Living MCF-7 Cells Research Articles

A Near-Infrared Fluorescent Probe with Large Stokes Shift for Sensitive Detection of Hydrogen Sulfide in Environmental Water, Food Spoilage, and Biological Systems.

Hydrogen sulfide (H2S) is an important endogenous gas transmitter that plays a critical role in various physiological and pathological processes and can also cause a negative impact on foodstuffs. In this study, we designed and synthesized a simple, easily available, high-yield, and low-cost near-infrared (λem = 710 nm) fluorescent probe, DEM-H2S, with a substantial Stokes shift (205 nm) for the detection of H2S. DEM-H2S features high selectivity and sensitivity (LOD = 80 nM) toward H2S, accompanied by a noticeable color change. Upon interaction with H2S, DEM-H2S exhibits a restored ICT (Intramolecular Charge Transfer) process, thereby manifesting near-infrared fluorescence. DEM-H2S has been successfully utilized to detect H2S in actual water samples and to monitor the spoilage of food items, such as pork, shrimp, and eggs. Furthermore, DEM-H2S enables the imaging of endogenous and exogenous H2S in living MCF-7 cells and zebrafish. Hence, DEM-H2S provides an attractive method for the detection of H2S in environmental, food, and biological systems, holding potential value in physiological and pathological research.

A near-infrared fluorescent probe for the detection of Cu2+ in Chinese herbal medicine and imaging in living cells

Copper is one of the common among the heavy metal pollution in Chinese herbal medicine (CHM). So, it is essential to develop rapid and accurate testing method to quantify the Cu2+ content in CHM. Herein, we prepared a coordination-based near-infrared fluorescent probe (NRh6G-FA) by introducing a hemicyanine dye in rhodamine 6G scaffold. NRh6G-FA had a high sensitivity, anti-interference performance, fast response (within 60 s), visualization (from light yellow to green) for Cu2+ and excellent sensing performance for the detection of Cu2+ at low concentrations (LOD = 0.225 μM). The most likely mechanism was verified on the basis of Job’s plot, ESI-HRMS and DFT calculations. NRh6G-FA could be successfully applied for the detection and “naked eye” recognition of Cu2+ in CHM samples. Moreover, NRh6G-FA was used to visualize Cu2+ in living MCF-7 cells by confocal fluorescence imaging.

A Red-Emission Fluorescent Probe for Intracellular Biothiols and Hydrogen Sulfide Imaging in Living Cells.

This research centers on the development and synthesis of a longwave fluorescence probe, labeled as 60T, designed for the simultaneous detection of hydrogen sulfide, cysteine/homocysteine, and glutathione. The probe showcases a swift response, good linearity range, and heightened sensitivity, boasting that the detection limits of the probe for Cys, Hcy, GSH and H2S were 0.140, 0.202, 0.259 and 0.396 μM, respectively. Notably, its efficacy in monitoring thiol status changes in live MCF-7 cells is underscored by a substantial decrease in fluorescence intensity upon exposure to the thiol trapping reagent, N-ethyl maleimide (NEM). With an impressive red emission signal at 630 nm and a substantial Stokes shift of 80 nm, this probe exhibits remarkable sensitivity and selectivity for biothiols and H2S, indicating promising applications in the diagnosis and surgical navigation of relevant cancers.

Carrier capability of halloysite nanotubes for the intracellular delivery of antisense PNA targeting mRNA of neuroglobin gene

