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1.
Adv Sci (Weinh) ; : e2307591, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38864546

RESUMO

Image-based cytometry faces challenges due to technical variations arising from different experimental batches and conditions, such as differences in instrument configurations or image acquisition protocols, impeding genuine biological interpretation of cell morphology. Existing solutions, often necessitating extensive pre-existing data knowledge or control samples across batches, have proved limited, especially with complex cell image data. To overcome this, "Cyto-Morphology Adversarial Distillation" (CytoMAD), a self-supervised multi-task learning strategy that distills biologically relevant cellular morphological information from batch variations, is introduced to enable integrated analysis across multiple data batches without complex data assumptions or extensive manual annotation. Unique to CytoMAD is its "morphology distillation", symbiotically paired with deep-learning image-contrast translation-offering additional interpretable insights into label-free cell morphology. The versatile efficacy of CytoMAD is demonstrated in augmenting the power of biophysical imaging cytometry. It allows integrated label-free classification of human lung cancer cell types and accurately recapitulates their progressive drug responses, even when trained without the drug concentration information. CytoMAD  also allows joint analysis of tumor biophysical cellular heterogeneity, linked to epithelial-mesenchymal plasticity, that standard fluorescence markers overlook. CytoMAD can substantiate the wide adoption of biophysical cytometry for cost-effective diagnosis and screening.

2.
J Clin Transl Sci ; 8(1): e9, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38384917

RESUMO

The proposal of improving reproducibility by lowering the significance threshold to 0.005 has been discussed, but the impact on conducting clinical trials has yet to be examined from a study design perspective. The impact on sample size and study duration was investigated using design setups from 125 phase II studies published between 2015 and 2022. The impact was assessed using percent increase in sample size and additional years of accrual with the medians being 110.97% higher and 2.65 years longer respectively. The results indicated that this proposal causes additional financial burdens that reduce the efficiency of conducting clinical trials.

3.
J Am Chem Soc ; 146(5): 3250-3261, 2024 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-38266489

RESUMO

Phospholipid bilayers are dynamic cellular components that undergo constant changes in their topology, facilitating a broad diversity of physiological functions including endo- and exocytosis, cell division, and intracellular trafficking. These shape transformations consume energy, supplied invariably by the activity of proteins. Here, we show that cycles of oppositely directed osmotic stresses─unassisted by any protein activity─can induce well-defined remodeling of giant unilamellar vesicles, minimally recapitulating the phenomenologies of surface area homeostasis and macropinocytosis. We find that a stress cycle consisting of deflationary hypertonic stress followed by an inflationary hypotonic one prompts an elaborate sequence of membrane shape changes ultimately transporting molecular cargo from the outside into the intravesicular milieu. The initial osmotic deflation produces microscopic spherical invaginations. During the subsequent inflation, the first subpopulation contributes area to the swelling membrane, thereby providing a means for surface area regulation and tensional homeostasis. The second subpopulation vesiculates into the lumens of the mother vesicles, producing pinocytic vesicles. Remarkably, the gradients of solute concentrations between the GUV and the daughter pinocytic vesicles create cascades of water current, inducing pulsatory transient poration that enable solute exchange between the buds and the GUV interior. This results in an efficient water-flux-mediated delivery of molecular cargo across the membrane boundary. Our findings suggest a primitive physical mechanism for communication and transport across protocellular compartments driven only by osmotic stresses. They also suggest plausible physical routes for intravesicular, and possibly intracellular, delivery of ions, solutes, and molecular cargo stimulated simply by cycles of osmotic currents of water.


Assuntos
Fosfolipídeos , Lipossomas Unilamelares , Pressão Osmótica , Lipossomas Unilamelares/metabolismo , Osmose , Água
4.
Respir Res ; 25(1): 36, 2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-38238804

