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1.
Cell ; 166(1): 47-62, 2016 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-27368100

RESUMO

Genetic screening identifies the atypical tetraspanin TM4SF1 as a strong mediator of metastatic reactivation of breast cancer. Intriguingly, TM4SF1 couples the collagen receptor tyrosine kinase DDR1 to the cortical adaptor syntenin 2 and, hence, to PKCα. The latter kinase phosphorylates and activates JAK2, leading to the activation of STAT3. This non-canonical mechanism of signaling induces the expression of SOX2 and NANOG; sustains the manifestation of cancer stem cell traits; and drives metastatic reactivation in the lung, bone, and brain. Bioinformatic analyses and pathological studies corroborate the clinical relevance of these findings. We conclude that non-canonical DDR1 signaling enables breast cancer cells to exploit the ubiquitous interstitial matrix component collagen I to undergo metastatic reactivation in multiple target organs.


Assuntos
Neoplasias da Mama/patologia , Receptor com Domínio Discoidina 1/metabolismo , Metástase Neoplásica , Transdução de Sinais , Animais , Antígenos de Superfície/metabolismo , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Receptor com Domínio Discoidina 1/química , Humanos , Neoplasias Pulmonares/secundário , Camundongos , Proteínas de Neoplasias/metabolismo , Células-Tronco Neoplásicas/patologia
2.
Cell ; 150(4): 764-79, 2012 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-22901808

RESUMO

The mechanistic underpinnings of metastatic dormancy and reactivation are poorly understood. A gain-of-function cDNA screen reveals that Coco, a secreted antagonist of TGF-ß ligands, induces dormant breast cancer cells to undergo reactivation in the lung. Mechanistic studies indicate that Coco exerts this effect by blocking lung-derived BMP ligands. Whereas Coco enhances the manifestation of traits associated with cancer stem cells, BMP signaling suppresses it. Coco induces a discrete gene expression signature, which is strongly associated with metastatic relapse to the lung, but not to the bone or brain in patients. Experiments in mouse models suggest that these latter organs contain niches devoid of bioactive BMP. These findings reveal that metastasis-initiating cells need to overcome organ-specific antimetastatic signals in order to undergo reactivation.


Assuntos
Neoplasias da Mama/patologia , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Neoplasias Pulmonares/secundário , Animais , Proteínas Morfogenéticas Ósseas/metabolismo , Linhagem Celular Tumoral , Humanos , Neoplasias Pulmonares/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Metástase Neoplásica , Análise de Sequência com Séries de Oligonucleotídeos
3.
Carcinogenesis ; 45(1-2): 35-44, 2024 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-37856781

RESUMO

Solute carrier organic anion (SLCO) transporters (OATP transporters) are involved in cellular uptake of drugs and hormones. Germline variants in SLCO1B3 and SLCO2B1 have been implicated in prostate cancer progression and therapy response, including to androgen deprivation and statin medications, but results have appeared heterogeneous. We conducted a cohort study of five single-nucleotide polymorphisms (SNPs) in SLCO1B3 and SLCO2B1 with prior evidence among 3208 men with prostate cancer who participated in the Health Professionals Follow-up Study or the Physicians' Health Study, following participants prospectively after diagnosis over 32 years (median, 14 years) for development of metastases and cancer-specific death (lethal disease, 382 events). Results were suggestive of, but not conclusive for, associations between some SNPs and lethal disease and differences by androgen deprivation and statin use. All candidate SNPs were associated with SLCO mRNA expression in tumor-adjacent prostate tissue. We also conducted a systematic review and harmonized estimates for a dose-response meta-analysis of all available data, including 9 further studies, for a total of 5598 patients and 1473 clinical events. The A allele of the exonic SNP rs12422149 (14% prevalence), which leads to lower cellular testosterone precursor uptake via SLCO2B1, was associated with lower rates of prostate cancer progression (hazard ratio per A allele, 0.80; 95% confidence interval, 0.69-0.93), with little heterogeneity between studies (I2, 0.27). Collectively, the totality of evidence suggests a strong association between inherited genetic variation in SLCO2B1 and prostate cancer prognosis, with potential clinical use in risk stratification related to androgen deprivation therapy.


