how rotaviruses evolve over time in the human population.


Assuntos
Evolução Molecular , Rotavirus/genética , Rotavirus/isolamento & purificação , Proteínas Virais/genética , Adaptação Biológica , Pré-Escolar , Análise por Conglomerados , District of Columbia , Genoma Viral , Humanos , Lactente , Dados de Sequência Molecular , Filogenia , Rotavirus/classificação , Análise de Sequência de DNA
8.
Subcell Biochem ; 75: 255-69, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24146383

RESUMO

The development of hypoxic microenvironments within many types of solid tumors imposes a significant stress on cancer cells to which they must respond appropriately in order to survive and grow. Tumor-specific, hypoxia-induced upregulation of Carbonic Anhydrase IX (CAIX) is a component of the complex response of cancer cells to the evolving low oxygen environment. Here, we discuss evidence from in vivo tumor models employing inhibition or enhancement of CAIX expression, using gene depletion or overexpression strategies, respectively, or inhibition of its catalytic activity, using CAIX-specific small molecules or antibodies, to demonstrate that CAIX is a functional mediator of tumor growth and metastasis. We also discuss the functional contribution of CAIX to several specific biological processes critical for cancer progression, including pH regulation and cell survival, adhesion, migration and invasion, the maintenance of cancer stem cell function, and the acquisition of chemo and radioresistant properties. The demonstration of CAIX as a functional mediator of cancer progression provides a biological rationale for its use as a cancer-specific, clinically relevant therapeutic target.


Assuntos
Antígenos de Neoplasias/genética , Anidrases Carbônicas/genética , Terapia de Alvo Molecular , Neoplasias/tratamento farmacológico , Neoplasias/enzimologia , Antígenos de Neoplasias/metabolismo , Dióxido de Carbono/metabolismo , Anidrase Carbônica IX , Anidrases Carbônicas/metabolismo , Carcinogênese/genética , Hipóxia Celular/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias/patologia , Estresse Fisiológico/genética
9.
Artigo em Inglês | MEDLINE | ID: mdl-39302042

RESUMO

This position paper explores famous colonial Australian politician Sir Henry Parkes use of relationships to reform colonial Australian mental healthcare by facilitating the integration of Nightingale-trained nurses into hospitals for the insane in the late nineteenth century. A review of historical sources including primary documents reveals that Parkes exhibited astute political skill by developing relationships with influential healthcare leaders such as Florence Nightingale, Lucy Osburn and Dr. Frederic Norton Manning. As Parkes cultivated friendships with such people, he was able to sow seeds for the deployment of Nightingale nurses including two members from the original group of six nurses sent by Nightingale to Australia in 1868, as well as three nurses trained under their supervision (probationers) into hospitals for the insane. This historical account provides evidence that enables current-day nurses to understand ways in which events of the past have contributed to the development of present-day mental health services and systems. Parkes' legacy also encourages contemporary nurses who are interested in change to consider the importance of forging diverse strategic relationships to bring their own visions into reality.

10.
Animal ; 18(3): 101091, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38428372

RESUMO

Pasture-based beef cattle are raised in a range of production environments. Some paddocks may contain trees and other objects that allow for grooming, hence being naturally enriching, whilst others may be barren without these opportunities. Additionally, it is not uncommon for cattle to move between these enriched and barren environments as part of routine management. While the benefits of enrichment are well studied, how this 'enrichment loss' impacts cattle welfare as access to stimuli is removed is unknown. This trial assessed the impacts of the loss of an enriching object (grooming brush) on grazing beef cattle welfare and production characteristics. When grooming brush access was blocked, cattle became dirtier, showed reduced average daily gain, and had elevated faecal cortisol metabolites, although this varied according to the degree of initial individual brush use. Additionally, allogrooming and grooming on other objects were reduced when access to the brush was returned, potentially indicating a rebound effect. These results demonstrate that the loss of adequate grooming objects can impair the overall welfare of grazing cattle; however, further work is needed to determine exactly which natural or artificial objects provide adequate grooming opportunities.


