title: [Effects of Clostridium difficile toxin a on proliferation of K562 cells].
abstract: This study was aimed to investigate the effect of clostridium difficile toxin A (Tcd A) on proliferation of K562 cells and its mechanism. The proliferative activity of K562 cells exposed to Tcd A was tested by MTT assay; cell cycle distribution and mitochondrial membrane potential were analyzed by flow cytometry; the protein expression of cytochrome C and DNA fragmentation were observed by immunohistochemistry staining and agarose gel electrophoresis respectively. The results indicated that Tcd A inhibited proliferation of K562 cells in a time-and concentration-dependent manner. Cells were arrested at G(0)/G(1) phase. Peak of apoptosis appeared. The protein expression of cytochrome C increased as compared with control group (p < 0.05). Agarose gel electrophoresis of DNA from K562 treated with Tcd A revealed a "ladder" pattern. It is concluded that clostridium difficile toxin A can inhibit proliferation and induce apoptosis of K562 cells. The mechanism may be in relation to decrease of mitochondrial membrane potential and the release of cytochrome C from mitochondria matrix.
authors.affiliation: Department of Hematology, Lanzhou University First Hospital, Lanzhou , Gansu Province, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.forename: Ya-Ming
authors.initials: YM
authors.lastname: Xi
authors.forename: Che
authors.initials: C
authors.lastname: Chen
authors.forename: Hui-Yuan
authors.initials: HY
authors.lastname: Chu
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
authors.forename: Pei
authors.initials: P
authors.lastname: Li
authors.forename: Wei
authors.initials: W
authors.lastname: Deng
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D001427:Bacterial Toxins / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects*; D004768:Enterotoxins / Q000494:pharmacology*; D006801:Humans; D020014:K562 Cells
chemical_list: D001427:Bacterial Toxins; D004768:Enterotoxins; C041348:tcdA protein, Clostridium difficile