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2.
J Oncol Pharm Pract ; 25(4): 998-1002, 2019 Jun.
Article in English | MEDLINE | ID: mdl-29690814

ABSTRACT

Progressive multifocal leukoencephalopathy rarely occurs in patients with multiple myeloma. Intracranial central nervous system invasion is also an uncommon event in multiple myeloma, occurring in less than 1% of cases. We describe herein an exceptional case of coexisting progressive multifocal leukoencephalopathy and intraparenchymal central nervous system myeloma infiltration. A 73-year-old woman with relapsed multiple myeloma was treated with 15 cycles of lenalidomide and dexamethasone, but therapy had to be stopped because of a hip fracture after a fall. During hospitalization, the patient developed progressive multifocal leukoencephalopathy caused by John Cunningham virus, and a prominent intra-parenchymal CD138-positive infiltrate was detected. VDJ rearrangements of the immunoglobulin heavy chain gene and the mutational profile of plasma cells in bone marrow at the time of diagnosis and in brain biopsy after progression were analyzed by next generation sequencing, showing genetic differences between medullary and extramedullary myeloma cells. The role of long-term treatment with lenalidomide and dexamethasone in the development progressive multifocal leukoencephalopathy or intraparenchymal central nervous system myeloma infiltration remains unknown. However, our results suggest that both events may have arisen as a consequence of treatment-related immunosuppression. Thus, an appropriate clinical approach compatible with the simultaneous treatment of progressive multifocal leukoencephalopathy and multiple myeloma should be developed.


Subject(s)
Brain/pathology , Leukoencephalopathy, Progressive Multifocal/etiology , Multiple Myeloma/complications , Aged , Brain/diagnostic imaging , Dexamethasone/therapeutic use , Female , Humans , JC Virus , Lenalidomide/adverse effects , Magnetic Resonance Imaging , Multiple Myeloma/drug therapy , Multiple Myeloma/pathology , Neoplasm Invasiveness
3.
Haematologica ; 104(2): 288-296, 2019 02.
Article in English | MEDLINE | ID: mdl-30093399

ABSTRACT

A high proportion of patients with acute myeloid leukemia who achieve minimal residual disease negative status ultimately relapse because a fraction of pathological clones remains undetected by standard methods. We designed and validated a high-throughput sequencing method for minimal residual disease assessment of cell clonotypes with mutations of NPM1, IDH1/2 and/or FLT3-single nucleotide variants. For clinical validation, 106 follow-up samples from 63 patients in complete remission were studied by sequencing, evaluating the level of mutations detected at diagnosis. The predictive value of minimal residual disease status by sequencing, multiparameter flow cytometry, or quantitative polymerase chain reaction analysis was determined by survival analysis. The sequencing method achieved a sensitivity of 10-4 for single nucleotide variants and 10-5 for insertions/deletions and could be used in acute myeloid leukemia patients who carry any mutation (86% in our diagnostic data set). Sequencing-determined minimal residual disease positive status was associated with lower disease-free survival (hazard ratio 3.4, P=0.005) and lower overall survival (hazard ratio 4.2, P<0.001). Multivariate analysis showed that minimal residual disease positive status determined by sequencing was an independent factor associated with risk of death (hazard ratio 4.54, P=0.005) and the only independent factor conferring risk of relapse (hazard ratio 3.76, P=0.012). This sequencing-based method simplifies and standardizes minimal residual disease evaluation, with high applicability in acute myeloid leukemia. It is also an improvement upon flow cytometry- and quantitative polymerase chain reaction-based prediction of outcomes of patients with acute myeloid leukemia and could be incorporated in clinical settings and clinical trials.


Subject(s)
Biomarkers, Tumor , High-Throughput Nucleotide Sequencing , Leukemia, Myeloid, Acute/diagnosis , Leukemia, Myeloid, Acute/genetics , Neoplasm, Residual/diagnosis , Neoplasm, Residual/genetics , Adult , Female , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Nucleophosmin , Polymorphism, Single Nucleotide , Prognosis , Proportional Hazards Models , Workflow
5.
Blood ; 127(24): 3035-9, 2016 06 16.
Article in English | MEDLINE | ID: mdl-27069257