Assuntos
Inibidores de Hidroximetilglutaril-CoA Redutases , Transportadores de Ânions Orgânicos , Neoplasias da Próstata , Masculino , Humanos , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Antagonistas de Androgênios/uso terapêutico , Androgênios , Seguimentos , Estudos de Coortes , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Estudos Prospectivos , Genótipo , Transportadores de Ânions Orgânicos/genética , Membro 1B3 da Família de Transportadores de Ânion Orgânico Carreador de Soluto/genética , Membro 1B3 da Família de Transportadores de Ânion Orgânico Carreador de Soluto/uso terapêutico
4.
Org Biomol Chem ; 21(24): 5079-5089, 2023 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-37278315

RESUMO

Amongst the various existing methods of analyte quantification, fluorescent-based methods, especially the ratiometric methods, continue to gain significant attention due to their high reproducibility, low environmental influence, and self-calibrating behavior. This paper presents the modulation in a monomer-aggregate equilibrium of coumarin-7 (C7) dye at pH ∼ 3, under the influence of a multi-anionic polymer, poly(styrene sulfonate) (PSS), leading to a significant modification in the ratiometric optical signal of the dye. At pH ∼ 3, cationic C7 formed aggregates in the presence of PSS via a strong electrostatic interaction, resulting in the development of a new emission peak at 650 nm at the expense of the monomer emission at 513 nm. Such contradicting changes in fluorescence intensities at two different wavelengths gave rise to a ratiometric signal, which was found to be highly sensitive towards external stimuli such as pH, and ionic strength. The stability of the C7-PSS complex was found to decrease as the pH of the solution was increased beyond 5, which indicated the decline in the electrostatic attraction between C7 and PSS due to the deprotonation of the C7 dye. Furthermore, an increase in the monomeric peak and a concomitant decrease of the aggregate peak with added salt in the solution (at pH ∼ 3) clearly justified the presence of an electrostatic attraction between C7 and PSS for the complex formation. This was further validated by the excited-state lifetime measurement of the C7-PSS complex, which showed a systematic increase in lifetime contribution from the monomeric species at the expense of aggregated species, as the concentration of NaCl increased in the solution. Thus, protamine (Pr), being a highly positively charged polypeptide, largely affected the monomer-aggregate equilibrium of the C7-PSS system, leading to a phenomenal change in the ratiometric signal, which was utilized to quantify with LOD as low as ∼2.8 nM in buffer for the bio-analyte Pr. Moreover, the ratiometric response of the C7-PSS assembly demonstrated excellent selectivity towards Pr, facilitating its practical relevance for the quantification of Pr in a 1% human serum matrix. Therefore, the studied C7-PSS can be utilized as a potential candidate for the quantification of the protamine even in complex biological media.

