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Activation of the Wnt signaling pathway has been implicated recently in the pathogenesis of leukemia. We studied the function of epigenetic regulation of the Wnt pathway and its prognostic relevance in acute myelogenous leukemia (AML). We used a methylation-specific polymerase chain reaction approach to analyze the promoter methylation status of a panel of Wnt antagonists including sFRP1, sFRP2, sFRP4, sFRP5, DKK1 and DKK3. Aberrant methylation of Wnt antagonists was detected in four AML cell lines and in up to 64% of AML marrow samples. Treatment of the cell lines with 5-aza-2′-deoxycytidine induced reexpression of methylated Wnt antagonists and inactivation of the Wnt pathway by downregulating the Wnt pathway genes cyclin D1, TCF1 and LEF1 and reducing nuclear localization of β-catenin. In a subgroup of patients 60 years and younger with newly diagnosed AML and intermediate-risk cytogenetics, abnormal methylation of Wnt antagonists was associated with decreased 4-year relapse-free survival (28 vs 61%, respectively, P=0.03). Our results indicate a function of the epigenetic regulation of the Wnt pathway in predicting relapse in a subgroup of AML patients. [ABSTRACT FROM AUTHOR]

Therapy-related myelodysplasia and acute myeloid leukemia (t-MDS/AML) is a malignancy occurring after exposure to chemotherapy and/or radiotherapy. Polymorphisms involved in chemotherapy/radiotherapy response genes could be related to an increased risk of developing this neoplasia. We have studied 11 polymorphisms in genes of drug detoxification pathways (NQO1, glutathione S-transferase pi) and DNA repair xeroderma pigmentosum, complementation group (3) (XPC(3), X-ray repair cross complementing protein (1)), Nijmegen breakage syndrome (1), excision repair cross-complementing rodent repair deficiency, complementation group (5) and X-ray repair cross complementing protein (3) and in the methylene tetrahydrofolate reductase gene (MTHFR(2), 677C>T, 1298A>C), involved in DNA synthesis. The analyzed groups were a t-MDS/AML patients group (n=81) and a matched control group (n=64) treated similarly, and they did not develop t-MDS/AML. We found no significant differences when the groups were compared globally. However, when analysis was carried out according to the primary neoplasia involved, a significant association was observed between the MTHFR haplotype (single nucleotide polymorphisms 677 and 1298) and the risk of developing t-MDS/AML in the breast cancer patients group (P=0.016) and cyclophosphamide-treated hematological disease group (P=0.005). Risk haplotype was different for each case, corresponding to the 677T1298A haplotype after breast cancer treatment and the 677C1298C haplotype after hematological malignancy treatment. We postulate that such differences are related to variations in chemotherapy schemes between hematological and breast cancers and their differential interaction with the MTHFR route.Leukemia (2007) 21, 1413–1422; doi:10.1038/sj.leu.2404709; published online 3 May 2007 [ABSTRACT FROM AUTHOR]

To determine prognosis of acute promyelocytic leukemia (APL) failing to front-line therapy with all-trans retinoic acid (ATRA) and anthracyclines, outcome of 52 patients (32 M/20 F; age: 37, 3–72) included in PETHEMA trials LPA96 and LPA99 who presented with either molecular failure (MOLrel, n=16) or hematological relapse (HEMrel, n=36) was analyzed. Salvage therapy consisted of ATRA and high-dose ara-C-based chemotherapy (HDAC) in most cases (83%), followed by stem-cell transplantation (autologous, 18; allogeneic, 10; syngeneic, 1). Fourteen patients with MOLrel (88%) achieved second molecular complete response (molCR), whereas 81% HEMrel patients responded to second-line treatment, with 58% molCR. After median follow-up of 45 months, four MOLrel and 18 HEMrel patients, respectively, experienced a second relapse. Outcome after MOLrel compared favorably to HEMrel, with longer survival (5-year survival: 64±14 vs 24±8%, P=0.01) and lower relapse risk (5-year relapse risk: 30±13 vs 64±9%; P=0.044). Additionally, age40 and male gender were favorable variables for survival, whereas molecular response predicted longer leukemia-free survival. In conclusion, early institution of salvage therapy at molecular failure, before onset of hematological relapse, is beneficial in APL. Moreover, given the poor outcome of HEMrel managed with ATRA and HDAC, use of alternative therapeutic strategies in this setting is warranted.Leukemia (2007) 21, 446–452. doi:10.1038/sj.leu.2404501; published online 4 January 2007 [ABSTRACT FROM AUTHOR]