ABSTRACT

Immunoglobulin light-chain amyloidosis (AL) and multiple myeloma (MM) are 2 distinct monoclonal gammopathies that involve the same cellular compartment: clonal plasma cells (PCs). Despite the fact that knowledge about MM PC biology has significantly increased in the last decade, the same does not apply for AL. Here, we used an integrative phenotypic, molecular, and genomic approach to study clonal PCs from 24 newly diagnosed patients with AL. Through principal-component-analysis, we demonstrated highly overlapping phenotypic profiles between AL and both monoclonal gammopathy of undetermined significance and MM PCs. However, in contrast to MM, highly purified fluorescence-activated cell-sorted clonal PCs from AL (n = 9) showed almost normal transcriptome, with only 38 deregulated genes vs normal PCs; these included a few tumor-suppressor (CDH1, RCAN) and proapoptotic (GLIPR1, FAS) genes. Notwithstanding, clonal PCs in AL (n = 11) were genomically unstable, with a median of 9 copy number alterations (CNAs) per case, many of such CNAs being similar to those found in MM. Whole-exome sequencing (WES) performed in 5 AL patients revealed a median of 15 nonrecurrent mutations per case. Altogether, our results show that in the absence of a unifying mutation by WES, clonal PCs in AL display phenotypic and CNA profiles similar to MM, but their transcriptome is remarkably similar to that of normal PCs.


Subject(s)
Amyloidosis/genetics , Immunoglobulin Light Chains/genetics , Paraproteinemias/genetics , Plasma Cells/metabolism , Transcriptome , Amyloidosis/metabolism , Amyloidosis/pathology , Clone Cells/metabolism , Clone Cells/pathology , Gene Expression Profiling , Genome-Wide Association Study , Genomics , High-Throughput Nucleotide Sequencing , Humans , Immunophenotyping , Microarray Analysis , Paraproteinemias/metabolism , Paraproteinemias/pathology , Phenotype , Plasma Cells/pathology
6.
Oncologist ; 18(4): 446-53, 2013.
Article in English | MEDLINE | ID: mdl-23576480

ABSTRACT

OBJECTIVE: Treatment with anthracyclines may cause cardiac dysfunction, but the sequence of anthracycline-induced heart lesions has been incompletely characterized. NADPH oxidase, a key mediator of oxidative cardiac damage and remodeling, modulates anthracycline clinical cardiotoxicity. Our aim was to determine which cardiac histological lesions are specifically induced by anthracycline treatment and to investigate the role of NADPH functional genetic polymorphisms in their development. PATIENTS AND METHODS: Using a retrospective case-control design, we evaluated cardiac histological lesions and NADPH genotype (polymorphisms rs1883112, rs4673, and rs13058338) in 97 consecutive decedents with a cancer diagnosis (48 treated with anthracyclines). RESULTS: Myocytolysis (60%), patched myocardial necrosis (19%), and myocardial fibrosis (diffuse and patched; 62% and 23%, respectively) were associated with anthracycline treatment. In patients receiving anthracyclines, NADPH oxidase polymorphism rs4673 protected against focal myocardial necrosis (odds ratio [OR], 0.11; 95% confidence interval [CI], 0.20-0.63) whereas rs1883112 was strongly associated with cardiac fibrosis (OR, 5.11; 95% CI, 1.59-16.43), which was present in all homozygotes. CONCLUSION: Anthracyclines induce a cardiac remodeling pattern characterized by interstitial or patched fibrosis. The contribution of the functionally relevant NADPH polymorphisms rs1883112 and rs4673 to anthracycline-related heart lesions provides a plausible explanation for their modulation of cardiotoxicity. If confirmed, these findings may lead to better individualized strategies for early detection and prevention of anthracycline cardiotoxicity.


Subject(s)
Anthracyclines/administration & dosage , Heart Failure/genetics , Heart/drug effects , Myocardium/pathology , NADPH Oxidases/genetics , Adult , Anthracyclines/adverse effects , Autopsy , Case-Control Studies , Drug-Related Side Effects and Adverse Reactions/genetics , Drug-Related Side Effects and Adverse Reactions/pathology , Female , Genetic Association Studies , Heart Failure/chemically induced , Heart Failure/pathology , Humans , Male , Middle Aged , Neoplasms/drug therapy , Neoplasms/pathology , Oxidative Stress , Polymorphism, Genetic , Retrospective Studies
7.
Rev. esp. cardiol. (Ed. impr.) ; 65(3): 219-226, mar. 2012. ilus
Article in Spanish | IBECS | ID: ibc-97725