Peptide nucleic acid (PNA) is a DNA mimic that shows good stability against nucleases and proteases, forming strongly recognized complementary strands of DNA and RNA. However, due to its feeble ability to cross the cellular membrane, PNA activity and its targeting gene action is limited. Halloysite nanotubes (HNTs) are a natural and low-cost aluminosilicate clay. Because of their peculiar ability to cross cellular membrane, HNTs represent a valuable candidate for delivering genetic materials into cells. Herein, two differently charged 12-mer PNAs capable of recognizing as molecular target a 12-mer DNA molecule mimicking a purine-rich tract of neuroglobin were synthetized and loaded onto HNTs by electrostatic attraction interactions. After characterization, the kinetic release was also assessed in media mimicking physiological conditions. Resonance light scattering measurements assessed their ability to bind complementary single-stranded DNA. Furthermore, their intracellular delivery was assessed by confocal laser scanning microscopy on living MCF-7 cells incubated with fluorescence isothiocyanate (FITC)-PNA and HNTs labeled with a probe. The nanomaterials were found to cross cellular membrane and cell nuclei efficiently.Finally, it is worth mentioning that the HNTs/PNA can reduce the level of neuroglobin gene expression, as shown by reverse transcription-quantitative polymerase chain reaction and western blotting analysis.

Turn-on fluorescent probe based on dicyanoisophorone for bioimaging and rapid detection of peroxynitrite in aqueous media.

A novel dicyanoisophorone-based colorimetric fluorescent probe 3 has been prepared for recognizing peroxynitrite in aqueous conditions. A large bathochromic shift of the absorption band is observed upon titration with ONOO-, inducing a clearly visible solution color change from yellow to pale pink, which makes "naked-eye" detection possible. Moreover, probe 3 can react instantly with ONOO- and is accompanied by a significant fluorescence enhancement at 621 nm while the detection limit is as low as 37 nM. Most importantly, probe 3 exhibits high selectivity and sensitivity towards ONOO- in the presence of other competitive ions in aqueous solution. Probe 3 has also been successfully applied in living MCF-7 cells, and the results suggest that probe 3 could be applied as a potential candidate for the detection of ONOO-.

A pyridinium-based strategy for lysine-selective protein modification and chemoproteomic profiling in live cells.

Protein active states are dynamically regulated by various modifications; thus, endogenous protein modification is an important tool for understanding protein functions and networks in complicated biological systems. Here we developed a new pyridinium-based approach to label lysine residues under physiological conditions that is low-toxicity, efficient, and lysine-selective. Furthermore, we performed a large-scale analysis of the ∼70% lysine-selective proteome in MCF-7 cells using activity-based protein profiling (ABPP). We quantifically assessed 1216 lysine-labeled peptides in cell lysates and identified 386 modified lysine sites including 43 mitochondrial-localized proteins in live MCF-7 cells. Labeled proteins significantly preferred the mitochondria. This pyridinium-based methodology demonstrates the importance of analyzing endogenous proteins under native conditions and provides a robust chemical strategy utilizing either lysine-selective protein labeling or spatiotemporal profiling in a living system.

Potentilla fulgens root extract's effect on breast cancer (MCF-7) and osteosarcoma (U2OS) cells proliferation and migration

Aim: This study evaluates the cytotoxic effect of Potentilla fulgens root extract on MCF-7, U2OS, and RPE-1 cell lines and investigates its impact on cell migration. Material and Methods: The effect of Potentilla fulgens root extract on the cell viability of MCF-7, U2OS, and RPE-1 cells was analyzed using an MTT assay. The effect of the compounds on cell migration was evaluated at 24 and 48 hours using the wound healing assay. A wound-healing assay was used to measure the metastatic ability of cells in vitro. Results: MTT assay showed that PRE had a cytotoxic effect on all three cell lines, depending on dose and time, and this effect was statistically significant. The wound healing assay results showed that PRE slowed the migration of live MCF-7 and U2OS cancer cells, and these effects increased over time. Conclusion: As a result, this study indicates that PRE may be very useful in treating human osteosarcoma and breast cancer.