RESUMO

INTRODUCTION: Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is a common and preventable event in patients with chronic obstructive pulmonary disease (COPD). Data regarding the impact of AECOPD on short- and long-term renal outcomes are lacking. METHODS: We included all COPD patients who were followed at Queen Mary Hospital (QMH) in year 2015 and reviewed their clinical/renal outcomes in subsequent five years. Relationships between AECOPD and adverse renal outcomes were evaluated. RESULTS: 371 COPD patients were included. 169 patients had hospitalized AECOPD in past one year (HAE group) while 202 patients did not (non-HAE group). 285 patients (76.8%) had renal progression/death and 102 (27.5%) patients developed acute kidney injury (AKI). HAE group showed a more rapid eGFR decline than non-HAE group (-4.64 mL/min/1.73m2/year vs. -2.40 mL/min/1.73m2/year, p = 0.025). HAE group had significantly higher risk for renal progression/death at 5 years [adjusted OR (aOR) 2.380 (95% CI = 1.144-4.954), p = 0.020]. The frequency of hospitalized AECOPD in past 3 years, any AECOPD in past 3 years, hospitalized AECOPD in past 3 years were also predictive of renal progression/death at 5 years [aOR were 1.176 (95% CI = 1.038- 1.331), 2.998 (95% CI = 1.438-6.250) and 2.887 (95% CI = 1.409-5.917) respectively; p = 0.011, 0.003 and 0.004]. HAE group also showed significantly higher risk of AKI [adjusted HR (aHR) 2.430; 95% CI = 1.306-4.519, p = 0.005]. CONCLUSIONS: AECOPD, in particular HAE, was associated with increased risk of renal progression/death and AKI. Prevention of AECOPD, especially HAE, may potentially improve short- and long-term renal outcomes in COPD patients.


Assuntos
Injúria Renal Aguda , Doença Pulmonar Obstrutiva Crônica , Humanos , Progressão da Doença , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Doença Pulmonar Obstrutiva Crônica/complicações , Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/epidemiologia , Doença Aguda
5.
Nat Chem ; 16(1): 54-62, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37414881

RESUMO

A variety of cellular processes use liquid-liquid phase separation (LLPS) to create functional levels of organization, but the kinetic pathways by which it proceeds remain incompletely understood. Here in real time, we monitor the dynamics of LLPS of mixtures of segregatively phase-separating polymers inside all-synthetic, giant unilamellar vesicles. After dynamically triggering phase separation, we find that the ensuing relaxation-en route to the new equilibrium-is non-trivially modulated by a dynamic interplay between the coarsening of the evolving droplet phase and the interactive membrane boundary. The membrane boundary is preferentially wetted by one of the incipient phases, dynamically arresting the progression of coarsening and deforming the membrane. When the vesicles are composed of phase-separating mixtures of common lipids, LLPS within the vesicular interior becomes coupled to the membrane's compositional degrees of freedom, producing microphase-separated membrane textures. This coupling of bulk and surface phase-separation processes suggests a physical principle by which LLPS inside living cells might be dynamically regulated and communicated to the cellular boundaries.


Assuntos
Separação de Fases , Lipossomas Unilamelares
6.
Cancer Med ; 12(24): 22316-22324, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-38063337

RESUMO

BACKGROUND: Despite the growth in primary cancer (PC) survivors, the trends and disparities in this population have yet to be comprehensively examined using competing risk analysis. The objective is to examine trends in time to second primary cancer (SPC) and to characterize age, sex, and racial disparities in time-to-SPC. METHODS: A retrospective analysis was conducted based on Surveillance, Epidemiology, and End Results (SEER). Two datasets for this study are (1) the discovery dataset with patients from SEER-8 (1990-2019) and (2) the validation dataset with patients from SEER-17 (2000-2019), excluding those in the discovery dataset. Patients were survivors of lung, colorectal, breast (female only), and prostate PCs. RESULTS: The 5-year SPC cumulative incidences of lung PC increased from 1990 to 2019, with the cumulative incidence ratio being 1.73 (95% confidence intervals [CI], 1.64-1.82; p < 0.001). Age disparities among all PCs remained from 2010 to 2019, and the adjusted HRs (aHRs) of all PCs were above 1.43 when those below 65 were compared with those 65 and above. Sex disparity exists among colorectal and lung PC survivors. Racial disparities existed among non-Hispanic (NH) Black breast PC survivors (aHR: 1.11; 95% CI: 1.07-1.17; p < 0.001). The types of SPC vary according to PC and sex. CONCLUSIONS: Over the past three decades, there has been a noticeably shortened time-to-SPC among lung PC survivors. This is likely attributed to the reduced number of lung cancer deaths due to advancements in effective treatments. However, disparities in age, sex, and race still exist, indicating that further effort is needed to close the gap.


