Fluorescent imaging of cytoplasmic nucleolin in live cells by a functionalized-engineered aptamer

2020 ◽  
Vol 56 (91) ◽  
pp. 14171-14174
Author(s):  
Junfa Yin ◽  
Shaokun Chen ◽  
Yuanyuan Song ◽  
Hailin Wang

A novel biosensing nanoplatform based on aptamer and polymer-grafted graphene oxides can specifically fluorescently visualize nucleolin in live cell cytoplasm, distinguishing cancer cells from normal cells.

2020 ◽  
Author(s):  
Lei Wang ◽  
Louis Riel ◽  
Bekim Bajrami ◽  
Bin Deng ◽  
Amy Howell ◽  
...  

The novel use of the α-methylene-β-lactone (MeLac) moiety as a warhead of multiple electrophilic sites is reported. In this study, we demonstrate that a MeLac-alkyne is a competent covalent probe and reacts with diverse proteins in live cells. Proteomics analysis of affinity-enriched samples identifies probe-reacted proteins, resolves their modified peptides/residues, and thus characterizes probe-protein reactions. Unique methods are developed to evaluate confidence in the identification of the reacted proteins and modified peptides. Tandem mass spectra of the peptides reveal that MeLac reacts with nucleophilic cysteine, serine, lysine, threonine, and tyrosine residues, through either Michael addition or acyl addition. A peptide-centric proteomics platform, using MeLac-alkyne as the measurement probe, successfully analyzes the Orlistat selectivity in live HT-29 cells. MeLac is a versatile warhead demonstrating enormous potential to expedite the development of covalent probes and inhibitors in interrogating protein (re)activity. MeLac-empowered platforms in chemical proteomics are widely adaptable for measuring the live-cell action of reactive molecules.


2019 ◽  
Vol 18 (15) ◽  
pp. 2156-2168 ◽  
Author(s):  
Magda F. Mohamed ◽  
Nada S. Ibrahim ◽  
Ahmed H.M. Elwahy ◽  
Ismail A. Abdelhamid

Background: Cancer is a complex genetic disease which is characterized by an abnormal cell growth, invasion and spreading to other parts of the body. There are several factors that lead to cancer by causing DNA damage and the impairment of its repair. Treatment of cancer using the chemotherapeutic drugs have adverse side effects such as toxicity as they lose their specificity toward cancer cells and affect also normal cells. Moreover, the cancer cells can resist the chemotherapeutic agents and make them ineffective. For these reasons, much attentions have been paid to develop new drugs with limited side effects on normal cells and to diminish cancer resistance to drug chemotherapy. Recently, some 1,4-dihydropyridine derivatives were reported to act as Multi-Drug Resistance (MDR) modulators that inhibit p-glycoprotein which is responsible for the inability of drugs to enter the cancer cells. Also 1,4-DHPs have antimutagenic properties against chemicals via modulating DNA repair when studied on drosophila. Objective: The objective of this study is the synthesis of bis 1,4-DHPs incorporating ester as well as ether linkages and evaluate the anticancer activity of new compounds for synergistic purpose. Different genetic tools were used in an attempt to know the mechanism of action of this compound against lung cancer. Method: An efficient one pot synthesis of bis 1,4-DHPs using 3-aminocrotononitrile and bis(aldehydes) has been developed. The cytotoxic effect against human cell lines MCF7, and A549 cell lines was evaluated. Results: All compounds exhibited better cytotoxicity toward lung carcinoma cells than breast cancer cells. With respect to lung carcinoma cell line (A549), compound 10 was the most active compound and the three other compounds 7, 8, and 9 showed comparable IC50 values. In case of breast cancer cell line (MCF7), the most active one was compound 7, while compound 8 recorded the least activity. Conclusion: we have developed an efficient method for the synthesis of novel bis 1,4-dihydropyridine derivatives incorporating ester or ether linkage. All compounds showed better cytotoxicity results against A549 than MCF7, so that lung carcinoma cell line was chosen to perform the molecular studies on it. The results showed that all compounds (7, 8, 9 and 10) caused cell cycle arrest at G1 phase. The molecular docking study on CDK2 confirmed the results of cell cycle assay which showed good binding energy between the compounds and the active site of enzyme indicating the inhibition of the enzyme.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yu-An Chen ◽  
Yong-Da Sie ◽  
Tsung-Yun Liu ◽  
Hsiang-Ling Kuo ◽  
Pei-Yi Chou ◽  
...  

