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Cell division cycle 20 homologue (CDC20) is a well-known regulator of cell cycle, as it controls the correct segregation of chromosomes during mitosis. Many studies have focused on the biological role of CDC20 in cancer development, as alterations of its functionality have been linked to genomic instability and evidence demonstrated that high CDC20 expression levels are associated with poor overall survival in solid cancers. More recently, novel CDC20 functions have been demonstrated or suggested, including the regulation of apoptosis and stemness properties and a correlation with immune cell infiltration. Here, we here summarize and discuss the role of CDC20 inside and outside mitosis, starting from its network of interacting proteins. In the last years, CDC20 has also attracted more interest in the blood cancer field, being overexpressed and showing an association with prognosis both in myeloid and lymphoid malignancies. Preclinical findings showed that selective CDC20 and APC/CCDC20/APC/CCDH1 inhibitors, namely Apcin and proTAME, are effective against lymphoma and multiple myeloma cells, resulting in mitotic arrest and apoptosis and synergizing with clinically-relevant drugs. The evidence and hypothesis presented in this review provide the input for further biological and chemical studies aiming to dissect novel potential CDC20 roles and targeting strategies in hematological malignancies.

There are different BCR-ABL1 fusion genes that are translated into proteins that are different from each other, yet all leukemogenic, causing chronic myeloid leukemia (CML) or acute lymphoblastic leukemia. Their frequency has never been systematically investigated. In a series of 45503 newly diagnosed CML patients reported from 45 countries, it was found that the proportion of e13a2 (also known as b2a2) and of e14a2 (also known as b3a2), including the cases co-expressing e14a2 and e13a2, was 37.9% and 62.1%, respectively. The proportion of these two transcripts was correlated with gender, e13a2 being more frequent in males (39.2%) than in females (36.2%), was correlated with age, decreasing from 39.6% in children and adolescents down to 31.6% in patients ≥ 80 years old, and was not constant worldwide. Other, rare transcripts were reported in 666/34561 patients (1.93%). The proportion of rare transcripts was associatedwith gender (2.27% in females and 1.69% in males) and with age (from 1.79% in children and adolescents up to 3.84% in patients ≥ 80 years old). These data show that the differences in proportion are not by chance. This is important, as the transcript type is a variable that is suspected to be of prognostic importance for response to treatment, outcome of treatment, and rate of treatment-free remission.

Purpose: Most patients with chronic-phase chronic myeloid leukemia (CML) who receive imatinib achieve a complete cytogenetic remission (CCgR) and low levels of BCR-ABL transcripts. CCgR is durable in the majority of patients but relapse occurs in a subset. Experimental Design: To determine the potential of quantitative reverse transcription-PCR of BCR-ABL to predict cytogenetic relapse, we serially monitored residual disease in 97 CML patients with an imatinib-induced CCgR. Patients with late chronic phase CML after IFN-α failure were treated with imatinib (400 mg daily). Results: During the imatinib median follow-up time of 36 months (range, 12-54 months), disease monitoring occurred by cytogenetics and quantitative PCR. Twenty percent of patients experienced cytogenetic relapse at a median of 18 months after CCgR and a median of 24 months after starting imatinib. None of the possible prognostic factors studied in univariate and multivariate analyses seemed to predict for loss of cytogenetic response but the reduction of BCR-ABL transcript levels at the time of CCgR is an important prognostic factor. Conclusions: In our study, we showed not only that achieving a major molecular remission at 12 months is predictive of a durable cytogenetic remission but also that patients who achieved a major molecular remission (expressed both as the BCR-ABL/β2 microglobulin ratio %

Background: Despite the efficacy of the BCR-ABL tyrosine kinase inhibitor Imatinib mesylate for the treatment of chronic myeloid leukemia (CML), resistance has been observed in a proportion of cases, especially those with advanced stages of the disease. Point mutations within the ABL kinase domain are emerging as the most frequent mechanism for reactivation of kinase activity within the leukemic clone. Methods: We developed a denaturing-HPLC (D-HPLC)-based assay for screening for ABL point mutations. For each sample, two partially overlapping fragments of 393 and 482 bp corresponding to the kinase domain were amplified by nested reverse transcription-PCR and analyzed under selected temperature and acetonitrile gradient conditions. Fifty-one bone marrow and/or peripheral blood specimens from 27 CML patients who showed cytogenetic resistance to Imatinib were screened in parallel by D-HPLC and by direct sequencing. Results: In 12 of 27 (44%) patients, D-HPLC showed an abnormal elution profile suggesting the presence of a nucleotide change. Direct sequencing confirmed the presence of a point mutation in all cases. Conversely, all samples scored as wild type by D-HPLC showed no evidence of mutations by direct sequencing. In two cases, novel amino acid substitutions at codons already known for being hot-spots of mutation were identified (F311I and E355D). Conclusions: The proposed D-HPLC-based assay is highly specific and at least as sensitive as sequencing; with respect to the latter, it provides a much faster and less expensive semiautomated system for mutational screening. It may therefore potentially be a valuable tool for regular, large-scale testing of patients undergoing Imatinib treatment.

