Presence Of Philadelphia Chromosome Research Articles

Abstract 3687: Expression of a Src-family kinase in CML cells induces resistance to imatinib in a kinase-dependent manner

Abstract Chronic Myelogenous Leukemia (CML) is characterized by the presence of Philadelphia Chromosome, which results in the expression of the 210 kDa Bcr-Abl tyrosine kinase. Bcr-Abl constitutively activates signaling pathways important for the proliferation, survival and cytokine independence of myeloid progenitors, including the Src family kinases (SFKs). Imatinib, an inhibitor of Bcr-Abl tyrosine kinase activity, is the frontline therapy for CML. Although imatinib is remarkably effective in the chronic phase of the disease, patients with accelerated or blast crisis CML often develop resistance. Several recent studies performed on clinical specimens from imatinib-resistant patients with wild-type Bcr-Abl found that the Src family kinase members Hck and Lyn are overexpressed or highly active, suggesting that Src kinases may play a role in imatinib resistance. While the role of Lyn has been addressed in some detail, the contribution of Hck to this type of imatinib resistance is less well understood. To test whether Hck overexpression in CML cells induces resistance to imatinib in a kinase-dependent manner, we employed a Hck mutant (Hck-T338A) that is uniquely sensitive to the pyrazolo-pyrimidine inhibitor, NaPP1. In vitro, Hck-T338A was 48 times more sensitive to NaPP1 than the wild-type kinase. Importantly, this “gatekeeper” mutation was functionally silent and did not confer a loss or gain of function on Hck in a control fibroblast transformation assay. Expression of wild-type Hck or the T338A mutant in K562 CML cells resulted in resistance to imatinib-induced apoptosis and inhibition of soft-agar colony formation. Treatment with NaPP1 restored sensitivity to imatinib in a concentration-dependent manner only in cells expressing the Hck-T338A mutant. In contrast, cells expressing wild-type Hck were not affected by NaPP1, demonstrating the selectivity of NaPP1 for the Hck-T338A mutant. This result shows that Hck-induced imatinib resistance requires Hck kinase activity. In addition, NaPP1 also reduced Hck-mediated phosphorylation of Bcr-Abl at sites that may affect imatinib binding exclusively in cells expressing Hck-T338A. Together, these data establish a direct cause and effect relationship between Hck overexpression and imatinib resistance in CML cells. Furthermore, our results show that imatinib resistance requires Hck kinase function and may occur via direct Hck-induced trans-phosphorylation of Bcr-Abl. Selective drug targeting of Hck may be of therapeutic benefit in imatinib-resistant CML patients with increased Hck expression or activity. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3687.

Reduced-Intensity Conditioning followed by Peripheral Blood Stem Cell Transplantation for Adult Patients with High-Risk Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia (ALL) with high-risk features has a poor prognosis in adults despite aggressive chemotherapy. Reduced-intensity conditioning (RIC) is a lower toxicity alternative for high-risk patients requiring hematopoietic cell transplantation (HCT); however, it has not been widely used for ALL. We conducted a retrospective study of 24 high-risk adult ALL patients who received an RIC regimen of fludarabine (Flu)/melphalan (Mel) prior to allogeneic peripheral blood stem cell transplantation (PBSCT) between 6/14/02 and 6/15/07 at the City of Hope. Indications for the RIC regimen were: (1) aged 50 years or older (42%), (2) compromised organ function (54%), or (3) recipient of a previous HCT (37.5%). Patients had a median age of 47.5 years and the median follow-up was 28.5 months for living patients. Both overall survival (OS) and disease-free survival (DFS) at 2 years was 61.5%. Relapse incidence was 21.1% and nonrelapse mortality (NRM) was 21.5% at 2 years. Chronic graft-versus-host (cGVHD) developed in 86% of evaluable patients. In this series, no significant correlations were made between outcomes and patient age, presence of Philadelphia chromosome, relatedness of donor source, or prior HCT. These high survival rates for high-risk ALL patients following RIC HCT may offer a promising option for patients not eligible for a standard myeloablative transplant.

