PI-103, a dual inhibitor of Class IA phosphatidylinositide 3-kinase and mTOR, has antileukemic activity in AML.

The phosphatidylinositol 3-kinase (PI3K)/Akt and mammalian target of rapamycin complex 1 (mTORC1) signaling pathways are frequently activated in acute myelogenous leukemia (AML). mTORC1 inhibition with RAD001 induces PI3K/Akt activation and both pathways are activated independently, providing a rationale for dual inhibition of both pathways. PI-103 is a new potent PI3K/Akt and mTOR inhibitor. In human leukemic cell lines and in primary blast cells from AML patients, PI-103 inhibited constitutive and growth factor-induced PI3K/Akt and mTORC1 activation. PI-103 was essentially cytostatic for cell lines and induced cell cycle arrest in the G1 phase. In blast cells, PI-103 inhibited leukemic proliferation, the clonogenicity of leukemic progenitors and induced mitochondrial apoptosis, especially in the compartment containing leukemic stem cells. In contrast, apoptosis was not induced with RAD001 and IC87114 association, which specifically inhibits mTORC1 and p110delta activity, respectively. PI-103 had additive proapoptotic effects with etoposide in blast cells and in immature leukemic cells. Interestingly, PI-103 did not induce apoptosis in normal CD34(+) cells and had moderate effects on their clonogenic and proliferative properties. Here, we demonstrate that multitargeted therapy against PI3K/Akt and mTOR with PI-103 may be of therapeutic value in AML.

TRAF4 overexpression is a common characteristic of human carcinomas.

Tumor necrosis factor receptor (TNFR) associated factor 4 (TRAF4) was initially identified as a gene amplified and overexpressed in breast carcinomas. Our aim was to evaluate whether TRAF4 protein overexpression exists in other cancer types. Immunohistochemistry analysis of tumor samples from 623 patients with 20 different tumor types showed that TRAF4 was overexpressed in 268 tumors (43%), including 82 of 137 lung adenocarcinomas (60%). Interestingly, 32 primary tumors and their matching metastases exhibited mostly similar TRAF4 expression pattern. TRAF4 protein overexpression was limited to cancer cells and the subcellular localization was consistently cytoplasmic in a large majority of cases. To investigate changes in TRAF4 gene copy number, 125 cases from six different types of carcinomas were also analysed by fluorescence in situ hybridization. Out of the 28 cases (22%) showing an increased TRAF4 gene copy number, 23 (82%) were overexpressing the protein. Thus, TRAF4 gene amplification is one of the mechanisms responsible for TRAF4 protein overexpression in human cancers. Considering that TRAF4 is located at 17q11.2 in a region of amplification devoid of known oncogenes and is commonly overexpressed in cancer, our data support an oncogenic role for TRAF4.

Common 4q24 deletion in four cases of hematopoietic malignancy: early stem cell involvement?

We determined bone marrow karyotype at diagnosis in four female acute myeloid leukemia (AML) or myelodysplasia patients, aged between 52 and 56 years. In each case, we observed chromosome rearrangement involving the same 4q24 band. Three patients had a balanced reciprocal translocation as the sole abnormality - t(3;4)(q26;q24), t(4;5)(q24;p16) and t(4;7)(q24;q21) - and the fourth had del(4)(q23q24), +4. We used a set of 4q BAC probes for fluorescent in situ hybridization (FISH) in these four cases. We found a 4q24 submicroscopic deletion in all three translocations, with a common deletion of approximately 0.5 Mb. In three cases, we concluded that rearrangement occurred in an early hematopoietic stem cell, as it was detected, in mosaic with a normal karyotype, in a fraction of remission bone marrow cells, peripheral T and B lymphocytes, malignant lymph node T-lymphoma cells in one case and B-lymphoblastoid cell lines established in two cases. Moreover, one of 10 additional AML patients tested by FISH had a normal karyotype and deletion of one of the commonly deleted probe sequences. A tumor suppressor gene may therefore be involved, especially as two patients developed malignant lymphoma at the same time as myeloid proliferation.

