title: [Apoptosis-inducing effect of clostridium difficile toxin A on K562 cells and its mechanism].
abstract: This study was purposed to investigate the growth inhibition and apoptosis-inducing effect of Clostridium difficile toxin A (TcdA) on the leukemia cell line K562. The proliferative activity of K562 cells exposed to Tcd A was tested by MTT assay, cell apoptosis was detected by flow cytometry; immunocytochemistry and colorimetric assay were employed to detect the protein expressions of BCL-2/BAX and the activity of Caspase-3, respectively. The results indicated that the proliferation of K562 cells was inhibited in a time-and dose-dependent manner after exposure to Tcd A for 24, 48 and 72 hours, the cells displayed the typical apoptotic, morphological changes, the expression of BCL-2 protein was down-regulated but the expression of BAX protein was signficantly increased, compared with control group (p < 0.05). In addition, caspase-3 was activated in a concentration-dependent manner. It is concluded that Tcd A inhibits cell growth of K562 by inducing apoptosis, and the up-regulation of BAX protein and activation of caspase-3 may play important roles in these processes.
authors: Institute of Hematology, Department of Hematology, Lanzhou University First Clinical Hospital, Lanzhou 730000, Gansu Province, China.
authors: Pei
authors: P
authors: Li
authors: Che
authors: C
authors: Chen
authors: Ya-Ming
authors: YM
authors: Xi
authors: Hao
authors: H
authors: Zhang
authors: Ming
authors: M
authors: Li
authors: Wei
authors: W
authors: Deng
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D001427:Bacterial Toxins / Q000494:pharmacology*; D053148:Caspase 3 / Q000378:metabolism; D004768:Enterotoxins / Q000494:pharmacology*; D015973:Gene Expression Regulation, Leukemic; D006801:Humans; D020014:K562 Cells / Q000187:drug effects; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: C494826:BAX protein, human; D001427:Bacterial Toxins; D004768:Enterotoxins; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; C041348:tcdA protein, Clostridium difficile; C505407:CASP3 protein, human; D053148:Caspase 3