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Susana Bizarro

    Susana Bizarro

    We report the analysis of altogether 1050 suspected hereditary breast/ovarian cancer (HBOC) families, 524 fully screened for BRCA1/BRCA2 mutations and 526 tested only for the most common mutations. Of the 119 families with pathogenic... more
    We report the analysis of altogether 1050 suspected hereditary breast/ovarian cancer (HBOC) families, 524 fully screened for BRCA1/BRCA2 mutations and 526 tested only for the most common mutations. Of the 119 families with pathogenic mutations, 40 (33.6%) had the BRCA2 c.156_157insAlu rearrangement and 15 (12.6%) the BRCA1 c.3331_3334del mutation, the former being specific of Portuguese ancestry and the latter showing a founder effect in Portugal. Interestingly, the two most common mutations were found in a significant proportion of the HBOC families with an a priori BRCAPRO mutation probability <10%. We recommend that all suspected HBOC families from Portugal or with Portuguese ancestry, even those fulfilling moderately stringent clinical-criteria for genetic testing, should be specifically analyzed for the two most common BRCA1/BRCA2 founder mutations, and we here present a simple method for this first tier test. Screening of the entire coding regions of BRCA1 and BRCA2 should subsequently be offered to those families with a mutation probability ≥10% if none of those founder mutations are found.
    ABL1 tyrosine kinase inhibitors (TKI) have dramatically improved the outcome for CML (chronic myeloid leukemia) patients. When TKI therapy is addressed appropriately, it can lead to an optimal molecular response in the majority of CML... more
    ABL1 tyrosine kinase inhibitors (TKI) have dramatically improved the outcome for CML (chronic myeloid leukemia) patients. When TKI therapy is addressed appropriately, it can lead to an optimal molecular response in the majority of CML patients and a life expectancy that approaches that of the general population. However, lifelong TKI therapy may have consequences, including chronic, mostly low-grade, adverse events that can substantially impact patients’ quality of life, adherence to therapy and, consequently, success of treatment. In the last few years, several groups have demonstrated that approximately 50% of chronic phase CML patients (CP-CML) who have achieved a stable deep molecular response (DMR) can stop therapy without suffering molecular relapse. Nowadays, treatment-free remission (TFR) has a significant role in the management of CML and should be considered in selected motivated patients that fulfill well-defined requirements to maximize the probability of successful discontinuation of TKI therapy.
    Chronic lymphocytic leukemia (CLL) is frequently an indolent diagnosis, with most of the patients being under surveillance for long time. There is an increased risk of a second neoplasia in CLL, rarely hematological (in the myeloid... more
    Chronic lymphocytic leukemia (CLL) is frequently an indolent diagnosis, with most of the patients being under surveillance for long time. There is an increased risk of a second neoplasia in CLL, rarely hematological (in the myeloid lineage is even rarer). A 58-year-old male was diagnosed with CLL in 2012, remaining in regular surveillance until 2014. Then, the CLL progressed, and 6 cycles of rituximab, fludarabine, and cyclophosphamide were prescribed with partial response. He remained in surveillance and suffered 2 episodes of autoimmune hemolytic anemia until 2019. Then, the hemolytic anemia relapsed and a neutrophilia became evident (progressing slowly), as well as a thrombocytopenia and splenomegaly without adenopathy were found. The bone marrow aspirate showed a chronic myeloproliferative disease without dysplasia. A peripheral blood search for the CSF3R mutation (T618I) was positive, also suggesting Chronic Neutrophilic Leukemia (CNL). For a discrete monocytosis, a chronic mye...