5.
Eur J Nucl Med Mol Imaging ; 48(8): 2642-2651, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33495926

RESUMO

PURPOSE: Peptide-based prostate-specific membrane antigen (PSMA) targeted radionuclide therapy (TRT) agent [177Lu]-PSMA-617 has emerged as leading TRT candidate for treatment of castration-resistant prostate cancer (mCRPC). [177Lu]-PSMA-617 and other small molecule-based PSMA ligands have shown efficacy in reducing the tumor burden in mCRPC patients but irradiation to the salivary gland and kidneys is a concern and dose-limiting factor. Therefore, methods to reduce non-target organ toxicity are needed to safely treat patients and preserve their quality of life. Herein, we report that addition of cold PSMA ligand PSMA-11 can aid in reducing the uptake of [177Lu]-PSMA-617 in the salivary glands and kidneys. METHODS: Groups of athymic nude mice (n = 4) bearing PC3-PIP (PSMA+) tumor xenografts were administered with [177Lu]-PSMA-617 along with 0, 5, 100, 500, 1000, and 2000 pmoles of PSMA-11 and biodistribution studies were performed at 1 h. RESULTS: Biodistribution studies at 1 h post-administration revealed that [177Lu]-PSMA-617 uptake in PC3-PIP tumors was 21.71 ± 6.13, 18.7 ± 2.03, 26.44 ± 2.94, 16.21 ± 3.5, 13.52 ± 3.68, and 12.03 ± 1.96 %ID/g when 0, 5, 100, 500, 1000, and 2000 pmoles of PSMA-11 were added, respectively. Corresponding uptake values in kidney were 123.14 ± 52.52, 132.31 ± 47.4, 84.29 ± 78.25, 2.12 ± 1.88, 1.16 ± 0.36, and 0.64 ± 0.23 %ID/g, respectively. Corresponding salivary gland uptake values were 0.48 ± 0.11, 0.45 ± 0.15, 0.38 ± 0.3, 0.08 ± 0.03, 0.09 ± 0.07, and 0.05 ± 0.02 % ID/g, respectively. CONCLUSION: The uptake of [177Lu]-PSMA-617 in the salivary gland and kidney can be substantially reduced without significantly impacting tumor uptake by adding cold PSMA-11.


Assuntos
Rim , Compostos Radiofarmacêuticos , Glândulas Salivares/metabolismo , Animais , Antígenos de Superfície/metabolismo , Glutamato Carboxipeptidase II/metabolismo , Compostos Heterocíclicos com 1 Anel/metabolismo , Humanos , Rim/metabolismo , Camundongos , Camundongos Nus , Qualidade de Vida , Compostos Radiofarmacêuticos/farmacocinética , Distribuição Tecidual , Proteína Tumoral 1 Controlada por Tradução
6.
Org Biomol Chem ; 19(36): 7920-7929, 2021 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-34549222

RESUMO

Highly sensitive and selective near-infrared fluorescent bioprobes for serum albumin detection and quantification are in high demand for biomedical applications. Herein, we report a near-infrared emitting BODIPY-O-glycoside dye as a turn-on emission sensor for serum albumin. To the best of our knowledge, this is the first report of NIR-emitting BODIPY dyes for serum albumin sensing. Despite the various outstanding photophysical properties of the BODIPY dyes, their insolubility in water/biological media restricts their real biomedical applications. To overcome this issue, highly stable unadulterated BODIPY-O-glycoside nanoparticles (BDP-Glu-NPs) were prepared in aqueous solution by self-assembly of amphiphilic BODIPY-O-glycoside dyes. The BDP-Glu-NPs were characterized by spectroscopic, NMR, DLS and TEM studies. The ability of the BDP-Glu-NPs for the detection and quantification of serum albumin was demonstrated. It showed a 150-fold fluorescence enhancement in the presence of serum albumin, with excellent selectivity over other amino acids, porphyrin, proteins and various inorganic salts. Detection of human serum albumin (HSA) in urine samples showed that the bioprobe is applicable to a clinically significant range of the analytes with very low detection limit. These results suggested that the BDP-Glu-NPs can act as potential bioprobe to quantify albumin in biochemical and clinical samples.


Assuntos
Compostos de Boro
7.
Photochem Photobiol Sci ; 19(7): 956-965, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32519735

