title: Increase of telomerase activity and hTERT expression in myelodysplastic syndromes.
abstract: Telomerase enzyme, containing a catalytic subunit, the human telomerase reverse transcriptase (hTERT), and a small integral RNA component, synthesises the telomeres, the ends of eukaryotic chromosomes. Inhibition of telomerase activity leads the cells to senescence and death. Myelodysplastic syndromes (MSD) are hematological malignancies characterized by peripheral blood cytopenia and ineffective hematopoiesis. Telomerase activity and hTERT expression in MDS patients were independently investigated by different groups obtaining contradictory results. We analyzed telomerase activity and hTERT expression in the bone marrow of ten control, 15 MDS patients and two patients with AML, likely evolved from a previous MDS. Moreover, the expression of c-myc, mad1, p53 (transcription factors involved in hTERT expression regulation), has been investigated. Telomerase activity and hTERT expression increased in the MDS patients with respect to the controls. The analysis of the MDS subgroups, indicated that patients with more severe disease demonstrated significantly higher levels of hTERT expression and telomerase activity with respect to the patients with more favorable disease. c-Myc and p53 expressions were not significantly different between controls and MDS patients, whereas mad1 expression was increased in MDS patiens, particularly in those with more favorable disease. We hypothesize that mad1 increase can contribute to reduce the hTERT expression in the early stage of disease and we suggest that hTERT expression and telomerase activity, whether confirmed in larger series of cases could support other parameters in the diagnosis and stadiation of MDS.
authors.affiliation: Dipartimento di Medicina e Oncologia Sperimentale, Sezione di Patologia Generale, Università di Torino, Torino, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Briatore
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Barrera
authors.forename: Stefania
authors.initials: S
authors.lastname: Pizzimenti
authors.forename: Cristina
authors.initials: C
authors.lastname: Toaldo
authors.forename: Chiara Della
authors.initials: CD
authors.lastname: Casa
authors.forename: Stefano
authors.initials: S
authors.lastname: Laurora
authors.forename: Piergiorgio
authors.initials: P
authors.lastname: Pettazzoni
authors.forename: Mario Umberto
authors.initials: MU
authors.lastname: Dianzani
authors.forename: Dario
authors.initials: D
authors.lastname: Ferrero
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D005260:Female; D015870:Gene Expression; D006801:Humans; D008297:Male; D008875:Middle Aged; D009190:Myelodysplastic Syndromes / Q000175:diagnosis / Q000235:genetics*; D011379:Prognosis; D012333:RNA, Messenger / Q000032:analysis; D012307:Risk Factors; D019098:Telomerase / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics
chemical_list: D012333:RNA, Messenger; D014157:Transcription Factors; C509186:TERT protein, human; D019098:Telomerase