Report of 34 patients with clonal chromosomal abnormalities in Philadelphia-negative cells during imatinib treatment of Philadelphia-positive chronic myeloid leukemia.

Imatinib mesylate (Gleevec), an inhibitor of the BCR-ABL tyrosine kinase, was introduced recently into the therapy of chronic myeloid leukemia (CML). Several cases of emergence of clonal chromosomal abnormalities after therapy with imatinib have been reported, but their incidence, etiology and prognosis remain to be clarified. We report here a large series of 34 CML patients treated with imatinib who developed Philadelphia (Ph)-negative clones. Among 1001 patients with Ph-positive CML treated with imatinib, 34 (3.4%) developed clonal chromosomal abnormalities in Ph-negative cells. Three patients were treated with imatinib up-front. The most common cytogenetic abnormalities were trisomy 8 and monosomy 7 in twelve and seven patients, respectively. In 15 patients, fluorescent in situ hybridization with specific probes was performed in materials archived before the initiation of imatinib. The Ph-negative clone was related to previous therapy in three patients, and represented a minor pre-existing clone that expanded after the eradication of Ph-positive cells with imatinib in two others. However, in 11 patients, the new clonal chromosomal abnormalities were not detected and imatinib may have had a direct effect. No myelodysplasia was found in our cohort. With a median follow-up of 24 months, one patient showed CML acceleration and two relapsed.

Therapy-related acute myeloid leukaemia after successful therapy for acute promyelocytic leukaemia with t(15;17): a report of two cases and a review of the literature.

We describe two patients with positive t(15;17) acute promyelocytic leukaemia (APL) that developed into a therapy-related myelodysplasia 2-2.5 years after complete remission (CR) and then evolved into therapy-related acute myeloid leukaemia (t-AML). Both patients received anthracyclines as potential leukaemogenic drugs. In both cases, cytogenetic changes usually occurring after use of alkylating agents were noticed: monosomy 7 associated with monosomy 5 or 5q- chromosome. A review of the literature on t-AML occurring after successful therapy for APL showed only one report similar to these two cases. These observations suggest that anthracyclines can cause t-AML similar to that induced by alkylating agents.

Submicroscopic insertion of RARalpha gene into chromosome 15 in two cases of acute promyelocytic leukemia.

Acute promyelocytic leukemia (APL) is characterized by a specific translocation (15;17)(q22;q21), resulting in the formation of PML/RARalpha chimeric transcripts. We report two female patients with PML/RARalpha-positive classical APL, whose leukemic cells expressed a variant translocation, t(5;15)(q13;q22) and t(15;17)(q22;p13), respectively. Both translocations were confirmed by whole chromosome painting which revealed no apparent involvement of 17q. A two-color fluorescence in situ hybridization with a 5' PML and a 3' RARalpha probe showed, in both cases, the presence of a PML-RARalpha fusion gene, on the der(15)t(5;15) long arm, and on the der(17)t(15;17) short arm, respectively. These two complex rearrangements resulted most probably from a two-step mechanism: (1) a submicroscopic insertion into 15q of a 17q segment including the 3' part of the RARalpha gene; (2) a reciprocal translocation between der(15) and a variable chromosome arm, with a breakpoint distal and proximal to RARalpha insertion in the case of t(5;15) and t(15;17), respectively. Molecular and prognosis significance of these variant translocations are discussed.

Cytogenetic analysis from DNA by comparative genomic hybridization.

Comparative genomic hybridization (CGH) is a modified in situ hybridization technique which allows detection and mapping of DNA sequence copy differences between two genomes in a single experiment. In CGH analysis, two differentially labelled genomic DNA (study and reference) are co-hybridized to normal metaphase spreads. Chromosomal locations of copy number changes in the DNA segments of the study genome are revealed by a variable fluorescence intensity ratio along each target chromosome. Since its development, CGH has been applied mostly as a research tool in the field of cancer cytogenetics to identify genetic changes in many previously unknown regions. CGH may also have a role in clinical cytogenetics for detection and identification of unbalanced chromosomal abnormalities.

