title: [Cytotoxic effect of Acanthamoeba trophozoite on HeLa cells].
abstract: OBJECTIVE
  To investigate the cytotoxic effect(CTE) on human cervix cancer HeLa cells induced by five strains of pathogenic free-living Acanthamoeba.
  
  
  METHODS
  The cytotoxic effect of five isolates of Acanthamoeba on HeLa cells was investigated by light microscopy and MTT method.
  
  
  RESULTS
  The photomicrographs of HeLa cells showed a sequence of cardinal morphological features of apoptosis when HeLa cells were exposed to Acanthamoeba in a time-dependent manner at a ratio of 1:1 for 12 h. MTT method showed more than 50% of tumor cells underwent cytolysis following exposure to A. lugdunensis trophozoites, and only 18% of cells treated with A. polyphaga underwent CTE. The CTE produced by A. lugdunensis and A. quina trophozoites was more rapid than the others, beginning as early as 6 h after coincubation and resulting in cytolysis by 72 h.
  
  
  CONCLUSIONS
  These five strains of Acanthamoeba exhibit cytotoxic effects of varying degrees on HeLa cells, inducing apoptosis.
authors.affiliation: Department of Biology, East China Normal University, Shanghai 200062.
authors.forename: M
authors.initials: M
authors.lastname: Qian
authors.forename: X H
authors.initials: XH
authors.lastname: Zhang
authors.forename: B
authors.initials: B
authors.lastname: Mei
authors.forename: P
authors.initials: P
authors.lastname: Zhang
authors.forename: Z
authors.initials: Z
authors.lastname: Yan
authors.forename: M
authors.initials: M
authors.lastname: Yu
mesh_terms: D000048:Acanthamoeba / Q000472:pathogenicity*; D000818:Animals; D017209:Apoptosis; D006367:HeLa Cells / Q000469:parasitology; D006801:Humans