Assuntos
Asseio Animal , Animais , Bovinos , Fezes
11.
Brain Tumor Pathol ; 2024 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-39316272

RESUMO

Diffuse intrinsic pontine glioma (DIPG) remains a significant therapeutic challenge due to the lack of effective and safe treatment options. This study explores the potential of combining histone deacetylase (HDAC) and carbonic anhydrase 9 (CA9) inhibitors in treating DIPG. Analysis of RNA sequencing data and tumor tissue from patient samples for the expression of the carbonic anhydrase family and hypoxia signaling pathway activity revealed clinical relevance for targeting CA9 in DIPG. A synergy screen was conducted using CA9 inhibitor SLC-0111 and HDAC inhibitors panobinostat, vorinostat, entinostat, and pyroxamide. The combination of SLC-0111 and pyroxamide demonstrated the highest synergy and was selected for further analysis. Combining SLC-0111 and pyroxamide effectively inhibited DIPG cell proliferation, reduced cell migration and invasion potential, and enhanced histone acetylation, leading to decreased cell population in S Phase. Additionally, the combination therapy induced a greater reduction in intracellular pH than either agent alone. Data from this study suggest that the combination of SLC-0111 and pyroxamide holds promise for treating experimental DIPG, and further investigation of this combination therapy in preclinical models is warranted to evaluate its potential as a viable treatment for DIPG.

12.
Behav Ecol ; 35(1): arad097, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38550303

RESUMO

Aposematic prey advertise their unprofitability with conspicuous warning signals that are often composed of multiple color patterns. Many species show intraspecific variation in these patterns even though selection is expected to favor invariable warning signals that enhance predator learning. However, if predators acquire avoidance to specific signal components, this might relax selection on other aposematic traits and explain variability. Here, we investigated this idea in the aposematic moth Amata nigriceps that has conspicuous black and orange coloration. The size of the orange spots in the wings is highly variable between individuals, whereas the number and width of orange abdominal stripes remains consistent. We produced artificial moths that varied in the proportion of orange in the wings or the presence of abdominal stripes. We presented these to a natural avian predator, the noisy miner (Manorina melanocephala), and recorded how different warning signal components influenced their attack decisions. When moth models had orange stripes on the abdomen, birds did not discriminate between different wing signals. However, when the stripes on the abdomen were removed, birds chose the model with smaller wing spots. In addition, we found that birds were more likely to attack moths with a smaller number of abdominal stripes. Together, our results suggest that bird predators primarily pay attention to the abdominal stripes of A. nigriceps, and this could relax selection on wing coloration. Our study highlights the importance of considering individual warning signal components if we are to understand how predation shapes selection on prey warning coloration.

13.
Prev Med ; 56(6): 390-7, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23480968

RESUMO

OBJECTIVE: To determine whether telephone-based smoking cessation follow-up counseling (FC), when delivered as part of a multi-component intervention program is associated with increased rates of follow-up support and smoking abstinence. METHODS: A cluster randomized controlled-trial was conducted within family medicine practices in Ontario, Canada. Consecutive adult patients who smoked were enrolled at two time points, the baseline period (2009) and the post-intervention period (2009-2011). Smoking abstinence was determined by telephone interview 4 months following enrollment. Both groups implemented a multi-component intervention program. Practices randomized to the FC group could also refer patients to a follow-up support program which involved 5 telephone contacts over a 2-month period. RESULTS: Eight practices, 130 providers, and 928 eligible patients participated in the study. No statistically significant difference in 7-day point-prevalence abstinence was observed between intervention groups. There was a significant increase in referral to follow-up in both intervention groups. Significantly higher rates of smoking abstinence [25.7% vs. 11.3%; adjusted OR 3.1 (95% CI: 1.1, 8.6), p<0.05] were documented among the twenty-nine percent of FC participants who were referred to the follow-up support program compared to the MC group. CONCLUSION: Access to external follow-up support did not increase rates at which follow-up support was delivered.


Assuntos
Aconselhamento/métodos , Abandono do Hábito de Fumar/métodos , Fumar/terapia , Adulto , Medicina de Família e Comunidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação de Programas e Projetos de Saúde , Fumar/epidemiologia , Abandono do Hábito de Fumar/estatística & dados numéricos , Telefone , Resultado do Tratamento
14.
Nicotine Tob Res ; 15(7): 1201-10, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23231826

