Zeynep Sercan

sFRP1 promoter methylation is associated with persistent Philadelphia chromosome in chronic myeloid leukemia

Epigenetic silencing of sFRP genes has been shown to lead to constitutive activation of the canonical Wnt-signaling pathway. The first description of deregulated Wnt-signaling activation in a hematological malignancy was reported in chronic myeloid leukemia (CML). To investigate whether epigenetic silencing of sFRP is responsible for the observed Wnt activation in CML, we studied the methylation and mutational status of the sFRP1 promoter in 48 chronic phase CML patients. Of the 48 CML patients 41 were shown to be unmethylated, 6 patients hemi-methylated and 1 patient fully methylated at the sFRP1 promoter. Albeit observed infrequently in chronic phase CML, sFRP1 promoter methylation correlated with primary cytogenetic resistance to imatinib mesylate. sFRP1 promoter methylation may indicate a genetically more unstable form of disease resistant to therapy and provide a key biological difference in therapy resistant patients, in addition to a possible mechanism for the observed activation of canonical Wnt signaling in CML.

Consistent Loss of Heterozygosity at 14q32 in Lymphoid Blast Crisis of Chronic Myeloid Leukemia

Little is understood about the basic biological mechanisms that underlie the reasons for acute transformation in chronic myeloid leukemia (CML). Progression of disease may include inactivation of one or more tumor suppressor genes (TSGs). A widely used methodology for indirectly detecting somatic inactivation of TSGs is searching loss of heterozygosity (LOH) for polymorphic loci located in or near the gene(s) of interest. We aimed to analyze DNA of chronic phase and blastic phase archive material of 15 CML patients for LOH using D1S430, D2S123, D3S1611, D11S29, D14S65, D17S520, BAT 40 markers, the dinucleotide repeat located in the ABL gene and the trinucleotide repeat located in the BCR gene (amplification of the trinucleotide in the BCR gene could not be succeeded). LOH was identified by a %50 lost of one of the alleles intensity. LOH was detected with the ABL dinucletide repeat and D2S123 marker in two patients and with the D14S65 marker in three patients. The three patients exhibiting LOH at the D14S6S locus, all proceeded through lymphoid blast crisis. The D14S65 marker is located at the 14q32 locus which contains the immunglobulin heavy chain gene and the TCL1 oncogene. 14q32 abnormalities at the molecular level, may be predictive for lymphoid blast crisis, whether or not they are detectable cytogenetically

Beta-catenin mutations are not observed in chronic myeloid leukemia.

AIMS AND BACKGROUND Studies reporting activated Wnt signaling in all stages of chronic myeloid leukemia (CML) have demonstrated that deregulation of the pathway plays a role in the pathogenesis of this disease. Several reports have suggested mechanisms for the deregulated Wnt signaling and beta-catenin stabilization observed in CML. One possible mechanism for beta-catenin stabilization could be the acquisition of mutations at its N-terminal domain, especially in the third exon where it is marked via phosphorylation for degradation. We sought to determine whether mutations in the third exon of the beta-catenin gene are responsible for the observed Wnt activation in CML. MATERIAL AND METHODS We screened bone marrow specimens from 33 patients with CML in the chronic phase and also examined the K562 cell line for beta-catenin mutations. RESULTS None of the patients nor the K562 cell line were found to carry mutations. CONCLUSION Beta-catenin amino-terminal mutations are not observed or very rare and therefore are not the underlying mechanism of activated Wnt signaling in CML.

Rapid transformation of atypical myeloproliferative disorder with consistent t(8;13) to B-cell acute lymphoblastic leukemia: A case report

Abstract 8p11 myeloproliferative syndrome (EMS; also known as the stem cell leukemia syndrome-SCLL) is a rare atypical myeloproliferative disorder associated with chromosomal abnormalities involving the 8p11 chromosomal band. Translocations associated with this syndrome result in the fusion of the fibroblast growth factor receptor 1 (FGFR 1) gene with various partners, resulting in ligand independent FGFR activity. The most commonly observed translocation of this syndrome is t(8;13), which results in the expression of a chimeric ZNF198-FGFR1 tyrosine kinase. Disease phenotype associated with this translocation has some typical features such as poor prognosis, and transformation to mainly acute leukemia and non-Hodgkin lymphoma; commonly with a T-cell phenotype in which obtaining and maintenance of remission is difficult by conventional chemotherapy. We hereby present a case diagnosed as atypical chronic myeloproliferative disease with consistent t(8;13)(p12;q12) and transformed rapidly to pre-B-cell acute lymphoblastic leukemia which is a rare clinical presentation.

