title: [Preliminary study of apoptosis of human hepatocarcinoma cell line HepG2 induced by topotecan].
abstract: OBJECTIVE
  Topotecan, a semisynthetic water-soluble derivative of camptothecin, is a potent inhibitor of DNA topoisomerase I and cell cycle specific antitumor agent; The incidence rate of hepatocarcinoma ranks the third in all types of malignant tumor in China. The clinical curative effect of the present treatments and drugs for hepatocarcinoma are not so satisfactory. The inducing effect of topotecan on apoptosis of hepatocarcinoma cell line HepG2 and its cytotoxicity on HepG2 were studied in this paper.
  
  
  METHODS
  Microculture tetrazolium assay (MTT), HE staining, transmission electron microscope (TEM), flow cytometer (FCM) and immunohistochemistry were employed to determine and observe the apoptosis of HepG2 induced by topotecan and its lethal action on HepG2.
  
  
  RESULTS
  Topotecan killed HepG2 cell by inducing apoptosis. Topotecan had strong anti-HepG2 activity in vitro, suggesting distinct dose- and time-dependent relationship. The drug IC50 was about 95 micrograms/L. Topotecan block HepG2 in S-phase, then further initiate apoptosis program. The morphologic characteristic of apoptosis showed that it is a typical interphase apoptosis process: the nuclei showed chromatin pycnosis, and clustered on the inner border of karyotheca, cytoplasm condensed, many vacuoles occurred in it. The expression of bcl-2 were not affected in the course of HepG2 apoptosis induced by topotecon (P > 0.05).
  
  
  CONCLUSIONS
  Topotecan had significant cytotoxicity on HepG2 by inducing apoptosis.
authors.affiliation: Department of Biology, Institute of Basic Medical Sciences, Chongqing University of Medical Sciences, Chongqing 400016, P. R. China. zhangjun1017@hotmail.com
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.forename: Shu-ping
authors.initials: SP
authors.lastname: Pu
authors.forename: Yu-jian
authors.initials: YJ
authors.lastname: Zhou
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis; D006528:Carcinoma, Hepatocellular / Q000473:pathology; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008113:Liver Neoplasms / Q000473:pathology; D019772:Topotecan / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D019772:Topotecan