In budding (Saccharomyces cerevisiae) and fission (Schizosaccharomyces pombe) yeast and other unicellular organisms, DNA damage and other stimuli can induce cell death resembling apoptosis in metazoans, including the activation of a recently discovered caspase-like molecule in budding yeast. Induction of apoptotic-like cell death in yeasts requires homologues of cell cycle checkpoint proteins t...

DNA strand breaks which occur in HL-60 cells as a result of activation of endonuclease during apoptosis induced by cell treatment with the DNA topoisomerase I inhibitor camptothecin and topoisomerase II inhibitors teniposide, 4'-(9-acridinylamino)-3-methanesulfon-/n-anisidide, and fostriecin were labeled in situ, in individual fixed and permeabilized cells, with biotinylated dUTP (detected by f...

DNA alkylating agent exposure results in the formation of a number of DNA adducts, with O6-methyl-deoxyguanosine (O6-medG) being the major mutagenic and cytotoxic DNA lesion. Critical to the prevention of colon cancer is the removal of O6-medG DNA adducts, either through repair, for example, by O6-alkylguanine-DNA alkyltransferase (ATase) or targeted apoptosis. We report how rat colonocytes res...

BACKGROUND Components of the DNA damage checkpoint are essential for surviving exposure to DNA damaging agents. Checkpoint activation leads to cell cycle arrest, DNA repair, and apoptosis in eukaryotes. Cell cycle regulation and DNA repair appear essential for unicellular systems to survive DNA damage. The relative importance of these responses and apoptosis for surviving DNA damage in multicel...

Nonhomologous end-joining (NHEJ) DNA factors maintain genomic stability through their DNA double-strand break (DSB) repair and telomere-associated activities. Unrepaired or misrepaired DSBs can lead to apoptotic death or chromosomal damage. The B cells of some B-chronic lymphocytic leukemia (B-CLL) patients are resistant to radiation-induced apoptosis in vitro. We show here that the novel DNA-d...

primula auriculata (tootia) is one of the most important local medicinal plants in hamedan district, iran. to investigate cytotoxicity and apoptosis induction of crude methanolic extract and different fraction of it we compared several methods on ht-29 human colon adenocarcinoma cells. cancer cell proliferation was measured by 3-(4, 5‑dimethylthiazolyl)-2, 5‑diphenyl‑tetrazolium bromide (mtt) a...

Helicobacter pylori (H. pylori) induced DNA damage which may be related to gastric cancer development. The DNA damage response coordinates DNA repair, cell-cycle transition, and apoptosis through activation of DNA damage response molecules. The damaged DNA is repaired through non-homologous end joining (NHEJ) or homologous recombination (HR). In the present study, we investigated the changes of...

All cells are unavoidably exposed to chemicals that can alkylate DNA to form genotoxic damage. Among the various DNA lesions formed, O(6)-alkylguanine lesions can be highly cytotoxic, and we recently demonstrated that O(6)-methylguanine (O(6)MeG) and O(6)-chloroethylguanine (O(6)CEG) specifically initiate apoptosis in hamster cells. Here we show, in both hamster and human cells, that the MutSal...

Taxol-induced polymerization of tubulin into stable microtubules and cell cycle metaphase arrest have been demonstrated to result in internucleosomal DNA fragmentation and morphological features of apoptosis in human leukemia cells. Recent studies have also shown that Taxol-induced apoptosis, but not Taxol-induced microtubular bundling or mitotic arrest, is significantly inhibited in cells that...

CD44 is a marker of cancer stem cells in head and neck squamous cell carcinoma, and CD44 expression is related to prognosis in cancer patients. We examined whether herbal medicine components affect CD44 expression and induce cancer cell apoptosis. Baicalin enhanced apoptosis with no effect on CD44 levels, while baicalein did not enhance apoptosis and upregulated CD44 in head and neck squamous c...