Isolated myelosarcoma development in an adolescent chronic myeloid leukemia patient with t(9;22)(q34;q11.2), +8, +14, +21, and der(1)(p36).

Additional chromosomal abnormalities are found in 5-20% of patients during chronic phase of chronic myeloid leukemia and in 60-80% preceding or accompanying blast crisis. These abnormalities are important in disease progression and, because they may occur before hematological and clinical symptoms, can be taken as a prognostic indicator. An adolescent with chronic myeloid leukemia initially presented with extreme thrombocytosis, increased megakaryopoiesis with dysmorphic features, and focal myelofibrosis in bone marrow examinations and then developed isolated myelosarcoma 1 year after onset, with t(9;22)(q34;q11.2), +8, +14, +21, and der(1)(p36).

New paraneoplastic syndrome in chronic basophilic leukemia

Chronic basophilic leukemia (CBL) is an extremely rare disorder. A female patient presented with recurrent attacks of chills, fever and abdominal pain was found to have simultaneous cyclic oscillation in leukocyte counts and C-reactive protein values. She was initially diagnosed with familial Mediterranean fever and treated with colchicine. Diagnosis of CBL was established by morphologic studies of peripheral blood and bone marrow. Her febrile attacks recurred with marked elevation in serum interleukin-6 (IL-6) level when basophil counts climbed to peak levels during cyclic oscillation. Molecular studies by real-time PCR showed IL-6 gene expression in neoplastic basophils separated by magnetic-activated cell sorting infiltrating the bone marrow, suggesting that IL-6 is released by neoplastic basophils of an underlying CBL, resulting in a new paraneoplastic syndrome that mimics autoinflammatory disorders.

An In-House Method for Molecular Monitoring of BCR-ABL.

Objective: At present, there are a limited number of facilities in Turkey that can provide reliable real-time quantitative(RQ)-PCR BCR-ABL results. The present study aimed to test a cost-effective, in-house method of BCR-ABL quantification,including verification of the method by RQ-PCR validation tests. Material and Methods: BCR-ABL and ABL target sequences were cloned into pJET1.2 vectors, from whichcalibrators were prepared and used as templates in RQ-PCR reactions to generate standard curves. Dilutions of K562cells (representing an in vitro simulation of BCR-ABL transcript reduction) were analyzed. Results: Standard curves were generated from calibrators. These curves were then used to calculate the BCR-ABL andABL copy numbers; in which linear BCR-ABL results were obtained. Repetitive experiments showed that our methodologywas able to detect 1 BCR-ABL positive cell from amnong 1x105 cells. Conclusion: The method described herein is suitable for implementation with any RQ-PCR instrument and/or kit forquantify BCR-ABL transcripts. Conflict of interest:None declared.

İmatinib Mesilat ile Tedavi Edilen Kronik Myeloid Lösemi Vakalarında Belirlenen Trizomi 8

Kronik myeloid losemi vakalarinda t(9;22)(q34;q11) translokasyonu sonucu Philadelphia (Ph) kromozomu olusmakta ve bu translokasyon bcr-abl gen fuzyonuna yol acmaktadir. Imatinib mesilat (STI571, Glivec) bcr-abl gen fuzyonu sonucu sentezlenen bcr-abl tirozin kinaz proteininin inhibitorudur. Ileri faz kronik myeloid losemi vakalarinda en sik gozlenen sekonder karyotipik anomaliler, ikinci Ph, trizomi 8, izokromozom 17q ve trizomi 19 dur. Cok sayida vakada Ph(-) ve Ph(+) hucrelerde klonal karyotipik anomaliler gelismektedir. Bu calismada imatinib mesilat ile tedavi edilmis biri Ph(-) trizomi 8, ucu de Ph(+) trizomi 8 olmak uzere dort vaka rapor edilmektedir