An AIE-based ratiometric fluorescent probe for reversible detection of bisulfite and hydrogen peroxide and its application in food samples and biological imaging

Reversible detection of bisulfite (HSO3-) and hydrogen peroxide (H2O2) is highly desirable in biology and food safety owing to their redox pair function in biological systems and their utilization in food industry. In this work, a ratiometric fluorescent probe (TPA-Y) with aggregation-induced emission (AIE) properties based on triphenylamine fluorophore was designed and synthesized for reversibly monitoring of HSO3-/H2O2. Reaction of HSO3- with TPA-Y can result in ratiometric fluorescence changes (I444/I629), and the emission spectrum blue shift reaches 185 nm, which can effectively avoid spectral overlap. Meanwhile, the solution color changed obviously from orange to colorless, enabling naked eye detection of HSO3-. TPA-Y was capable of quantitatively detect HSO3- in sugar and wine samples with the recovery rates ranging from 94.52 to 102.18%. In addition, TPA-Y is suitable to prepare paper strips and anti-counterfeiting ink for HSO3- detection. In addition, the original TPA-Y can be released after the addition product (TPA-Y-HSO3-) is oxidized by H2O2, and the HSO3-/H2O2 redox cycle can repeat for at least six times. The probe TPA-Y can be applied to fluorescence imaging of reversible and dynamic interconversion between HSO3- and H2O2 in living MCF-7 cells.

Analytical performance of the FDA-cleared Parsortix® PC1 system.

The Parsortix® PC1 system, Food and Drug Administration (FDA) cleared for use in metastatic breast cancer (MBC) patients, is an epitope-independent microfluidic device for the capture and harvest of circulating tumor cells from whole blood based on cell size and deformability. This report details the analytical characterization of linearity, detection limit, precision, and reproducibility for this device. System performance was determined using K2-EDTA blood samples collected from self-declared healthy female volunteers (HVs) and MBC patients spiked with prelabeled cultured breast cancer cell lines (SKBR3, MCF7, or Hs578T). Samples were processed on Parsortix® PC1 systems and captured cells were harvested and enumerated. The system captured and harvested live SKBR3, MCF7, and Hs578T cells and fixed SKBR3 cells linearly between 2 and ~100 cells, with average harvest rates of 69%, 73%, 79%, and 90%, respectively. To harvest ≥1 cell ≥95% of the time, the system required 3, 5 or 4 live SKBR3, MCF7 or Hs578T cells, respectively. Average harvest rates from precision studies using 5, 10, and ~50 live cells spiked into blood for each cell line ranged from 63.5% to 76.2%, with repeatability and reproducibility percent coefficient of variation (%CV) estimates ranging from 12.3% to 32.4% and 13.3% to 34.1%, respectively. Average harvest rates using ~20 fixed SKBR3 cells spiked into HV and MBC patient blood samples were 75.0% ± 16.1% (%CV = 22.3%) and 68.4% ± 14.3% (%CV = 21.1%), respectively. These evaluations demonstrate the Parsortix® PC1 system linearly and reproducibly harvests tumor cells from blood over a range of 1 to ~100 cells.

Highly sensitive fluorescent probes for selective detection of hypochlorite: Applications in blood serum and cell imaging.

Being one of the vital reactive oxygen species (ROS), abnormal level of hypochlorite ion (ClO-) may pose detrimental threats to living organisms. Therefore, highly selective, and rapid monitoring of ClO- in living system is of prime importance to protect living organisms from its harmful effects. In this regard, design of synthetic fluorescent probes for ClO- has garnered considerable attention. However less fluorescence emission in aggregated state and less photostability of several existing probes for ClO- inspired us to design aggregation induced emission (AIE) active fluorescent probes SH1 and SH2. Probes were rationally designed by introducing thiourea moiety that selectively reacted through desulfurization reaction and resulted in highly selective detection of ClO-. Hypochlorite induced desulfurization reaction was validated through 1H NMR titration and DFT studies. Fine tuning of probes SH1 and SH2 prompted highly sensitive nanoscale (55nM and 77nM) and rapid (15 and 35 sec) detection of ClO-. Probe SH1 displayed less cytotoxic effect to live cells before it was successfully applied for bioimaging of ClO- in live MCF-7 cells. Moreover, probes displayed excellent sensing potential for ClO- in blood serum and real water samples. Advantageously, probe coated portable fluorescent films were fabricated for the easy and fast monitoring of ClO-. Of note, this work offers excellent design strategy for highly selective detection of ClO- that may lead to clinical trials.

