[Regulative function of extracelluar regulated protein kinases and telomerase in apoptosis of hepatocarcinomatous cell SMMC-7721].
OBJECTIVE
To study the changes of telomerase activity and protein expression of phosphorylated (activated) extracellular regulated protein kinases (ERK1 and ERK2) in the course of inhibiting hepatocarcinomatous cell proliferation and inducing cell apoptosis by three kinds of chemotherapy drugs: Harringtonine (HRT), Vincristine (VCR), and Etoposide (Vp16). To discuss the regulative function to hepatocarcinomatous cell apoptosis and interrelation of telomerase and ERK.


METHODS
Cytotoxicity assay, flow cytometry analysis, telomerase repeat amplification protocol assay (TRAP), bioluminescence analysis, and western blot were used in this experiment.


RESULTS
HRT, VCR, and Vp16 could inhibit cell proliferation (0.28% 0.08%, 0.25% 0.16%, 0.24% 0.11%), induce apoptosis (21.12%, 28.83%, 12.30%), inhibit telomerase activity, and down-regulate the protein expression of phosphorylated ERK.


CONCLUSIONS
It might be through ERK signal transduction pathways that chemotherapy drugs down-regulate telomerase activity and induce apoptosis.
Li
Deng Ju
DJ
Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
Zhang
Yao Zhen
YZ
Cao
Wen Jing
WJ
Huang
Wei
W
Liu
Wen Li
WL
D017209:Apoptosis; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy / Q000201:enzymology* / Q000473:pathology; D005047:Etoposide / Q000494:pharmacology; D006248:Harringtonines / Q000494:pharmacology; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy / Q000201:enzymology* / Q000473:pathology; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors / Q000502:physiology*; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000502:physiology*; D015398:Signal Transduction; D019098:Telomerase / Q000502:physiology*; D014407:Tumor Cells, Cultured; D014750:Vincristine / Q000494:pharmacology
D006248:Harringtonines; C062500:harringtonin; D014750:Vincristine; D005047:Etoposide; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D019098:Telomerase