Assuntos
Neoplasias da Mama , Neoplasias Colorretais , Neoplasias Pulmonares , Segunda Neoplasia Primária , Masculino , Humanos , Feminino , Segunda Neoplasia Primária/epidemiologia , Estudos Retrospectivos , Neoplasias da Mama/epidemiologia , Neoplasias Pulmonares/epidemiologia , Neoplasias Colorretais/epidemiologia , Neoplasias Colorretais/terapia , Programa de SEER
7.
Chin Clin Oncol ; 12(5): 53, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37817506

RESUMO

BACKGROUND AND OBJECTIVE: The application of immunotherapy in cancers, including liver cancer, has been increasing. However, non-proportional hazard (NPH) is often observed in cancer immunotherapy trials. In presence of violation of proportional hazard (PH) assumption, restricted mean survival time (RMST) ratio was proposed as an alternative to hazard ratio (HR) for evaluating the treatment effects of such trials. To shorten the total study duration, an intermediate endpoint with shorter follow-up such as progression-free survival (PFS) is used as the primary endpoint. Our aim is to evaluate the applicability of RMST ratio in addition to the HR in assessing the level of PFS serving as a surrogacy of overall survival (OS). METHODS: Phase II or phase III hepatocellular carcinoma (HCC) immunotherapy studies that were published between January 2013 and August 2022 were identified via the search in PubMed. Weighted least-square regression (WLSR) was applied to analyze the trial level data with the sample size of study being set as the weight. The evaluation was conducted twice with RMST ratio and HR being applied in respective evaluation to examine the level of PFS as a surrogacy for OS. KEY CONTENT AND FINDINGS: Based on the results of eight included trials, the R-square values of WLSR with either HR or RMST ratio being applied were 0.31 and 0.16 separately, indicating a moderate and low correlation between PFS and OS respectively. CONCLUSIONS: In this study, our results demonstrated the potential of RMST ratio in addition to HR for evaluating the level of surrogacy in immunotherapy trials. Furthermore, including more large scale and homogeneous studies into the research may help better understand the level of surrogacy in liver cancer.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/terapia , Taxa de Sobrevida , Neoplasias Hepáticas/terapia , Imunoterapia/métodos , Intervalo Livre de Doença
8.
Membranes (Basel) ; 13(2)2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36837639

RESUMO

The stratum corneum (SC), the outer layer of the skin, plays a crucial role as a barrier protecting the underlying cells from external stress. The SC comprises three key components: ceramide (CER), free fatty acid (FFA), and cholesterol, along with small fractions of cholesterol sulfate and cholesterol ester. In order to gain a deeper understanding about the interdependence of the two major components, CER and FFA, on the organizational, structural, and functional properties of the SC layer, a library of SC lipid liposome (SCLL) models was developed by mixing CER (phytosphingosine or sphingosine), FFA (oleic acid, palmitic acid, or stearic acid), cholesterol, and cholesterol sulfate. Self-assembly of the SC lipids into lamellar phases was first confirmed by small-angle X-ray scattering. Short periodicity and long periodicity phases were identified for SCLLs containing phytosphingosines and sphingosine CERs, respectively. Furthermore, unsaturation in the CER acyl and FFA chains reduced the lipid conformational ordering and packing density of the liposomal bilayer, which were measured by differential scanning calorimetry and Fourier transform infrared spectroscopy. The introduction of unsaturation in the CER and/or FFA chains also impacted the lamellar integrity and permeability. This extensive library of SCLL models exhibiting physiologically relevant lamellar phases with defined structural and functional properties may potentially be used as a model system for screening pharmaceuticals or cosmetic agents.

9.
Pharmaceutics ; 15(2)2023 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-36839864

RESUMO

Multidrug-resistant tuberculosis (MDR) continues to pose a threat to public health. Previously, we identified a cationic host defense peptide with activity against Mycobacterium tuberculosis in vivo and with a bactericidal effect against MDR M. tuberculosis at therapeutic concentrations. To understand the mechanisms of this peptide, we investigated its interactions with live M. tuberculosis and liposomes as a model. Peptide interactions with M. tuberculosis inner membranes induced tube-shaped membranous structures and massive vesicle formation, thus leading to bubbling cell death and ghost cell formation. Liposomal studies revealed that peptide insertion into inner membranes induced changes in the peptides' secondary structure and that the membranes were pulled such that they aggregated without permeabilization, suggesting that the peptide has a strong inner membrane affinity. Finally, the peptide targeted essential proteins in M. tuberculosis, such as 60 kDa chaperonins and elongation factor Tu, that are involved in mycolic acid synthesis and protein folding, which had an impact on bacterial proliferation. The observed multifaceted targeting provides additional support for the therapeutic potential of this peptide.

