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Caspase-3 plays a vital role in intrinsic and extrinsic pathways of programed cell death and in cell proliferation. Its detection is an important tool for early detection of some cancers and apoptosis-related diseases, and for monitoring the efficacy of pharmaceuticals and of chemo- and radiotherapy of cancers. This review (with 72 references) summarizes nanomaterial based methods for signal amplification in optical methods for the determination of caspase-3 activity. Following an introduction into the field, a first large section covers optical assays, with subsections on luminescent and chemiluminescence, fluorometric (including FRET based), and colorimetric assays. Further section summarize methods for bioimaging of caspase-3. A concluding section covers current challenges and future perspectives. Graphical Abstract ᅟ.

Delivery of small interfering RNAs (siRNAs) into cells still remains a challenge in gene delivery studies. Here, we investigated the ability of synthesized Fe 3 O 4 -PEG-LAC-chitosan-PEI nanoparticles for siRNA delivery of survivin as the model gene into cells. The cellular uptake of survivin siRNA carried by synthesized nanoparticles into MCF-7 breast cancer cell line was evaluated by florescent microscopy and flowcytometry, both proving the efficacy of nanoparticles in delivery of up to 64.7% in comparison with lipofectamine 2000. Furthermore, the delivery of survivin siRNA by the nanoparticles (nanoplex) induced apoptosis that was assessed through DAPI staining and Annexin V/PI assays. In addition, we evaluated the efficacy of treatment with nanoplexes in the presence of mitoxantrone, as a chemotherapeutic agent. Our data indicated that inhibition of survivin expression increased the cell sensitivity to mitoxantrone. Real-time PCR and western blotting analysis revealed a significant reduction in mRNA and protein levels of survivin upon delivery of siRNA. Molecular docking studies showed that nanoparticles can bind to centeral BIR domain of survivin, exactly above zinc ion location with high affinity (ΔG: -10.3Kcal/mol). Also, thermodynamic studies proved the experimental results theoretically, revealing that the siRNA-loaded nanoparticles have a suppressing effect on survivin mRNA. Therefore, delivery of survivin siRNA into MCF-7 cells using Fe 3 O 4 -PEG-LAC-chitosan-PEI nanoparticles as a carrier enhances the cell death., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Previous studies have suggested that quinazolinone derivatives are potent apoptosis-inducing agents in various cancer cell lines. In the present study, we have investigated cytotoxic, apoptosis induction, and molecular docking activities of the spiroquinazolinone benzamide derivatives family on MCF-7 human breast cancer cells. The MTT cytotoxicity assays and docking studies showed that 4t-CHQB was the most active compound among the prepared spiroquinazolinone benzamide compounds with IC50 of 50 ± 1.2 μM and was selected for further assessments. Apoptosis, as the mechanism of cell death, was assessed morphologically by acridine orange/ethidium bromide (AO/EtBr) double staining, evaluation of the cell surface phosphatidylserine (PS) expression through annexin V/PI technique and, the formation of DNA ladder. Down regulation of survivin was evaluated in protein level after cell treatment with 4t-CHQB using western blotting method. Molecular modeling experiments involving 4t-CHQB binding site of survivin showed several strong hydrogen bonds and hydrophobic interactions between many important amino acid residues. Overall, the obtained data suggest that the assessed spiroquinazolinone benzamide compounds may provide a novel therapeutic approach for further evaluation, as an effective chemotherapeutic family acting through down regulation of survivin and apoptosis induction in breast cancer., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

