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F Lo Coco

Publications and source records attributed to F Lo Coco.

At least 19 recordsLinked to original sources
PubMed1992

Molecular evaluation of residual disease as a predictor of relapse in acute promyelocytic leukaemia.

Acute promyelocytic leukaemia (APL) is characterised by a unique fusion transcript, PML/RAR alpha. We tested for this transcript in 35 APL patients who were in apparent remission after various treatments. 11 of 13 patients who tested positive 4 months after achieving remission were in relapse 1-4 months later. All 22 patients who tested negative at 4 months were disease-free after a further 3 months to five years. The test may therefore prove useful in determining the need for additional treatment during clinical remission.

Carrier Proteins↗
PubMed1992

Molecular monitoring of the myl/retinoic acid receptor-alpha fusion gene in acute promyelocytic leukemia by polymerase chain reaction.

The acute promyelocytic leukemia (APL) t(15;17) translocation generates a myl/retinoic acid receptor-alpha (RAR-alpha) chimeric gene that is transcribed as a fusion myl/RAR-alpha messenger RNA. Using primer sets derived from RAR-alpha and myl cDNAs, we were able to amplify the breakpoint sites of the fusion transcripts of all 35 APL RNA samples by reverse polymerase chain reaction (PCR) and nested primer approach of two rounds of amplification. DNA fragments of different size were obtained according to the chromosome 15 breakpoints (intron 3-bcr 3; exon 6-bcr 2; and intron 6-bcr 1). bcr 1 and bcr 3 represent the regions of the myl locus most frequently involved among APL (48.5 and 34.2 of cases, respectively); bcr 3 constitutes 62.5% of cases among M3V as compared with 25.9% of M3 cases. The feasibility of monitoring the APL clone by PCR analysis in five APL patients who received different treatment (chemotherapy, all-trans-retinoic acid or bone marrow transplantation) was evaluated. In five of nine bone marrow samples of patients in complete remission, t(15;17)-positive cells could be detected by PCR analysis. We conclude that PCR amplification of the myl/RAR-alpha junctions represents the easiest and rapid method for diagnosis and monitoring of the APL clone.

Adolescent↗
PubMed1992

Characterization of the PML-RAR alpha chimeric product of the acute promyelocytic leukemia-specific t(15;17) translocation.

The acute promyelocytic leukemia 15;17 chromosomal translocation fuses the PML gene to the RAR alpha locus. The resulting chimeric gene encodes for a putative PML-RAR alpha fusion protein. PML is a putative transcriptional factor and RAR alpha is one of the nuclear retinoic acid receptors through which retinoic acid regulates gene expression. In this study, we investigated the retinoid binding and biochemical properties of the PML-RAR alpha protein by size exclusion high-performance liquid chromatography and immunoblot analysis and compared them with those of normal RAR alpha. The introduction of the expression vector PSG5/PML-RAR alpha into COS-1 cells led to high levels of expression of the PML-RAR alpha fusion protein. This protein was primarily localized in the nucleus and bound retinoids with the same affinity and specificity as the wild type RAR alpha receptor. The PML-RAR alpha fusion protein, but not the RAR alpha, was found in high molecular weight complexes with either itself or other nuclear factors. In the acute promyelocytic leukemia-derived cell line NB4, which contains the t(15;17) chromosomal marker, the PML-RAR alpha product was also found as a high molecular complex. The interaction of the PML-RAR alpha with itself or with other nuclear proteins may be important in understanding the role of the PML-RAR alpha fusion protein in promyelocytic leukemogenesis.

Carrier Proteins↗
PubMed1992

Identification of DNA rearrangements at the retinoic acid receptor-alpha (RAR-alpha) locus in all patients with acute promyelocytic leukemia (APL) and mapping of APL breakpoints within the RAR-alpha second intron. Italian Cooperative Study Group "GIMEMA".