RESUMO

Although cyclodextrins have been extensively utilized in various branches of supramolecular chemistry due to their numerous attractive attributes, however, to achieve even advanced applications, they often need structural modification through substitutions of suitable functional groups at their rims. A systematic investigation on how the degree of substitution on the cyclodextrin rims affects the binding affinity for a given guest molecule has however rarely been reported, especially from the perspective of photophysical studies. Herein, we report the non-covalent interaction of a styryl based dye, LDS-798, with three different sulfobutylether beta cyclodextrin (SBEnßCD) derivatives bearing varying degrees of substitution (n), using ground state absorption, steady-state emission, excited-state lifetime and time-resolved fluorescence anisotropy measurements. The dye-host binding constant values indicate that the strength of the interaction between LDS-798 and SBEnßCD derivatives follows an increasing trend with an increasing number of tethered sulfobutylether substituents on the cyclodextrin rims, which is attributed to the gradual increase of the electrostatic interaction between the negatively charged sulfobutylether groups and the positively charged LDS-798. Excited state lifetime measurements and ionic strength dependent studies on the dye-SBEnßCD complexes further support the increased affinity between the dye and the host in the supramolecular complexes, with an increasing number of sulfobutylether substituents on the ßCD rims. The obtained results suggest that the molecular recognition of LDS-798 with SBEnßCD derivatives can be tuned very effectively by varying the number of sulfobutylether substituents on the cyclodextrin rims. Considering that SBE7ßCD is one of the FDA approved agents for drug formulations, the obtained results with other SBEnßCD hosts may be useful in designing selective drug delivery applications, drug formulations, and effective fluorescence on-off switches.


Assuntos
Compostos de Anilina/química , Ciclodextrinas/química , Corantes Fluorescentes/química , Compostos de Quinolínio/química , Fluorescência , Estrutura Molecular
8.
Org Biomol Chem ; 17(28): 6895-6904, 2019 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-31270520

RESUMO

Supramolecular host-guest pairs, with a very high association constant, represent excellent molecular recognition motifs, and serve as useful building blocks for numerous exciting supramolecular functional materials. Cyclodextrins, an important class of glucopyranose-based hosts, generally, suffer from low affinity for most guest molecules (102-104 M-1). Herein, we report a styryl-based fluorogenic probe which registers a very high association constant of 7.84 × 105 M-1 with sulfobutylether substituted ß-cyclodextrin in contrast to a low association constant of 1.89 × 102 M-1 with unmodified ß-cyclodextrin (ß-CD). This exceptionally high binding affinity of the fluorogenic probe with the sulfobutylether substituted ß-CD has been attributed to the strong electrostatic interactions between the cationic guest and the polyanionic host along with improved hydrophobic interactions due to the extended butylether groups present on the rims of the cyclodextrin cavity. The significant modulations in the photophysical properties of guest molecule, upon interaction with host molecule, have been investigated, in detail, using ground-state absorption, steady-state fluorescence and time-resolved emission measurements. The effect of temperature and ionic strength of the medium have been employed to investigate the nature of the underlying interactions in the present host-guest system. The possibility of indicator displacement assay involving the present host-guest system has also been demonstrated using a competitive binder.

9.
J Indian Assoc Pediatr Surg ; 24(4): 303-306, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31571767

RESUMO

Despite various theories to explain the pathogenesis of atresias, the exact mechanism is still controversial. Currently, atresias are believed to result from vascular accidents and less likely due to the failure of recanalization. We report a case which challenges this belief. A 1-day-old neonate was explored for suspected jejunal atresia. Apart from Type III jejunal atresia, 15 cm from DJ junction, there was surprisingly no distal lumen in the intestine from jejunum till rectum. Multiple enterotomies revealed the whole of the remaining jejunum, ileum, and large colon to be a solid cord-like structure. No distal luminal contents or histopathological evidence of ischemic damage was seen, thus suggesting the probable etiology to be a failure of recanalization of the gut cord rather than a late vascular accident. Such rare cases provide insights into possible embryogenetic mechanisms which can then aid in formulating preventive measures.

10.
J Fluoresc ; 28(1): 381-392, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29256096

RESUMO

Photophysical properties of BODIPY dyes containing acetyl acetone and benzoyl acetone BF2 unit as an electron accepting substituent at beta position linked via double bond have been investigated using a wide range of solvents of different polarities. The substitution effect at beta position of the BODIPY dyes on their absorption, emission and quantum yield of fluorescence have been the aim of present study. For the synthesized BODIPY dyes fluorescence quantum yields and lifetimes show very sharp decrease with an increase in the solvent polarity, suggesting the involvement of highly polar ICT state de-excitation mechanism along with the local excitation process. The polarity dependent changes in average fluorescence life time and quantum yield values rationalize the formation of ICT states.

