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1.
Soft Matter ; 20(1): 201-211, 2023 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-38078383

RESUMO

Herein, the adsorption of polystyrene (PS) on phenyl-modified SiO2-Si substrates was investigated. Different from those for PS adsorption on a neat SiO2-Si substrate, the growth rate (vads) in the linear regime and hads/Rg (hads, thickness of flattened and loosely adsorbed layers on the substrate; Rg, radius of gyration) declined with increasing molecular weight (Mw) of PS and the phenyl content on the modified substrates, while the thickness of the flattened layer (hflat) and its coverage increased with increasing phenyl content. The results indicated that the adsorption of loose chains was controlled by the adsorption of flattened chains, as it only occurred in the empty contact sites remaining after the adsorption of flattened chains. Before approaching quasi-equilibrium (t < tcross), the number of flattened chain contact sites increased due to an enthalpically favorable process and, correspondingly, their spatial positions dynamically changed, which perturbed the adsorption of loose chains. When the adsorption of flattened chains reached quasi-equilibrium (t > tcross), the adsorption of loose chains was determined by the empty contact sites. The coverage of flattened chains and time to reach quasi-equilibrium were increased with more phenyl groups on the substrate, enhancing π-π interfacial interactions and resulting in a decreased adsorption rate and fewer loosely adsorbed chains. Mw-dependent vads and hads/Rg differed on phenyl-modified substrates compared to the neat SiO2-Si substrate owing to fewer empty contact sites for loose chains. The study findings improve our understanding of the mechanism responsible for the formation and structure of the adsorbed layer on solid surfaces.

2.
Cell Mol Biol (Noisy-le-grand) ; 67(5): 38-44, 2022 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-35818274

RESUMO

Tuberculosis is a highly contagious infectious disease. Mycobacterium tuberculosis infection is the main cause of tuberculosis. During the infection of M. tuberculosis, the expression of the resistance gene BAG2 will change, and miR-27b will play a certain role in dynamic regulation. The purpose of this article is to explore in-depth the effect of BAG2 on cell autophagy during M. tuberculosis infection and the dynamic regulatory mechanism of miR-27b on BAG2 activated cell autophagy. Fifty rats were used as experimental subjects, and M. tuberculosis strains H37Ra and H37Rv were implanted into the rats. Fluorescence quantitative PCR was used to detect the dynamic changes of BAG2 and miR-27b expression levels in rats and the regulatory effect of miR-27b on BAG2, and the effect of changes in BAG2 expression levels on cell autophagy was studied by immunoblotting. The results showed that after M. tuberculosis-infected macrophages, the expression level of BAG2 decreased from (284.24±6.31) to (156.48.24±4.49), and the expression level of miR-27b was increased from (43.72±3.35) to (78.35± 4.17), the apoptosis rate increased by 17.8%, and the autophagy rate increased by 20.6%. Therefore, it can be seen that the up-regulation of miR-27b expression level during M. tuberculosis infection will inhibit BAG2 expression, thereby promoting cell autophagy and apoptosis to reduce the survival rate of M. tuberculosis.


Assuntos
Autofagia , MicroRNAs , Chaperonas Moleculares , Tuberculose , Animais , Macrófagos/metabolismo , MicroRNAs/genética , Chaperonas Moleculares/metabolismo , Mycobacterium tuberculosis , Ratos , Tuberculose/genética
3.
Langmuir ; 37(15): 4632-4638, 2021 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-33822628

RESUMO

Thermally sensitive polymers have attracted tremendous interest in the design of stimulus-responsive surfactants. In this article, poly(propylene oxide)-b-poly(N-isopropylacrylamide) (PPO-b-PNIPAm) with different block lengths of PNIPAm was synthesized through atom transfer radical polymerization (ATRP). Different from commercial Pluronic surfactants, four distinct sections appeared in the decrease of surface tension with concentration. First, with increasing concentration, the amount of adsorbed polymers increased and the surface tension decreased sharply until a plateau was reached, which was caused by the rearrangement of methyl groups. The increasing adsorbed amount of PPO-b-PNIPAm resulted in the rearrangement of isopropyl groups, which changed from a lying down or horizontal conformation to a standing up or vertical conformation. This behavior led to the decrease in surface tension in part III until the critical micelle concentration (CMC) was reached. The surface tension of PPO-b-PNIPAm was thermally responsive. Except for the hysteresis observed in the first cycle, the surface tension was reversible during the heating-and-cooling cycles. At low concentrations, the low surface tension at higher temperatures was mainly caused by the increasing adsorption amount and ordered arrangement of methyl groups, while the standing up conformation of isopropyl groups at higher concentrations resulted in the low surface tension observed at high temperatures.