RESUMO

INTRODUCTION: Few studies have examined the transitions of smokers in the general population through multiple periods of daily, occasional smoking, or abstinence over time. Transitions from daily to occasional smoking are particularly of interest as these may be steps toward cessation. METHODS: The Ontario Tobacco Survey panel study followed 4,355 baseline smokers, semiannually for up to 3 years. Probabilities of all possible changes in smoking status more than 6 months were estimated using 13,000 repeated measures observations generated from sets of 3 consecutive interviews (n = 9,932 daily smokers, 1,245 occasion smokers, and 1,823 abstinent for at least 30 days, at Time 1). RESULTS: For initial daily smokers, an estimated 83% remained daily smokers more than 2 follow-ups. The majority of those who had been abstinent for 30 days at 1 interview, were also former smokers at the following interview. In contrast, occasional smoking status was unstable and future smoking status was dependent upon smoking history and subjective dependence. Among daily smokers who became occasional smokers 6 months later, an estimated 20% became a former smoker, at the next interview, but 50% returned to daily smoking. Daily, turned occasional smokers who rebounded back to daily smoking were more likely to describe themselves as addicted at Time 1. Continuing occasional smokers were somewhat less likely to intend to quit, or have tried, despite considering themselves less addicted. CONCLUSIONS: Reducing to occasional smoking can be a stepping stone toward cessation but entails a greater risk of return to daily smoking, compared with complete abstinence.


Assuntos
Abandono do Hábito de Fumar/métodos , Fumar/psicologia , Adulto , Feminino , Humanos , Entrevistas como Assunto , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Ontário/epidemiologia , Fumar/epidemiologia , Abandono do Hábito de Fumar/psicologia , Fatores de Tempo
15.
Front Mol Biosci ; 10: 1327310, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38099193

RESUMO

The tumour-associated carbonic anhydrases (CA) IX and XII are upregulated by cancer cells to combat cellular and metabolic stress imparted by hypoxia and acidosis in solid tumours. Owing to its tumour-specific expression and function, CAIX is an attractive therapeutic target and this has driven intense efforts to develop pharmacologic agents to target its activity, including small molecule inhibitors. Many studies in multiple solid tumour models have demonstrated that targeting CAIX activity with the selective CAIX/XII inhibitor, SLC-0111, results in anti-tumour efficacy, particularly when used in combination with chemotherapy or immune checkpoint blockade, and has now advanced to the clinic. However, it has been observed that sustainability and durability of CAIX inhibition, even in combination with chemotherapy agents, is limited by the occurrence of adaptive resistance, resulting in tumour recurrence. Importantly, the data from these models demonstrates that CAIX inhibition may sensitize tumour cells to cytotoxic drugs and evidence now points to ferroptosis, an iron-dependent form of regulated cell death (RCD) that results from accumulation of toxic levels of phospholipid peroxidation as a major mechanism involved in CAIX-mediated sensitization to cancer therapy. In this mini-review, we discuss recent advances demonstrating the mechanistic role CAIX plays in sensitizing cancer cells to ferroptosis.

16.
Mol Cancer Ther ; 22(10): 1228-1242, 2023 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-37348875

RESUMO

The ability of tumor cells to alter their metabolism to support survival and growth presents a challenge to effectively treat cancers. Carbonic anhydrase IX (CAIX) is a hypoxia-induced, metabolic enzyme that plays a crucial role in pH regulation in tumor cells. Recently, through a synthetic lethal screen, we identified CAIX to play an important role in redox homeostasis. In this study, we show that CAIX interacts with the glutamine (Gln) transporter, solute carrier family 1 member 5 (SLC1A5), and coordinately functions to maintain redox homeostasis through the glutathione/glutathione peroxidase 4 (GSH/GPX4) axis. Inhibition of CAIX increases Gln uptake by SLC1A5 and concomitantly increases GSH levels. The combined inhibition of CAIX activity and Gln metabolism or the GSH/GPX4 axis results in an increase in lipid peroxidation and induces ferroptosis, both in vitro and in vivo. Thus, this study demonstrates cotargeting of CAIX and Gln metabolism as a potential strategy to induce ferroptosis in tumor cells.


Assuntos
Anidrases Carbônicas , Ferroptose , Humanos , Anidrase Carbônica IX/metabolismo , Glutamina , Anidrases Carbônicas/metabolismo , Linhagem Celular Tumoral , Antígenos de Neoplasias/metabolismo , Hipóxia , Antígenos de Histocompatibilidade Menor , Sistema ASC de Transporte de Aminoácidos/genética
17.
Biol Lett ; 8(3): 365-8, 2012 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-22258445