11.
J Fluoresc ; 27(6): 2313-2322, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28879506

RESUMO

BODIPY fluorophores linked with an imidazo-phenanthroline donor at α and ß positions have been synthesized. Intriguing intramolecular charge transfer phenomenon is observed in both the dyes which has been extensively investigated using UV-vis absorption, steady-state and time-resolved fluorescence measurements. H-bonding and intrinsic polarity of the solvents has modulated the absorption and emission bands of these fluorophores strongly causing significant increase in the Stokes shifts. In spite of having difference only in terms of the position of donor subunit, the photophysics of these dyes are not only significantly different from each other, but contradictory too. Interestingly, acidochromic studies revealed the shuttling mechanism between ICT and PET processes for BDP 2. Quantum chemical calculations have been employed further to support experimental findings. DFT and TD-DFT method of analysis have been used to optimize ground and excited state geometries of the synthesized dyes.

12.
Proc Natl Acad Sci U S A ; 111(46): 16532-7, 2014 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-25378704

RESUMO

We have developed a screening platform for the isolation of genetic entities involved in metastatic reactivation. Retroviral libraries of cDNAs from fully metastatic breast-cancer cells or pooled microRNAs were transduced into breast-cancer cells that become dormant upon infiltrating the lung. Upon inoculation in the tail vein of mice, the cells that had acquired the ability to undergo reactivation generated metastatic lesions. Integrated retroviral vectors were recovered from these lesions, sequenced, and subjected to a second round of validation. By using this strategy, we isolated canonical genes and microRNAs that mediate metastatic reactivation in the lung. To identify genes that oppose reactivation, we screened an expression library encoding shRNAs, and we identified target genes that encode potential enforcers of dormancy. Our screening strategy enables the identification and rapid biological validation of single genetic entities that are necessary to maintain dormancy or to induce reactivation. This technology should facilitate the elucidation of the molecular underpinnings of these processes.


Assuntos
Regulação Neoplásica da Expressão Gênica , Genes Neoplásicos , Ensaios de Triagem em Larga Escala/métodos , Neoplasias Mamárias Experimentais/patologia , Metástase Neoplásica/genética , Animais , Carcinoma/secundário , Linhagem Celular Tumoral , DNA Complementar/genética , DNA de Neoplasias/genética , Feminino , Biblioteca Gênica , Vetores Genéticos/genética , Vetores Genéticos/isolamento & purificação , Neoplasias Pulmonares/secundário , Camundongos , Camundongos Endogâmicos BALB C , MicroRNAs/genética , MicroRNAs/isolamento & purificação , Metástase Neoplásica/patologia , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/fisiologia , Transplante de Neoplasias , Provírus/genética , Provírus/isolamento & purificação , RNA Neoplásico/genética , RNA Neoplásico/isolamento & purificação , RNA Interferente Pequeno/genética , Retroviridae/genética , Retroviridae/isolamento & purificação , Transdução Genética , Integração Viral
13.
J Neurosci ; 33(6): 2338-55, 2013 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-23392664

RESUMO

Androgens have dramatic effects on neuronal structure and function in hippocampus. However, androgen depletion does not always lead to hippocampal impairment. To address this apparent paradox, we evaluated the hippocampus of adult male rats after gonadectomy (Gdx) or sham surgery. Surprisingly, Gdx rats showed increased synaptic transmission and long-term potentiation of the mossy fiber (MF) pathway. Gdx rats also exhibited increased excitability and MF sprouting. We then addressed the possible underlying mechanisms and found that Gdx induced a long-lasting upregulation of MF BDNF immunoreactivity. Antagonism of Trk receptors, which bind neurotrophins, such as BDNF, reversed the increase in MF transmission, excitability, and long-term potentiation in Gdx rats, but there were no effects of Trk antagonism in sham controls. To determine which androgens were responsible, the effects of testosterone metabolites DHT and 5α-androstane-3α,17ß-diol were examined. Exposure of slices to 50 nm DHT decreased the effects of Gdx on MF transmission, but 50 nm 5α-androstane-3α,17ß-diol had no effect. Remarkably, there was no effect of DHT in control males. The data suggest that a Trk- and androgen receptor-sensitive form of MF transmission and synaptic plasticity emerges after Gdx. We suggest that androgens may normally be important in area CA3 to prevent hyperexcitability and aberrant axon outgrowth but limit MF synaptic transmission and some forms of plasticity. The results also suggest a potential explanation for the maintenance of hippocampal-dependent cognitive function after androgen depletion: a reduction in androgens may lead to compensatory upregulation of MF transmission and plasticity.