    Table S2. Outcome of CML patients who remain in treatment-free remission. (DOCX 16 kb)
    Table S1. Outcome of CML patients who restarted TKI treatment after molecular relapse. (DOCX 16 kb)
    Table S1. Clinical and laboratory data of the patient. (DOCX 17 kb)
    Molecular characterization of the MLL-SEPT6 fusion gene
    We present the characterization at the RNA level of an acute myeloid leukemia with a t(11;17)(q23;q25) and a MLL rearrangement demonstrated by FISH. Molecular analysis led to the identification of two coexistent in-frame MLL-SEPT9 fusion... more
    We present the characterization at the RNA level of an acute myeloid leukemia with a t(11;17)(q23;q25) and a MLL rearrangement demonstrated by FISH. Molecular analysis led to the identification of two coexistent in-frame MLL-SEPT9 fusion transcripts (variants 1 and 2), presumably resulting from alternative splicing. Real-time quantitative RT-PCR analysis showed that the relative expression of the MLL-SEPT9 fusion variant 2 was 1.88 fold higher than the relative expression of MLL-SEPT9 fusion variant 1. This is the first description of a MLL-SEPT9 fusion resulting in coexistence of two alternative splicing variants, each of which previously found isolated
    Background: A relevant role of septins in leukemogenesis has been uncovered by their involvement as fusion partners in MLL-related leukemia. Recently, we have established the MLL-SEPT2 gene fusion as the molecular abnormality subjacent to... more
    Background: A relevant role of septins in leukemogenesis has been uncovered by their involvement as fusion partners in MLL-related leukemia. Recently, we have established the MLL-SEPT2 gene fusion as the molecular abnormality subjacent to the translocation t(2;11)(q37;q23) in therapy-related acute myeloid leukemia. In this work we quantified MLL and SEPT2 gene expression in 58 acute myeloid leukemia patients selected to represent the major AML genetic subgroups, as well as in all three cases of MLL-SEPT2-associated myeloid neoplasms so far described in the literature. Methods: Cytogenetics, fluorescence in situ hybridization (FISH) and molecular studies (RT-PCR, qRT-PCR and qMSP) were used to characterize 58 acute myeloid leukemia patients (AML) at diagnosis selected to represent the major AML genetic subgroups: CBFB-MYH11 (n = 13), PML-RARA (n = 12); RUNX1-RUNX1T1 (n = 12), normal karyotype (n = 11), and MLL gene fusions other than MLL-SEPT2 (n = 10). We also studied all three MLL-...
    1435 Introduction: The response to AML treatment is very heterogeneous and relapse risk is high. Hematogones (HG) are B lymphoid cell precursors present in all individuals. HG absolute count grows after chemotherapy, during medullar... more
    1435 Introduction: The response to AML treatment is very heterogeneous and relapse risk is high. Hematogones (HG) are B lymphoid cell precursors present in all individuals. HG absolute count grows after chemotherapy, during medullar recovery and it seems to be related to prognosis. Objectives: Determination of HG number in AML patients with intermediate-risk karyotype, with complete response (CR). Determine prognostic value for HG number in these patients. Methods: Retrospective analysis of 148 patients with non promyelocytic AML, treated with “7+3” chemotherapy induction, followed in our centre, from 1998 to 2011. HG quantification was executed after induction chemotherapy, with flow cytometry pannel (4 colours - CD34, CD10, CD19, CD20 e CD45) in blood marrow samples in patients with CR, according to Cheson et al. (JCO 2003). The patients characteristics were compared with a X2test for binary variables and a Mann-Whitney test for continuous variables. Survival was plotted with Kapl...
    We report the analysis of altogether 1050 suspected hereditary breast/ovarian cancer (HBOC) families, 524 fully screened for BRCA1/BRCA2 mutations and 526 tested only for the most common mutations. Of the 119 families with pathogenic... more
    We report the analysis of altogether 1050 suspected hereditary breast/ovarian cancer (HBOC) families, 524 fully screened for BRCA1/BRCA2 mutations and 526 tested only for the most common mutations. Of the 119 families with pathogenic mutations, 40 (33.6%) had the BRCA2 c.156_157insAlu rearrangement and 15 (12.6%) the BRCA1 c.3331_3334del mutation, the former being specific of Portuguese ancestry and the latter showing a founder effect in Portugal. Interestingly, the two most common mutations were found in a significant proportion of the HBOC families with an a priori BRCAPRO mutation probability <10%. We recommend that all suspected HBOC families from Portugal or with Portuguese ancestry, even those fulfilling moderately stringent clinical-criteria for genetic testing, should be specifically analyzed for the two most common BRCA1/BRCA2 founder mutations, and we here present a simple method for this first tier test. Screening of the entire coding regions of BRCA1 and BRCA2 should subsequently be offered to those families with a mutation probability ≥10% if none of those founder mutations are found.