10.
Ann Transl Med ; 11(1): 2, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36760246

RESUMO

Background: Appropriate analyses and reporting are essential to the reproducibility and interpretation of clinical trials. However, the coronavirus disease 19 (COVID-19) pandemic and other force majeure events, like the war in Ukraine, have impacted the conduct of clinical trials. Methods: The number of clinical trials potentially impacted were estimated from clinicaltrials.gov. To identify reporting items considered vital for assessing the impact of COVID-19, we reviewed 35 randomized phase III trials from three top oncology journals published between July and December 2020. For validation, we reviewed 29 phase III trials published between January and December 2021. Results: Our results show that the number of clinical trials being potentially impacted in cancer, cardiovascular diseases, and diabetes is at least 1,484, 535, and 145, respectively. The magnitude of disruption is most significant in oncology trials. Based on the review of 35 trials, a modified checklist with ten new and four modified items covering pandemic's impact on trial conduct, protocol changes, delays, data capture, analysis and interpretation was developed to ensure comprehensive and transparent reporting. Our validation shows that six out of seven applicable reporting items were reported in less than 21% of the articles. Conclusions: Our recommendations were proposed to improve the reporting of randomized clinical trials impacted by COVID-19 and force majeure events that are broadly applicable to different areas of medical research.

11.
Nutr Cancer ; 75(1): 219-227, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35930377

RESUMO

Dietary factors show different effects on genetically diverse populations. Scientific research uses gene-environment interaction models to study the effects of dietary factors on genetically diverse populations for lung cancer risk. However, previous study designs have not investigated the degree of type I error inflation and, in some instances, have not corrected for multiple testing. Using a motivating investigation of diet-gene interaction and lung cancer risk, we propose a training and testing strategy and perform real-world simulations to select the appropriate statistical methods to reduce false-positive discoveries. The simulation results show that the unconstrained maximum likelihood (UML) method controls the type I error better than the constrained maximum likelihood (CML). The empirical Bayesian (EB) method can compete with the UML method in achieving statistical power and controlling type I error. We observed a significant interaction between SNP rs7175421 with dietary whole grain in lung cancer prevention, with an effect size (standard error) of -0.312 (0.112) for EB estimate. SNP rs7175421 may interact with dietary whole grains in modulating lung cancer risk. Evaluating statistical methods for gene-diet interaction analysis can help balance the statistical power and type I error.


Assuntos
Neoplasias Pulmonares , Grãos Integrais , Humanos , Teorema de Bayes , Dieta , Interação Gene-Ambiente , Neoplasias Pulmonares/genética
12.
Langmuir ; 38(29): 8805-8816, 2022 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-35816731

RESUMO

Lamellar mesophases of insoluble lipids are readily solubilized by the micellar mesophases of soluble surfactants. This simple process underscores a broad array of biochemical methodologies, including purification, reconstitution, and crystallization of membrane proteins, as well as the isolation of detergent-resistant membrane fractions. Although much is now known about the thermodynamic driving forces of membrane solubilization, the kinetic pathways by which the surfactant alters vesicular mesophases are only beginning to be appreciated. Little is known about how these interactions affect the solubilization of more complex, multilamellar mesophases. Here, we investigate how a common zwitterionic detergent affects the solubilization of a smectic, multilamellar, cylindrical mesophase of lipids, called the myelin figure. Our results reveal that myelin solubilization occurs in a multistep manner, producing a well-defined sequence of morphologically distinct intermediates en route to complete solubilization. The kinetic processes producing these intermediates include (1) coiling, which encompasses the formation, propagation, and tightening of extended helices; (2) thinning, which reflects the unbinding of lamellae in the smectic stacks; and (3) detachment or retraction, which either dissociates the myelinic protrusion from the source lipid mass or returns the myelinic protrusion to the source lipid mass─all in transit toward complete solubilization. These occasionally overlapping steps are most pronounced in single-lipid component myelins, while compositionally graded multicomponent myelins inhibit the coiling step and detach more frequently. Taken together, the appearance of these intermediates during the solubilization of myelins suggests a complex free-energy landscape characterizing myelin solubilization populated by metastable, morphological intermediates correlated with locally minimized changes in energy dependent upon the mesophase's composition. This then predicts the accessibility of structurally distinct, kinetic intermediates─such as loose and tight coiled helices, peeled myelins, retracted tubes, and detached protrusions─before reaching the stable ground state corresponding to a dissolved suspension of mixed surfactant-lipid micelles.