Aplastic anemia responsive to cyclosporine complicating the evolution of polycythemia vera.

We report here a very unusual patient with Polycythemia vera treated with Pipobroman who developed severe aplastic anemia following administration of the drug. Six months later, because of lack of response, cyclosporine therapy was given there was rapid and complete hematological recovery, highly suggestive of an immune-mediated mechanism, in this case.

Pentasomy 13q in a case of acute myelogenous leukemia (Mo).

A case of acute myelogenous leukemia Mo FAB subtype with a pentasomy 13q (associated with a trisomy 19 in a subclone) in the initial bone marrow metaphase cells is reported. The pentasomy 13q is the result of the presence of double isochromosome 13q and one normal chromosome 13. In our case, this abnormality had a poor prognosis.

Adult biphenotypic acute leukaemia: an entity with poor prognosis which is related to unfavourable cytogenetics and P-glycoprotein over-expression.

Biphenotypic acute leukaemia (BAL) patients represented 8% of the 287 de novo consecutive adult acute leukaemias (23 BAL, 230 acute myeloid leukaemia (AML) and 34 acute lymphoblastic leukaemia (ALL)) referred to our department during the last 4-year period. Of these 23 BAL patients, 14 patients showed myeloid morphology and nine cases lymphoid morphology according to FAB criteria. There were no differences between lymphoid and myeloid BAL according to clinical and biological presentation and treatment outcome. We confirm the poor prognosis of BAL when compared to AML or ALL seen during the same period of time, in terms of complete remission (47%, 62% and 82% respectively, BAL v AML, NS and BAL v ALL, P = 0.006) and 4-year overall survival (8.1%, 25.8% and 23.8% respectively, BAL v AML, P = 0.05 and BAL v ALL, P = 0.003). Comparing adult BAL patients with AML patients, we found an increase in poor prognostic factors: CD34+ phenotype (82% v 60% respectively, P = 0.03), unfavourable karyotype (60% v 20%, P < 0.0001) and Pgp over-expression by RT-PCR (0.705 v 0.107, P < 0.0001) and flow cytometry (0.824 v 0.391, P = 0.0001). MRP and LRP were not found to be poor prognostic factors. Comparing BAL patients with ALL patients, we found also an increase in poor prognostic factors: age (51 v 39, P = 0.003) and CD34+ phenotype (82% v 50%, P = 0.02). We conclude that BAL patients need a more aggressive treatment procedure, including high-dose AraC or the use of Pgp modulators for first-line therapy.

Different proximal and distal rearrangements of chromosome 7q associated with holoprosencephaly.

Four new cases of holoprosencephaly are described in fetuses exhibiting abnormal karyotypes with different distal and proximal rearrangements of the long arm of chromosome 7. Three of them showed terminal deletions of chromosome 7q, confirming the importance of the 7q36 region in holoprosencephaly. The karyotype of the fourth fetus showed an apparently balanced de novo translocation, t(7;13) (q21.2;q33), without any visible loss of the distal part of chromosome 7q. The involvement of new genes, different from the human Sonic Hedgehog gene (hShh) responsible for holoprosencephaly, or a positional effect are discussed.

Prognostic factors in elderly acute lymphoblastic leukaemia.

A retrospective study was performed on 46 unselected acute lymphoblastic leukaemia (ALL) elderly patients aged 60 years or more. Only 50% of these patients were included in the EORTC cooperative clinical trials, thus confirming the important selection bias in most of the published series on elderly ALL patients. 43% of the elderly patients achieved a complete remission (CR). The median survival was 10 months and the 5-year overall survival was only 7.6 +/- 4%. In multivariate analysis, W.H.O. performance status and peripheral blast counts at day 7 were found to significantly influence achievement of CR and survival. In patients with W.H.O. performance status > or = 2, 35% died during induction treatment versus 4% in patients with W.H.O. performance status < 2. Patients > 70 years old showed a marked drop of the CR rate (27%) compared to those aged 60-69 (67%), and a very high death rate during the induction period (38% versus 4%). This suggests that ALL protocol treatments should be proposed until 70 years in patients with good-performance status, whereas less intensive treatment should be offered to elderly patients with performance status > or = 2 and/or age > or = 70. Peripheral blast counts at day 7 may help to adjust the treatment during induction phase.