    Acute megakaryoblastic leukemia (AMKL) with t(1;22)(p13;q13) is a subset of acute myeloid leukemia (AML) representing... more
    Acute megakaryoblastic leukemia (AMKL) with t(1;22)(p13;q13) is a subset of acute myeloid leukemia (AML) representing <1% of all cases and about 70% of pediatric AMKL in the first year of life. We present a case of a 7-month-old female in whom the bone marrow karyotype showed the derivative chromosome der(22)t(1;22)(p13;q13). The RBM15-MKL1 fusion transcript was detected by RT-PCR and confirmed by sequencing analyses. FISH analyses revealed the presence of the four-way translocation t(1;22;17;18)(p13;q13;q22;q12).
    Background NUP98 gene rearrangements have been reported in acute myeloid leukemia, giving rise to fusion proteins that seem to function as aberrant transcription factors, and are thought to be associated with poor prognosis. Findings A... more
    Background NUP98 gene rearrangements have been reported in acute myeloid leukemia, giving rise to fusion proteins that seem to function as aberrant transcription factors, and are thought to be associated with poor prognosis. Findings A patient with treatment-related acute myeloid leukemia presented a t(3;11)(p11;p15) as the only cytogenetic abnormality. FISH and molecular genetic analyses identified a class 1 homeobox gene, POU1F1, located on chromosome 3p11, as the fusion partner of NUP98. In addition, we have found that the patient harbored an FLT3-ITD mutation, which most likely collaborated with the NUP98-POU1F1 fusion gene in malignant transformation. Conclusions We have identified POU1F1 as the NUP98 fusion partner in therapy-related AML with a t(3;11)(p11;p15). This is the first POU family member identified as a fusion partner in human cancer.
    Background Abnormalities of 11q23 involving the MLL gene are found in approximately 10% of human leukemias. To date, nearly 100 different chromosome bands have been described in rearrangements involving 11q23 and 64 fusion genes have been... more
    Background Abnormalities of 11q23 involving the MLL gene are found in approximately 10% of human leukemias. To date, nearly 100 different chromosome bands have been described in rearrangements involving 11q23 and 64 fusion genes have been cloned and characterized at the molecular level. In this work we present the identification of a novel MLL fusion partner in a pediatric patient with de novo biphenotypic acute leukemia. Methods Cytogenetics, fluorescence in situ hybridization (FISH), molecular studies (RT-PCR and LDI-PCR), and bioinformatic sequence analysis were used to characterize the CT45A2 gene as novel MLL fusion partner in pediatric acute leukemia. Results Fluorescence in situ hybridization of bone marrow G-banded metaphases demonstrated a cryptic insertion of 11q23 in Xq26.3 involving the MLL gene. Breakpoint fusion analysis revealed that a DNA fragment of 653 kb from 11q23, containing MLL exons 1-9 in addition to 16 other 11q23 genes, was inserted into the upstream region...
    The mixed lineage leukemia (MLL) locus is involved in more than 60 different rearrangements with a remarkably diverse group of fusion partners in approximately 10% of human leukemias. MLL rearrangements include chromosomal translocations,... more
    The mixed lineage leukemia (MLL) locus is involved in more than 60 different rearrangements with a remarkably diverse group of fusion partners in approximately 10% of human leukemias. MLL rearrangements include chromosomal translocations, gene internal duplications, chromosome 11q deletions or inversions and MLL gene insertions into other chromosomes, or vice versa. MLL fusion partners can be classified into four distinct categories: nuclear proteins, cytoplasmatic proteins, histone acetyltransferases and septins. Five different septin genes (SEPT2, SEPT5, SEPT6, SEPT9, and SEPT11) have been identified as MLL fusion partners, giving rise to chimeric fusion proteins in which the N terminus of MLL is fused, in frame, to almost the entire open reading frame of the septin partner gene. The rearranged alleles result from heterogeneous breaks in distinct introns of both MLL and its septin fusion partner, originating distinct gene fusion variants. MLL-SEPTIN rearrangements have been repeat...
