scholarly journals A Radioligand Binding Assay for Antitubulin Activity in Tumor Cells

2005 ◽  
Vol 11 (1) ◽  
pp. 82-89 ◽  
Author(s):  
David H. Young ◽  
Fernando M. Rubio ◽  
Paul O. Danis

The benzamide RH-5854 is shown to be highly potent toward tumor cells and to arrest nuclear division by a highly specific covalent binding to the β-subunit of tubulin in the colchicine binding region. Binding of 3H-RH-5854 to β-tubulin in HCT-116 colon cancer cells is saturable and has been exploited in the development of a cell-based competitive binding assay, which allows antitubulin effects to be detected inwhole cells. 3H-RH-5854 binding is strongly inhibited by preincubating the cells with compounds that bind to the colchicine site andwith paclitaxel. Binding of 3H-RH-5854 is enhanced by preincubating the cells with vinblastine but not by other agents that bind at or near the vinblastine site (ansamitocin P-3 and phomopsin A). Various cytotoxic agents that do not act on tubulin do not affect binding of 3H-RH-5854 in HCT-116 cells, demonstrating specificity of the assay for detection of antitubulin activity. As an alternative to traditional assays that employ isolated brain tubulin, the 3HRH-5854 binding assay enables screening for antitubulin effects directly in tumor cells, providing an assay that accounts for cell-specific criteria that influence sensitivity such as different tubulin isotypes, tubulin mutations, drug metabolism, and efflux mechanisms.

Medicines ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 27
Author(s):  
Kinjal Lakhani ◽  
Edgar A. Borrego ◽  
Karla G. Cano ◽  
Jonathan R. Dimmock ◽  
Renato J. Aguilera ◽  
...  

A series of novel N2-acryloylhydrazides 1a–m and a related series of compounds 6a–c were prepared as potential chemostimulants. In general, these compounds are cytotoxic to human HCT 116 colon cancer cells, as well as human MCF-7 and MDA-MB-231 breast cancer cell lines. A representative compound N1-(3,4-dimethoxyphenylcarbonyl)-N2-acryloylhydrazine 1m sensitized HCT 116 cells to the potent antineoplastic agent 3,5-bis(benzylidene)-4-piperidone 2a, and also to 5-fluorouracil. A series of compounds was prepared that incorporated some of the molecular features of 2a and related compounds with various N2-acryloylhydrazides in series 1. These compounds are potent cytotoxins. Two modes of action of representative compounds are the lowering of mitochondrial membrane potential and increasing the concentration of reactive oxygen species.


Author(s):  
Weihua Dong ◽  
Fang Wang ◽  
Qingyu Liu ◽  
Tianyun Wang ◽  
Yun Yang ◽  
...  

Background: Vincristine (VCR) is a chemotherapeutic drug commonly used in the treatment of Colorectal Cancer (CRC). However, VCR drug resistance may result in reduced efficacy and even failure of chemotherapy in CRC treatment. MiRNA has been demonstrated to be associated with the sensitivity of tumor cells to chemotherapy. Objective: This study aimed to identify a novel miRNA-14669 that can reverse vincristine resistance and sensitize drug-resistant colorectal cancer cells. Methods: High-throughput sequencing was performed to screen miRNAs that are associated with VCR drug resistance, and qRT-PCR was used for further validation. The miRNA mimic and inhibitor were designed and transfected into HCT-8,HCT-116 and HCT-8/VCR cells. Wound healing test examined the effect of the miRNA on the migration of colorectal cancer cells. Flow cytometry was used to evaluate cell apoptosis of HCT-8 cells. Survivin, Bcl-2, GST3, MDR1 and MRP1 expressions were detected by Western blot. Results: The expression of miRNA-14669 in HCT-8/VCR cells was 1.925 times higher than that of the HCT-8 cells. After transfecting with mimic miRNA, HCT-8 and HCT-116 cells showed an increased survival rate. The survival rate of HCT-8/VCR cells decreased by transfection of inhibitor. The inhibitor also sensitized HCT-8 and HCT-116 cells to VCR or 5-Fluorouracil (5-FU). The migratory ability of HCT-8 and HCT-116 cells increased by miRNA mimic while reduced by miRNA inhibitor. Overexpression of miRNA-14669 reduced apoptosis, while downregulation of miRNA-14669 increased cell apoptosis in HCT-8 cells. The mechanism of the miRNA involved in drug resistance may be attributed to apoptosis of tumor cells, detoxification of GST3 and drug efflux induced by MDR1 and MRP1. PI3K / AKT is the signaling pathway related to drug resistance. Conclusion: We identified a novel miRNA-14669 that may be associated with the chemotherapeutic resistance in CRC cells.