Assuntos
Região CA3 Hipocampal/fisiologia , Potenciação de Longa Duração/fisiologia , Fibras Musgosas Hipocampais/fisiologia , Transmissão Sináptica/fisiologia , Testosterona/deficiência , Fatores Etários , Animais , Masculino , Vias Neurais/fisiologia , Orquiectomia , Ratos , Ratos Endogâmicos F344 , Testosterona/metabolismo
14.
Biochim Biophys Acta ; 1828(3): 1083-93, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23262193

RESUMO

MFG-E8 (also known as lactadherin), which is a secreted glycoprotein from a variety of cell types, possesses two EGF domains and tandem C domains with sequence homology to that of blood coagulation proteins factor V and factor VIII. MFG-E8 binds to phosphatidylserine (PS) in membranes with high affinity. We have recently shown that the C2 domain of MFG-E8 bears more specificity toward PS when compared with phosphatidylcholine (PC), another phospholipid thought to be involved in the immune function of phagocytes. In our current study, we have determined the solution structure of the C2 domain by nuclear magnetic resonance (NMR) spectroscopy, and characterized the molecular basis of binding between the C2 domain and PS by (31)P-NMR spectroscopy. Furthermore, we also verified that that positively charged and aromatic residues clustered in loops 1-3 of the C2 domain play key roles in recognizing PS in apoptotic cells.


Assuntos
Antígenos de Superfície/química , Espectroscopia de Ressonância Magnética/métodos , Proteínas do Leite/química , Sequência de Aminoácidos , Animais , Apoptose , Coagulação Sanguínea , Glicoproteínas/química , Células HeLa , Humanos , Sistema Imunitário , Camundongos , Modelos Moleculares , Conformação Molecular , Dados de Sequência Molecular , Fosfatidilcolinas/química , Fosfatidilserinas/química , Ligação Proteica , Conformação Proteica , Estrutura Terciária de Proteína , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos
15.
Colloids Surf B Biointerfaces ; 237: 113839, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38492411

RESUMO

Herein, we have employed a supramolecular assembly of a cationic dye, LDS-698 and a common surfactant sodium dodecyl sulfate (SDS) as a turn-on fluorescent sensor for protamine (Pr) detection. Addition of cationic Pr to the solution of dye-surfactant complex brings negatively charged SDS molecules together through strong electrostatic interaction, assisting aggregation of SDS way before its critical micellar concentration (CMC). These aggregates encapsulate the dye molecules within their hydrophobic region, arresting non-radiative decay channels of the excited dye. Thus, the LDS-698•SDS assembly displays substantial enhancement in fluorescence intensity that follows a nice linear trend with Pr concentration, providing limit of detection (LOD) for Pr as low as 3.84(±0.11) nM in buffer, 124.4(±6.7) nM in 1% human serum and 28.3(±0.5) nM in 100% human urine. Furthermore, high selectivity, low background signal, large stokes shift, and emission in the biologically favorable deep-red region make the studied assembly a promising platform for Pr sensing. As of our knowledge it is the first ever Pr sensory platform, using a very common surfactant (SDS), which is economically affordable and very easily available in the market. This innovative approach can replace the expensive, exotic and specialized chemicals considered for the purpose and thus showcase its potential in practical applications.