Seventy patients with acute promyelocytic leukemia (APL) were characterized at the DNA level using genomic retinoic acid receptor-alpha (RAR-alpha) probes on Southern blot experiments. Sixty-two cases were defined as M3 according to the French-American-British (FAB) criteria, and eight had a diagnosis of microgranular or variant (M3v) APL. The use of two restriction enzymes and three probes exploring the second intron of the RAR-alpha gene allowed us to detect specific abnormal DNA fragments in every case, with clustering of rearrangements within the 20-kb intronic region between RAR-alpha exons II and III. A more detailed mapping of APL breakpoints was performed in 52 cases in which three EcoRI subregions of the RAR-alpha second intron were analyzed with corresponding probes. Comparison of clinical and hematological features in the three subgroups of patients with distinct RAR-alpha breakpoints did not show significant differences regarding age, peripheral blood (PB) counts, presence of coagulopathy, or FAB classification (M3 v M3v). Interestingly, a significant difference was observed in the M/F ratio of the three subgroups, with a higher incidence of rearrangements at the 5' end of the RAR-alpha second intron in female patients, and more frequent 3' breakpoints in males. The results of this study indicate that a unique genomic alteration consistently occurs on the 17q- derivative of the APL specific t(15;17) aberration. Moreover, the clinical relevance of RAR-alpha gene analysis both at diagnosis and in follow-up studies is further emphasized.

Adolescent↗
PubMed1992

Expression pattern of the RAR alpha-PML fusion gene in acute promyelocytic leukemia.

Two chimeric genes, PML-RAR alpha and RAR alpha-PML, are formed as a consequence of the acute promyelocytic leukemia (APL)-specific reciprocal translocation of chromosomes 15 and 17 [t(15;17)]. PML-RAR alpha is expressed as a fusion protein. We investigated the organization and expression pattern of the RAR alpha-PML gene in a series of APL patients representative of the molecular heterogeneity of the t(15;17) and found (i) two types of RAR alpha-PML mRNA junctions (RAR alpha exon 2/PML exon 4 or RAR alpha exon 2/PML exon 7) that maintain the RAR alpha and PML longest open reading frames aligned and are the result of chromosome 15 breaking at two different sites; and (ii) 10 different RAR alpha-PML fusion transcripts that differ for the assembly of their PML coding exons. A RAR alpha-PML transcript was present in most, but not all, APL patients.

Base Sequence↗
PubMed1992

High-performance liquid chromatographic determination of 2-furaldehyde in spirits.

Official methods for the determination of 2-furaldehyde in spirits involve for a spectrophotometric evaluation, which is characterized by poor specificity. Gas chromatographic evaluations have also been proposed, which offer a much higher sensitivity, particularly when capillary columns are used. In this paper a high-performance liquid chromatographic (HPLC) method based on the formation of the 2,4-dinitrophenylhydrazones of carbonyl compounds and subsequent reversed-phase separation of these derivatives is described. Derivatization is carried out by utilizing an acidic solution of 2,4-dinitrophenylhydrazine in acetonitrile. Precipitation of the derivatives is avoided and direct injection of the sample into the HPLC system is allowed. The determination offers a high specificity and a detection limit of the order of 10(-8) mol/l. Accuracy and reproducibility data are presented.

Alcoholic Beverages↗
PubMed1992

Genomic variability and alternative splicing generate multiple PML/RAR alpha transcripts that encode aberrant PML proteins and PML/RAR alpha isoforms in acute promyelocytic leukaemia.

The acute promyelocytic leukaemia (APL) 15;17 translocation generates a PML/RAR alpha chimeric gene which is transcribed as a fusion PML/RAR alpha mRNA. Molecular studies on a large series of APLs revealed great heterogeneity of the PML/RAR alpha transcripts due to: (i) variable breaking of chromosome 15 within three PML breakpoint cluster regions (bcr1, bcr2 and bcr3), (ii) alternative splicings of the PML portion and (iii) alternative usage of two RAR alpha polyadenylation sites. Nucleotide sequence analysis predicted two types of proteins: multiple PML/RAR alpha and aberrant PML. The PML/RAR alpha proteins varied among bcr1, 2 and 3 APL cases and within single cases. The fusion proteins contained variable portions of the PML N terminus joined to the B-F RAR alpha domains; the only PML region retained was the putative DNA binding domain. The aberrant PML proteins lacked the C terminus, which had been replaced by from two to ten amino acid residues from the RAR alpha sequence. Multiple PML/RAR alpha isoforms and aberrant PML proteins were found to coexist in all APLs. These findings indicate that two potential oncogenic proteins are generated by the t(15;17) and suggest that the PML activation pathway is altered in APLs.