Assuntos
Surfactantes Pulmonares , Tensoativos , Detergentes/química , Excipientes , Lipídeos , Micelas , Bainha de Mielina , Solubilidade , Tensoativos/química
13.
Biofactors ; 48(5): 1145-1159, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35388547

RESUMO

Complexes formed by the alpha1 N-terminal peptide of alpha-lactalbumin and oleic acid (alpha1-oleate) interact with lipid bilayers. Plasma membrane perturbations trigger tumor cell death but normal differentiated cells are more resistant, and their plasma membranes are less strongly affected. This study examined membrane lipid composition as a determinant of tumor cell reactivity. Bladder cancer tissue showed a higher abundance of unsaturated lipids enriched in phosphatidylcholine, PC (36:4) and PC (38:4), and sphingomyelin, SM (36:1) than healthy bladder tissue, where saturated lipids predominated and the lipid extracts from bladder cancer tissue inhibited the tumoricidal effect of the complex more effectively than healthy tissue extracts. Furthermore, unsaturated PC in solution inhibited tumor cell death, and the complex interacted with giant unilamellar vesicles formed by PC, confirming the affinity of alpha1-oleate for fluid membranes enriched in PC. Quartz Crystal Microbalance with dissipation monitoring (QCM-D) detected a preference of the complex for the liquid-disordered phase, suggesting that the insertion into PC-based membranes and the resulting membrane perturbations are influenced by membrane lipid saturation. The results suggest that the membrane lipid composition is functionally important and that specific unsaturated membrane lipids may serve as "recognition motifs" for broad-spectrum tumoricidal molecules such as alpha1-oleate.


Assuntos
Bicamadas Lipídicas , Neoplasias da Bexiga Urinária , Humanos , Lactalbumina/química , Lactalbumina/metabolismo , Lactalbumina/farmacologia , Bicamadas Lipídicas/química , Bicamadas Lipídicas/metabolismo , Lipídeos de Membrana/química , Lipídeos de Membrana/metabolismo , Ácido Oleico/química , Ácido Oleico/metabolismo , Ácido Oleico/farmacologia , Fosfatidilcolinas/química , Esfingomielinas/química , Extratos de Tecidos , Lipossomas Unilamelares
14.
Chin Clin Oncol ; 11(1): 7, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35255696

RESUMO

BACKGROUND: Proportional hazards (PH) assumption is often violated in cancer immunotherapy studies. Restricted mean survival time (RMST) ratio is a valid metric to quantify the size of treatment effect when non-proportional hazard (NPH) is present. This study investigated the use of RMST ratio and hazard ratio (HR) in studying progression-free survival (PFS) as a surrogate endpoint for overall survival (OS) in non-small cell lung cancer immunotherapy trials. METHODS: Trial level data were collected from 14 phase III trials published between 2012 and 2018. A weighted least-square regression (WLSR) was performed to evaluate the trial-level surrogacy. Surrogacy was evaluated via the association between RMST ratios for PFS and OS and between HRs for PFS and OS. RESULTS: Using data extracted from published articles, low to moderate correlation (0.49) between PFS and OS was observed for HR while low correlation (0.35) was observed for RMST ratio. When trials violating PH in PFS were included, more consistent correlations for both HR (0.43) and RMST ratio (0.44) were observed. CONCLUSIONS: In summary, the strength of PFS surrogacy for OS depends on whether HR or RMST ratio are chosen. RMST ratio and additional sensitivity analysis should be considered in addition to HR.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Imunoterapia , Neoplasias Pulmonares , Carcinoma Pulmonar de Células não Pequenas/terapia , Ensaios Clínicos Fase III como Assunto , Intervalo Livre de Doença , Humanos , Neoplasias Pulmonares/terapia , Análise de Sobrevida , Taxa de Sobrevida
15.
Langmuir ; 38(3): 1045-1056, 2022 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-35020400