Prognostic significance of CD20 expression in adults with de novo precursor B-lineage acute lymphoblastic leukemia

AbstractImmunophenotypic classification of acute lymphoblastic leukemia (ALL) has well-recognized prognostic implications. The significance of CD20 expression has been evaluated in childhood precursor B-lineage ALL with conflicting results. We retrospectively analyzed the influence of CD20 expression on outcome in 253 adults with de novo precursor B-lineage ALL treated with either conventional (VAD/CVAD) or intensive (hyper-CVAD) frontline chemotherapy regimens in the pre-rituximab era. Overall, CD20 positivity of at least 20% was associated with lower 3-year rates of complete remission duration (CRD; 20% vs 55%, P < .001) and overall survival (OS; 27% vs 40%, p = .03). In the CD20 negative subset, the 3-year rates for CRD (58% vs 42%, p = .04) and OS (60% vs 28%, P < .001) were superior for hyper-CVAD compared with VAD/CVAD; rates were particularly favorable for the CD20 negative younger age group (68% and 85%, respectively). In contrast, 3-year CRD and OS rates were uniformly poor for the CD20-positive group regardless of therapy (27% or less). Multivariate analysis for event-free survival identified older age, leukocyte count higher than 30 × 109/L, presence of Philadelphia chromosome, high systemic risk classification, and CD20 positivity as independent predictors of worse outcome. In conclusion, CD20 expression in de novo adult precursor B-lineage ALL appears to be associated with a poor prognosis. Incorporation of monoclonal antibodies directed against CD20 into frontline chemotherapy regimens warrants investigation.

Chronic Myeloid Leukemia in Two Patients with Gastrointestinal Stromal Tumor.

Imatinib competitively binds to the ATP binding site of Bcr-Abl kinase and inhibits Abl tyrosine kinase activity. Most patients with chronic myeloid leukemia (CML) achieve clinically relevant hematologic and cytogenetic responses to imatinib. It is also a potent inhibitor of a receptor-type c-Kit tyrosine kinase. Therefore, it was examined for therapeutic efficacy against malignant Gastrointestinal Stromal Tumor (GIST), which is a rare tumor of the gastrointestinal tract and is mainly caused by aberrant expression of a mutated c-Kit that is constitutively active without binding of a ligand, stem cell factor. We report two rare cases of double cancer involving CML and GIST. The first case is a 66-year-old Japanese male patient who was presented to our hospital with leukothrombocytosis on February 27, 2006. The patient was diagnosed to be suffering from CML by the presence of Philadelphia chromosome. Several days later, he was admitted with acute peritonitis. A ruptured tumor on 80 cm oral side of ileum end was found by an emergency partial ilectomy. Microscopically, spindle-shaped and round epithelioid cells were growing externally from the intestinal muscular propia. Immunohistochemical analysis showed that the tumor cells were positive for c-kit and CD34 and negative for S-100 protein and desmin. The tumors were identified as GIST. Imatinib was administered to treat CML on the 8th postoperative day. The second case is a 57-year-old Japanese female patient who was presented to our hospital with marked thrombocytosis on March 6, 2006. The patient was diagnosed to be suffering from CML by the presence of Philadelphia chromosome. One year ago, she underwent distal gastrectomy for submucosal tumor. Pathological examination revealed proliferation of submucosal spindle-shaped cells with elongated cigar-shaped nuclei arranged in fascicles. Immunohistochemical stains confirmed the diagnosis of GIST.These two cases provided a valuable opportunity for treating GIST with CML. We look forward to active effect of imatinib, not only in CML treatment but also in preventing recurrence of GIST. The occurrence mechanism of either CML or GIST at the biomolecular level has been established. However, we can show no relation between these malignancies. Therefore, it is natural for us to understand accidental coincidence. We should follow-up these patients carefully. Accumulation of such cases may contribute to clarify more precise mechanism of tumorgenesis.