Amino Acid Sequence↗
PubMed1992

Ph-negative and bcr-negative atypical chronic myelogenous leukemia: biological features and clinical outcome.

We report the clinical, hematologic, cytogenetic, and molecular characteristics of 13 patients with Philadelphia-negative (Ph-), bcr-negative atypical chronic myelogenous leukemia (CML). In the majority of cases, the phenotypic features at presentation resembled those of typical CML. However, these patients presented with a higher median age, lower median hemoglobin levels, and lower leukocyte and platelet counts than patients with Ph-positive CML. Cytogenetic analysis showed an abnormal karyotype in only one case. Southern blot investigation, using probes exploring the entire M-bcr region, demonstrated the absence of genomic bcr-abl rearrangements. The assessment of clonality in five patients (study of X-methylation patterns in females heterozygous at the DXS255 locus) indicated the proliferation of a monoclonal cell population. Disease evolution was mostly characterized by bone marrow failure, extramedullary infiltrates, and poor response to chemotherapy, without evidence of overt acute transformation. Our observations suggest that some hematologic and clinical features and the modalities of disease progression are presently the most helpful factors in distinguishing these bcr/abl-negative patients from those with typical bcr+CML. The differences existing also with chronic myelomonocytic leukemia (CMMoL), allow the consideration of ph-/bcr- CML as a separate entity, the nature of which remains to be elucidated.

Cytogenetics↗
PubMed1992

PML/RAR-alpha rearrangement in acute promyelocytic leukaemias apparently lacking the t(15;17) translocation.

Recent investigations have clarified some of the molecular mechanisms underlying the t(15;17) translocation specific for acute promyelocytic leukaemia (APL). Together with providing new insights into the pathogenesis of the disease, the identification of breakpoints within the RAR-alpha and PML loci on chromosomes 17 and 15 has allowed a new relevant diagnostic tool for the recognition of this leukaemic form. We report the molecular characterization of 6 cases of acute myelogenous leukaemia (AML) in which a diagnosis of typical M3 by conventional morphocytochemistry (FAB criteria) was not accompanied by cytogenetic evidence of the specific t(15;17) aberration. DNA rearrangements were documented in all cases at the PML and RAR-alpha loci. Moreover, in 4 cases also analysed by Northern blot hybridization, we could detect aberrant RAR-alpha transcripts. These findings highlight the specificity of PML/RAR-alpha rearrangements in APL, whereas the lack of t(15;17) may be attributed to sub-microscopic translocations as well as to the presence of non-neoplastic cells undergoing mitosis in the samples examined for karyotype.

Adolescent↗
PubMed1991

Molecular evaluation of response to all-trans-retinoic acid therapy in patients with acute promyelocytic leukemia.

The advent of retinoic acid (RA) in the treatment of acute promyelocytic leukemia (APL) has led to a high frequency of short-lasting complete remissions (CR). We studied the response to RA by molecularly analyzing the RA receptor alpha (RAR alpha) locus, which has recently been shown to be rearranged in all APLs. Southern blot analysis demonstrated that the RAR alpha rearrangements persisted in the APL samples containing maturing myeloid cells 2 to 3 weeks after the start of RA treatment, but disappeared after 5 to 8 weeks, when the patients achieved CR. Our investigations provide clear evidence that CR occurs at molecular level and that there is reconstitution of an apparently normal, nonclonal hematopoiesis. Further, it shows that RA acts by triggering differentiation rather than by exerting a cytotoxic effect on the leukemic clone.

Adult↗
PubMed1991

RAR-alpha gene rearrangements as a genetic marker for diagnosis and monitoring in acute promyelocytic leukemia.