In this experimental study, cancer and normal cells behavior during an in vitro photodynamic therapy (PDT) under exposure of continuous wave (CW) and fractionated mode of laser with different irradiation power and time intervals was compared and investigated. At the first, human fibroblast cancer cell line (SW 872) and human dermal normal (HFFF2) cell line were incubated with different concentrations of zinc phthalocyanine (ZnPc), as a PDT drug. The cells, then, were irradiated with a 675nm diode laser and the cell viability was evaluated using MTT assay. Under optimized conditions, the viability of the cancer cells was eventually reduced to 3.23% and 13.17%, and that of normal cells was decreased to 20.83% and 36.23% using CW and fractionated diode lasers, respectively. In general, the ratio of ZnPc LD50 values for the normal cells to the cancer cells with CW laser was much higher than that of the fractionated laser. Subsequently, cancer cells in comparison with normal ones were found to be more sensitive toward the photodynamic damage induced by ZnPc. In addition, treatment with CW laser was found to be more effective against the cancer cells with a lower toxicity to the normal cells compared with the fractionated diode laser., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Previous studies suggested that dithio-carbamates are potent apoptosis and anti-apoptosis inducing agents in various cancer cells. Here, the anti-proliferative and apoptosis inducing effects of a new derivative (2-NDC) from the dithio-carbamate family was examined in human leukemia K562 cells. We use thiazolyl blue tetrazolium bromide (MTT) to measure viability and cell growth inhibition. The 2-NDC showed effects on viability in a dose and time-dependent manner, inhibiting proliferation at concentrations of 10-30 μM after 24-48 hours of treatment and increasing values after 72 hours at 40-120 μM. The cytotoxic effect of the compound was calculated with an IC50 of 30 μM after 24-hour. Apoptosis induction was confirmed by acridine orange-ethidium bromide (AO/EtBr) staining, DNA fragmentation assay, flow cytometric assessment and also caspase-3 activation assay. Furthermore, enzymes level such as superoxide dismutase (SOD) and catalase (CAT) involved in oxidative stress were evaluated. The results of this study demonstrated insignificant increase of intracellular ROS levels for 24 hours and reduction after 48-72 hours. In addition to reduction of intracellular thiol, caspase-3 like activity was also decreased in a time-dependent manner in cells treated with 2-NDC. Thus 2-NDC can be considered as a good candidate for further pharmaceutical evaluations.

Introduction: Growing demands for ultrasensitive biosensing have led to the development of numerous signal amplification strategies. In this report, a novel electrochemiluminescence (ECL) method was developed for the detection and determination of caspase-3 activity based on reduced graphene oxide sheets decorated by gold nanoparticles as signal amplification element and horseradish peroxidase enzyme (HRP) as ECL intensity enhancing agent. Methods: The ECL intensity of the luminol was improved by using the streptavidin coated magnetic beads and HRP in the presence of hydrogen peroxide. The cleavage behavior of caspase-3 was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques using biotinylated peptide (DEVD containing peptide) which was coated on reduced graphene oxide decorated with gold nanoparticle. The surface modification of graphene oxide was successfully confirmed by FTIR, UV-vis and x-ray spectroscopy. Results: ECL based biosensor showed that the linear dynamic range (LDR) and the lower limit of quantification (LLOQ) were 0.5-100 and 0.5 femtomolar (fM), respectively. Finally, the performance of the engineered peptide based biosensor was validated in the A549 cell line as real samples. Conclusion: The prepared peptide based biosensor could be considered as an excellent candidate for early detection of apoptosis, cell turnover, and cancer related diseases. [ABSTRACT FROM AUTHOR]

Caspase-3 has a critical role in the apoptotic process and hematopoietic stem cell differentiation and its detection has been a major focus of research interest and attention. In this study, an ultrasensitive novel electrochemical biosensor for convenient, sensitive and selective detection of caspase-3 activity was developed. Gold nanoparticles functionalized silica-based mesoporous material (MCM-41) modified glassy carbon electrode was designed and fabricated for measurement of caspase-3 activity, more importantly, in its active form. Thiolated MCM-41 was decorated by gold nanoparticle using post modification method and characterized by different analytical methods such as atomic force microscopy, FTIR spectroscopy, scanning electron microscopy and X-ray diffraction. Hydroquinone was used as electroactive mediator. The biotinylated peptide was self-assembled on gold nanoparticles-MCM-41. The electrochemical behavior of the prepared biosensor was investigated by electrochemical techniques. The use of gold nanoparticles resulted in a significant improvement in the radial mass transfer flux at the electrode surface and enhancement in the electrochemical signal. Under the optimized conditions, the assay’s lower limit of quantification (LLOQ) was obtained as 5 femtomolar (fM) with a relative standard deviation of 0.67%. Finally, the proposed biosensor was successfully applied for detection of caspase-3 activity during hematopoietic stem cell differentiation steps as a real sample. [ABSTRACT FROM AUTHOR]