Philadelphia Chromosome

Dasatinib (Sprycel) is a potent Breakpoint Cluster Region-Abelson
(BCR-ABL) oral tyrosine kinase inhibitor which has been used in
the treatment of Philadelphia-positive hematological malignancies
such as Chronic Myeloid Leukemia (CML) and Acute Lymphoblastic
Leukemia (ALL). Herein, we describe a case in which the continuous
administration of Dasatinib led, after two months, to the transient
appearance of a clonal, Natural-Killer (NK)-like T-cell population.
This was first detected by the presence of an increased white blood
cell count consisting of lymphocytes, and review of the peripheral
smear showed large granular lymphocytes. The lymphocytosis and
the associated leukocytosis resolved within three weeks without
any interventions while the patient continued Dasatinib. This paper
will review the current literature on this subject, which suggests
that Dasatinib-associated large granular lymphocytosis (LGL) is
associated with a superior disease response.

The aims of this study are to investigate the frequency of derivative chromosome 9 (der (9)) deletion in Tunisian patients with chronic myeloid leukemia (CML) and to assess the correlation between this deletion and the cytogenetic response for patients treated with hydroxyurea (HU) or imatinib (IM). Karyotype analysis of 336 patients with CML was performed with R-banding technique. Fluorescence in situ hybridization (FISH) was carried using home-brew probes 17L7 and 248J22 for detecting, respectively, adjacent 5′ABL and 3′BCR deletions on der(9). Cytogenetic study demonstrated typical t(9;22)(q34;q11) translocation in 89.6% and variant translocation in 10.4% of patients. Interphase FISH studies showed deletion of der(9) in 59 (17.6%) of the 336 patients, 23 (39%) of them had variant rearrangements. There are 19 patients with solely 5′ABL deletion and 40 with concomitant 5′ABL and 3′BCR deletions. Cytogenetic response was evaluated during 18 months with HU or IM therapy. Our results demonstrate that (a) 3′BCR deletion is associated with 5′ABL deletion in all patients with der(9) deletions, (b) the 5′ABL and 3′BCR deletions arise simultaneously with t(9;22), (c) deletions on der(9) chromosome were frequently encountered in older patients and in patients presenting variant rearrangements, (d) both 5′ABL and 3′BCR deletions were associated with cytogenetic response failure in patients treated with HU, however, patients treated with IM and carrying der(9) deletions presented better cytogenetic response.

In Greek, the word “nature” derives from the verb phyō, to come forth, to grow, to become. It is life independent of thought, and non-constructed. Aristotle calls physis “the coming-to-be what it is” (1960: 193a). Nature as physis contains both the movement of emergence and the specific growth, becoming and being, productivity and product. Growth in this context implies that withering and demise belong to it; genesis is always phthora, decay is integral to the act of coming-to-light. In pre-Socratic thought, the human being is seen as part of physis, which contains the human as a whole and in his/her individuality. The focus of the Roman words nasci and natura is, however, on being conceived and being born. Natura now means “native” and “inherent,” but is also defined in terms of the right of disposal, which influenced the formation of the modern term of object (cf. Picht 1998: 90). Nature as the quintessence of objects is nature as the sum of everything that is at our disposal in thought and action.

The Philadelphia chromosome (Ph+), corresponding to translocation t(9;22), is found in chronic myeloid leukemia (CML) and acute lymphoblastic leukemia. Several cases of Ph+ acute myeloid leukemia (AML) have been reported in the literature. A retrospective study of Ph+ AML between 2001 and 2012 was conducted through a review of the literature. Among 400 AML patients, two cases of Ph+ AML (0.5%) were identified and treated with conventional chemotherapy with or without tyrosine kinase inhibitors (TKIs), followed by allogeneic hematopoietic stem cell transplantation (allo-HSCT). One patient had a complex karyotype including 7 monosomy (-7) and p190 BCR-ABL fusion transcript. Both patients remain in complete molecular remission. To date, 21 Ph+ AML cases treated with TKIs have been described in the literature with a median overall survival of 18months. One-third of the patients had additional karyotypic abnormalities, and 14% had -7. Molecular analysis showed 59% p210 and 41% p190 fusio...

ABL1 is a proto-oncogene well known as part of the fusion gene BCR-ABL1 in the Philadelphia chromosome of leukemia cancer cells. Inherited germline ABL1 changes have not been associated with genetic disorders. Here we report ABL1 germline variants cosegregating with an autosomal dominant disorder characterized by congenital heart disease, skeletal abnormalities, and failure to thrive. The variant c.734A>G (p.Tyr245Cys) was found to occur de novo or cosegregate with disease in five individuals (families 1-3). Additionally, a de novo c.1066G>A (p.Ala356Thr) variant was identified in a sixth individual (family 4). We overexpressed the mutant constructs in HEK 293T cells and observed increased tyrosine phosphorylation, suggesting increased ABL1 kinase activities associated with both the p.Tyr245Cys and p.Ala356Thr substitutions. Our clinical and experimental findings, together with previously reported teratogenic effects of selective BCR-ABL inhibitors in humans and developmental ...