In the past decade, the treatment of chronic myeloid leukemia (CML) has undergone a drastic evolution. The discovery and success of imatinib and second-generation tyrosine kinase inhibitors have substantially increased the outcome for CML patients. The next step in medical and scientific research is to better understand the malignancy so as to eventually find a cure to eliminate all leukemic cells from patients. One of the key issues is about the resistance of the leukemic stem cells to tyrosine kinase inhibitors. Here, we briefly describe our current studies on CML resistance, and leukemic stem cell modeling and characterization.

Dasatinib is a potent BCR-ABL inhibitor effective in chronic myeloid leukemia and Ph+ acute lymphoblastic leukemia (ALL) resistant/intolerant to imatinib. In the GIMEMA LAL1205 protocol, patients with newly diagnosed Ph+ ALL older than 18 years (with no upper age limit) received dasatinib induction therapy for 84 days combined with steroids for the first 32 days and intrathecal chemotherapy. Postremission therapy was free. Fifty-three patients were evaluable (median age, 53.6 years). All patients achieved a complete hematologic remission (CHR), 49 (92.5%) at day 22. At this time point, 10 patients achieved a BCR-ABL reduction to < 10−3. At 20 months, the overall survival was 69.2% and disease-free survival was 51.1%. A significant difference in DFS was observed between patients who showed at day 22 a decrease in BCR-ABL levels to < 10−3 compared with patients who never reached these levels during induction. In multivariate analysis, BCR-ABL levels of < 10−3 at day 85 correlated with disease-free survival. No deaths or relapses occurred during induction. Twenty-three patients relapsed after completing induction. A T315I mutation was detected in 12 of 17 relapsed cases. Treatment was well tolerated; only 4 patients discontinued therapy during the last phase of the induction when already in CHR. In adult Ph+ ALL, induction treatment with dasatinib plus steroids is associated with a CHR in virtually all patients, irrespective of age, good compliance, no deaths, and a very rapid debulking of the neoplastic clone. This trial was registered at [www.clinicaltrials.gov][1] as #[NCT00391989][2]. [1]: http://www.clinicaltrials.gov [2]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT00391989&atom=%2Fbloodjournal%2F118%2F25%2F6521.atom

The most frequent BCR-ABL1 fusion transcripts in chronic myeloid leukemia (CML) are the e13a2 (b2a2) and the e14a2 (b3a2) ones. In the imatinib era few studies addressing the prognostic significance of the BCR-ABL1 transcript type in early chronic phase CML have been published. Overall, these studies suggest that in e14a2 patients the response to imatinib is faster and deeper. To evaluate if the BCR-ABL1 transcript type (e13a2 compared to e14a2) affect the response to imatinib and the clinical outcome in newly diagnosed adult CML patients, 559 patients enrolled in 3 prospective studies (NCT00514488, NCT00510926, observational study CML/023) were analyzed. A qualitative PCR was performed at baseline: 52% patients had a e14a2 transcript, 37% a e13a2 transcript, 11% co-expressed both transcripts and 1% had other rare transcripts. The median follow-up was 76 months (95% of the patients had at least a 5-year observation). The complete cytogenetic response rates were comparable in e14a2 and e13a2 patients. The median time to MR(3.0) (6 and 12 months) and MR(4.0) (41 and 61 months) was significantly shorter for e14a2 patients compared to e13a2 patients, with a higher cumulative probability of MR(3.0) (88% and 83%, p

