Search results for "tumor cell"
showing 10 items of 694 documents
Circulating Tumor Cells (CTCs): A Unique Model of Cancer Metastases and Non-invasive Biomarkers of Therapeutic Response
2021
Late-stage cancer metastasis remains incurable in the clinic and is the major cause death in patients. Circulating tumor cells (CTCs) are thought to be metastatic precursors shed from the primary tumor or metastatic deposits and circulate in the blood. The molecular network regulating CTC survival, extravasation, and colonization in distant metastatic sites is poorly defined, largely due to challenges in isolating rare CTCs. Recent advances in CTC isolation and ex vivo culture techniques facilitates single-cell omics and the development of related animal models to study CTC-mediated metastatic progression. With these powerful tools, CTCs can potentially be used as non-invasive biomarkers pr…
Carcinogenic aspect of xenobiotic molecules belonging to the peroxisome proliferator family.
1999
It is known that a short-term exposure of rat, mice or incubation of hepatic cells with fibrate molecules leads to increase in peroxisome number and cell hyperplasia. Further, long-term incubation of cells (at least a year) show transformed characteristics with foci and nodules. To explain the hepatocarcinogenic effect of peroxisome proliferators in rodents we studied the effect of peroxisome proliferators on rat liver oncogenes expression. Earlier, we reported an increase in liver and kidney mRNA level of c-myc and N-myc. Since several metabolic genes are activated by PPAR (peroxisome proliferators activated receptor) through a PPRE (peroxisome proliferator response element), we suggest th…
Synergistic cytotoxic interactions between sodium butyrate, MG132 and camptothecin in human retinoblastoma Y79 cells.
2000
This paper studies the effects caused in human retinoblastoma Y79 cells by treatment with combinations of sodium butyrate, the inhibitor of topoisomerase I camptothecin and the inhibitor of 26S proteasome MG132. The combination of sodium butyrate and camptothecin resulted in a strong synergistic cytotoxicity, as revealed by combination indices of 0.77 and 0.52 calculated at IC(50) and IC(75). Synergistic interactions were also demonstrated for combinations of sodium butyrate and MG132, camptothecin and MG132 and for a combination of all three compounds. The cytotoxic effects observed after the combined treatments can be considered a consequence of apoptosis, as suggested by the appearance o…
Cytotoxic effects of Jay Amin hydroxamic acid (JAHA), a ferrocene-based class I histone deacetylase inhibitor, on triple-negative MDA-MB231 breast ca…
2012
The histone deacetylase inhibitors (HDACis) are a class of chemically heterogeneous anticancer agents of which suberoylanilide hydroxamic acid (SAHA) is a prototypical member. SAHA derivatives may be obtained by three-dimensional manipulation of SAHA aryl cap, such as the incorporation of a ferrocene unit like that present in Jay Amin hydroxamic acid (JAHA) and homo-JAHA [ Spencer , et al. ( 2011 ) ACS Med. Chem. Lett. 2 , 358 - 362 ]. These metal-based SAHA analogues have been tested for their cytotoxic activity toward triple-negative MDA-MB231 breast cancer cells. The results obtained indicate that of the two compounds tested, only JAHA was prominently active on breast cancer cells with a…
The role of the Thomsen-Friedenreich antigen as a tumor-associated molecule.
1990
The Thomsen-Friedenreich antigen (Gal-GalNAc) represents a tumor-associated molecule, which is assumed to be one of the few chemically well-defined antigens with a proven association with malignancy. In order to analyze the role of the carbohydrate structure Gal-GalNAc for gastrointestinal tumors, we immunized Balb/c mice with MCF-7 breast tumor cells together with synthetic Gal-GalNAc linked to a BSA carrier. One monoclonal antibody (82-A6) was established which recognizes the Thomsen-Friedenreich antigen according to the biochemical and serological analysis presented here. In contrast to the studies performed in the past, immunohistochemical results using this antibody 82-A6 did not exhib…
Mechanisms of arachidonic acid induced glial swelling
2000
Accumulation of arachidonic acid (AA) in the brain during ischaemia may contribute to development of brain oedema. In this study we investigated the effect of selected drugs on AA-induced cytotoxic brain oedema in C6 glioma cells. Suspended C6 glioma cells were preincubated with drugs and AA (0.1 mM) was added. When no drug was administered cell volume increased immediately after the addition of AA with a maximum cell swelling of 13.1+/-1.9% at 15 min (mean +/- S.E. M.). Preincubation of cells with BW 755C, a dual inhibitor of cyclo- and lipoxygenases, showed no reduction in cell swelling from AA, whereas superoxide dismutase, amiloride and the protein kinase inhibitor H-9370 led to a signi…
Preparation of a dansylated fibrate, a new fluorescent tool to study peroxisome proliferation. Effect on hepatic-derived cell lines.
1997
The synthesis of a dansylated fibrate (DNS-X) has been performed in order to identify the cellular affinity sites of peroxisome proliferators and to establish the subcellular localization of such molecules. DNS-X has been obtained by coupling the dansy1 chloride with the amine resulting from the bezafibrate alkaline hydrolysis. The purified DNS-X has been further characterized by spectrum analysis (UV-Vis, fluorescence, [1H]/[13C]-NMR and mass). At 250 microM and incubated for 48 h with the rat hepatic derived cells (Fao cells), DNS-X stimulates 12-fold the palmitoyl-CoA oxidase, a peroxisome proliferation marker enzyme. This increase is comparable to the one obtained with well known peroxi…
Domains of the E1 Protein of Human Papillomavirus Type 33 Involved in Binding to the E2 Protein
1996
Papillomavirus E1 and E2 proteins are essential for the initiation of viral DNA replication. We have now analyzed the interaction of E1 and E2 of human papillomavirus type 33, which is associated with cervical carcinoma. When synthesized in insect cells using the baculovirus expression system, the E1 and E2 proteins interacted efficiently at 4 degree. A monoclonal antibody recognizing E1 amino acids 584--600 inhibited the binding of E2 and vice versa, indicating that these amino acids are involved in E2 binding. To confirm this result, a mutational analysis of E1 was performed. The E2 binding activity of E1 deletion and point mutant proteins was assayed using glutathione S-transferase E1 fu…
Design, synthesis, DNA-binding and cytotoxicity evaluation of new potential combilexines
2002
Combilexines, compounds in which a DNA intercalator is linked to a minor groove binding component, interact with the DNA in a sequence specific manner to yield in most cases compounds with anticancer activity. A series of new compounds closely related to netropsin in which the two components were linked by an amide group was synthesised as potential combilexines. As some of these compounds showed cytotoxic activity in vitro, an attempt was made to rationalise their mechanism of action. The DNA binding characteristics of the carboxamides were evaluated by thermal denaturation experiments and by ethidium bromide displacement assay. Their ability to inhibit the topoisomerase I was also determi…
Clearance and metabolism of arachidonic acid by C6 glioma cells and astrocytes.
1995
Effects of increased levels of arachidonic acid (AA) were analyzed in vitro by employment of C6 glioma cells and astrocytes from primary culture. The cells were suspended in a physiological medium added with arachidonic acid (AA) in a concentration range from 0.01 to 0.5 mM. The concentration profiles of the fatty acid and AA-metabolites were subsequently followed for 90 min. AA was measured by gas chromatography, whereas the AA-metabolites PGF2 alpha and LTB4 by radioimmunoassay (RIA). Following administration of AA at 0.05 or 0.1 mM the medium was completely cleared from the fatty acid within 10 to 15 min. However, when 0.5 mM were added, AA concentrations of 0.36 +/- 0.055 mM were found …