2019 ◽  
Vol 19 (10) ◽  
pp. 1285-1292 ◽  
Author(s):  
Kuldip D. Upadhyay ◽  
Anamik K. Shah

Background: Quinoline analogues exhibited diversified biological activities depending on the structure type. A number of natural products with pyrano[3,2-c]quinolone structural motifs and patented chromenes were reported as promising cytotoxic agents. Objective: The present study is aimed to evaluate a new series of pyrano[3,2-c]quinoline scaffolds derived from the fusion of bioactive quinolone pharmacophore with structurally diverse aryl substituted chromene for its cytotoxicity. Methods: A library of pyrano[3,2-c]quinoline analogues was prepared from one-pot multi component synthesis using various aromatic aldehydes, malononitrile and 2,4-dihydroxy-1-methylquinoline. The new synthetics were primarily screened for its cytotoxicity (IC50) against different human cancer cell lines in vitro. The promising synthetics were further evaluated in vitro for their potency against different kinase activity. The promising compounds were finally tested for their in vivo efficacy in SCID type mice HCT-116 tumor model. Results: The screening results revealed that compounds 4c, 4f, 4i and 4j showed promising activity in in vitro study. However, compound 4c was found to be the most potent candidate with 23% tumor growth inhibition in HCT-116 tumor mice model. Conclusion: The structure activity relationship suggested that 3-substitution on the aryl ring at C4 position of the pyrano[3,2 c]quinolone moiety seems to have an important position for cytotoxicity activity. However, 3- chloro substitution at C4 aryl ring showed a significant alteration of the bioactive conformer of the parent scaffold and outcome with compound 4c as the most potent candidate of the series.


BIO-PROTOCOL ◽  
2016 ◽  
Vol 6 (18) ◽  
Author(s):  
Loredana Cifaldi ◽  
Franco Locatelli ◽  
Doriana Fruci

2021 ◽  
Vol 14 (2) ◽  
pp. 139
Author(s):  
Mohammad Azam Ansari ◽  
Sarah Mousa Maadi Asiri ◽  
Mohammad A. Alzohairy ◽  
Mohammad N. Alomary ◽  
Ahmad Almatroudi ◽  
...  

The current study demonstrates the synthesis of fatty acids (FAs) capped silver nanoparticles (AgNPs) using aqueous poly-herbal drug Liv52 extract (PLE) as a reducing, dispersing and stabilizing agent. The NPs were characterized by various techniques and used to investigate their potent antibacterial, antibiofilm, antifungal and anticancer activities. GC-MS analysis of PLE shows a total of 37 peaks for a variety of bio-actives compounds. Amongst them, n-hexadecanoic acid (21.95%), linoleic acid (20.45%), oleic acid (18.01%) and stearic acid (13.99%) were found predominately and most likely acted as reducing, stabilizing and encapsulation FAs in LIV-AgNPs formation. FTIR analysis of LIV-AgNPs shows some other functional bio-actives like proteins, sugars and alkenes in the soft PLE corona. The zone of inhibition was 10.0 ± 2.2–18.5 ± 1.0 mm, 10.5 ± 2.5–22.5 ± 1.5 mm and 13.7 ± 1.0–16.5 ± 1.2 against P. aeruginosa, S. aureus and C. albicans, respectively. LIV-AgNPs inhibit biofilm formation in a dose-dependent manner i.e., 54.4 ± 3.1%—10.12 ± 2.3% (S. aureus), 72.7 ± 2.2%–23.3 ± 5.2% (P. aeruginosa) and 85.4 ± 3.3%–25.6 ± 2.2% (C. albicans), and SEM analysis of treated planktonic cells and their biofilm biomass validated the fitness of LIV-AgNPs in future nanoantibiotics. In addition, as prepared FAs rich PLE capped AgNPs have also exhibited significant (p < 0.05 *) antiproliferative activity against cultured HCT-116 cells. Overall, this is a very first demonstration on employment of FAs rich PLE for the synthesis of highly dispersible, stable and uniform sized AgNPs and their antibacterial, antifungal, antibiofilm and anticancer efficacy.


2021 ◽  
Vol 12 (3) ◽  
Author(s):  
Shuang Cui ◽  
Qiong Wu ◽  
Ming Liu ◽  
Mu Su ◽  
ShiYou Liu ◽  
...  