A patient with Ph1-positive chronic myeloid leukaemia (CML) presented in extramedullary blast crisis. Whereas the peripheral blood and bone marrow features were consistent with the chronic phase of CML, study of the enlarged lymph nodes demonstrated massive replacement by Ph1-positive blast cells of lymphoblastic morphology. Such blast cells showed diffuse acid phosphatase positivity, were positive for TdT, and had an enzyme pattern (adenosin-deaminase, purine-nucleosidephosphorilase and lactate-dehydrogenase) typical of immature T-cells. To further characterize the phenotype of the blast cells, they were analyzed for surface markers using a panel of monoclonal antibodies selected to identify differentiation antigens of T cells, B cells and myeloid cells. The results of the latter analysis were consistent with an early T-cell origin of the blast cells, since they were positive for TdT, CRIS1 (T1), E rosettes and OKT10, and were negative for OKT3, Leu3 and OKT8. These features demonstrate that T-cell markers may also be expressed in blast crisis of CML and provide evidence that T-cells may share a common stem cell with myeloid and B-cells in CML.

Cytogenetic analysis is one of the most reliable prognostic factors in acute lymphoblastic leukemia. The objective of this study was to analyze the prognostic value of cytogenetic analysis in children and adults with high-risk acute lymphoblastic leukemia (HR-ALL) included in a prospective multicenter trial. One hundred and thirty patients (44 children and 86 adults) with HR-ALL included in the PETHEMA ALL-93 trial had an adequate cytogenetic study after review. Cytogenetic subgroups were established according to the cancer and acute leukemia group B criteria (unfavorable: 11q23, t(9;22), -7 and +8; normal; miscellaneous: the remaining chromosome abnormalities) and their main clinicobiological features were compared. Univariable and multivariable analyses for complete remission (CR) attainment, event-free survival (EFS) and overall survival (OS) were performed. The mean SD age was 26 14 years. Two were infants (<1 year), 42 were children and 86 adults (19-50 years). The cytogenet...

Ten patients in first or second relapse with Philadelphia chromosome acute lymphoblastic leukaemia, ineligible for allogeneic sibling marrow transplantation, were treated with an intensive chemotherapy regimen including idarubicin, intermediate-dose arabinosylcytosine, etoposide and G-CSF. Peripheral blood stem cells were collected by leukapheresis during initial early WBC recovery from chemotherapy-Induced aplasia. In 5/10 patients all metaphases in leukapheresis products were found to be Philadelphia-chromosome-negative and they have been used as autotransplants after conditioning with TBI/etoposide/cyclophosphamide (or idarubicin) and G-CSF. All five patients showed sustained engraftment and one of them is alive and well Philadelphia-chromosome-negative 18 months after transplant. These preliminary results suggest that it is possible to recover Philadelphia-chromosome-negative blood stem cells after intensive chemotherapy, even in advanced patients, and to perform autografting with these cells.

The Ph chromosome is the hallmark of CML, where it is found in more than 90% of the cases. Cytogenetically, it usually results from a t(9;22)(q34;q11). The Ph arises in a stem cell and in chronic phase is found in all haematopoietic cell lineages, although it causes only increased granulopoiesis, and sometimes increased thrombopoiesis; furthermore blast crisis may occur in all differentiative patterns of the pluripotent stem cell. Recently, molecular investigations of Ph positive CML cases have revealed a consistent genomic recombination between two genes, BCR on chromosome 22 and the ABL oncogene. The latter is translocated from 9q34, its normal site, to the 22q- or Ph chromosome. This molecular rearrangement expresses a unique 8.5 kb BCR-ABL hybrid mRNA transcript, that encodes an altered BCR-ABL protein of approximately 210 kD with enhanced in vitro tyrosine kinase activity. The breakpoints on chromosome 22q- are clustered in a 5 kb DNA fragment, allowing their study using Southern blot analysis. Cytogenetic variant forms of the Ph translocation involving three or more chromosomes are found in about 5% of the cases. Southern blot and in situ hybridization studies have demonstrated that these variants are cytogenetically more complex than the standard t(9;22) but molecularly they show the same essential genomic recombination. This is also true for a small number of cases of Ph negative CML. Clonal progression, indicated by the presence of clonal, non-random chromosome abnormalities, in addition to the Ph is rare during chronic phase but is found in 80% of blast crisis. These additional aberrations may precede BC by weeks or months and have therefore a clear prognostic value. Ph is not restricted to CML, since it is also found in ALL (20% of adult cases) and rarely in AML. Ph in acute leukaemia is cytogenetically indistinguishable from Ph in CML, but molecular studies have shown that in 50% of the cases the breakpoint on chromosome 22 is different from the very consistent and characteristic breakpoint in CML. Nevertheless genomic recombination takes place that results in a novel ABL protein at least in some of the cases. Despite extensive cytogenetic and molecular investigations, the mechanisms underlying the formation of the Ph as well as the pathogenesis of Ph positive CML are still unknown but are now the object of intensive research.