ABSTRACT

Introducción y objetivos. Los alelos CYP2C19*2 y *17 parecen relacionarse con la variabilidad en el metabolismo del clopidogrel. Los objetivos del presente estudio son valorar la relación fenotipo-genotipo asociada a los polimorfismos CYP2C19*2 y *17 y explorar el impacto clínico de estos polimorfismos durante 6 meses de seguimiento en una población no seleccionada con síndrome coronario agudo sin elevación del segmento ST. Métodos. Se reclutó a 40 pacientes estables doblemente antiagregados, 12 meses después del implante de stent coronario para el primer objetivo, y a 493 pacientes ingresados con síndrome coronario agudo sin elevación del segmento ST para el segundo. La reactividad plaquetaria se evaluó mediante agregometría óptica estimulando las plaquetas con adenosina difosfato o péptido activador del receptor de trombina, y valorando la fosfoproteína estimulada por vasodilatadores fosforilada mediante citometría de flujo. El genotipo para los polimorfismos CYP2C19*2 y *17 se analizó con sondas TaqMan. Resultados. Sólo el test de fosforilación de fosfoproteína estimulada por vasodilatadores mostró diferencias significativas en la reactividad plaquetaria entre los pacientes portadores y no portadores de los alelos CYP2C19*2 (p=0,020) y *17 (p=0,048). No se observó asociación con el pronóstico a 6 meses de los alelos CYP2C19*2 ([HR (IC95%): 1 (0,94-1,55)], p=0,984) y *17 ([HR (IC95%): 0,93 (0,61-1,43)], p=0,753). Conclusiones. Los polimorfismos de CYP2C19 *2 y *17 se relacionaron con la reactividad plaquetaria, pero no con el pronóstico a 6 meses, en el que multitud de variables deben influir (AU)


Introduction and objectives. CYP2C19*2 and CYP2C19*17 alleles appear to contribute to heterogeneous clopidogrel metabolism. The aims of the present study were to assess the phenotype-genotype relationship of CYP2C19*2 and *17 allele carriage and to explore the clinical impact of those polymorphisms at 6-month follow-up of an acute event in an unselected population of non-ST elevation acute coronary syndrome. Methods. Recruitment for the first and second objectives was 40 stable acute coronary syndrome patients under dual antiplatelet therapy at 12 months after coronary stent placement and an unselected population of 493 consecutive patients with non-ST elevation acute coronary syndrome, respectively. Platelet reactivity was assessed by optical aggregometry induced by adenosine diphosphate and thrombin receptor activating peptide, and by vasodilator-stimulated phosphoprotein phosphorylation measurement using flow cytometry. Genotypes were determined with a TaqMan assay. Results. Only the vasodilator-stimulated phosphoprotein phosphorylation measurement detected significant differences in on-clopidogrel platelet reactivity between the wild-type subjects and the CYP2C19*2 (P=.020) and *17 allele carriers (P=.048). No significant difference was found between CYP2C19*2 ([HR (95%CI): 1 (0.94-1.55)], P=.984) or *17 ([HR (95%CI): 0.93 (0.61-1.43)], P=.753) allele carriage and the occurrence of adverse events at 6-month follow-up. Conclusions. Even though CYP2C19 genotype is associated with variable on-clopidogrel platelet reactivity, it has no significant clinical influence. Prognosis of acute coronary syndromes may be influenced by a myriad of variables (AU)


Subject(s)
Humans , Male , Female , Middle Aged , Polymorphism, Genetic , Polymorphism, Genetic/physiology , Prognosis , Acute Coronary Syndrome/drug therapy , Acute Coronary Syndrome/prevention & control , Platelet Aggregation Inhibitors , Platelet Aggregation Inhibitors/metabolism , Reactivity-Stability , Acute Coronary Syndrome/metabolism , Acute Coronary Syndrome/physiopathology , Alleles
8.
Int J Cardiol ; 154(3): 282-6, 2012 Feb 09.
Article in English | MEDLINE | ID: mdl-20974500

