Journal of

Background and Aim: Acute promyelocytic leukemia (APL) is associated with the t(1517) ,fusing promyelocytic leukemia (PML) and retinoic acid receptor-a (RARa) genes. This disease is uniquely sensitive to treatment with all-trans retinoic acid (ATRA) and highly responsive to conventional chemotherapy. The t(1117)(q23q21) abnormality associated with a PLZF-RARa rearrangement is the commonest of the alternative translocations accounting for less than 1% APL. Blasts from PLZF-RARa cases have been found to be resistant to the differentiating effects of retinoids. In this study we aimed to determine the PLZF-RARa and fusion genes in patients with APL morphology who referred to Hematology-Oncology and BMT research center, Tehran Shariaty Hospital in 2006.

Materials & Methods: Peripheral blood and/or bone marrow samples were taken from 200 patients with APL morphology and 200 patients with other subtypes of AML. The mono-nuclear cells were enriched by centrifugation over a ficoll-isopaque gradient. RNA extracted by Trizol or TriReagent and then reverse transcribed to cDNA using random primers. PCR performed using specific primers for each fusion. PCR products electerophoresed on a 2% agarose gel containing 0.05% ethidiume bromide.

Results: In 2 (1%) patients with APL-morphology the RT-PCR analysis showed PLZF-RARa fusion transcripts.

Conclusion: It can be concluded that RT-PCR is a rapid and sensitive method for detection of abnormal fusion genes in leukemia and allows the definition of a correct strategy for treatment and subsequent minimal residual disease monitoring

Background and Aim: Chronic Myelogenous Leukemia (CML) is a clonal hematopoietic stem cell disorder characterized by a translocation between chromosome 9 and 22 called Philadelphia Chromosome. Telomerase- essential enzyme that adds telomeric repeats into the telomeres- maintains integrity of  chromosomal ends. Most normal somatic cells do not express hTERT (catalytic subunit of telomerase) but most neoplasia and cancer cells express it. In this study we evaluated the hTERT expression in patients with CML at different phases of the disease.

Materials and Methods: In this cross sectional study, 73 samples of 45 patients with CML were studied. Twenty six of samples were taken from patients in chronic phase before therapy and 26 samples three month after therapy. Nine samples were taken in accelerated phase and 12 in blastic phase. hTERT expression was studied by RT-PCR and the results were analyzed using SPSS 15.

Results: Thirty three (73%) of patients were male and 12 (23%) were female. Patients were divided into three age groups 17-29, 30-40 and 41-75 years. Of 73 samples, 43 samples (58.9%) were positive for hTERT and 30 samples (41.1%) were negative for this gene. In chronic phase (before therapy) 69.2% of the samples were PCR positive, but after therapy only 38.5% of samples were PCR positive. In accelerated and blastic phases, 55.6% and 83.3% of samples were PCR positive respectively. The hTERT positivity was differently significant (p<0.05) among different phases of the disease.

Conclusion: Significant difference between hTERT expression in different phases of CML disease can be used as a useful molecular marker for fallowing up, prognosis and disease progression after treatment

Background & Aim : Chronic myeloid leukemia (CML) is a disorder of pluripotential hematopoietic stem cell that is as a myeloproliferative disease and occurs in about 15 percent of all leukemia. Two cell cycle regulatory proteins that function as tumor suppressor are P16INK4A and P14ARF. The origin of these two proteins is a human INK4A-ARF gene locus that located on chromosome 9p21. P16INK4A control retinoblastoma (Rb) and P14ARF control with p53 thought negative feedback. The purposes of this study, this was that whether these genes are preferable use as a factor in prognosis and progression of disease.

Materials and Methods: This research was a Cross sectional study.  The expression of p16INK4A and p14ARF mRNA in about 73 peripheral bloods (PB) Samples were collected from 45 CML patients at different phases of disease were assayed by reverse transcriptase polymerase chain reaction (RT-PCR). 26 samples were from patients at chronic phase before any treatment, 26 samples 3 month after treatment with imatinib, 9 samples in accelerated phase and 12 samples in Blastic phase.

Results. From 45 patients with CML, 33 patients (73%) were men and 12 patients (27%) were women. About 26 samples (35%) were p16INK4A positive and 55 samples (75%) were p14ARF RT-PCR positive. This expression of the two genes at different phases of disease were not statistically significant (p>0.05).

Conclusion: High percentage of the CML patients expressed P14ARF and P16INK4A genes. The expression of these gene at different phases of disease (diagnosis, accelerate, and Blastic phases) was not statistically significant even though, the expression of these genes was higher after the treatment.  The increased expression of these genes was probably because of the Imatinib treatment.