Antiproliferative effects of celecoxib in Hep-2 cells through telomerase inhibition and induction of apoptosis.

Background: To investigate the effect of celecoxib on telomerase activity and apoptosis in a human laryngeal squamous carcinoma cell line (Hep-2 cells).
Materials and Methods: The growth inhibition rate of Hep-2 cells in vitro was measured by MTT assay, and apoptosis by TUNEL assay and flow cytometry (FCM). The TRAP-ELISA method was used to determine telomerase activity in Hep-2 cells. The mRNA expression of human telomerase RNA component(hTR), human telomerase reverse transcriptase (hTERT) and human telomerase-associated protein(hTEP1) was determined by RT-PCR assay. Expression of Bax and Bcl-2 proteins was assessed by Western blotting.
Results: Celecoxib can inhibit proliferation and induce apoptosis in a dose- and time-dependent manner, repress telomerase activity, decrease hTERT mRNA and Bcl-2 protein expression and increase Bax protein expression, PGE2 had no effect on telomerase.
Conclusions: Celecoxib had the antiproliferative and pro-apoptotic effect in Hep-2 cells. Apoptosis was accompanied by a decrease in telomerase activity which was directly correlated with hTERT mRNA and up-regulation of Bax/Bcl-2. Bcl-2 may thus play an important role in telomerase activity as well as apoptosis.