RESUMO

When a dry mass of certain amphiphiles encounters water, a spectacular interfacial instability ensues: It gives rise to the formation of ensembles of fingerlike tubular protrusions called myelin figures─tens of micrometers wide and tens to hundreds of micrometers long─representing a novel class of nonequilibrium higher-order self-organization. Here, we report that when phase-separating mixtures of unsaturated lipid, cholesterol, and sphingomyelin are hydrated, the resulting myelins break symmetry and couple their compositional degrees of freedom with the extended myelinic morphology: They produce complementary, interlamellar radial gradients of concentrations of cholesterol (and sphingomyelin) and unsaturated lipid, which stands in stark contrast to interlamellar, lateral phase separation in equilibrated morphologies. Furthermore, the corresponding gradients of molecule-specific chemistries (i.e., cholesterol extraction by methyl-ß-cyclodextrin and GM1 binding by cholera toxin) produce unusual morphologies comprising compositionally graded vesicles and buckled tubes. We propose that kinetic differences in the information processing of hydration characteristics of individual molecules while expending energy dictate this novel behavior of lipid mixtures undergoing hydration.


Assuntos
Bicamadas Lipídicas , Esfingomielinas , Fenômenos Biofísicos , Colesterol
16.
ACS Bio Med Chem Au ; 2(1): 73-83, 2022 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-37102179

RESUMO

The role of an amphiphilic environment in the functional regulation of integral membrane proteins is well appreciated but how specific amphiphilic surrounding influences the conformational plasticity and function of a protein is less obvious. We focus on the Salmonella phosphoglycerate transport system (pgt)-encoded outer membrane protease E (PgtE), which plays an important role in tissue infiltration and survival of Salmonella enterica. Despite our understanding of its physiological functions, elucidation of its enzymatic behavior in response to the immediate amphiphilic surrounding is lacking. We monitor the proteolytic activity of PgtE reconstituted in Zwittergent 3-12 detergent micelles or a 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (POPC) bilayer and examine factors that influence its activity. We find, to our surprise, that PgtE, which is thought to elicit a rapid response toward various substrates, showed hysteretic enzymatic behavior, characterized by a prominent lag phase prior to achieving the exponential steady state in its detergent-stabilized form as well as in the outer membrane embedded native state in live bacteria. The lag phase was abolished under three conditions: preformation of an inactive detergent-stabilized PgtE-substrate complex without lipopolysaccharide (LPS), LPS-bound detergent-stabilized PgtE that had reached steady state velocity, or PgtE reconstituted into a POPC bilayer environment. Interestingly, detergent- and bilayer-stabilized PgtE showed comparable steady-state activity. And strikingly, lipopolysaccharide (LPS) becomes nonessential for the activation of PgtE when the protein is reconstituted in the phospholipid bilayer, contrasting a long-standing notion that LPS is required for proteases belonging to the omptin family to be proteolytically active. These findings suggest intriguing biological nuances for the proteolytic function of PgtE that were not well appreciated previously and offer new perspectives that may generally be applicable for omptins.

17.
Mol Cell Oncol ; 8(5): 1974278, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34859140

RESUMO

The protein-lipid complex alpha1-oleate, derived from HAMLET (Human Alpha-lactalbumin Made LEthal to Tumor cells), is identified as a molecular entity with significant therapeutic potential. Structural characterization of the complex and results of a successful placebo-controlled clinical trial are presented.

18.
Nat Commun ; 12(1): 3427, 2021 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-34103518

RESUMO

Partially unfolded alpha-lactalbumin forms the oleic acid complex HAMLET, with potent tumoricidal activity. Here we define a peptide-based molecular approach for targeting and killing tumor cells, and evidence of its clinical potential (ClinicalTrials.gov NCT03560479). A 39-residue alpha-helical peptide from alpha-lactalbumin is shown to gain lethality for tumor cells by forming oleic acid complexes (alpha1-oleate). Nuclear magnetic resonance measurements and computational simulations reveal a lipid core surrounded by conformationally fluid, alpha-helical peptide motifs. In a single center, placebo controlled, double blinded Phase I/II interventional clinical trial of non-muscle invasive bladder cancer, all primary end points of safety and efficacy of alpha1-oleate treatment are reached, as evaluated in an interim analysis. Intra-vesical instillations of alpha1-oleate triggers massive shedding of tumor cells and the tumor size is reduced but no drug-related side effects are detected (primary endpoints). Shed cells contain alpha1-oleate, treated tumors show evidence of apoptosis and the expression of cancer-related genes is inhibited (secondary endpoints). The results are especially encouraging for bladder cancer, where therapeutic failures and high recurrence rates create a great, unmet medical need.