ABSTRACT

BACKGROUND: The involvement of iron in anthracycline cardiotoxicity is supported by extensive experimental data, and by the preventive efficacy of dexrazoxane, an iron chelator. However, no clinical evidence of anthracycline-induced cardiac iron accumulation is available and the influence of previous iron overload or of genetic factors in human-induced heart disease is largely unknown. Our aim was to test the hypothesis that anthracyclines increase iron heart concentration and that HFE genotype modulates this iron deposit. METHODS: We retrospectively evaluated cardiac events, cardiac iron and HFE genotype in 97 consecutive necropsies from patients with solid and hematological neoplasms. Heart and liver iron concentration was determined by atomic absorption spectroscopy. HFE gene mutations (C282Y and H63D) linked to hereditary hemochromatosis were analyzed by Fluorescence Resonance Energy Transfer (FRET) genotyping. RESULTS: Heart iron concentration was increased in cases treated with a cumulative doxorubicin dose greater than 200mg/m(2) (490 vs 240 µg/g; p=0.01), independently of liver iron load or transfusion history. HFE mutated haplotypes 282C/63D (p=0.049) and 282Y/63H (p=0.027) were associated to higher cardiac iron deposits. The haplotype C282Y-Y/H63D-H interacted with anthracyclines for increasing cardiac iron load. In a multivariate linear regression analysis both HFE genotypes and anthracyclines contributed to heart iron concentration (R(2)=0.284). CONCLUSIONS: Our data support the occurrence of an HFE-modulated heart iron accumulation in individuals treated with anthracyclines, independently of systemic iron load. If prospectively confirmed, iron-related parameters might be useful as predictive factors for anthracycline cardiotoxicity.


Subject(s)
Anthracyclines/adverse effects , Hemochromatosis/genetics , Hemochromatosis/metabolism , Histocompatibility Antigens Class I/genetics , Iron/metabolism , Membrane Proteins/genetics , Mutation , Myocardium/metabolism , Adult , Cadaver , Female , Genotype , Hemochromatosis Protein , Humans , Male , Middle Aged , Retrospective Studies
9.
Rev Esp Cardiol (Engl Ed) ; 65(3): 219-26, 2012 Mar.
Article in English, Spanish | MEDLINE | ID: mdl-22116003

ABSTRACT

INTRODUCTION AND OBJECTIVES: CYP2C19*2 and CYP2C19*17 alleles appear to contribute to heterogeneous clopidogrel metabolism. The aims of the present study were to assess the phenotype-genotype relationship of CYP2C19*2 and *17 allele carriage and to explore the clinical impact of those polymorphisms at 6-month follow-up of an acute event in an unselected population of non-ST elevation acute coronary syndrome. METHODS: Recruitment for the first and second objectives was 40 stable acute coronary syndrome patients under dual antiplatelet therapy at 12 months after coronary stent placement and an unselected population of 493 consecutive patients with non-ST elevation acute coronary syndrome, respectively. Platelet reactivity was assessed by optical aggregometry induced by adenosine diphosphate and thrombin receptor activating peptide, and by vasodilator-stimulated phosphoprotein phosphorylation measurement using flow cytometry. Genotypes were determined with a TaqMan assay. RESULTS: Only the vasodilator-stimulated phosphoprotein phosphorylation measurement detected significant differences in on-clopidogrel platelet reactivity between the wild-type subjects and the CYP2C19*2 (P=.020) and *17 allele carriers (P=.048). No significant difference was found between CYP2C19*2 ([HR (95%CI): 1 (0.94-1.55)], P=.984) or *17 ([HR (95%CI): 0.93 (0.61-1.43)], P=.753) allele carriage and the occurrence of adverse events at 6-month follow-up. CONCLUSIONS: Even though CYP2C19 genotype is associated with variable on-clopidogrel platelet reactivity, it has no significant clinical influence. Prognosis of acute coronary syndromes may be influenced by a myriad of variables.


Subject(s)
Acute Coronary Syndrome/genetics , Aryl Hydrocarbon Hydroxylases/genetics , Platelet Aggregation Inhibitors/therapeutic use , Ticlopidine/analogs & derivatives , Acute Coronary Syndrome/blood , Acute Coronary Syndrome/enzymology , Aged , Clopidogrel , Cohort Studies , Cytochrome P-450 CYP2C19 , Female , Follow-Up Studies , Genotype , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Phenotype , Phosphoproteins/metabolism , Platelet Aggregation/drug effects , Platelet Function Tests , Polymorphism, Genetic , Prognosis , Regression Analysis , Ticlopidine/therapeutic use
10.
Ann Hematol ; 89(11): 1147-54, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20532885

