Different effects of interferon-α on melanoma cell lines: a study on telomerase reverse transcriptase, telomerase activity and apoptosis.

Autor: Maellaro, E., Pacenti, L., Del Bello, B., Valentini, M.A., Mangiavacchi, P., Felice, C.De, Rubegni, P., Luzi, P., Miracco, C.
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Zdroj: British Journal of Dermatology; Jun2003, Vol. 148 Issue 6, p1115, 10p
Abstrakt: Background Although the antiproliferative and proapoptotic effects of interferon (IFN)-α are widely recognized, its antitumour mechanisms are not completely known. Recent studies indicate that the derepressed expression of the catalytic subunit of telomerase, human telomerase reverse transcriptase (hTERT), and telomerase activity (TA) are involved in the process of human carcinogenesis. Only a few studies have investigated the effects of IFN-α on hTERT and TA, with controversial results. Objectives To study the hTERT mRNA expression, TA and apoptosis in human melanoma cells treated with IFN-α. Methods Five human melanoma cell lines (Me665 /2 /21, Me665 /2 /60, HT-144, SK-Mel-28 and SK-Mel-5) were cultured in standard conditions and treated with 20 000 IU mL[sup--1] of human recombinant IFN-a-2b. Apoptosis was evaluated as hypodiploid DNA content determined by flow cytometry, caspase-3 /7 activity by enzymatic assay, and poly(adenosine diphosphate-ribose) polymerase cleavage by Western blot analysis. IFN-α receptor (IFNA-R) and hTERT mRNA expression levels were evaluated by semiquantitative reverse transcription--polymerase chain reaction. TA was evaluated by a polymerase chain reaction-based telomerase repeat amplification protocol assay. Results Besides a variable degree of cell proliferation inhibition in all cell lines tested, we found different responses, ranging from no significant effects in SK-Mel-28 cells, to a high degree of apoptosis with no hTERT mRNA expression and TA modification in HT-144 cells, and induction of apoptosis, along with decrease in hTERT mRNA expression and TA in Me665 /2 /21 cells. No induction of apoptosis was observed in SK-Mel-5 and Me665 /2 /60 cells, although an early decrease in hTERT mRNA expression, and a minor increase of both hTERT mRNA expression and TA were found, respectively. Conclusions Our results suggest that the effects of IFN-α on hTERT and TA can result from... [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index