Acute promyelocytic leukemias (APLs) are characterized by a translocation that involves chromosomes 15 and 17. The translocation breakpoints have recently been identified and shown to involve the RAR-alpha gene on 17 and myl on 15. Here we report Southern blotting analysis of 26 APLs, including cases with normal karyotypes and atypical morphology, which showed RAR-alpha rearrangements in 92% cases, myl rearrangements in 73%, and either RAR-alpha or myl rearrangements in 100%. Despite a negative clinical and morphologic picture, DNA rearrangement analysis showed that neoplastic promyelocytes persisted in the bone marrow of two patients sampled after induction chemotherapy. Therefore, the RAR-alpha and myl rearrangements provide molecular markers for accurately diagnosing APLs and monitoring the course of the disease during and after chemotherapy.

Adolescent↗
PubMed1991

Translocation breakpoint of acute promyelocytic leukemia lies within the retinoic acid receptor alpha locus.

Acute promyelocytic leukemias (APLs) are characterized by a reciprocal balanced translocation that involves chromosomes 15 and 17 [t(15;17)]. We report the isolation and characterization of one of the two reciprocal break sites and demonstrate that the chromosome 17 breakpoint lies within the retinoic acid receptor alpha locus. Nucleotide sequencing of the 15;17 cross-over junction on 15q+ showed that the retinoic acid receptor alpha gene is truncated within its first intron, 370 base pairs upstream from the splicing donor site of exon II. Such a recombination would be expected to generate abnormal RAR alpha mRNA and protein. Southern blot analysis of a number of APLs with chromosome 15- and 17-derived DNA probes revealed similar 15;17 recombinations in the majority of other APLs. Our data are strong evidence that the retinoic acid receptor alpha gene plays a crucial role in the leukemogenesis of APL.

Animals↗
PubMed1991

Rearrangements of the RAR-alpha gene in acute promyelocytic leukaemia: correlations with morphology and immunophenotype.

We have used genomic probes which specifically recognize DNA rearrangements of the RAR-alpha locus on chromosome 17q21 in patients with acute promyelocytic leukaemia (APL) and acute myeloid leukaemia (AML) subtypes. Molecular data were examined in comparison with morphological and immunophenotypic characterization at diagnosis in 20 hypergranular FAB M3 cases, five microgranular APL (M3v), 51 non-M3 AML and 12 myeloid CML blast crises. Rearrangements of the RAR-alpha locus were only detected in 23/25 APL cases and in none of the other FAB subtypes analysed. Surface marker characterization showed a consistent immunophenotypic profile--HLADR negative, CD9 and CD13/33 positive--in all M3 and M3v cases. Neither HLADR negativity nor CD9 positivity were associated with RAR-alpha rearrangements in non M3 AML. Our data indicate that RAR-alpha gene rearrangements are relevant diagnostic features of both M3 and M3v, and may prove useful molecular marker for follow-up analysis in APL patients.

Acute Disease↗
PubMed1991

Chronic myeloid leukaemia lymphoid blast crisis. Relevance of molecular analysis at the bcr and immunoglobulin heavy chain gene level in monitoring response to therapy and residual disease.

Southern blot analyses were performed in sequential DNA samples from 4 patients with Ph' + chronic myeloid leukaemia (CML) who underwent lymphoid or mixed blast crisis (BC). Genomic rearrangements at the breakpoint cluster region (bcr) and immunoglobulin heavy chain (IgH) gene level provided, in these cases, a sensitive and specific evaluation of response to therapy both in terms of blasts and Ph' + cell suppression. Recurrent BC was molecularly characterized in the 4 patients, showing each time identical individual specific DNA rearrangement patterns. Residual blasts were detected in 2 cases during intervening chronic phases by IgH rearrangements. Such findings highlight the specificity of these molecular markers, clearly indicating the failure of ablative therapy in eradicating the neoplastic clone. Finally, molecular and phenotypic identity in individual recurrent BC also suggested, in our cases, a lack of clonal evolution during disease progression.