ABSTRACT

Hereditary disorders of primary hemostasis, characterized by mucocutaneous bleeding (MCB), are highly prevalent in children. Few cases are clearly monogenic, but the overwhelming majority are classified as mild bleeding disorders, with wide clinical and laboratory heterogeneity suggestive of complex polygenic diseases. In this framework, and by homology with venous thrombosis, some functional polymorphisms affecting the hemostatic system should be considered. We evaluated the role of 18 common hemostatic polymorphisms on the occurrence and severity of MCB in a case-control study including 269 patients and 286 matched controls consecutively recruited. FV Leiden was associated with milder bleeding severity, assessed by a standardized bleeding score (p = 0.013). Multivariate analysis revealed that three additional polymorphisms protected against MCB (F13 Leu34, OR = 0.66; 95% CI, 0.47-0.94; p = 0.024; VKORC1 1173T, OR = 0.59; 95% CI, 0.40-0.87; p = 0.009; and non-O blood group alleles, OR = 0.59; 95% CI, 0.41-0.86; p = 0.006). When combined, these polymorphisms showed an additive protection (OR = 0.24; 95% CI, 0.11-0.52), supporting the polygenic nature of MCB. Our data suggest that some common polymorphisms affecting hemostasis-related genes could protect from bleeding.


Subject(s)
Hemorrhagic Disorders/genetics , Hemostasis/genetics , Mucous Membrane/physiopathology , Polymorphism, Genetic , Adolescent , Adult , Animals , Case-Control Studies , Child , Child, Preschool , Factor V/genetics , Female , Genetic Predisposition to Disease , Genotype , Humans , Middle Aged , Molecular Sequence Data , Young Adult
11.
Haematologica ; 94(4): 589-92, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19229049

ABSTRACT

Genetic factors involved in the interindividual variability of antithrombin have not been identified. We studied two polymorphisms of the gene coding for antithrombin (SER-PINC1) in 298 Spanish Caucasian blood donors: rs3138521, a DNA length polymorphism located on the promoter region and rs2227589, a SNP located on intron 1 that has been described as a mild thrombotic risk factor. We detected a complete linkage disequilibrium between these polymorphisms (D'=0.999). The rs3138521 polymorphism has no functional consequences. However, the rs2227589 SNP significantly associated with plasma anti-FXa activity and antithrombin levels: carriers of the A allele had slightly but significantly lower anticoagulant activity and levels than GG subjects (97.0+/-7.3% vs. 94.6+/-8.4%; p=0.032; 99.5+/-5.8% vs. 94.8+/-5.6%; p=0.001; respectively). Our results identified a functional effect of the rs2227589 polymorphism not explained by its linkage with the promoter polymorphism that support the moderate thrombotic risk associated with the A allele.


Subject(s)
Antithrombins/analysis , Polymorphism, Single Nucleotide/genetics , Serpins/genetics , Thrombophilia/genetics , Adult , Antithrombin III , Antithrombins/genetics , Antithrombins/physiology , Blood Coagulation Factor Inhibitors/genetics , Female , Humans , Linkage Disequilibrium , Male , Serpins/physiology , Spain/epidemiology , Thrombophilia/epidemiology
12.
Br J Haematol ; 144(6): 856-64, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19133980

ABSTRACT

Glucocorticoid (GC) effects are mediated by the glucocorticoid receptor (GR). Several studies have demonstrated that a lower number of receptors per cell were associated with poor GC response. The regulation of GR expression is complex; the levels of GR can be autologously regulated by its ligand and also by transcriptional, post-transcriptional and post-translational mechanisms. Using three human myeloma cell lines that parallel the development of GC resistance, this work describes the mechanism involved in the downregulation of GR expression. The decreased expression was neither due to mutations in the gene encoding GR, NR3C1, nor due to methylation of the promoters. A gradual decrease in NR3C1 transcripts was seen during the development of resistance, the level of expression of exon 1 to 2 RNA fragments remained the same in sensitive and resistant cell lines but a chromatin immunoprecipitation assay demonstrated that RNA polymerase II, detectable throughout exon 2 to 3 in the sensitive cells, was undetectable on exon 3 in the resistant variant, suggesting lower or no transcription at this site. These studies demonstrated that downregulation of NR3C1 mRNA in a resistant cell line involves a block to transcriptional elongation within intron B of NR3C1. This block may represent an important element in the regulation of GR expression.