3,5-bis(styryl)pyrazole inhibits mitosis and induces cell death independent of BubR1 and p53 levels by depolymerizing microtubules.

Here, we show that 3,5-bis[(1E)-2-(2,6-dichlorophenyl)ethenyl]-1H-pyrazole 2l depolymerizes microtubules and reduces the number of growing tips of microtubules. The fluorescence recovery after photobleaching experiment in live MCF-7 cells showed that pyrazole 2l suppresses spindle microtubule dynamics. Further, the compound inhibits chromosome movements, activates the spindle assembly checkpoint, and blocks mitosis in MCF-7 cells. Pyrazole 2l treatment induced cell death in a variety of pathways. Pyrazole 2l induces cell death independent of BubR1 and p53 levels of MCF-7 cells upon microtubule depolymerization. Further, pyrazole 2l increases the interaction between NF-κB and microtubules and enhances the nuclear localization of NF-κB at its half-maximal proliferation inhibitory concentration while a high concentration of the compound reduced the nuclear localization of NF-κB. Interestingly, the compound exerted significantly stronger antiproliferative effects in cancerous cells than in non-cancerous cells. The results indicated that pyrazole 2l inhibits mitosis by targeting microtubules, induces several types of cell death stimuli, and suggest its potential as a lead in developing anticancer agent.

An AIE mechanism-based fluorescent probe for relay recognition of HSO3−/H2O2 and its application in food detection and bioimaging

In view of the important physiological role of HSO3− and H2O2, it is of great significance to develop fluorescent probes to detect HSO3− and H2O2 in aqueous medium. We herein report a new fluorescent probe (E)-3-(2-(4-(1,2,2-triphenylvinyl)styryl)benzo [d]thiazol-3-ium-3-yl)propane-1-sulfonate (TPE-y) possessing benzothiazolium salt based on tetraphenylethene (TPE) moiety with aggregation-induced emission (AIE) characteristics. TPE-y can sequentially recognize HSO3− and H2O2 through colorimetric and fluorescence dual-channel response in HEPES (pH = 7.4, 1% DMSO) buffer solution, and exhibits high sensitivity and selectivity, a large Stokes shift (189 nm), as well as a wide applicable pH range. The detection limits of TPE-y and TPE-y-HSO3 for HSO3− and H2O2 are 3.52 μM and 0.15 μM, respectively. The recognition mechanism is verified by 1H NMR and HRMS methods. Furthermore, TPE-y can detect HSO3− in sugar samples, and can image exogenous HSO3− and H2O2 in living MCF-7 cells. TPE-y can relay detect HSO3− and H2O2, which is of great significance to maintain the redox balance in organisms.

A new aggregation-induced emission-based fluorescent probe for effective detection of Hg2+ and its multiple applications

Detection of mercury ions (Hg2+) in actual samples is of significant importance due to the toxicity of Hg2+ to human health. In this work, a simple tetraphenylethene (TPE) derived fluorescent probe TPE-Hg based on aggregation-induced emission (AIE) mechanism was synthesized. TPE-Hg can visually recognize Hg2+ in THF/HEPES (1:9, v/v, HEPES 20 mmol/L, pH 7.3) system with rapid response, strong anti-interference ability, large Stokes shift (203 nm), and low detection limit (7.548 × 10−7 mol/L). The results show that Hg2+ triggered elimination of TPE-Hg lead to releasing of an AIE-active compound 2 is responsible to the sensing mechanism. TPE-Hg is applicable to detect Hg2+ in actual water samples and image Hg2+ in living MCF-7 cells. In addition, TPE-Hg is suitable to assay the Hg2+ level in seafood and tea samples, and it is also applicable in test strips.