Pregnancy during Treatment with Imatinib: A Case Report.

Abstract CFSA, an 18-year-old woman with a history of weight loss and abdominal discomfort was diagnosed with chronic myelogenous leukemia (CML) in December 2002. The WBC were 440 x 109 /L with 25% neutrophils, 20% bands, 9% metamyelocytes, 9% myelocytes, 8% promyelocytes, 10% basophils, 9% eosinophils, 1% lymphocytes and 8% blasts. The hemoglobin was 9,8 g/dL and platelet count 416 x 109/ L. A bone marrow examination demonstrated granulocytic hyperplasia and the presence of Philadelphia chromosome in 100% of the metaphasis. A diagnosis of CML was made and she was started on hydroxyurea and imatinib 600mg daily. No matched HLA donor was found. There was a partial hematological response. In February 2005 on imatinib (600 mg) she was pregnant and an ultrasound scan showed a viable fetus of 17 weeks. The WBC were 22 x 109 /L with 50% neutrophils, 23% bands, 8% metamyelocytes, 12% myelocytes, 1% promyelocytes, 5% lymphocytes, hemoglobin 11,4 g/dl and platelet count 290 x 109. Imatinib was stopped and she remained off treatment during pregnancy. Cesarean section was performed at 38th week because of preeclampsia (hypertension, headache and scotomas). A healthy girl weighing 2980 g, 46,5 cm in length with Apgar score of 9 was delivered. The infant’s physical examination, WBC, hemoglobin, platelet count and cranial ultrasonography were normal. The baby is presently healthy with no developmental abnormalities. There are few reports on the use of 600 mg a day of imatinib and pregnancy. It is of notice, although probably unrelated, the event of preeclampsia. The effects of imatinib on fetus are unkown and should be considered teratogenic until more studies or cases are reported.

Ovarian Tissue Storing for Fertility Preservation in Clinical Practice: Successful Pregnancy, Technology, and Risk Assessment

Cryopreservation of ovarian tissue has been experimentally practiced during the last decade in an attempt to preserve fertility, mostly in cancer patients before administration of chemotherapy. In order to establish the procedure in clinical practice a successful transplantation of cryopreserved thawed tissue- as indicated by fertility restoration and a normal pregnancy- should be demonstrated. A simple transplantation technique that allows conventional infertility treatments or natural conception, and methods that maximize the safety of the procedure and prevent cancer cells transplantation are indicated. We report of 2 patients who requested transplantation of stored ovarian tissue in order to overcome ovarian failure post bone marrow transplantation. Ovarian tissue was harvested from 150 cancer patients by laparoscopic procedure before administration of high dose chemotherapy, in a tertiary medical center. Two young patients, suffering from ovarian failure post therapy requested transplantation of stored ovarian tissue in order to overcome infertility. One was treated for Chronic Myeloid Leukemia (CML) (age 25), and the 2nd suffered from Non Hodgkin Lymphoma (NHL) (age 30). Minimal disease detection:In both patients small frozen fragments (separately kept) were initially thawed for detection of possible malignant cells and assessing the quality of follicles post thawing. For the CML patient real time RT-PCR for bcr-abl m-RNA indicating the presence of Philadelphia chromosome was performed. There were no molecular markers for the NHL patient. Transplantation technique:By laparotomy, three pairs of 5mm transverse incisions were made through the tunica albuginea, and using blunt dissection, cavities were formed beneath the cortex, into which three thawed ovarian strips (0.5X1.5cm each) were gently placed and sutured with 4/0 Vicryl. PCR product was detected in the ovarian tissue of the CML patient, thus the tissue was not transplanted. Following transplantation to the NHL patient endocrine studies (gonadotrophins, ovarian steroids, inhibin B and AMH) indicated full recovery 8 months post transplantation. An IVF cycle was performed using controlled stimulation cycle followed by egg retrieval using conventional setting for follicle aspiration. A mature egg was aspirated fertilized and a four-cell embryo was transplanted (48h). A normal pregnancy, currently at third trimester is monitored 1. In order to increase the safety of ovarian tissue cryopreservation-transplantation procedure and reduce the risk of transferring malignant cells back to cured cancer patients it is mandatory to use the best methods to detect microscopic ovarian metastases. 2. This is the first report of oocyte retrieval, IVF and pregnancy in a sterilized patient following transplantation of cryopreserved-thawed ovarian tissue. The pregnancy and production of ovarian hormones provided strong evidence for the recovery of the transplant and confirmed the quality and fertility potential of cryopreserved thawed ovarian tissue. Fertility preservation with ovarian cortical tissue storing is effective in humans and the ovary is a good location for transplantation since conventional fertility procedures can be used.

