International Journal of Hematology and Oncology 2018, Vol 28, Num 1 Page(s): 061-068
Human Telomerase Reverse Transcriptase (hTERT) Expression and Telomerase Activity in Acute and Chronic Lymphocytic Leukemia Patients

Dalia G. AMIN1, Shahira K. ANIS1, Sarah YOUNAN1, Rasha adel Al GAMAL1

Cairo University, Faculty of Medicine, Department of Clinical and Chemical Pathology, Cairo, EGYPT

Keywords: Telomerase activity, hTERT expression, B-ALL/CLL, qRT-PCR; TRAP
Telomerase activity is crucial for pathogenesis and progression of some hematological malignancies. Telomerase is composed of human telomerase reverse transcriptase (hTERT) and RNA component (hTR). Our aim was to determine hTERT expression and Telomerase activity in acute and chronic lymphocytic leukemia patients (ALL, CLL) and to study their correlation with clinical, hematological and available prognostic parameters. This case control study was conducted on 43 patients (24 B-ALL, 19 B-CLL), and 24 age and sex matched controls. Real-time quantitative polymerase chain reaction and PCR-based telomeric repeats amplification protocol were used for determination of hTERT expression and Telomerase activity, respectively. hTERT was expressed in 20/24 (83.3 %) ALL patients, 12/19 (63.15%) CLL patients with no significant difference in the incidence or the median expression of hTERT among both groups. ALL had a significantly higher telomerase activity compared to both CLL and controls, while the latter 2 groups showed no significant difference. Telomerase activity wasn’t correlated with hTERT expression. hTERT expression was positively correlated with BM blast % in ALL patients and with the % of CD38 (p = 0.001) and ZAP 70 % (p = 0.001) in CLL patients. Telomerase activity was correlated positively with the absolute lymphocytic counts in CLL (p = 0.021) and negatively with the patient’s age of both groups (p=0.003). Developing new targeted therapy directed against telomerase and/or hTERT could ultimately be of special benefit in patients with high telomerase activity and/or hTERT expression among ALL and CLL patients.