Chronic myeloid leukemia (CML) treatment is based on company-sponsored and academic trials testing different tyrosine kinase inhibitors (TKIs) as first-line therapy. These studies included patients selected according to many inclusion–exclusion criteria, particularly age and comorbidities, with specific treatment obligations. In daily clinical practice (real-life), inclusion–exclusion criteria do not exist, and the treatment outcome does not only depend on the choice of first-line TKI but also on second- and third-line TKIs. To investigate in a real-life setting the response and the outcome on first-line imatinib, with switch to second generation TKIs in case of unsatisfying response or intolerance, we analyzed all newly diagnosed patients (N = 236), living in two Italian regions, registered in a prospective study according to population-based criteria and treated front-line with imatinib. A switch from imatinib to second-generation TKIs was reported in 14% of patients for side effects and in 24% for failure or suboptimal response, with an improvement of molecular response in 57% of them. The 5-year overall survival (OS) and leukemia-related survival (LRS) were 85% and 93%, respectively; the 4-year rates of MR3.0 and MR4.0 were 75% and 48%, respectively. Cardiovascular complications were reported in 4% of patients treated with imatinib alone and in 6% of patients receiving nilotinib as second-line. Older age (≥70 years) affected OS, but not LRS. These data provide an unbiased reference on the CML management and on the results of TKI treatment in real-life, according to ELN recommendations, using imatinib as first-line treatment and second-generation TKIs as second-line therapy. Am. J. Hematol. 92:82–87, 2017. © 2016 Wiley Periodicals, Inc.

Background: Although recent high-resolution genome-wide profiling analysis of B-cell precursor acute lymphoblastic leukemia (BCP-ALL) samples has contributed to the identification of many novel somatic genetic alterations, a deep molecular characterization of adult ALL is still challenging, especially for those cases lacking recurrent fusion genes. Aims: In order to better molecularly dissect this ALL subgroup, we performed an integrative molecular approach including gene-candidate high-resolution screening and genome-wide profiling analyses. Methods: We retrospectively analyzed 28 newly diagnosed BCR-ABL1- negative BCP-ALL subjects (19 males/9 females; median age 41.5 years; negative for known fusion genes) and 28 BCR-ABL1-positive BCP-ALL subjects as a comparison group. In BCR-ABL1-negative ALL karyotype was normal in 10/28 (36%). Copy number alterations (CNA) of know leukemiarelated genes, such as IKZF1, CDKN2A/B, PAX5, EBF1, ETV6, BTG1, RB1, and genes within PAR1: CRLF2, CSF2RA, IL3RA have been assessed by the SALSA MLPA kit P335 IKZF1 (MRC Holland). In addition, sequence mutations have been investigated in TP53, CRLF2, JAK2, LEF1, PAX5 and IL7R by nextgeneration deep-sequencing (NGS) (Roche Applied Science; IRON-II study oligonucleotide primer plates). Positivity for newly described BCR-JAK2, PAX5- JAK2, ETV6-ABL1, EBF1-PDGFRB, NUP-ABL1 gene fusions occurring in BCR-ABL1-like ALL (Roberts KG et al., Cancer Cell. 2012) was assessed by PCR amplification and sequencing. Finally, SNP arrays (SNP 6.0, Affymetrix), gene expression profile analyses (GeneChip® Human Transcriptome Array 2.0) and whole exome sequencing (Illumina) were performed to more fully assess genomic complexity. Results: Overall, 76% of BCR-ABL1-negative subjects showed an abnormality of at least one of the analyzed known leukemia genes: 7 (25%) had one, 4 (14%) had two, 6 (21%) had three, and 6 (21%) had four or more alterations. In subjects showing no abnormalities, SNP arrays analysis revealed amplifications of chromosome 1q in 2/6 cases (33%). Deletions of CDKN2A/B were the most frequent (39%) and in 73%, they occurred together with other abnormalities, suggesting that multiple events are needed to induce the full leukemia phenotype. Other common CNA included: deletions of IKZF1 (25%), ETV6 (25%), PAX5 (14%), EBF1 (11%), PAR1 region (11%) and RB1 (7%). NGS showed mutations of JAK2 and CRLF2 in 7% (R683S/G) and 4% (F232C), respectively. No positivity for newly described fusion genes activating tyrosine kinase was confirmed. Importantly, subjects with no abnormalities showed better survival rates compared to those with one or more molecular alterations (p