A Case of Avascular Necrosis of the Femoral Head as Initial Presentation of Chronic Myelogenous Leukemia

Chronic myelogenous leukemia (CML) is a malignant clonal disorder of hemopoietic stem cells characterized by abnormal proliferation and accumulation of immature granulocyte. Leukostasis is one of the complications of CML and is characterized by partial or total occlusion of microcirculation by aggregation of leukemic cells and thrombi leading to respiratory, ophthalmic or neurologic symptoms. We experienced a rare case of avascular necrosis of the femoral head as the initial presentation of chronic myelogenous leukemia. A 24-year-old male patient was admitted to our hospital with pain in the right hip joint. The patient was diagnosed to be suffering from chronic myelogenous leukemia by packed marrow with granulocytic and megakaryocytic hyperplasia and the presence of Philadelphia chromosome. The right hip joint pain was attributed to avascular necrosis of the femoral head. And the avascular necrosis could be considered as the complication of chronic myelogenous leukemia due to microcirculatory obstruction of the femoral head. The avascular necrosis of the right femoral head was treated with bipolar hemiarthoplasty.

Actin polymerization in response to different chemoattractants is reduced in granulocytes from chronic myeloid leukemia patients.

Chronic myeloid leukemia (CML), a hematopoietic stem cell disorder, is characterized by the presence of Philadelphia chromosome (Ph1). Earlier studies have shown that various functions, such as chemotaxis, fluid phase pinocytosis, phagocytosis, and degranulation in response to chemotactic peptide formyl-methionyl-leucyl-phenylalanine (fMLP), were defective in polymorphonuclear leukocytes (PMNL) from CML patients. These functions depend on actin microfilaments (MF). Further studies showed that fMLP-induced actin polymerization was lower in CML PMNL. To see if this defect is specific to stimulation by fMLP alone or is a global phenomenon involving other chemoattractant receptors, chemotaxis and actin polymerization were studied in response to fMLP, an analog of fMLP, formyl-methionine-1 aminocyclooctane 1 carboxylic acid-phenyalanine-O-methionine (FACC8), platelet-activating factor (PAF), and leukotriene B4 (LTB4). These compounds bind to different chemoattractant receptors. Chemotaxis and actin polymerization in response to all four chemoattractants were significantly lower in CML PMNL compared with PMNL from normal subjects and were differentially affected for the different chemoattractants. These results suggest a global phenomenon involving all four chemoattractant-stimulated pathways. This lower amount of F-actin may be responsible for the defective chemotaxis seen in these cells.

Molecular Pathology of Chronic Myelogenous Leukemia

The presence of Philadelphia chromosome t(9:22) is a hallmark of 95% of clinical cases of chronic myelogenous leukemia (CML) as well as 20% of adult acute lymphoblastic leukemia (ALL) and 5% of acute myeloid leukemia (AML). The product of t(9;22) is a fusion protein BCR-ABL. The fusion proteins of CML, ALL and AML have increased tyrosine kinase activity and show a transforming potential in vitro and in animal models. The shorter p190 protein is associated almost only with ALL and AML, while the protein p210 is present in both chronic phase and blast crisis of CML and also in 50% of Philadelphia-positive (Ph1+) ALL. In CML the transition from chronic phase to blast crisis is usually accompanied by additional genetic events, e.g. additional chromosomal abnormalities, and oncogene activation(s). The detailed understanding of molecular basis of CML, and Ph1+ ALL and AML provides highly sensitive molecular and serological methods to complement classical cytogenetics. The advantages and limitations of these techniques are described and discussed below.