4.
Langmuir ; 35(5): 1828-1836, 2019 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-30032624

RESUMO

Zwitterionic hydrogels are promising biomaterials because of their high water content, three-dimensional network structure, and antifouling property. However, it still remains unclear about how mechanical properties of zwitterionic hydrogels affect their antifouling property. In this work, we propose a simple, thermal-pretreatment method to fabricate poly(sulfobetaine methacrylate) (pSBMA) hydrogels with varied mechanical properties that can be readily tuned by thermal pretreatment time and cross-linker density, as well as to correlate their mechanical property with antifouling property. The resulting thermal-treated pSBMA hydrogels show significantly enhanced mechanical properties with tunable compressive modulus and elastic modulus as compared to the untreated hydrogels. A combination of ELISA investigations and short-term cell adhesion assays also confirm that pSBMA hydrogels exhibit superior antifouling properties to resist protein adsorption and cell adhesion. Further analysis shows a linear inversion correlation between elastic modulus and protein adsorption of pSBMA hydrogels, i.e., the hydrogel with the higher elastic modulus exhibits the lower protein adsorption (the better antifouling property). This work not only provides a simple thermal-pretreatment strategy for fabricating pSBMA hydrogels, but also demonstrates multifunctional properties of the pSBMA hydrogels, which possess a great potential to fulfill some biomedical applications.

5.
J Nat Prod ; 82(4): 756-764, 2019 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-30817151

RESUMO

Six new lathyrane diterpenoids (1-6) and 10 known analogues (7-16), were separated from the seeds of Euphorbia lathyris. The absolute configuration of 1 was determined by X-ray crystallography, and the C-2' configuration of 5 was elucidated by comparing experimental and calculated ECD data. These compounds were studied for their inhibition against nitric oxide (NO) generation induced by lipopolysaccharide in RAW264.7 macrophage cells. Compounds 1-3, 7, 9, 11, 13, 14, and 16 displayed inhibitory effects on NO production, with IC50 values of 2.6-26.0 µM. The new compound 1 (IC50 3.0 ± 1.1 µM), with no obvious cytotoxicity, was selected for further experiments. The production of cytokines such as IL-6 and IL-1ß, as well as the protein expression of iNOS, NF-κB, and phosphorylated IκBα, was reduced by 1 dose-dependently. These results suggested that lathyrane diterpenoids may be used as potential anti-inflammatory agents and are worth being further researched.


Assuntos
Anti-Inflamatórios/farmacologia , Diterpenos/farmacologia , Euphorbia/química , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/isolamento & purificação , Diterpenos/química , Diterpenos/isolamento & purificação , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Óxido Nítrico/biossíntese , Células RAW 264.7 , Relação Estrutura-Atividade
6.
Anal Bioanal Chem ; 409(20): 4771-4778, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28616667

RESUMO

A fluorescence turn-on assay for alkaline phosphatase (ALP) activity is developed through the controlled release of polyethyleneimine-capped copper nanoclusters (PEI-capped CuNCs) from the MnO2 nanosheets. In an aqueous solution, the positively charged PEI-capped CuNCs could be adsorbed onto the surface of the negatively charged MnO2 nanosheets. Such adsorption through favorable electrostatic interactions could efficiently quench the nanocluster fluorescence emission via resonance energy transfer from the PEI-capped CuNCs to the MnO2 nanosheets. 2-Phospho-L-ascorbic acid (AAP) could be hydrolyzed to L-ascorbic acid (AA) in the presence of ALP. AA could reduce MnO2 into Mn2+ and trigger the disintegration of the MnO2 nanosheets. As a result, the CuNCs were released and the quenched fluorescence was recovered efficiently. The detection strategy is simple, inexpensive, sensitive, selective, with low toxicity, and has better biocompatibility. The newly fabricated biosensor for ALP activity will potentially make it a robust candidate for numerous biological and biomedical applications.