The potential role of unrelated donor cord blood transplantation (UD-CBT) in adults is not well established. We report the results of UD-CBT in nine adult patients with chronic myeloid leukemia (CML). The median age was 27 years (range, 19–41 years), and the median weight was 62 kg (range, 45–78 kg). At transplant, six patients were in chronic phase (five in first, and one in second), two in blast crisis, and one in accelerated phase. Eight had received intensive chemotherapy, and three had undergone autologous peripheral blood hematopoietic stem cell transplantation. Four had received interferon with no cytogenetic response, and only three underwent UD-CBT within 1 year of diagnosis. After serological typing for class I antigens, and high-resolution DNA typing for DRB1, the degree of HLA match between patients and cord blood (CB) units was 4/6 in six cases and 5/6 in three cases. The median number of nucleated cells infused was 1.7 × 107/kg (range, 1.2 to 4.9 × 107/kg), and was above 2 × 107/kg in only two cases. All patients received thiotepa, busulfan, cyclophosphamide and anti-thymocyte globulin as conditioning; cyclosporine and prednisone for graft-versus-host disease (GVHD) prophylaxis; and G-CSF from day +7 until engraftment. All seven evaluable cases engrafted. The median time to reach an absolute neutrophil count 0.5 × 109/l and 1 × 109/l was 22 days (range, 19–52 days) and 28 days (range, 23–64 days), respectively. In the four patients evaluable for platelet recovery time to levels of 20 × 109 platelets/l, 50 × 109 platelets/l, and 100 × 109 platelets/l, these ranged from 50 to 128 days, 60 to 139 days, and 105 to 167 days, respectively. Three patients developed acute GVHD above grade II, and three of the five patients at risk developed extensive chronic GVHD... [ABSTRACT FROM AUTHOR]

To standardize the results obtained in PML/RAR alpha RT-PCR detection by laboratories of hospitals involved in the Spanish Program for Treatment of Hematological Malignancies (PETHEMA) LPA-96, designed for the treatment of acute promyelocytic leukemia (APL), cDNA samples obtained by reverse transcription of RNA from bone marrow samples of patients with APL were sent to participating laboratories. During the first year of this external quality assessment trial nine samples were tested by a maximum of 12 laboratories. The control gene was satisfactorily amplified in 90% of the samples (62 of 69 samples), supporting the adequacy of the cDNA to be used as control sample. There was an 83% concordance between laboratories for PML/RAR alpha detection with similar results for the type of PML/RR alpha rearrangements. However, 17% disagreement still remained, attributable to low sensitivity or inadequacy of methods followed. The results stressed the need for implementation of an external quality assessment scheme to ensure the standardization of the results. [ABSTRACT FROM AUTHOR]

The contribution of residual malignant cells contaminating the autologous graft with the occurrence of post-transplant relapse in acute myeloid leukemia (AML) is still unclear. The presence of a specific molecular marker (the PML/RAR alpha rearrangement) in acute promyelocytic leukemia (APL) offers the opportunity to investigate better the pathogenesis of disease recurrence after transplant. We report an APL patient who received high-dose chemotherapy and peripheral blood stem cell (PBSC) autograft in second hematologic remission. Two leukaphereses that tested PML/RAR alpha positive by RT-PCR were obtained during the post-reinduction hematopoietic recovery, while the patient also tested PCR positive in the BM, and was reinfused after myeloablative chemotherapy (BUCY4), when the patient had spontaneously converted to PCR negative in the marrow. At present, he remains in continuous molecular and hematologic remission 22 months after PBSC transplantation. This is the second report of an APL patient who was transplanted in molecular remission with a PML/RAR alpha-positive PBSC autograft. As in the previous report, the prolonged clinical and molecular remission experienced post-transplant suggests that autologous PBSC infusion is still worthy of consideration for patients with APL in spite of the detection of PML/RAR alpha-positive cells in the PBSC collections. Possible underlying mechanisms and the potential role of molecular monitoring of the graft, as well as the host, before and after transplant, in patients with APL undergoing autologous HSCT are also discussed. [ABSTRACT FROM AUTHOR]

The contribution of residual malignant cells contaminating the autologous graft with the occurrence of post-transplant relapse in acute myeloid leukemia (AML) is still unclear. The presence of a specific molecular marker (the PML/RARα rearrangement) in acute promyelocytic leukemia (APL) offers the opportunity to investigate better the pathogenesis of disease recurrence after transplant. We report an APL patient who received high-dose chemotherapy and peripheral blood stem cell (PBSC) autograft in second hematologic remission. Two leukaphereses that tested PML/RARα positive by RT-PCR were obtained during the post-reinduction hematopoietic recovery, while the patient also tested PCR positive in the BM, and was reinfused after myeloablative chemotherapy (BUCY4), when the patient had spontaneously converted to PCR negative in the marrow. At present, he remains in continuous molecular and hematologic remission 22 months after PBSC transplantation. This is the second report of an APL patient who was transplanted in molecular remission with a PML/RARα-positive PBSC autograft. As in the previous report, the prolonged clinical and molecular remission experienced post-transplant suggests that autologous PBSC infusion is still worthy of consideration for patients with APL in spite of the detection of PML/RARα-positive cells in the PBSC collections. Possible underlying mechanisms and the potential role of molecular monitoring of the graft, as well as the host, before and after transplant, in patients with APL undergoing autologous HSCT are also discussed. [ABSTRACT FROM AUTHOR]