    We describe a new one-step RT-PCR assay for the detection of the mammaglobin (MGB1) gene transcript in the peripheral blood of breast cancer patients. With this approach, the MGB1 transcript could be detected in the peripheral blood of 22... more
    We describe a new one-step RT-PCR assay for the detection of the mammaglobin (MGB1) gene transcript in the peripheral blood of breast cancer patients. With this approach, the MGB1 transcript could be detected in the peripheral blood of 22 of 54 (41%) breast cancer patients prior to any therapy. This method, using specific primers for cDNA synthesis, proved to be more sensitive (10(-6) to 10(-11), usually 10(-7)) than previously reported methodologies. This increased sensitivity was achieved without compromising specificity, as the MGB1 transcript was not detected in 38 blood samples of healthy donors and in only 1 of 18 blood samples of patients presenting with hematologic malignancies. A positive correlation was seen between MGB1 positivity and breast cancer stage: 0/3 (0%) in stage 0, 3/13 (23%) in stage I, 6/17 (35%) in stage II, 5/10 (50%) in stage III, 8/11 (73%) in stage IV (p = 0.003). The prognostic and therapeutic implications of MGB1 positivity by one-step RT-PCR in the peripheral blood of breast cancer patients, especially in clinically localized disease (stages I and II), should be evaluated after long-term clinical follow-up of these patients.
    The most common types of rhabdomyosarcoma (RMS) are alveolar RMS (ARMS), which are characterized by the specific translocation t(2;13)(q35;q14) or its rarer variant, t(1;13)(p36;q14), producing the fusion genes PAX3-FKHR and PAX7-FKHR,... more
    The most common types of rhabdomyosarcoma (RMS) are alveolar RMS (ARMS), which are characterized by the specific translocation t(2;13)(q35;q14) or its rarer variant, t(1;13)(p36;q14), producing the fusion genes PAX3-FKHR and PAX7-FKHR, respectively, and embryonal RMS (ERMS), which is characterized by multiple numeric chromosome changes. A solid variant of ARMS that is morphologically indistinguishable from ERMS has been described recently. We present two cases with an initial histopathologic diagnosis of ERMS in which the combined findings by cytogenetic, reverse-transcriptase polymerase chain reaction (RT-PCR), and comparative genomic hybridization (CGH) analyses demonstrate that both tumors were in fact the solid variant of ARMS. The cytogenetic analysis of patient 1 revealed a t(2;13)(q35;q14) and the RT-PCR study detected the corresponding PAX3-FKHR chimeric transcript. In patient 2, the cytogenetic finding of multiple trisomies was compatible with the initial histopathologic diagnosis of ERMS, but the finding of a PAX7-FKHR fusion transcript by RT-PCR pointed to the diagnosis of ARMS. Interestingly, the CGH findings of this case reconciled the molecular and cytogenetic data by detecting, in addition to the trisomies, amplification of chromosomal bands 1p36 and 13q14, where the PAX7 and FKHR genes are located, respectively. Our data indicate that this multimodal genetic analysis could be important for the differential diagnosis of these tumors. Furthermore, our findings and previous studies indicate that there are no apparent genetic differences between solid variant and typical ARMS.
    Summary A herpes simplex thymidine kinase—green fluorescent protein (TK-GFP) fusion gene was constructed to couple a marker gene to a therapeutic gene. For testing the utility of the fusion gene, it was cloned into four different viral... more
    Summary A herpes simplex thymidine kinase—green fluorescent protein (TK-GFP) fusion gene was constructed to couple a marker gene to a therapeutic gene. For testing the utility of the fusion gene, it was cloned into four different viral vectors: Semliki forest virus (SFV), ...