Assuntos
Surfactantes Pulmonares , Tensoativos , Humanos , Tensoativos/química , Antídotos , Heparina , Dodecilsulfato de Sódio/química , Cátions/química
16.
Anal Methods ; 16(6): 950-956, 2024 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-38291911

RESUMO

Proteins play an important role in biological systems and several proteins are used in diagnosis, therapy, food industry etc. Thus, knowledge about the physical properties of the proteins is of utmost importance, which will aid in understanding their function and subsequent applications. The melting temperature (Tm) of a protein is one of the essential parameters which gives information about the stability of a protein under different conditions. In the present study, we have demonstrated a method for determining the Tm of proteins using the supramolecular interaction between Quinaldine Red (QR) and proteins. Using this method, we have determined the Tm of 5 proteins and compared our results with established protocols. Our results showed good agreement with the other methods and published values. The method developed in this study is inexpensive, quick, and devoid of complex instruments and pre/post-treatment of the samples. In addition, this method can be adopted for high throughput in multi-plate mode. Thus, this study projects a new methodology for Tm determination of various proteins with user friendly operation.


Assuntos
Corantes Fluorescentes , Quinaldinas , Temperatura , Proteínas
17.
PLoS One ; 19(4): e0301989, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38683764

RESUMO

Somatic Y chromosome loss in hematopoietic cells is associated with higher mortality in men. However, the status of the Y chromosome in cancer tissue is not fully known due to technical limitations, such as difficulties in labelling and sequencing DNA from the Y chromosome. We have developed a system to quantify Y chromosome gain or loss in patient-derived prostate cancer organoids. Using our system, we observed Y chromosome loss in 4 of the 13 (31%) patient-derived metastatic castration-resistant prostate cancer (mCRPC) organoids; interestingly, loss of Yq (long arm of the Y chromosome) was seen in 38% of patient-derived organoids. Additionally, potential associations were observed between mCRPC and Y chromosome nullisomy. The prevalence of Y chromosome loss was similar in primary and metastatic tissue, suggesting that Y chromosome loss is an early event in prostate cancer evolution and may not a result of drug resistance or organoid derivation. This study reports quantification of Y chromosome loss and gain in primary and metastatic prostate cancer tissue and lays the groundwork for further studies investigating the clinical relevance of Y chromosome loss or gain in mCRPC.


Assuntos
Coloração Cromossômica , Cromossomos Humanos Y , Metástase Neoplásica , Masculino , Humanos , Cromossomos Humanos Y/genética , Metástase Neoplásica/genética , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/patologia , Organoides/patologia , Deleção Cromossômica
18.
Mol Pharmacol ; 83(2): 367-76, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23150487

RESUMO

Targeting specific molecules is a promising cancer treatment because certain types of cancer cells are dependent on specific oncogenes. This strategy led to the development of therapeutics that use monoclonal antibodies or small-molecule inhibitors. However, the continued development of novel molecular targeting inhibitors is required to target the various oncogenes associated with the diverse types and stages of cancer. Obtusilactone B is a butanolide derivative purified from Machilus thunbergii. In this study, we show that obtusilactone B functions as a small-molecule inhibitor that causes abnormal nuclear envelope dynamics and inhibits growth by suppressing vaccinia-related kinase 1 (VRK1)-mediated phosphorylation of barrier-to-autointegration factor (BAF). BAF is important in maintaining lamin integrity, which is closely associated with diseases that include cancer. Specific binding of obtusilactone B to BAF suppressed VRK1-mediated BAF phosphorylation and the subsequent dissociation of the nuclear envelope from DNA that allows cells to progress through the cell cycle. Obtusilactone B potently induced tumor cell death in vitro, indicating that specific targeting of BAF to block cell cycle progression can be an effective anticancer strategy. Our results demonstrate that targeting a major constituent of the nuclear envelope may be a novel and promising alternative approach to cancer treatment.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Proteínas de Ligação a DNA/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Neoplasias/tratamento farmacológico , Membrana Nuclear/efeitos dos fármacos , Proteínas Nucleares/metabolismo , Extratos Vegetais/farmacologia , Proteínas Serina-Treonina Quinases/metabolismo , Antineoplásicos Fitogênicos/química , Ciclo Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , DNA/efeitos dos fármacos , Proteínas de Ligação a DNA/antagonistas & inibidores , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Neoplasias/enzimologia , Neoplasias/metabolismo , Neoplasias/patologia , Membrana Nuclear/metabolismo , Proteínas Nucleares/antagonistas & inibidores , Fosforilação/efeitos dos fármacos , Extratos Vegetais/química , Caules de Planta/química , Proteínas Serina-Treonina Quinases/antagonistas & inibidores
19.
J Biol Chem ; 287(8): 5278-89, 2012 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-22194607