Subject(s)
Down-Regulation , Drug Resistance, Neoplasm/genetics , Multiple Myeloma/genetics , Mutation , Promoter Regions, Genetic , Receptors, Glucocorticoid/genetics , Base Sequence , Cell Line , Chromatin Immunoprecipitation/methods , DNA Mutational Analysis/methods , Glucocorticoids/therapeutic use , Humans , Introns , Molecular Sequence Data , Multiple Myeloma/drug therapy , Multiple Myeloma/metabolism , Receptors, Glucocorticoid/metabolism , Reverse Transcriptase Polymerase Chain Reaction/methods , Transcription, Genetic
13.
Mol Cancer Ther ; 5(12): 3062-70, 2006 Dec.
Article in English | MEDLINE | ID: mdl-17172408

ABSTRACT

Although glucocorticoids play an important role in the treatment of multiple myeloma, some patients do not respond or develop resistance. The glucocorticoid receptor (GR), a single gene, mediates the effects of glucocorticoids. Using a model system of a multiple myeloma cell line sensitive to glucocorticoids and its early and late resistant variants, we have analyzed mutations in the GR gene, detected the presence of different transcriptional isoforms, quantified their levels of expression, and identified the promoters that regulate their expression. Levels of GR transcripts were comparable with the expression of total GR protein. Development of resistance correlates with an overall reduction in GR mRNA levels. This decrease in GR levels is neither due to mutation of the gene nor due to methylation. GRalpha is the predominant isoform in the sensitive cell line decreasing in expression in the early resistant cells and virtually undetectable in late resistant cells. GR-P is expressed at equivalent levels in both sensitive and early resistant cells, whereas in the late resistant cells, GR-P is the predominant isoform. GR-A is only expressed in the early resistant cell line. GRbeta is the least expressed isoform in all cell lines. Interestingly, the level of expression of exon 1-exon 2 RNA fragments remains similar in sensitive and resistant cell lines. Resistant cells became sensitive to glucocorticoids after GRalpha transfection. In conclusion, we show different patterns of expression of the GR isoforms and provide evidence that a decline in the expression of GRalpha may be associated with development of resistance.


Subject(s)
Multiple Myeloma/genetics , Receptors, Glucocorticoid/genetics , Cell Line, Tumor , DNA Methylation , Drug Resistance, Neoplasm , Gene Expression Profiling , Gene Expression Regulation, Neoplastic , Glucocorticoids/pharmacology , Humans , Multiple Myeloma/drug therapy , Multiple Myeloma/metabolism , Promoter Regions, Genetic , Protein Isoforms , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , Receptors, Glucocorticoid/biosynthesis , Transcription, Genetic , Transfection
14.
Mod Pathol ; 17(1): 96-103, 2004 Jan.
Article in English | MEDLINE | ID: mdl-14657955

ABSTRACT

Chronic myelogenous leukemia is characterized by the presence of the reciprocal t(9;22)(q34;q11) in which c-abl located on chromosome 9, and the bcr locus located on chromosome 22, are disrupted and translocated creating a novel bcr-abl fusion gene residing on the derivative chromosome 22. In most cases, the breakpoint in abl occurs within intron 1. Depending on the breakpoint in bcr, exon 2 of abl (a2) joins with exons 1 (e1), 13 (b2), or 14 (b3), or rarely to exon 19 (e19) of bcr resulting in chimeric proteins of p190, p210 and p230, respectively. Currently, several multiplex real-time reverse transcriptase-polymerase chain reaction (RT-PCR)-based assays for detecting bcr-abl are available to assess the levels of the three common fusion transcripts, b2a2, b3a2 and e1a2. Although these assays circumvent the requirement for individual fusion sequence quantitative polymerase chain reaction-based assays, they do not identify the specific fusion transcript. Knowledge of the latter is useful to rule out false-positive results and to compare clones before and after therapy. We designed a novel multiplex real-time RT-PCR assay to detect bcr-abl that allows accurate quantification and determination of the specific fusion transcript. In this assay, abl primer labeled at its 5' end with the fluorescent dye NED (Applied Biosystems) is incorporated into the bcr-abl fusion product during amplification. The NED fluorescent dye in abl primer, without interfering with fluorescent TaqMan probe signal, allows subsequent identification of the fusion transcript by semiautomated high-resolution capillary electrophoresis and GeneScan analysis.