AbstractMetastatic cancer cells are frequently deficient in WWOX protein or express dysfunctional WWOX (designated WWOXd). Here, we determined that functional WWOX-expressing (WWOXf) cells migrate collectively and expel the individually migrating WWOXd cells. For return, WWOXd cells induces apoptosis of WWOXf cells from a remote distance. Survival of WWOXd from the cell-to-cell encounter is due to activation of the survival IκBα/ERK/WWOX signaling. Mechanistically, cell surface epitope WWOX286-299 (repl) in WWOXf repels the invading WWOXd to undergo retrograde migration. However, when epitope WWOX7-21 (gre) is exposed, WWOXf greets WWOXd to migrate forward for merge. WWOX binds membrane type II TGFβ receptor (TβRII), and TβRII IgG-pretreated WWOXf greet WWOXd to migrate forward and merge with each other. In contrast, TβRII IgG-pretreated WWOXd loses recognition by WWOXf, and WWOXf mediates apoptosis of WWOXd. The observatons suggest that normal cells can be activated to attack metastatic cancer cells. WWOXd cells are less efficient in generating Ca2+ influx and undergo non-apoptotic explosion in response to UV irradiation in room temperature. WWOXf cells exhibit bubbling cell death and Ca2+ influx effectively caused by UV or apoptotic stress. Together, membrane WWOX/TβRII complex is needed for cell-to-cell recognition, maintaining the efficacy of Ca2+ influx, and control of cell invasiveness.


Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3575
Author(s):  
Shenggang Wang ◽  
Yue Huang ◽  
Xiangming Guan

Thiols play vital and irreplaceable roles in the biological system. Abnormality of thiol levels has been linked with various diseases and biological disorders. Thiols are known to distribute unevenly and change dynamically in the biological system. Methods that can determine thiols’ concentration and distribution in live cells are in high demand. In the last two decades, fluorescent probes have emerged as a powerful tool for achieving that goal for the simplicity, high sensitivity, and capability of visualizing the analytes in live cells in a non-invasive way. They also enable the determination of intracellular distribution and dynamitic movement of thiols in the intact native environments. This review focuses on some of the major strategies/mechanisms being used for detecting GSH, Cys/Hcy, and other thiols in live cells via fluorescent probes, and how they are applied at the cellular and subcellular levels. The sensing mechanisms (for GSH and Cys/Hcy) and bio-applications of the probes are illustrated followed by a summary of probes for selectively detecting cellular and subcellular thiols.


Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 462 ◽  
Author(s):  
Joanna Pilch ◽  
Patrycja Kowalik ◽  
Piotr Bujak ◽  
Anna M. Nowicka ◽  
Ewa Augustin

Nanotechnology-based drug delivery provides a promising area for improving the efficacy of cancer treatments. Therefore, we investigate the potential of using quantum dots (QDs) as drug carriers for antitumor unsymmetrical bisacridine derivatives (UAs) to cancer cells. We examine the influence of QD–UA hybrids on the cellular uptake, internalization (Confocal Laser Scanning Microscope), and the biological response (flow cytometry and light microscopy) in lung H460 and colon HCT116 cancer cells. We show the time-dependent cellular uptake of QD–UA hybrids, which were more efficiently retained inside the cells compared to UAs alone, especially in H460 cells, which could be due to multiple endocytosis pathways. In contrast, in HCT116 cells, the hybrids were taken up only by one endocytosis mechanism. Both UAs and their hybrids induced apoptosis in H460 and HCT116 cells (to a greater extent in H460). Cells which did not die underwent senescence more efficiently following QDs–UAs treatment, compared to UAs alone. Cellular senescence was not observed in HCT116 cells following treatment with both UAs and their hybrids. Importantly, QDgreen/red themselves did not provoke toxic responses in cancer or normal cells. In conclusion, QDs are good candidates for targeted UA delivery carriers to cancer cells while protecting normal cells from toxic drug activities.