Introduction. Mastocytosis is a myeloid neoplasm characterized by abnormal accumulation and frequent activation of mast cells (MCs) in various organs. The recent WHO classification (2008) includes an indolent form (ISM), an aggressive form (ASM) and a leukemic subvariant (MCL). The c-kit mutation D816V is detectable in most adult patients with SM. Treatment of SM usually focuses on symptom relief by histamine receptor antagonists and other supportive therapy. However, in aggressive and leukemic variants, cytoreductive and targeted drugs must be applied. Methods. From 2008, 22 patients (male/female=11/11) affected by SM have been referred to our Institution. Among these, 12 (55%) presented with systemic symptoms associated with signs of organ involvement (skeletal lesions, ascites, liver function impairment or bon marrow disfunction), thus identifying an ASM. Therefore, since a first line therapy (IFNalfa, Imatinib and 2CdA in 56%, 11% and 33% of the patients, respectively) and supportive care with histamine receptor antagonists weren’t followed by a significant benefit, a personalized use of PKC412 was asked and obtained for 9 out of 12 ASM patients. Thus, from March 2011 9 (M/F =3/9) patients with ASM have been treated with PKC412, administered orally, at the dosage of 100 mg twice daily, without rest periods. The median age was 60 years (range 39-75); the median time from diagnosis was 6 months (range 2-53). Median serum tryptase level was 100 mcg/L(range 19.3-1160). C-kit mutation D816V was present in 8 out of 9 patients. Cytogenetic analysis was normal in all the patients. Results. Seven out of nine patients were evaluable for response. The median duration of therapy was 517 days (range 327-970+). According to European Criteria, a Major response was observed in one patient, and a partial response in 6 patients. Overall, the drug was well tolerated, and no serious adverse events were observed. All the patients obtained a quick and prolonged improvement of clinical symptoms, in terms of weight gain, bowel function and skeletal pain. At the bone marrow evaluation, the persistence of the D816V c-kit mutation was observed, despite a significant decrease of mast cell marrow involvement. Conclusions. In a small cohort of ASM patient, the prolonged therapy with PKC412 is safe and effective, mainly on symptoms improvement and haematological profile. Nevertheless, the persistence of the D816V c-kit mutation, despite significant responses, suggests that many other oncogenic factors may be responsible for the pathogenesis of the disease. UDS approaches are needed in order to clarify this issue. Acknowledgments. Work supported by European LeukemiaNet, AIRC, AIL, PRIN 2010-2011, University of Bologna, FP7 NGS-PTL project. Introduction. Mastocytosis is a myeloid neoplasm characterized by abnormal accumulation and frequent activation of mast cells (MCs) in various organs. The recent WHO classification (2008) includes an indolent form (ISM), an aggressive form (ASM) and a leukemic subvariant (MCL). The c-kit mutation D816V is detectable in most adult patients with SM. Treatment of SM usually focuses on symptom relief by histamine receptor antagonists and other supportive therapy. However, in aggressive and leukemic variants, cytoreductive and targeted drugs must be applied. Methods. From 2008, 22 patients (male/female=11/11) affected by SM have been referred to our Institution. Among these, 12 (55%) presented with systemic symptoms associated with signs of organ involvement (skeletal lesions, ascites, liver function impairment or bon marrow disfunction), thus identifying an ASM. Therefore, since a first line therapy (IFNalfa, Imatinib and 2CdA in 56%, 11% and 33% of the patients, respectively) and supportive care with histamine receptor antagonists weren’t followed by a significant benefit, a personalized use of PKC412 was asked and obtained for 9 out of 12 ASM patients. Thus, from March 2011 9 (M/F =3/9) patients with ASM have been treated with PKC412, administered orally, at the dosage of 100 mg twice daily, without rest periods. The median age was 60 years (range 39-75); the median time from diagnosis was 6 months (range 2-53). Median serum tryptase level was 100 mcg/L(range 19.3-1160). C-kit mutation D816V was present in 8 out of 9 patients. Cytogenetic analysis was normal in all the patients. Results. Seven out of nine patients were evaluable for response. The median duration of therapy was 517 days (range 327-970+). According to European Criteria, a Major response was observed in one patient, and a partial response in 6 patients. Overall, the drug was well tolerated, and no serious adverse events were observed. All the patients obtained a quick and prolonged improvement of clinical symptoms, in terms of weight gain, bowel function and skeletal pain. At the bone marrow evaluation, the persistence of the D816V c-kit mutation was observed, despite a significant decrease of mast cell marrow involvement. Conclusions. In a small cohort of ASM patient, the prolonged therapy with PKC412 is safe and effective, mainly on symptoms improvement and haematological profile. Nevertheless, the persistence of the D816V c-kit mutation, despite significant responses, suggests that many other oncogenic factors may be responsible for the pathogenesis of the disease. UDS approaches are needed in order to clarify this issue. Acknowledgments. Work supported by European LeukemiaNet, AIRC, AIL, PRIN 2010-2011, University of Bologna, FP7 NGS-PTL project.