Antineoplastic Agents↗
PubMed1991

Second primary cancer following Hodgkin's disease: updated results of an Italian multicentric study.

The risk of second primary cancer (SPC) was evaluated in 947 patients treated for Hodgkin's disease (HD) during the period January 1969 to December 1979. The median follow-up of this series was 10.5 years (range, 9 to 19). Treatment categories included radiotherapy (RT) alone (115 patients, 12%), chemotherapy (CHT) alone (161 patients, 17%), combined RT plus CHT (381 patients, 40%), and salvage treatment for resistant or relapsing HD (290 patients, 30.6%). Fifty-six SPCs were observed, occurring between 1 and 17 years from initial treatment. Among these, secondary acute nonlymphoid leukemia (s-ANLL) was the most frequent SPC (23 cases). Secondary non-Hodgkin's lymphoma (s-NHL) occurred in 5 patients, whereas a secondary solid tumor (s-ST) was observed in 28 patients. The calculated actuarial risk (+/- SE) of developing SPC was 5.0% (+/- 0.9%) and 23.1% (+/- 5.8%) at 10 and 19 years, respectively. Concerning treatment modalities and s-ANLL risk, no cases were observed in the radiotherapy group, whereas CHT plus RT and salvage groups showed the highest actuarial risk. This was, in fact, at 10 and 19 years, 3.1% (+/- 0.9%) and 8.1% (+/- 4.0%) in the former group, and 1.8% (+/- 1.0%) and 16% (+/- 9.0%) in the latter. A statistically significant difference was observed when the CHT plus RT group was compared with CHT and RT groups (P = .04). Concerning the relationships with chemotherapeutic regimens, 12 s-ANLL cases occurred in the mechlorethamine, vincristine, procarbazine, and prednisone (MOPP) plus RT group, and only one case in the group receiving doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) plus RT. A statistically significant difference of s-ANLL actuarial risk was found comparing patients receiving MOPP plus RT to all other treatment groups (P = .04). With respect to s-ST, the actuarial risk at 10 and 19 years was 2.0% (+/- 0.6%) and 13.0% (+/- 3.8%), respectively. No significant differences were found among groups treated with different modalities. These data were confirmed by a multivariate analysis, which indicated treatment modality and age as independent variables for s-ANLL and s-ST development, respectively. Based on the prolonged follow-up analysis, the actuarial SPC risk at 10 years hereby reported should reflect the real SPC incidence in our series.

Actuarial Analysis↗
PubMed1991

Identical utilization of T-cell receptor gene regions in B-lymphoid blast crisis of chronic myeloid leukemia and B-precursor acute lymphoblastic leukemia.

The configuration of the T-cell receptor (TCR) beta, gamma and delta chain genes was analyzed in 16 cases of B-lymphoid blastic crisis of chronic myeloid leukemia (BC-CML) for a better definition of the biological aspects of this cellular population, in comparison with the molecular features of B-precursor acute lymphoblastic leukemia (ALL). All cases displayed B-phenotypic features, were Ph'-positive and had a rearranged configuration of the breakpoint cluster region (bcr) and of the immunoglobulin heavy chain gene region (JH). The TCR beta chain gene was rearranged in four cases (25%), all of which displayed a monoallelic rearrangement involving the J beta 2 region. The TCR gamma chain gene was rearranged in 13 cases (81%); 13 rearranged alleles utilized the J1/2 regions, while the remaining five utilized JP1. The V regions of the group I were mostly involved. The TCR delta chain gene was rearranged or deleted in 15 cases (94%); the 10 rearranged chromosomes displayed exclusively two patterns referable to partial recombinations, a V2-(D)-D3 and a (D)-D3 type. These two configurations are predominant in B-precursor ALL (75% of rearranged chromosomes) and almost absent in T-ALL. Taken together, these results document the close similarities between the genotypic features of B-lymphoid BC-CML and B-precursor ALL, not only in terms of the incidence of rearrangement but more relevantly with regard to the choice of regions involved in the recombinations. This aspect is particularly evident at the TCR delta locus level.

Blast Crisis↗