RESUMO

Hypotheses proposed to explain the evolution of cooperative behaviour typically require differentiation between either groups of conspecifics (e.g. kin/non-kin) or, more typically, individuals (e.g. reciprocal altruism). Despite this, the mechanisms that facilitate individual or class recognition have rarely been explored in cooperative species. This study examines the individual differentiation abilities of noisy miners (Manorina melanocephala), a species with one of the most complex avian societies known. Miners permanently occupy colonies numbering into hundreds of individuals. Within these colonies, cooperative coalitions form on a fission-fusion basis across numerous contexts, from social foraging through to mobbing predators. Birds often use individually distinctive 'chur' calls to recruit others to a caller's location, facilitating coalition formation. I used the habituation-discrimination paradigm to test the ability of miners to differentiate between the chur calls of two individuals that were both either: (i) familiar, or (ii) unfamiliar to the focal subject. This technique had not, to my knowledge, been used to assess vocalization differentiation in cooperative birds previously, but here demonstrated that miners could correctly use the spectral features of signals to differentiate between the vocalizations of different individuals, regardless of their familiarity. By attending to individual differences in recruitment calls, miners have a communication system that is capable of accommodating even the most complex cooperative hypotheses based upon acoustic information.


Assuntos
Sinais (Psicologia) , Aves Canoras/fisiologia , Vocalização Animal , Acústica , Animais , Austrália , Comportamento Cooperativo
18.
Cancers (Basel) ; 14(13)2022 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-35804980

RESUMO

Cancer metastasis is a major barrier to the long-term survival of cancer patients. In cancer cells, integrin engagement downstream of cell-extracellular matrix (ECM) interactions results in the recruitment of cytoskeletal and signaling molecules to form multi-protein complexes to promote processes critical for metastasis. One of the major functional components of these complexes is Integrin Linked Kinase (ILK). Here, we discuss recent advances in our understanding of the importance of ILK as a signaling effector in processes linked to tumor progression and metastasis. New mechanistic insights as to the role of ILK in cellular plasticity, epithelial mesenchymal transition (EMT), migration, and invasion, including the impact of ILK on the formation of invadopodia, filopodia-like protrusions (FLPs), and Neutrophil Extracellular Trap (NET)-induced motility are highlighted. Recent findings detailing the contribution of ILK to therapeutic resistance and the importance of ILK as a potentially therapeutically tractable vulnerability in both solid tumors and hematologic malignancies are discussed. Indeed, pharmacologic inhibition of ILK activity using specific small molecule inhibitors is effective in curtailing the contribution of ILK to these processes, potentially offering a novel therapeutic avenue for inhibiting critical steps in the metastatic cascade leading to reduced drug resistance and increased therapeutic efficacy.

19.
Cancers (Basel) ; 14(14)2022 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-35884358

RESUMO

Carbonic Anhydrase IX (CAIX) is a major metabolic effector of tumor hypoxia and regulates intra- and extracellular pH and acidosis. Significant advances have been made recently in the development of therapeutic targeting of CAIX. These approaches include antibody-based immunotherapy, as well as use of antibodies to deliver toxic and radioactive payloads. In addition, a large number of small molecule inhibitors which inhibit the enzymatic activity of CAIX have been described. In this commentary, we highlight the current status of strategies targeting CAIX in both the pre-clinical and clinical space, and discuss future perspectives that leverage inhibition of CAIX in combination with additional targeted therapies to enable effective, durable approaches for cancer therapy.

20.
Animals (Basel) ; 12(24)2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36552464

RESUMO

Environmental enrichment can improve livestock welfare through increasing environmental complexity to promote a greater range of natural behaviours. However, there is limited understanding of the need for and impacts of enrichments for extensively managed beef cattle that can sometimes be kept in grassed paddocks devoid of additional natural and artificial features, i.e., 'barren pastures'. This trial assessed which enrichments beef cattle preferred and utilised in a barren paddock environment. Eight groups of seven Angus steers housed on pastured paddocks devoid of natural or artificial features were observed during daylight hours for two days a week over a period of three weeks, after being presented with four enrichments simultaneously: a cattle brush, a piece of hanging rope, a tree stump, and a woodchip pile. Although enrichment use generally decreased over time, the brush, stump, and woodchip maintained a higher level of use than the rope, based on the frequency of interactions and number of displacements around the enrichments (both p < 0.001). This suggests that the brush, stump, and woodchip pile were more valuable resources to the cattle, allowing for grooming and lying behaviours, although oral manipulations also occurred on the stump, woodchip, and rope. The inclusion of these enrichments can increase the complexity of barren pasture environments and allow for the increased expression of natural behaviours, potentially contributing to improved welfare.

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