Assuntos
Fosfatase Alcalina/metabolismo , Cobre/química , Compostos de Manganês/química , Nanopartículas Metálicas/química , Óxidos/química , Polietilenoimina/química , Espectrometria de Fluorescência/métodos , Microscopia Eletrônica de Transmissão
7.
Luminescence ; 32(7): 1150-1156, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28429838

RESUMO

A sensitive and convenient flow-injection chemiluminescence (FI-CL) turn-on assay for alkaline phosphatase (ALP) activity without any label and synthesis is developed. Cu2+ can catalyze the luminol-H2 O2 CL reaction. Pyrophosphate (PPi) can chelate Cu2+ and therefore the Cu2+ -mediated luminol-H2 O2 CL reaction is inhibited. The addition of ALP can catalyze the hydrolysis of PPi into phosphate ions, Cu2+ is released and the chemiluminescence recovers. A detection limit of 1 mU/mL ALP is obtained.


Assuntos
Fosfatase Alcalina/metabolismo , Difosfatos/metabolismo , Medições Luminescentes/métodos , Fosfatase Alcalina/análise , Fosfatase Alcalina/sangue , Cobre/química , Enzimas/metabolismo , Humanos , Peróxido de Hidrogênio/química , Limite de Detecção , Medições Luminescentes/instrumentação , Luminol/química , Especificidade por Substrato
8.
Anal Chem ; 87(16): 8336-41, 2015 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-26214035

RESUMO

Sensitive and selective protein detection based on the aptamer-controlled noncovalent porphyrin probe self-assembly is reported for the first time. Vascular endothelial growth factor (VEGF) is a predominant biomarker in cancer angiogenesis. In this work, a positively charged porphyrin probe, manganese(III) meso-tetrakis(N-methylpyridinum-4-yl)porphyrin (Mn-PyP), was prepared. Using it as a catalyst, a label-free chemiluminescence (CL) turn-on approach for sensitive VEGF detection is developed. Mn-PyP could catalyze the luminol CL reaction. The VEGF aptamer could induce aggregation of Mn-PyP. As a result, the Mn-PyP-catalyzed CL reaction is efficiently suppressed. Upon the addition of VEGF, the specific binding of VEGF to the aptamer weakens the interactions between the aptamer and Mn-PyP. The Mn-PyP monomers are released, and a turn-on CL signal is thus detected. Our method is quite sensitive; 50 pM of VEGF could be easily detected. It is also very selective against other proteins. Our assay provides an aptamer-based efficient way for protein quantification.


Assuntos
Aptâmeros de Nucleotídeos/química , Técnicas de Química Analítica/métodos , Luminescência , Manganês/química , Porfirinas/metabolismo , Proteínas/análise , Catálise , Corantes Fluorescentes/metabolismo , Limite de Detecção , Estrutura Molecular , Porfirinas/química , Proteínas/química , Fator A de Crescimento do Endotélio Vascular/análise , Fator A de Crescimento do Endotélio Vascular/química
9.
BMC Genomics ; 15: 978, 2014 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-25404570

RESUMO

BACKGROUND: Human induced pluripotent stem cells (iPSCs) have a wide range of applications throughout the fields of basic research, disease modeling and drug screening. Epigenetic instable iPSCs with aberrant DNA methylation may divide and differentiate into cancer cells. Unfortunately, little effort has been taken to compare the epigenetic variation in iPSCs with that in differentiated cells. Here, we developed an analytical procedure to decipher the DNA methylation heterogeneity of mixed cells and further exploited it to quantitatively assess the DNA methylation variation in the methylomes of adipose-derived stem cells (ADS), mature adipocytes differentiated from ADS cells (ADS-adipose) and iPSCs reprogrammed from ADS cells (ADS-iPSCs). RESULTS: We observed that the degree of DNA methylation variation varies across distinct genomic regions with promoter and 5'UTR regions exhibiting low methylation variation and Satellite showing high methylation variation. Compared with differentiated cells, ADS-iPSCs possess globally decreased methylation variation, in particular in repetitive elements. Interestingly, DNA methylation variation decreases in promoter regions during differentiation but increases during reprogramming. Methylation variation in promoter regions is negatively correlated with gene expression. In addition, genes showing a bipolar methylation pattern, with both completely methylated and completely unmethylated reads, are related to the carbohydrate metabolic process, cellular development, cellular growth, proliferation, etc. CONCLUSIONS: This study delivers a way to detect cell-subset specific methylation genes in a mixed cell population and provides a better understanding of methylation dynamics during stem cell differentiation and reprogramming.