Terminal deoxynucleotidyl transferase activity and cell surface antigens of two unique cell lines (NALM-1 and BALM-2) of human leukemic origin.

Two unique cell lines, NALM-1 and BALM-2 derived from lymphoblast-like cells of chronic myelogenous leukemia and rare B cell acute lymphoblastic leukemia patients, respectively, were compared with fresh parent cells from the patients and with a Philadelphia chromosome positive K-562 cell line previously established from a chronic myelogenous leukemia patient in blastic phase. NALM-1 resembled the parent cells in the presence of Philadelphia chromosome, non-T/non-B acute lymphoblastic leukemia specific antigens and lack of T or B cell markers, whereas BALB-2, like the parent cells, had two chromosome markers and bore kappa, delta and mu immunoglobulins. NALM-1 lacked Epstein-Barr virus genome, whereas BALM-2 showed the presence of Epstein-Barr virus genome. K-562 cells lacked all the antigen markers examined. All cells had high DNA polymerase alpha activity and low DNA polymerase gamma activity. NALM-1, like the parent cells and unlike K-562 cells, had high terminal deoxynucleotidyl transferase activity of about 200 mu/mg DNA, whereas BALM-2, like its parent cells, had terminal deoxynucleotidyl transferase activity of 1-2 mu/mg DNA (1 u = 1 nmole Mn++-dGTP/h on dA12-18 initiator). Terminal deoxynucleotidyl transferase was characterized by its chromatographic and sedimentation behavior, thermal sensitivity and specific inhibition by streptolydigin and terminal deoxynucleotidyl transferase antisera. These results indicate that NALM-1 and K-562 may represent different phenotypes of cells in CML blastic crisis. Moreover, NALM-1 and BALM-2 seem to have retained the characteristics of original leukemic cells from which they may have been derived.

Chronic Myelogenous Leukemia with Elevated Leukocyte Alkaline Phosphatase, Positive Indirect Coombs’ Test, Neutrophilic Leukocytosis and Unusual Cytogenetical Findings

An unusual case of chronic myelogeous leukemia (CML) is reported which was characterized by leukocytosis without a shift to the left, elevated leukocyte alkaline phosphatase, positive indirect Coombs' test, anemia and thrombocytosis, as well as the absence of hepatosplenomegaly. The diagnosis of CML was ascertained by the presence of Philadelphia chromosome with translocation of its deleted arms on the short arms on the short arms of a chromosome No. 6. The possible relationship between the chromosomal aberration and the unusual hematological and clinical features of this case is discussed.

Hemolysis in Chronic Myelocytic Leukemia

The role of hemolysis in the anemia of chronic myelocytic leukemia (CML) remains controversial. The authors reviewed the records of 68 consecutive CML patients to evaluate occurrence and clinical significance of hemolysis. Thirty-one (46%) had increased fecal urobilinogen excretion, and this hemolysis group was compared with the remaining 37. There was no difference in age, presence of Philadelphia chromosome, thrombocytopenia, bleeding, occurrence of blast crisis, or chemotherapy in the two groups. There was no correlation between spleen size and hemolysis. Infections and administration of corticosteroids were more frequent in the hemolysis group. Hemolysis was a late complication and had an ominous prognosis, with a temporal association with blast crisis.

Continuous Cell Culture From a Patient With Chronic Myelogenous Leukemia. I. Propagation and Presence of Philadelphia Chromosome

Continuous Cell Culture From a Patient With Chronic Myelogenous Leukemia. I. Propagation and Presence of Philadelphia Chromosome