Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) emerged in December 2019, causing a range of respiratory infections from mild to severe. This resulted in the ongoing global COVID-19 pandemic, which has had a significant impact on public health. The World Health Organization declared COVID-19 as a global pandemic in March 2020.
View Article and Find Full Text PDFHead and neck squamous cell carcinoma (HNSCC) is the sixth most common malignancy globally. The etiology of HNSCC is multifactorial, including cellular stress induced by a tobacco smoking, tobacco chewing excess alcohol consumption, and human papillomavirus infection. The induction of stress includes autophagy as one of the response pathways in maintaining homeostatic equilibrium.
View Article and Find Full Text PDFHeat shock proteins (HSPs) are evolutionary conserved 'stress-response' proteins that facilitate cell survival against various adverse conditions. HSP-mediated cytoprotection was hitherto reported to occur principally in two ways. Firstly, HSPs interact directly or indirectly with apoptosis signaling components and suppress apoptosis.
View Article and Find Full Text PDFPurpose: Anastasis is newly discovered process by which cells recover from late-stage apoptosis upon removal of a death stimulus. Recent reports suggest that cells may recover, even after the initiation of mitochondrial outer-membrane permeabilization (MOMP) and caspase activation. Here, we specifically studied the reversibility of late-stage apoptosis in cervical (HeLa) and breast (MDA-MB-231) cancer cells in relation to the extent of MOMP (limited or widespread).
View Article and Find Full Text PDFA dopamine receptor antagonist, Thioridazine (TDZ) is known for its cytotoxic activity against various cancers and its role in combinational chemotherapy is being actively investigated. Several molecular targets of TDZ have been studied to delineate its anticancer activities, with contrasting findings in different cancer types. Moreover, the underlying mechanism of cell death from TDZ treatment is not well defined.
View Article and Find Full Text PDFThe current study highlights rapid, sustainable, and cost-effective biosynthesis of silver (Ag), gold (Au) nanoparticles (NPs), and bimetallic Au-AgNPs composites using bio-waste extract of Trapa natans. Growth of the NPs was monitored spectrophotometrically and peak was observed at ∼525 nm, ∼450 nm, and ∼495 nm corresponding to Plasmon absorbance of AuNPs, AgNPs, and Au-AgNPs, respectively. Transmission electron microscopy (TEM) revealed the size of AgNPs (∼15 nm), AuNPs (∼25 nm), and Au-AgNPs (∼26-90 nm).
View Article and Find Full Text PDFProgrammed cell death is an evolutionarily conserved process essential for animal development and tissue homeostasis. Mitochondria have been demonstrated to play a central role in regulating both the activation and the execution of apoptosis. In particular, mitochondria release multiple proapoptotic factors from its intermembrane space, leading to both caspase-dependent and -independent cell death.
View Article and Find Full Text PDFDespite the use of new generation target specific drugs or combination treatments, drug-resistance caused by defective apoptosis signaling remains a major challenge in cancer treatment. A common apoptotic defect in drug-resistant tumor is the failure of cancer cells to undergo Bax/Bak-dependent mitochondrial permeabilization due to impaired signaling of Bcl-2 family proteins. Therefore, Bax and Bak-independent caspase-activating compounds appear to be effective in killing such tumor cells.
View Article and Find Full Text PDFFluorescent protein based signaling probes are emerging as valuable tools to study cell signaling because of their ability to provide spatio- temporal information in non invasive live cell mode. Previously, multiple fluorescent protein probes were employed to characterize key events of apoptosis in diverse experimental systems. We have employed a live cell image based approach to visualize the key events of apoptosis signaling induced by zerumbone, the active principle from ginger Zingiber zerumbet, in cancer cells that enabled us to analyze prominent apoptotic changes in a hierarchical manner with temporal resolution.
View Article and Find Full Text PDFEndothelial progenitor cells (EPCs) play a significant role in multiple biological processes such as vascular homeostasis, regeneration, and tumor angiogenesis. This makes them a promising cell of choice for studying a variety of biological processes, toxicity assays, biomaterial-cell interaction studies, as well as in tissue-engineering applications. In this study, we report the generation of two clones of SV40-immortalized EPCs from umbilical cord blood.
View Article and Find Full Text PDFCurrent cancer therapeutics are identified based on initial tumor regression screens that mostly kill differentiated tumor cells, sparing the rare cancer stem cells (CSCs). Being rare and difficult to characterize, it remains a challenge to identify compounds active against them. Side population (SP) cells identified in multiple cancer cell line panels expressing mitochondrial Cytochrome C-EGFP were evaluated for identifying possible drug candidates utilizing high-throughput imaging.
View Article and Find Full Text PDFRecent advancement in the area of green fluorescent protein techniques coupled with microscopic imaging has significantly contributed in defining and dissecting subcellular changes of apoptosis with high spatio-temporal resolution. Although single cell based studies using EGFP and associated techniques have provided valuable information of initiation and hierarchical changes of apoptosis, they are yet to be exploited for multiparameter cell based real time analysis for possible drug screening or pathway defining in a high throughput manner. Here we have developed multiple cancer cell lines expressing FRET sensors for active caspases and adapted them for high throughput live cell ratio imaging, enabling high content image based multiparameter analysis.
View Article and Find Full Text PDFTumors often acquire drug resistance due to functional loss of pro apoptotic gene Bax, a critical and essential component of cell death rendering them insensitive to most anti-tumor agents. Compounds that can induce Bax independent apoptotic cell death are expected to overcome such drug resistance. We have employed a live cell based screening platform to identify potential compounds that can induce programmed cell death in Bax deficiency.
View Article and Find Full Text PDFXIAP is an important antiapoptotic protein capable of conferring resistance to cancer cells. Embelin, the small molecular inhibitor of XIAP, possesses wide spectrum of biological activities with strong inhibition of nuclear factor kappa B and downstream antiapoptotic genes. However, the mechanism of its cell death induction is not known.
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