Assuntos
Diferenciação Celular/genética , Reprogramação Celular/genética , Metilação de DNA , Heterogeneidade Genética , Células-Tronco/citologia , Células-Tronco/metabolismo , Adipócitos/citologia , Adipócitos/metabolismo , Biologia Computacional , Ilhas de CpG , Genômica , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Sítio de Iniciação de Transcrição
10.
Adv Healthc Mater ; : e2401347, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38819639

RESUMO

Identifying infected stones is crucial due to their rapid growth and high recurrence rate. Here, the calcium-magnesium dual-responsive aggregation-induced emission (AIE)-active probe TCM-5COOH (Tricyano-methlene-pyridine-5COOH), distinctively engineered to distinguish high-threat infection calculi from metabolic stones, is presented. Upon incorporation of flexible alkyl carboxyl group, TCM-5COOH featuring five carboxyl moieties demonstrates excellent water solubility and enhanced penetration into porous infectious stones. The robust chelation of TCM-5COOH with stone surface-abundant Ca2+ and Mg2+ inhibits vibrational relaxation, thus triggering intense AIE signals. Remarkably, the resulting complex exhibits high insolubility, effectively anchoring within the porous structure of the infection calculi and offering prolonged illumination. Jobs' plot method reveals similar response characteristics for Ca2+ and Mg2+, with a 1:2 coordination number for both ions. Isothermal titration calorimetry (ITC) results demonstrate higher enthalpy change (ΔH) and lower entropy change (ΔS) for the reaction, indicating enhanced selectivity compared to TCM-4COOH lacking the alkyl carboxyl group. Synchrotron X-ray absorption fine spectroscopy (XAFS) validates TCM-5COOH's interaction with Ca2+ and Mg2+ at the microlevel. This dual-responsive probe excels in identifying infectious and metabolic calculi, compatible with endoscopic modalities and laser excitation, thereby prompting clinical visualization and diagnostic assessment.

11.
Appl Microbiol Biotechnol ; 97(13): 5933-42, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23467824

RESUMO

The VP2 protein of bluetongue virus (BTV) is an important structural protein and is the principal antigen responsible for BTV serotype specificity. In this study, we mapped the reactivity of two BTV16-specific monoclonal antibodies (MAbs) and identified two novel serotype-specific linear B cell epitopes on the BTV16 VP2 protein. By screening a series of peptides derived from the BTV16 VP2 protein and expressed as mannose-binding protein fusions, we determined that the linear epitopes recognized by the VP2-specific MAbs 3 G10 and 2B4 were located within the peptides 34EWSGHDVTEIPNRRMF49 and 540KNEDPYVKRTVKPIRA555, respectively. To define the minimal region required for antibody binding within these peptide regions, a series of progressively shorter peptides were synthesized and evaluated for 3 G10 and 2B4 binding. This work defined the motifs 34EWSGHDVTEIPNRRMF49 and 543DPYVKRTVK555 as the minimal linear peptides required for 3 G10 and 2B4 binding, respectively. Alignment of amino acid sequences from a number of BTV16 strains isolated from different regions indicated that these two epitopes are highly conserved among BTV16 strains. Furthermore, these two epitopes are not conserved among other BTV serotypes or prototype members of the genus Orbivirus in the family Reoviridae, as shown by sequence alignments. The MAb reagents and linear epitopes defined here provide the basis for the development of epitope-based serotype-specific differential diagnostic tools and may be useful in the design of epitope-based vaccines.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/imunologia , Vírus Bluetongue/imunologia , Proteínas do Capsídeo/imunologia , Mapeamento de Epitopos , Epitopos de Linfócito B/imunologia , Motivos de Aminoácidos , Sequência de Aminoácidos , Vírus Bluetongue/classificação , Ligação Proteica , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Sorotipagem
12.
Sci Total Environ ; 856(Pt 2): 159270, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36208741

