title: Dexamethasone decreases hepatocellular carcinoma cell sensitivity to cisplatin-induced apoptosis.
abstract: OBJECTIVE
  Despite the fact that dexamethasone (DEX), a synthesized glucocorticoid (GCs), in vitro has pro-apoptotic effects on lymphoid cells, it has been suggested to induce apoptosis resistance toward chemotherapy in lung, cervical and breast cancer cell lines. However, the mechanisms by which GCs inhibit apoptosis in some cells have not been elucidated. The aim of this study is to investigate the effect of DEX on cisplatin (CIS)-induced hepatocellular carcinoma cell proliferation, apoptosis and to determine apoptosis-related gene expression on mRNA and protein levels.
  
  
  METHODS
  MTT assay, annexin V-FITC as well as Hoechst33258 staining were performed to detect hepatocellular carcinoma cell proliferation and apoptosis, respectively. RT-PCR and western blot were used to determine Bcl-2 and Bcl-xL expression.
  
  
  RESULTS
  DEX alone did not cause any obvious change to HepG2 and SNU449 cell proliferation. When pretreated with DEX followed by CIS treatment, cells showed resistance to CIS-induced cytotoxicity by MTT assay and apoptosis detected by Annexin V-FITC kit double staining. Hoechst33258 staining showed that CIS caused cell nuclear condensation, a sign of apoptosis and DEX pretreatment reduced the proportion of apoptotic cells. Anti-apoptotic genes Bcl-2 and Bcl-xL expression levels decreased after CIS treatment, but increased again after DEX addition.
  
  
  CONCLUSIONS
  DEX can decrease hepatocellular carcinoma cell sensitivity to CIS-induced cell death by preventing cell apoptosis.
authors.affiliation: Department of Biliary Surgery, Second Military Medical University, Shanghai, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Yang
authors.forename: Haibin
authors.initials: H
authors.lastname: Zhang
authors.forename: Hui
authors.initials: H
authors.lastname: Si-Ma
authors.forename: Yong
authors.initials: Y
authors.lastname: Fu
authors.forename: Wenchao
authors.initials: W
authors.lastname: Zhao
authors.forename: Dongyu
authors.initials: D
authors.lastname: Li
authors.forename: Guangshun
authors.initials: G
authors.lastname: Yang
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D018931:Antineoplastic Agents, Hormonal / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy* / Q000235:genetics; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002945:Cisplatin / Q000494:pharmacology*; D003907:Dexamethasone / Q000494:pharmacology*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000235:genetics; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics; D013194:Staining and Labeling; D014407:Tumor Cells, Cultured; D051020:bcl-X Protein / Q000235:genetics
chemical_list: D000970:Antineoplastic Agents; D018931:Antineoplastic Agents, Hormonal; D019253:Proto-Oncogene Proteins c-bcl-2; D051020:bcl-X Protein; D003907:Dexamethasone; D002945:Cisplatin