Porphyrin-Based Covalent Organic Frameworks with Donor-Acceptor Structure for Enhanced Peroxidase-like Activity as a Colorimetric Biosensing Platform

Hydrogen peroxide (H2O2) and glucose play a key role in many cellular signaling pathways. The efficient and accurate in situ detection of H2O2 released from living cells has attracted extensive research interests. Herein, a new porphyrin-based porous covalent organic framework (TAP-COF) was fabricated via one-step condensation of 1,6,7,12-tetrachloroperylene tetracarboxylic acid dianhydride and 5,10,15,20-tetrakis (4-aminophenyl)porphyrin iron(III). The obtained TAP-COF has high surface areas, abundant surface catalytic active sites, and highly effective electron transport due to its precisely controllable donor-acceptor arrangement and 3D porous structure. Then, the new TAP-COF exhibited excellent peroxidase-like catalytic activity, which could effectively catalyze oxidation of the substrate 3,3',5,5'-tetramethylbenzidine by H2O2 to produce a typical blue-colored reaction. On this basis, simple, rapid and selective colorimetric methods for in situ H2O2 detection were developed with the detection limit of 2.6 nM in the wide range of 0.01 to 200 μM. The colorimetric approach also could be used for in situ detection of H2O2 released from living MCF-7 cells. This portable sensor based on a COF nanozyme not only opens a new path for point-of-care testing, but also has potential applications in the field of cell biology and clinical diagnosis.

Discovery of a triphenylamine-benzofuran derivative as fluorescent probe for hydrogen polysulfide in tea samples

In this work, a novel triphenylamine-benzofuran derived fluorescent probe, TBF-SS, was developed for detecting hydrogen polysulfide in tea samples and intracellular imaging. TBF-SS showed the practical advantages including high sensitivity (LOD = 0.01 μM), high selectivity, rapid response (within 15 min), and steadiness in various environmental conditions. The detecting system was steady within pH range of 6.0–11.0 and temperature range of 20–55 °C. The probe TBF-SS could guarantee the stable detection of H2Sn for 7 d in storage of either solid or solution. In particular, in the application of various tea samples with different brewing times and testing temperatures, the recovery percentages varied in the range of 95.22 % to 105.0 %. Therefore accurate monitoring of H2Sn could be achieved by using the probe TBF-SS. In addition, TBF-SS could monitor the exogenous level, the β-lapachone-induced generation and the tea-sample-treated introduction of H2Sn in living MCF-7 cells. This work might inspire the improvement of the serviceability of fluorescent implements.

Rational design of a GSH silent fluorescent probe for simultaneous detection of H2S and Cys/Hcy from distinct channels

In light of elucidating the intricacy relationship of cellular cross-talk for reactive sulfur species in cellular activity, it is an urgent demand for the development of effective assessment methods to detect H2S and Cys/Hcy concurrently. In this work, by introducing thiophene-2-carboxylate and NBD moiety as the reactive sites to the 7-hydroxycoumarin-4-acetic acid, we have designed and synthesized a GSH silent fluorescent probe (COT-NBD) for simultaneous detection of H2S and Cys/Hcy from distinct channels. With the existence of reactive sulfur species (Cys/Hcy and H2S), two kinds of distinct signals could be produced, blue for H2S (λex = 355 nm) and green for Cys/Hcy (λex = 450 nm). Additionally, remarkable fluorescence enhancement (77-fold for Cys, 61-fold for Hcy and 68-fold for H2S), high sensitivity (the limit of detection of probe COT-NBD was calculated to be 0.012 μM, 0.034 μM and 0.06 μM for Cys, Hcy and H2S, the limit of quantification of probe COT-NBD was calculated to be 0.040 μM, 0.113 μM and 0.200 μM for Cys, Hcy and H2S), desirable selectivity, large separation of the emission wavelengths (87 nm) and low cytotoxicity make it a ideal tool to detect H2S and Cys/Hcy concurrently. Furthermore, probe COT-NBD had high cell membrane permeability, enabling H2S and Cys/Hcy in living MCF-7 cells and zebrafish through different emission channels to be imaged. All in all, probe COT-NBD could be served as a promise molecular tool for investigating the function and synergy of H2S and Cys/Hcy in physiological processes.