Multidrug resistance gene expression in acute myeloid leukemia: major prognosis significance for in vivo drug resistance to induction treatment.

The clinical significance of the multidrug resistance (MDR 1) gene phenotype was investigated in newly diagnosed AML and was compared with other clinical and biological prognostic factors in patients who received at least one course of induction therapy with intercalating agents and conventional doses of Ara-C. MDR 1 gene was overexpressed in 40% of the 110 cases of AML at presentation, MRP in 15% of the 48 patients tested for both markers. Both gene expressions were closely linked (p = 0.008). Except for a lower frequency in the "good risk" cytogenetic group, MDR 1 overexpression was not associated with other prognostic factors. In univariate analysis, MDR 1 overexpression, age over 50 years, and cytogenetic were associated with a higher rate of resistance to induction treatment. The overall survival was shorter in the case of intermediate or poor cytogenetics, high leukocytosis, MDR 1 overexpression, age over 50 years, secondary AML, and poor cytologic differentiation. Using multivariate analysis on 64 patients receiving intensive treatment, MDR 1 overexpression was the first significant prognostic factor for resistance to the first course of induction treatment. Cytogenetic analysis maintained its prognostic value only in MDR 1-negative patients. These data underline the value of MDR 1 gene expression as a powerful prognostic factor in AML for response to the first induction treatment and overall survival, sustaining the use of MDR 1 modulators for first-line therapy in this disease.

Expression of the transcription factor Evi-1 in human erythroleukemia cell lines and in leukemias.

The Evi-1 proto-oncogene is a zinc finger DNA binding protein. Although activation of the Evi-1 gene has been associated with chromosomal rearrangements of the 3q25-q28 region, ectopic expression of Evi-1 could also be observed in acute myelogenous leukemias and myelodysplastic syndromes without cytogenetic abnormalities of the 3q26 locus. In this study, human erythroleukemic cell lines were screened for the expression of Evi-1 mRNA by northern blotting. Evi-1 was expressed in all the erythroid cell lines, whether undifferentiated (K 562, HEL, LAMA 84) or exhibiting spontaneous terminal erythroid differentiation (KU 812, JK-1). Evi-1 mRNA levels were constant or elevated in hemoglobin-synthesizing KU 812 or K 562 cells in response to erythropoietin or hemin treatment, respectively. In human acute myeloblastic leukemias (AML), 11/30 expressed Evi-1 by RT-PCR. Among these cases, 4/6 erythroleukemias without abnormalities of the 3q25-q28 region were found positive. The presence of acidophilic erythroblasts (15-47% of bone marrow cells) accounted for the existence of a terminal erythroid differentiation in all Evi-1-positive AML M6, whereas one negative case was poorly differentiated and referred to as AML M6 variant. These results suggest that Evi-1 mRNA expression can coexist with erythroid differentiation.

Thrombocytemia and abnormal megakaryopoiesis associated with abnormality of chromosome 1p34 in myelodysplastic syndromes.

Myelodysplastic syndromes (MDS) are a heterogeneous group of diseases characterized by a cytopenia related to abnormal proliferation and differentiation of marrow precursor cells. Some subtypes of MDS are associated with thrombocytemia or abnormal megakaryopoiesis and certain specific karyotypic abnormalities. We report on four cases of MDS with normal or elevated blood platelet count and a recurring abnormality in chromosome 1p34. The gene involved appears to be different from c-mpl and TPO.

Budd-Chiari syndrome associated with 5q deletion and hypereosinophilia.

Budd-Chiari syndrome was associated with a 5q deletion syndrome and hypereosinophilia in a 50-year-old woman. There may be a link between these syndromes and gene deletion on chromosome 5, particularly the IL-5 gene, which regulates eosinophils.