AbstractSuper-enhancers or stretch enhancers (SEs) consist of large clusters of active transcription enhancers which promote the expression of critical genes that define cell identity during development and disease. However, the role of many super-enhancers in tumor cells remains unclear. This study aims to explore the function and mechanism of a new super-enhancer in various tumor cells. A new super-enhancer that exists in a variety of tumors named EphA2-Super-enhancer (EphA2-SE) was found using multiple databases and further identified. CRISPR/Cas9-mediated deletion of EphA2-SE results in the significant downregulation of its target gene EphA2. Mechanistically, we revealed that the core active region of EphA2-SE comprises E1 component enhancer, which recruits TCF7L2 and FOSL2 transcription factors to drive the expression of EphA2, induce cell proliferation and metastasis. Bioinformatics analysis of RNA-seq data and functional experiments in vitro illustrated that EphA2-SE deletion inhibited cell growth and metastasis by blocking PI3K/AKT and Wnt/β-catenin pathway in HeLa, HCT-116 and MCF-7 cells. Overexpression of EphA2 in EphA2-SE−/− clones rescued the effect of EphA2-SE deletion on proliferation and metastasis. Subsequent xenograft animal model revealed that EphA2-SE deletion suppressed tumor proliferation and survival in vivo. Taken together, these findings demonstrate that EphA2-SE plays an oncogenic role and promotes tumor progression in various tumors by recruiting FOSL2 and TCF7L2 to drive the expression of oncogene EphA2.


Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 470
Author(s):  
Mustafa Mohsen El-Zayat ◽  
Mostafa M. Eraqi ◽  
Hani Alrefai ◽  
Ayman Y. El-Khateeb ◽  
Marwan A. Ibrahim ◽  
...  

The current work aimed to synthesize selenium and zinc nanoparticles using the aqueous extract of Ephedra aphylla as a valuable medicinal plant. The prepared nanoparticles were characterized by TEM, zeta potential, and changes in the phytochemical constituents. Hence, the phenolic, flavonoid, and tannin contents were reduced in the case of the prepared samples of nanoparticles than the original values in the aqueous extract. The prepared extract of Ephedra aphylla and its selenium and zinc nanoparticles showed high potency as antioxidant agents as a result of the DPPH• assay. The samples were assessed as anticancer agents against six tumor cells and a normal lung fibroblast (WI-38) cell line. The selenium nanoparticles of Ephedra aphylla extract revealed very strong cytotoxicity against HePG-2 cells (inhibitory concentration (IC50) = 7.56 ± 0.6 µg/mL), HCT-116 cells (IC50 = 10.02 ± 0.9 µg/mL), and HeLa cells (IC50 = 9.23 ± 0.8 µg/mL). The samples were evaluated as antimicrobial agents against bacterial and fungal strains. Thus, selenium nanoparticles showed potent activities against Gram-negative strains (Salmonella typhimurium, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli), Gram-positive strains (Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, and Staphylococcus epidermidis), and the fungal strain Candida albicans. In conclusion, the preparation of nanoparticles of either selenium or zinc is crucial for improved biological characteristics.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
C. Metzner ◽  
F. Hörsch ◽  
C. Mark ◽  
T. Czerwinski ◽  
A. Winterl ◽  
...  

AbstractChemotaxis enables cells to systematically approach distant targets that emit a diffusible guiding substance. However, the visual observation of an encounter between a cell and a target does not necessarily indicate the presence of a chemotactic approach mechanism, as even a blindly migrating cell can come across a target by chance. To distinguish between the chemotactic approach and blind migration, we present an objective method that is based on the analysis of time-lapse recorded cell migration trajectories: For each movement step of a cell relative to the position of a potential target, we compute a p value that quantifies the likelihood of the movement direction under the null-hypothesis of blind migration. The resulting distribution of p values, pooled over all recorded cell trajectories, is then compared to an ensemble of reference distributions in which the positions of targets are randomized. First, we validate our method with simulated data, demonstrating that it reliably detects the presence or absence of remote cell-cell interactions. In a second step, we apply the method to data from three-dimensional collagen gels, interspersed with highly migratory natural killer (NK) cells that were derived from two different human donors. We find for one of the donors an attractive interaction between the NK cells, pointing to a cooperative behavior of these immune cells. When adding nearly stationary K562 tumor cells to the system, we find a repulsive interaction between K562 and NK cells for one of the donors. By contrast, we find attractive interactions between NK cells and an IL-15-secreting variant of K562 tumor cells. We therefore speculate that NK cells find wild-type tumor cells only by chance, but are programmed to leave a target quickly after a close encounter. We provide a freely available Python implementation of our p value method that can serve as a general tool for detecting long-range interactions in collective systems of self-driven agents.


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