Photoinduced Carbene for Effective Photodynamic Therapy Against Hypoxic Cancer Cells

Photoinduced Carbene for Effective Photodynamic Therapy Against Hypoxic Cancer Cells

AIEE active sensors for fluorescence enhancement based detection of Ni2+ in living cells: Mechanofluorochromic and photochromic properties with reversible sensing of acid and base

Stimuli responsive sensors QI 1 and QI 2 were rationally developed which exhibited diverse features of mutable mechanofluorochromism, reversible photochromism, solvatochromism, aggregation induced emission enhancement (AIEE), and metal ion sensing. After observing the exceptional structural property relationship, sensors were applied for reversible colorimetric and fluorometric determination of Ni2+ with low detection limits of 12 and 17 nM, respectively. Fluorescence emission enhancement based Ni2+ sensing was induced by chelation enhanced fluorescence (CHEF) mechanism. CHEF is triggered by the inhibition of excited state intramolecular proton transfer (ESIPT) and –C=N isomerization. The proposed Ni2+ sensing mechanism was investigated through 1H NMR, FT-IR titration, theoretical studies, and Jobs plots. Further, the developed sensors successfully demonstrated the selective acid-base induced absorption/emission switching through reversible ring-opening/closing and keto–enol tautomerization, evidenced by 1H NMR titration experiments. Additionally, the sensitivity of the sensor QI 1 towards Ni2+ was effectively mimicked in live MCF-7 cells and industrial effluents. Furthermore, monitoring of Ni2+ ions was also accessed through inexpensive and portable sensors’ coated fluorescent films. Finally, an INHIBIT logic gate was fabricated imputing Ni2+ and EDTA as input signals to electronically scrutinize the targeted Ni2+.

SERS and dark-field scattering dual-mode detection of intracellular hydrogen peroxide using biocompatible Au@COF nanosensor

Hydrogen peroxide is widely involved in intracellular physiological activities, playing vital roles in regulating various intracellular metabolite and physiological events. Surface-enhanced Raman scattering (SERS) may serve as a promising technique to efficiently sensing metabolites in living cells owing to its non-invasiveness, low autofluorescence, and rapid detection capability. Herein, a size-controllable core-shell structure was constructed by covering 2D covalent organic frameworks (COFs) on Au nanoparticles (Au@COF), and the cellular hydrogen peroxide were detected by Raman spectroscopy/Dark-field scattering imaging dual-mode technique. The introduction of COFs endows Au@COF with perfect enrichment capacity as well as high stability and good biocompatibility. Combining the superior fingerprint identification of SERS and the imaging capability of dark-field microscopy, the present method exhibits high applicability for hydrogen peroxide detection in living cells. Results show that when the living MCF-7 cells were treated by different drugs, the level of hydrogen peroxide metabolite can be monitored in real-time. This study provides a simple but sensitive and facile platform for biosensing hydrogen peroxide and cellular metabolites.

An efficient turn-on fluorescence chemosensor system for Zn(II) ions detection and imaging in mitochondria.

Mitochondria-targetable fluorescent chemosensors, Rhodamine-B and rhodamine 6G bearing syringaldehyde based receptors were designed and synthesized for efficient chemosensing of Zinc(II) ions. The probes showed the very selective naked eye color change to pink from colorless upon addition of Zinc(II) ions, further these probes showing turn-on fluorescence enhancement with Zn(II) ions by opening of rhodamine spirolactam. The probes are very sensitive towards Zn(II) ions among other ions. These probes RBS and R6S will be applicable to detect zinc ions upto the low level concentration 0.18 and 0.19 nano molar respectively. The affinity of these sensors RBS and R6S for Zinc (II) ions was found to be in the range of 1.12×104M-1 and 7.28×104M-1 respectively. 1H-nmr titrations of the probes with Zn(II) ions clearly indicating the spiroring opening of the spirolactam. DFT calculations supporting that the perceived photophysical changes of the probes on appendage of the zinc ions. Probes RBS and R6S are useable for selective staining mitochondria. Both of the probes are applicable to reveal labile Zn(II) in live Hela and MCF-7 cells via fluorescence imaging. RBS and R6S are also finding application on quantification of Zinc(II) ions inside mitochondria via fluorescence imaging.