Biomedical subjects
Publications and source records attributed to Francesco Lo Coco.
Eleven patients with advanced APL were treated with ATO (0.15 mg/Kg daily). Eight (73%) achieved molecular CR, but 5 relapsed, 1 died in molecular CR, 1 was lost to follow-up and 1 is still alive in CR after allogeneic transplantation. We suggest that ATO may be effective also in advanced APL, but given the short CR, it seems indicated only in patients eligible for transplant procedures.
High-mobility group A (HMGA) proteins are non-histone nuclear proteins that bind DNA and several transcription factors. They are involved in the regulation of chromatin structure and function. HMGA protein expression is low in normal adult tissues, but abundant during embryonic development and in several human tumours. Rearrangements of the HMGA genes have been frequently detected in human benign tumours of mesenchymal origin, e.g. lipomas, lung hamartomas and uterine leiomiomas. HMGA proteins have been implicated in the control of cell growth and differentiation of the pre-adipocytic cell line 3T3-L1. In an attempt to better understand the role of HMGA1 proteins in haematological neoplasias and in the differentiation of haematopietic cells, we have investigated their expression in human leukaemias and in leukaemic cell lines induced to terminal differentiation. Here we report HMGA1 overexpression in most fresh human leukaemias of different origin and in several leukaemic cell lines. Moreover, differentiation of three cell lines towards the megakaryocytic phenotype was associated with HMGA1 protein induction, whereas induction of erythroid and monocytic differentiation generally resulted in reduced HMGA1 expression.
A new t(20;21)(q11;q11), associated with a deletion on the long arm of chromosome 20, was found in one patient with an acute myelocytic leukemia (AML) and in one with myelodysplastic syndrome (MDS). In both cases deletion was interstitial, extending from band q11 to band q13, as shown by comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH). FISH analysis with whole arm paints, subtelomeric probes, and locus-specific probes for the long arms of chromosomes 20 and 21 revealed in patient 1 a reciprocal translocation between the deleted 20q and the long arm of chromosome 21, that is, del(20)(q11q13)t(20;21)(q11;q11), and in patient 2, material from 21q was inserted into the deleted 20q, that is, del(20)(q11q13)ins(20;21)(q11;q11q22). This is the first identification of a complex 20;21 rearrangement in MDS/AML. Deletion at 20q and juxtaposition between 20q11 and 21q11 appear to be the critical genomic events.
Cure of acute promyelocytic leukaemia (APL) is now a reality for most patients through the use of combined all-trans retinoic acid (ATRA) and chemotherapy. The simultaneous administration of ATRA and anthracycline-based chemotherapy is currently considered the most appropriate induction therapy. However, no consensus has been reached on the consolidation strategy. Therapeutic efficacy apparently did not differ according to the number of cycles and types of drug combined with anthracyclines. Encouraging results have been reported recently using less-intensive chemotherapy with anthracyclines alone, leading to a significant reduction in treatment-related toxicity during the consolidation phase and a high degree of compliance. Some ongoing risk-adapted protocols are now exploring the potential synergistic effect of ATRA and chemotherapy given simultaneously in consolidation. Preliminary data suggest that higher molecular remission rates post-consolidation and improved outcome may be obtained through this strategy. Persistence or recurrence of molecular disease at the end of consolidation is strongly associated with impending relapse and poor prognosis, indicating the need for further aggressive therapy. As for maintenance therapy, once demonstrated, the advantage of using ATRA with or without low-dose methotrexate and 6-mercaptopurine has encouraged most groups to incorporate such treatment into their protocols for APL.
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We analyzed the clinicobiological features and treatment outcome of a series of acute promyelocytic leukemias (APLs) occurring as a second tumor (APL-st's, n = 51) and compared these with a large group of de novo APL cases (n = 641), both observed by the Italian cooperative group GIMEMA. In the APL-st group, 37 patients had received radiotherapy and/or chemotherapy for their primary malignancy (PM), while 14 had been treated by surgery alone. Compared with de novo APL patients, APL-st patients were characterized by a predominance of females (P <.003), higher median age (P <.05), and worse performance status (P <.005). The median time elapsed between PM and APL-st was 36 months, with a longer latency for patients treated with surgery alone. No significant differences were found with regard to karyotypic lesions or type of promyelocytic leukemia/retinoic acid receptor alpha (PML/RARalpha) fusion in the 2 cohorts. A high prevalence of PMs of the reproductive system was observed among the female APL-st population (24 [71%] of 34 patients in this group had suffered from breast, uterine, or ovarian cancer). Thirty-one APL-st and 641 de novo APL patients received homogeneous APL therapy according to the all-trans retinoic acid (ATRA) and idarubicin regimen (the AIDA regimen). The complete remission (CR), 4-year event-free survival (EFS), and 4-year overall survival (OS) rates were 97% and 93%, 65% and 68%, and 85% and 78% in the APL-st and de novo APL groups, respectively. In spite of important clinical differences (older age and poorer performance status), the APL-st group responded as well as the de novo APL group to upfront ATRA plus chemotherapy, probably reflecting genetic similarity.
