[Effect of inhibition of polyamine biosynthesis on the growth and telomerase activity of human laryngeal carcinoma cells Hep-2].
OBJECTIVE
To observe the effect of difluoromethylornithine (DFMO), an inhibitor of polyamine biosynthesis, on the growth and telomerase activity of human laryngeal carcinoma cells Hep-2, and try to find a new clue to search for the mechanism of reversion of tumor malignant phenotype via polyamine biosynthesis inhibition.


METHODS
The growth characteristics of Hep-2 cells treated with DFMO were studied by morphological observation, cell growth curve and FCM analysis. Telomerase activity was detected by Telomerase Repeat Amplification Protocol (TRAP).


RESULTS
The inhibition of cell proliferation, a marked increase in G1 and a decrease in S phase populations in the cell cycle of 2.5 mmol/L or 5 mmol/L DFMO treated Hep-2 cells were demonstrated; The cell apoptosis was shown by cell morphology and apoptosis peak in FCM; The telomerase activity of the treated cells was suppressed, while these changes were prevented by provision of exogenous putrescine(Pu) along with DFMO.


CONCLUSIONS
Inhibition of polyamine biosynthesis could result in the proliferation inhibition and apoptosis induction of Hep-2 cells, which was associated with suppressed telomerase activity. It is suggested that inactivation of telomerase would be one of the important molecular events in reversion of tumor malignant phenotype via inhibition of polyamine biosynthesis.
Li
Y
Y
Department of Otorhinolaryology, China-Japan Friendship Hospital, Beijing 100029, China.
Fan
M
M
Cao
S
S
Zhang
X
X
D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D015317:Biogenic Polyamines / Q000096:biosynthesis*; D002455:Cell Division / Q000187:drug effects; D000518:Eflornithine / Q000494:pharmacology*; D006801:Humans; D007822:Laryngeal Neoplasms / Q000201:enzymology* / Q000473:pathology; D019098:Telomerase / Q000187:drug effects*; D014407:Tumor Cells, Cultured
D000970:Antineoplastic Agents; D015317:Biogenic Polyamines; D019098:Telomerase; D000518:Eflornithine