RESUMO

Microplastics (MPs) pollution in aquatic environment has attracted global attention in recent years. To evaluate the potential toxic effects of MPs in freshwater cultured fish, grass carps (Ctenopharyngodon idella) (body length: 7.7 ± 0.1 cm, wet weight: 6.28 ± 0.23 g) were exposed to different sizes (0.5 µm, 15 µm) and concentrations (100 µg/L, 500 µg/L) of polystyrene microplastics (PS-MPs) suspension for 7 and 14 days, followed by 7 days of depuration, detecting the variations in growth rate, histological structure, oxidative response and intestinal microbiome. Our results indicate that MP toxicity elicited significant size- and concentration-dependent responses by grass carp. MP exposure caused obvious decrease in growth rate on day 14 but not on day 7. Additionally, MPs with large size and high concentration caused more severe intestinal damage and less weight gain, while MP particles with small size and high concentration induced more severe liver congestion and stronger oxidative stress. MP exposure dramatically shifted the gut microbial composition, with the top 10 genera in abundance being associated with the diameter and concentration of the MPs. After 7 days of depuration, only superoxide dismutase and malondialdehyde in liver, showed a tendency to recover to the initial values. Even though the differences in the gut microbial community between the control and treatment groups disappeared, and the proportion of potential pathogenic bacteria in intestine was still high. Thus, it is clear that a short-term depuration period of 7 days is not enough for complete normalization.


Assuntos
Carpas , Microbioma Gastrointestinal , Animais , Microplásticos/toxicidade , Poliestirenos/toxicidade , Plásticos , Água Doce
13.
ACS Macro Lett ; 12(7): 854-859, 2023 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-37338533

RESUMO

Herein, the desorption of the adsorbed chains (including two regions of flattened chains and loosely adsorbed chains) was examined by monitoring the chain exchange kinetics between the adsorbed chains and the top-free chains in a bilayer system by using fluorine-labeled polystyrene (PS). The results indicated that the exchange behavior of PS-flattened chains with the top-free chains is much slower than that of PS-loose chains and has a strong molecular weight (MW) dependence. Interestingly, in the presence of loosely adsorbed chains, the desorption of flattened chains was accelerated greatly and had weaker MW dependency. We attribute the MW-dependent desorption phenomena to the average number of contact sites between polymer adsorbed chains and the substrate, which rapidly increased with increasing MW. Likewise, the desorption of loosely adsorbed chains may provide extra conformational energy to accelerate the desorption of flattened chains.

14.
Clin Chim Acta ; 540: 117224, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36627008

RESUMO

The rapid development of next-generation sequencing (NGS) technology has promoted its wide clinical application in precision medicine for oncology. However, laborious and time-consuming manual operations, highly skilled personnel requirements, and cross-contamination are major challenges for the clinical implementation of NGS technology-based tests. The Automated NGS Diagnostic Solutions (ANDiS) 500 system is a fully enclosed cassette-dependent automated NGS library preparation system. This platform could produce qualified targeted amplicon library in three steps with only 15 min of hands-on time. Rigorous cross-contamination test using simulated contaminant plasmids confirmed that the design of disposable cassette guarantees zero sample cross-contamination. The BRCA1 and BRCA2 mutation detection panel and gastrointestinal cancer-related gene analysis panel for the ANDiS 500 platform showed 100% accuracy and precision in detecting germ-line mutations and somatic mutations respectively. Furthermore, those panels showed 100% concordance with verified methods in a prospective cohort study enrolling 363 patients and a cohort of 45 pan-cancer samples. In conclusion, the ANDiS 500 automated platform could overcome major challenges for implementing NGS assays clinically and is eligible for routine clinical tests.