Acute leukemia with the t(11;17) expressing the PLZF-RARalpha gene fusion is a rare variant of acute promyelocytic leukemia (APL) that has been associated with poor clinical response to all-trans retinoic acid (ATRA) treatment. However, some recent reports have put into question the absolute refractoriness of this leukemia to ATRA. We describe here a patient with PLZF/RARalpha APL who was treated at relapse with ATRA and low-dose hydroxyurea. Complete hematologic remission was obtained through differentiation of leukemic blasts, as proven by morphologic, immunophenophenotypic, and genetic studies carried out in sequential bone marrow samples. Moreover, in vitro studies indicated that blast differentiation was potentiated by the addition of the histone deacetylase inhibitor tricostatin A, but not of hydroxyurea, to ATRA. Our findings indicate that the maturation block may be overcome and terminal differentiation obtained in this leukemia subset and support the view that sensitivity/refractoriness of this form to ATRA should be revisited.
DNA methylation of tumor suppressor genes is a frequent mechanism of transcriptional silencing in cancer. The molecular mechanisms underlying the specificity of methylation are unknown. We report here that the leukemia-promoting PML-RAR fusion protein induces gene hypermethylation and silencing by recruiting DNA methyltransferases to target promoters and that hypermethylation contributes to its leukemogenic potential. Retinoic acid treatment induces promoter demethylation, gene reexpression, and reversion of the transformed phenotype. These results establish a mechanistic link between genetic and epigenetic changes during transformation and suggest that hypermethylation contributes to the early steps of carcinogenesis.
The use of all-trans retinoic acid (ATRA) in combination with chemotherapy has markedly improved the prognosis for patients with acute promyelocytic leukemia (APL); the higher complete remission (CR) and survival rates now reported in this disease almost approach those obtained for other highly curable hematologic malignancies. Of 77 patients with APL who were consecutively treated at a single institution and who achieved CR after induction and consolidation therapy, 5 (6.5%) acquired therapy-related myelodysplasia (tMDS), acute myelogenous leukemia (AML), or both (tMDS-AML). Of these, 3 of 46 (6.5%) patients received front-line chemotherapy with or without ATRA and acquired tMDS-AML while in first remission of APL. Two underwent repeated chemotherapy cycles with ATRA because of APL relapse and acquired tMDS-AML while in the second or third remission of APL. In 2 patients, clinical and biologic characteristics of tMDS-AML were as expected for postalkylating forms (long latency, MDS phase preceding AML, karyotypic aberrations involving chromosomes 5 or 7), even though one of them had not previously received alkylating drugs. Three of the 5 patients died shortly after tMDS-AML diagnosis, one is alive with tMDS, and one is alive and in CR after allogeneic bone marrow transplantation. The occurrence of tMDS-AML after successful therapy for APL is an emerging problem. The availability of prognostic score systems at initial diagnosis and monitoring of residual disease by polymerase chain reaction might allow better tailoring of treatment intensity in APL to spare unnecessary toxicity and to minimize the risk for tMDS-AML in patients who are presumably cured.
Considerable progress has been made over the past decade in the understanding and management of acute promyelocytic leukemia (APL). At the laboratory level, molecular mechanisms underlying the arrest of differentiation that typically features in this malignancy, have been clarified and currently provide important models for addressing future investigation aimed at releasing the maturation block in other malignancies. In the clinic, advances in the management of APL have converted this rapidly fatal disease into the most frequently curable leukemia in adults. Use of retinoids in combinatorial protocols with anthracycline-based chemotherapy for front line treatment currently results in long-term survival and potential cure in at least 60% of newly diagnosed patients. Even after relapse, the disease is still curable in a high percentage of cases by various approaches including combinations of chemotherapy, retinoids, arsenic trioxide, stem cell transplantation and antibody-targeted chemotherapy. Genetic testing for identification of the disease-specific gene rearrangement and monitoring of residual disease have proved critical in establishing correct diagnosis and better evaluate the response to therapy at the molecular level. Current 'hot' issues for clinical investigation include: (i) better understanding and management of the severe coagulopathy present at diagnosis in most patients; (ii) the definition of risk categories to improve identification of patients at highest risk of relapse and (iii) the translation of successful differentiation therapy to other leukemia subsets.
Genetic markers associated with hematologic malignancies such as acute promyelocytic leukemia (APL) can be detected with high sensitivity and specificity using the reverse-transcription polymerase chain reaction (RT-PCR). This procedure can be applied to monitor minimal residual disease. In patients with APL, RT-PCR is now being used to detect molecular relapse, and a strong association has been found between outcome and the treatment of molecular as opposed to hematologic relapse. In APL, results from PCR assays are also being used to guide therapy. Prognostic groups can be defined using molecular and clinical characteristics of the disease as well as patient characteristics. In the future, PCR monitoring strategies may be adapted to the risk of relapse of individual patients. Patients at high risk of relapse may be monitored much more rigorously than patients at low risk of relapse. Although RT-PCR is in routine use as a clinical tool, the lack of standardization of techniques in different laboratories has resulted in some difficulties in interpretation of results. There is a real need for an international consensus on standardization of PCR techniques.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.