2021 ◽  
Vol 22 (12) ◽  
pp. 6519
Author(s):  
Yuta Otani ◽  
Ken-ichi Fujita ◽  
Toshiki Kameyama ◽  
Akila Mayeda

Using TSG101 pre-mRNA, we previously discovered cancer-specific re-splicing of mature mRNA that generates aberrant transcripts/proteins. The fact that mRNA is aberrantly re-spliced in various cancer cells implies there must be an important mechanism to prevent deleterious re-splicing on the spliced mRNA in normal cells. We thus postulated that mRNA re-splicing is controlled by specific repressors, and we searched for repressor candidates by siRNA-based screening for mRNA re-splicing activity. We found that knock-down of EIF4A3, which is a core component of the exon junction complex (EJC), significantly promoted mRNA re-splicing. Remarkably, we could recapitulate cancer-specific mRNA re-splicing in normal cells by knock-down of any of the core EJC proteins, EIF4A3, MAGOH, or RBM8A (Y14), implicating the EJC core as the repressor of mRNA re-splicing often observed in cancer cells. We propose that the EJC core is a critical mRNA quality control factor to prevent over-splicing of mature mRNA.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Vida Ungerer ◽  
Abel J. Bronkhorst ◽  
Priscilla Van den Ackerveken ◽  
Marielle Herzog ◽  
Stefan Holdenrieder

AbstractRecent advances in basic research have unveiled several strategies for improving the sensitivity and specificity of cell-free DNA (cfDNA) based assays, which is a prerequisite for broadening its clinical use. Included among these strategies is leveraging knowledge of both the biogenesis and physico-chemical properties of cfDNA towards the identification of better disease-defining features and optimization of methods. While good progress has been made on this front, much of cfDNA biology remains uncharted. Here, we correlated serial measurements of cfDNA size, concentration and nucleosome histone modifications with various cellular parameters, including cell growth rate, viability, apoptosis, necrosis, and cell cycle phase in three different cell lines. Collectively, the picture emerged that temporal changes in cfDNA levels are rather irregular and not the result of constitutive release from live cells. Instead, changes in cfDNA levels correlated with intermittent cell death events, wherein apoptosis contributed more to cfDNA release in non-cancer cells and necrosis more in cancer cells. Interestingly, the presence of a ~ 3 kbp cfDNA population, which is often deemed to originate from accidental cell lysis or active release, was found to originate from necrosis. High-resolution analysis of this cfDNA population revealed an underlying DNA laddering pattern consisting of several oligo-nucleosomes, identical to those generated by apoptosis. This suggests that necrosis may contribute significantly to the pool of mono-nucleosomal cfDNA fragments that are generally interrogated for cancer mutational profiling. Furthermore, since active steps are often taken to exclude longer oligo-nucleosomes from clinical biospecimens and subsequent assays this raises the question of whether important pathological information is lost.


Virology ◽  
2021 ◽  
Author(s):  
Gustavo Martínez-Noël ◽  
Valdimara Corrêa Vieira ◽  
Patricia Szajner ◽  
Erin M. Lilienthal ◽  
Rebecca E. Kramer ◽  
...  

2008 ◽  
Vol 180 (4) ◽  
pp. 661-663 ◽  
Author(s):  
Karen W. Yuen ◽  
Arshad Desai

Aneuploidy and chromosome instability (CIN) are hallmarks of the majority of solid tumors, but the relationship between them is not well understood. In this issue, Thompson and Compton (Thompson, S.L., and D.A. Compton. 2008. Examining the link between chromosomal instability and aneuploidy in human cells. J. Cell. Biol. 180:665–672) investigate the mechanism of CIN in cancer cells and find that CIN arises primarily from defective kinetochore–spindle attachments that evade detection by the spindle checkpoint and persist into anaphase. They also explore the consequences of artificially elevating chromosome missegregation in otherwise karyotypically normal cells. Their finding that induced aneuploidy is rapidly selected against suggests that the persistence of aneuploid cells in tumors requires not only chromosome missegregation but also additional, as yet poorly defined events.


2021 ◽  
Vol 31 (15) ◽  
pp. R957-R959
Author(s):  
Sushila Ganguli ◽  
Helen K. Matthews

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