Assuntos
Peptídeos/química , Peptídeos/uso terapêutico , Neoplasias da Bexiga Urinária/tratamento farmacológico , Sequência de Aminoácidos , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Endocitose/efeitos dos fármacos , Determinação de Ponto Final , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Ácidos Oleicos/química , Peptídeos/farmacologia , Placebos , Conformação Proteica , Espectroscopia de Prótons por Ressonância Magnética , Termodinâmica , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/patologia
19.
Lung Cancer ; 155: 87-93, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33756357

RESUMO

OBJECTIVES: Inconsistent findings have been reported on the link between dietary carbohydrates and lung cancer. This study aims to comprehensively evaluate the role of dietary carbohydrates on lung cancer risk. MATERIALS AND METHODS: The prospective study is based on the PLCO trial, which recruited 113,096 eligible participants across the United States. Participants had to have completed baseline and diet history questionnaires. The incidence of lung cancer was acquired through self-report and medical record follow-up. A multivariable logistic model adjusted for confounders was used to estimate odds ratios (ORs) and 95 % confidence intervals (CIs) of dietary carbohydrates, fiber, whole grains, glycemic index (GI) and glycemic load (GL) for lung cancer. Similar methods were applied in analyzing the carbohydrates and fiber from different food sources. Multinomial logistic models were used for sensitivity analysis with lung cancer subtypes as outcomes. RESULTS: Dietary carbohydrates and GL were inversely associated with lung cancer incidence in the PLCO population. Among various carbohydrates, 30-g daily consumption of dietary fiber was related to a lower risk of lung cancer (fourth vs first quartile OR: 0.62, 95 % CI: 0.54-0.72) compared with 8.8-g. Furthermore, consuming whole grains 2.3 servings per day as opposed to 0.3 servings per day was associated with a lower risk of lung cancer (OR: 0.73, 95 % CI: 0.64-0.83). A higher risk of lung cancer was seen for the consumption of high-GI food (OR: 1.19, 95 % CI: 1.05-1.35) and refined carbohydrates from soft drinks (OR: 1.23, 95 % CI: 1.04-1.46). CONCLUSION: Carbohydrates and fiber from fruits, vegetables and whole grains are associated with lower lung cancer risk. Refined carbohydrates from processed food, such as soft drinks, appear to increase risk.


Assuntos
Carboidratos da Dieta , Neoplasias Pulmonares , Dieta , Carboidratos da Dieta/efeitos adversos , Índice Glicêmico , Humanos , Neoplasias Pulmonares/epidemiologia , Neoplasias Pulmonares/etiologia , Estudos Prospectivos , Fatores de Risco
20.
Lab Chip ; 20(20): 3696-3708, 2020 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-32935707

RESUMO

The association of the intrinsic optical and biophysical properties of cells to homeostasis and pathogenesis has long been acknowledged. Defining these label-free cellular features obviates the need for costly and time-consuming labelling protocols that perturb the living cells. However, wide-ranging applicability of such label-free cell-based assays requires sufficient throughput, statistical power and sensitivity that are unattainable with current technologies. To close this gap, we present a large-scale, integrative imaging flow cytometry platform and strategy that allows hierarchical analysis of intrinsic morphological descriptors of single-cell optical and mass density within a population of millions of cells. The optofluidic cytometry system also enables the synchronous single-cell acquisition of and correlation with fluorescently labeled biochemical markers. Combined with deep neural network and transfer learning, this massive single-cell profiling strategy demonstrates the label-free power to delineate the biophysical signatures of the cancer subtypes, to detect rare populations of cells in the heterogeneous samples (10-5), and to assess the efficacy of targeted therapeutics. This technique could spearhead the development of optofluidic imaging cell-based assays that stratify the underlying physiological and pathological processes based on the information-rich biophysical cellular phenotypes.


Assuntos
Aprendizado Profundo , Biofísica , Citometria de Fluxo , Citometria por Imagem , Fenótipo
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