Assuntos
Genes BRCA2 , Neoplasias , Humanos , Estudos Prospectivos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Mutação
15.
J Hazard Mater ; 426: 127824, 2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-34838354

RESUMO

Gold nanorods (GNRs) outstand in photothermal disinfection but are faced with severe surface chemistry and dose relevant biotoxicity. Herein, a naturally green building block, metal-phenolic networks (MPNs), was employed to functionalize GNRs via coordination reaction, yielding a tunable and biocompatible core-shell photothermal nano-bactericide (GNRs@MPNs). The bioactive GNRs@MPNs built with iron and polyphenols (tannic acid, epigallocatechin gallate, and procyanidins) exhibited superior light-to-heat conversion efficiencies with η = 29.29-44.00%, remarkably preceding that of GNRs (η = 12.24%), which could rapidly ablate 99.8% of Escherichia coli O157: H7 and 98.6% of Staphylococcus aureus bacteria in relatively low efficacy doses (10 ppm of Au). Moreover, local heat triggered by GNRs@MPNs accelerated the healing of the cutaneous wound of a mice model infected by methicillin-resistant S. aureus. The facile synthesis, photothermal synergy, polyphenolic bioactivity, and significantly low efficacy dose of GNRs@MPNs empower them satisfactory efficiency and biosafety in the future broad-spectrum photothermal sterilization applications.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Nanotubos , Animais , Antibacterianos/farmacologia , Ouro , Camundongos , Staphylococcus aureus
16.
ACS Macro Lett ; 11(2): 210-216, 2022 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-35574771

RESUMO

Due to the importance of the interface in the segmental dynamics of supported macromolecule ultrathin films, the glass transition temperature (Tg) of polystyrene (PS) ultrathin films upon solid substrates modified with a cross-linked PS (CLPS) layer has been investigated. The results showed that the Tg of the thin PS films on a silica surface with a ∼5 nm cross-linked layer increased with reducing film thickness. Meanwhile, the increase in Tg of the thin PS films became more pronounced with increasing the cross-linking density of the layer. For example, a 20 nm thick PS film supported on CLPS with 1.8 kDa of cross-linking degree exhibited a ∼35 and ∼50 K increase in Tg compared to its bulk and that on neat SiO2 substrate, respectively. Such a large Tg elevation for the ultrathin PS films was attributed to the interfacial aggregation states in which chains diffused through nanolevel voids formed in the cross-linked layer to the SiO2-Si surface. In such a situation, the chains were topologically constrained in the cross-linked layer with less mobility. These results offer us the opportunity to tailor interfacial effects by changing the degree of cross-linking, which has great potential application in many polymer nanocomposites.


Assuntos
Poliestirenos , Dióxido de Silício , Vidro/química , Poliestirenos/química , Temperatura , Temperatura de Transição
17.
Front Endocrinol (Lausanne) ; 13: 1006480, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36583000

RESUMO

Introduction: Transformation from lung adenocarcinoma (LUAD) to small cell lung cancer (SCLC) is one of the mechanisms responsible for acquired EGFR-TKIs resistance. Although it rarely happens this event determines a rapid disease deterioration and needs specific treatment. Patient and method: We report a case of 75-year-old LUAD female with a p.L858R mutation in Epidermal Growth Factor Receptor (EGFR) who presented with SCLC transformation after responding to first line osimertinib treatment for only 6 months. To understand the underlying molecular mechanism, we retrospectively sequenced the first (LUAD) and the second (SCLC) biopsy using a 56 multi-gene panel. Immunohistochemistry (IHC) staining and Fluorescence In Situ Hybridization (FISH) was applied to confirm the genetic aberrations identified. Results: EGFR p.E709A and p.L858R, Tumor Protein p53 (TP53) p.A159D and Retinoblastoma 1 (RB1) c.365-1G>A were detected in both the diagnostic LUAD and transformed SCLC samples. A high copy number gain for Proto-Oncogene C-Myc (MYC) and a Phosphoinositide 3-Kinase Alpha (PIK3CA) p.E545K mutation were found in the transformed sample specifically. Strong TP53 staining and negative RB1 staining were observed in both LUAD and SCLC samples, but FISH only identified MYC amplification in SCLC tissue. Conclusion: We consider the combined presence of MYC amplification with mutations in TP53 and RB1 as drivers of SCLC transformation. Our results highlight the need to systematically evaluate TP53 and RB1 status in LUAD patients to offer a different therapeutic strategy.


Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Carcinoma de Pequenas Células do Pulmão , Feminino , Humanos , Carcinoma de Pequenas Células do Pulmão/genética , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Proteína Supressora de Tumor p53/genética , Estudos Retrospectivos , Hibridização in Situ Fluorescente , Fosfatidilinositol 3-Quinases/genética , Adenocarcinoma de Pulmão/genética , Receptores ErbB/genética , Ubiquitina-Proteína Ligases/genética , Proteínas de Ligação a Retinoblastoma/genética
19.
Front Oncol ; 11: 812656, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35087763

RESUMO

Breast cancer gene 1 (BRCA1) and BRCA2 are tumor suppressors involved in DNA damage response and repair. Carriers of germline pathogenic or likely pathogenic variants in BRCA1 or BRCA2 have significantly increased lifetime risks of breast cancer, ovarian cancer, and other cancer types; this phenomenon is known as hereditary breast and ovarian cancer (HBOC) syndrome. Accurate interpretation of BRCA1 and BRCA2 variants is important not only for disease management in patients, but also for determining preventative measures for their families. BRCA1:c.132C>T (p.Cys44=) is a synonymous variant recorded in the ClinVar database with "conflicting interpretations of its pathogenicity". Here, we report our clinical tests in which we identified this variant in two unrelated patients, both of whom developed breast cancer at an early age with ovarian presentation a few years later and had a family history of relevant cancers. Minigene assay showed that this change caused a four-nucleotide loss at the end of exon 3, resulting in a truncated p.Cys44Tyrfs*5 protein. Reverse transcription-polymerase chain reaction identified two fragments (123 and 119 bp) using RNA isolated from patient blood samples, in consistency with the results of the minigene assay. Collectively, we classified BRCA1:c.132C>T (p.Cys44=) as a pathogenic variant, as evidenced by functional studies, RNA analysis, and the patients' family histories. By analyzing variants recorded in the BRCA Exchange database, we found synonymous changes at the ends of exons could potentially influence splicing; meanwhile, current in silico tools could not predict splicing changes efficiently if the variants were in the middle of an exon, or in the deep intron region. Future studies should attempt to identify variants that influence gene expression and post-transcription modifications to improve our understanding of BRCA1 and BRCA2, as well as their related cancers.

20.
Front Oncol ; 11: 655709, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34046351

RESUMO

Predisposition of germline BRCA1/2 mutations (gBRCAMUT ) increases the risk of breast and ovarian cancer in females, but the mutation prevalence and spectrum are highly ethnicity-specific with different recurrent mutations being reported in different populations. Hereby, we performed hybridization-based target sequencing of BRCA1/2 in 530 ovarian cancer patients from Henan, the central region of China, followed by haplotype analysis of six short tandem repeat (STR) markers in the patients with recurrent mutations to determine their founder effect. About 28.3% (150/530) of the OC patients in our cohort harbored gBRCAMUT ; of the 151 mutations, 117 in BRCA1 and 34 in BRCA2, identified in this study, BRCA1:c.5470_5477del, c.981_982del, and c.4065_4068del are the top three mutants, recurrently detected in eight, seven, and six independent patients respectively. Haplotype analysis identified a region of 0.6 MB genomic length covering BRCA1 highly conserved across all eight carriers of BRCA1:c.5470_5477del, but not c.981_982del, suggesting a consequence of founder effect. Retrospective analysis in a subgroup of serous ovarian cancer patients revealed gBRCAMUT status was not associated with the progression-free survival (PFS); instead, an expression of Ki-67% ≥50% was associated with a shorter PFS (p = 0.041). In conclusion, patients with pathogenic or likely pathogenic gBRCAMUT account for 28.3% of the OC cases from Henan, and BRCA1:c.5470_5477del, the most frequently detected mutation in Henan patients, is a founder mutation in the population.

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