    Chronic neutrophilic leukemia (CNL) is a rare myeloproliferative neoplasm characterized by sustained neutrophilia and the absence of the Philadelphia chromosome or the BCR-ABL1 fusion gene. The present study reports the case of a... more
    Chronic neutrophilic leukemia (CNL) is a rare myeloproliferative neoplasm characterized by sustained neutrophilia and the absence of the Philadelphia chromosome or the BCR-ABL1 fusion gene. The present study reports the case of a 59-year-old Caucasian female that was referred to The Francisco Gentil Portuguese Institute of Oncology (Porto, Portugal) with constitutional symptoms (mainly asthenia), marked leukocytosis (51.33×10(9)/l with 90% neutrophils), macrocytic anemia and splenomegaly. Bone marrow aspiration and biopsy revealed hypercellular marrow with clear predominance of segmented neutrophils. The karyotype was normal and the BCR-ABL1 fusion gene was not detected. After excluding a leukemoid reaction, a diagnosis of CNL was established. The clinical follow-up was complicated by hemorrhagic brain lesions and relapsing episodes of erythematous, well-demarcated and painful subcutaneous nodular lesions, consistent with Sweet's syndrome (SS). Multiple treatment strategies were administered, including use of hydroxyurea, imatinib and intensive chemotherapy. Nevertheless, progression was documented and the patient succumbed at 28 months post-diagnosis. The clinical course of CNL varies, and can be complicated by cerebral hemorrhage, blastic transformation or infection. Dermatological manifestations such as SS have seldom been reported in association. No evidence-based treatment currently exists and the majority of our knowledge is based on results from case reports and small series.
    Hereditary breast/ovarian cancer syndrome is caused by germline deleterious mutations in BRCA1 and BRCA2. A major problem of genetic testing and counseling is the finding of variants of uncertain significance (VUS). We sought to ascertain... more
    Hereditary breast/ovarian cancer syndrome is caused by germline deleterious mutations in BRCA1 and BRCA2. A major problem of genetic testing and counseling is the finding of variants of uncertain significance (VUS). We sought to ascertain the pathogenicity of 25 BRCA1 and BRCA2 VUS identified in Portuguese families during genetic testing. We performed cosegregation analysis of VUS with cancer in families, evaluated their frequency in unaffected controls, and looked for loss of heterozygosity in tumors. In addition, three different bioinformatic algorithms were used (Interactive Biosoftware, ESEfinder, and PolyPhen). Finally, six VUS located in exon-intron boundaries were analyzed by RT-PCR. We found that seven variants segregated with the disease, six variants co-occurred with a pathogenic mutation in the same gene, and four variants co-occurred with a deleterious mutation in the other BRCA gene. By RT-PCR, we observed that four variants (BRCA1 c.4484G>T, BRCA2 c.682-2A>C, BRCA2 c.8488-1G>A, and BRCA2 c.8954-5A>G) disrupted splicing. After the combined analysis, we were able to classify 4 splicing variants as pathogenic mutations, 16 variants as neutral, and 3 variants as polymorphisms; only 2 variants remained classified as VUS. This work highlights the contribution of DNA, RNA, and in silico data to assess the pathogenicity of BRCA1/2 VUS, which, in turn, allows more accurate genetic counseling and clinical management of the families carrying them.
    Acute megakaryoblastic leukemia (AMKL) with t(1;22)(p13;q13) is a subset of acute myeloid leukemia (AML) representing... more
    Acute megakaryoblastic leukemia (AMKL) with t(1;22)(p13;q13) is a subset of acute myeloid leukemia (AML) representing <1% of all cases and about 70% of pediatric AMKL in the first year of life. We present a case of a 7-month-old female in whom the bone marrow karyotype showed the derivative chromosome der(22)t(1;22)(p13;q13). The RBM15-MKL1 fusion transcript was detected by RT-PCR and confirmed by sequencing analyses. FISH analyses revealed the presence of the four-way translocation t(1;22;17;18)(p13;q13;q22;q12).
    ... | Article | PubMed | ISI | ChemPort |; Jaju RJ, Fidler C, Haas OA, Strickson AJ, Watkins F, Clark K et al. A novel gene, NSD1, is fused to NUP98 in the t(5;11)(q35;p15.5) in denovo childhood acute myeloid leukaemia. Blood 2001; 98:... more
    ... | Article | PubMed | ISI | ChemPort |; Jaju RJ, Fidler C, Haas OA, Strickson AJ, Watkins F, Clark K et al. A novel gene, NSD1, is fused to NUP98 in the t(5;11)(q35;p15.5) in denovo childhood acute myeloid leukaemia. Blood 2001; 98: 1264–1267. | Article | PubMed | ISI | ChemPo.

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