RESUMO

VRK1-mediated phosphorylation of histone H3 should be restricted in mitosis for consistent cell cycling, and defects in this process trigger cellular catastrophe. However, an interphasic regulator against VRK1 has not been actually investigated so far. Here, we show that the histone variant macrodomain-containing histone H2A1.2 functions as a suppressor against VRK1 during interphase. The level of macroH2A1.2 was markedly reduced in the mitotic phase, and the macroH2A1.2-mediated inhibition of histone H3 phosphorylation occurred mainly during interphase. We also found direct interaction and binding features between VRK1 and macroH2A1.2 by NMR spectroscopy. Hence, our findings might provide valuable insight into the underlying molecular mechanism regarding an epigenetic regulation of histone H3 during the cell cycle.


Assuntos
Histonas/metabolismo , Interfase , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Mitose , Proteínas Serina-Treonina Quinases/metabolismo , Células HEK293 , Células HeLa , Histonas/química , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/química , Modelos Moleculares , Fosforilação , Ligação Proteica , Proteínas Serina-Treonina Quinases/química , Estrutura Terciária de Proteína , Transporte Proteico
20.
Environ Sci Pollut Res Int ; 30(10): 24963-24974, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35459996

RESUMO

Fuel cells are gaining popularity because of their efficient energy production without causing environmental pollution. Recently, DRDO has developed a fuel cell-based air-independent propulsion (AIP) system. In this system, the hydrogen is produced onboard while oxygen is carried in liquefied form (LOX) from the land in specially designed insulated storage vessels called dewars. Such vessels are needed because LOX has a low boiling point (NBP ~ 90 K) and heat of vaporization (~ 213 kJ/kg), due to which it boils off easily even when there is a small amount of heat inleak from the ambient. A typical dewar consists of two vessels separated by insulation. Support members are used to hold the two vessels together. Heat inleak through the supports and the insulation of the dewar causes the boiling of LOX. The vessels are subjected to dynamic loads during the voyage due to the filling and consumption of LOX. Therefore, the support system should be designed to withstand the dynamic loads experienced by the dewar. While the support system should have enough mechanical strength to withstand the loads it is subjected to, it should also restrict the heat inleak from the ambient to minimize the LOX boil-off. To meet this requirement, we need to optimize the support system design. Design optimization of support systems is especially critical in submarines to reduce the snorkeling frequency. Even though the dewars are available commercially for various applications, their design methodologies are not available in the open literature. Cylindrical rods are generally used as support members. In earlier studies, the authors have shown that helical coils give better thermal performance than tension rods as dewar supports. These two support systems involve different design criteria. It is important to evolve an optimal design of the support system to maximize the mechanical strength of the support while minimizing the heat inleak through the support. In this paper, we present a design methodology for optimizing helical support. We have proposed a modified optimization technique derived from the classical genetic algorithm (GA) for this purpose. The modification has been done by ensuring the design feasibility of the coil at each step of the algorithm. The proposed optimization technique has been tested on a LOX dewar, and an optimal design of the helical coil support has been obtained.


Assuntos
Poluição Ambiental , Temperatura Alta , Algoritmos , Hidrogênio
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