Subject(s)
Electrophoresis, Capillary , Fusion Proteins, bcr-abl/genetics , Gene Expression Regulation, Neoplastic , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics , Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics , RNA, Messenger/analysis , Reverse Transcriptase Polymerase Chain Reaction/methods , Taq Polymerase , Bone Marrow/chemistry , Bone Marrow/pathology , Bone Marrow Examination , DNA Primers , Fluorescent Dyes , Humans , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology , Precursor Cell Lymphoblastic Leukemia-Lymphoma/pathology , Reproducibility of Results , Transcription, Genetic
15.
J Mol Diagn ; 4(4): 223-9, 2002 Nov.
Article in English | MEDLINE | ID: mdl-12411590

ABSTRACT

Follicular lymphoma is characterized by the presence of the t(14;18)(q32;q21) chromosomal translocation which juxtaposes the bcl-2 gene at 18q21 with the immunoglobulin heavy chain locus at 14q32. Quantification of t(14;18) carrying cells in FL patients can be achieved by real-time PCR, a highly sensitive technique for evaluating treatment efficacy and minimal residual disease. Despite the many advantages of real-time technology for this purpose, one disadvantage is that current real-time t(14;18) PCR assays amplify a control gene as a normalizer in a separate reaction. Since each PCR reaction has its own kinetics, separate PCR assays for target and control sequences can potentially result in inaccurate quantification of t(14;18)-positive cells. In addition, the real-time t(14;18) PCR assays do not determine the size of the amplified fusion sequence, which is helpful for excluding contamination and is commonly used to demonstrate clonal identity between pre- and post-treatment specimens from a patient. To address these limitations, we designed a multiplex real-time PCR protocol that allows amplification of control and target genes in the same reaction and precise size determination of bcl-2/JH fusion sequences by capillary electrophoresis. This multiplex PCR assay is equally sensitive to previous assays, allows more accurate quantification of bcl-2/JH fusion sequences, and is more convenient.


Subject(s)
Chromosomes, Human, Pair 14/genetics , Chromosomes, Human, Pair 18/genetics , Electrophoresis, Capillary/methods , Lymphoma, Follicular/genetics , Polymerase Chain Reaction/methods , Proto-Oncogene Proteins c-bcl-2/genetics , DNA Primers/chemistry , DNA, Neoplasm/genetics , HL-60 Cells , Humans , Immunoglobulin Joining Region/genetics , Lymphoma, Follicular/pathology , Oncogene Proteins, Fusion/genetics , Sensitivity and Specificity , Translocation, Genetic
16.
Mod Pathol ; 15(4): 448-53, 2002 Apr.
Article in English | MEDLINE | ID: mdl-11950920

ABSTRACT

Follicular lymphoma is characterized by the presence of the t(14;18)(q32;q21) chromosomal translocation that juxtaposes the bcl-2 gene at 18q21 with the immunoglobulin heavy chain (IgH) locus at 14q32. We have previously shown that accurate quantitation of t(14;18)-carrying cells in follicular lymphoma patients can be achieved by non-gel-based real-time TaqMan polymerase chain reaction (PCR; Applied Biosystems, Foster City, CA). Since our report, several studies have demonstrated that real-time PCR is highly sensitive and a reliable tool for evaluating treatment effectiveness and for following minimal residual disease in follicular lymphoma patients. Unfortunately, currently available real-time PCR methods do not determine the size of the amplification product, which is useful for excluding contamination and is commonly used as presumptive evidence of clonal identity or disparity when multiple samples from the same patient are analyzed. We describe a modified real-time PCR assay that rapidly allows accurate quantitation and precise determination of the size of the t(14;18) fusion sequence without the need for gel electrophoresis. In this assay, a consensus immunoglobulin heavy chain-joining region gene (JH) primer labeled at its 5' end with the fluorescent dye NED (Applied Biosystems) is included in the real-time PCR assay and thus is incorporated into the bcl-2/JH fusion product. The JH-NED primer did not interfere with the TaqMan probe fluorescent signal or target detection and allowed subsequent amplicon size determination by semiautomated high-resolution capillary electrophoresis.


Subject(s)
Chromosomes, Human, Pair 14/genetics , Chromosomes, Human, Pair 18/genetics , Electrophoresis, Capillary/methods , Polymerase Chain Reaction/methods , Translocation, Genetic , DNA, Neoplasm/genetics , HL-60 Cells , Humans , Immunoglobulin Joining Region/genetics , Lymphoma, Follicular/genetics , Lymphoma, Follicular/pathology , Oncogene Proteins, Fusion/genetics , Proto-Oncogene Proteins c-bcl-2/genetics , Sensitivity and Specificity
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