RESUMEN
BACKGROUND: Human herpesvirus 8 (HHV-8) infection has been linked to the development of Kaposi's sarcoma and to rare lymphoproliferative disorders. METHODS: We used molecular methods, serologic methods, in situ hybridization, and immunohistochemical analyses to study HHV-8 infection in association with nonmalignant illnesses in three patients after transplantation. RESULTS: Primary HHV-8 infections developed in two patients four months after each received a kidney from the same HHV-8-seropositive cadaveric donor. Seroconversion and viremia occurred coincidentally with disseminated Kaposi's sarcoma in one patient and with an acute syndrome of fever, splenomegaly, cytopenia, and marrow failure with plasmacytosis in the other patient. HHV-8 latent nuclear antigen was present in immature progenitor cells from the aplastic marrow of the latter patient. Identification of the highly variable K1 gene sequence of the HHV-8 genome in both the donor's peripheral-blood cells and the recipients' serum confirmed that transmission had occurred. HHV-8 viremia also occurred after autologous peripheral-blood stem-cell transplantation in an HHV-8-seropositive patient with non-Hodgkin's lymphoma. Reactivation of the infection was associated with the development of fever and marrow aplasia with plasmacytosis; there was no evidence of other infections. HHV-8 transcripts and latent nuclear antigen were expressed in the aplastic marrow but not in two normal marrow samples obtained before transplantation. CONCLUSIONS: Primary HHV-8 infection and reactivation of infection may be associated with nonneoplastic complications in immunosuppressed patients.
Asunto(s)
Enfermedades de la Médula Ósea/etiología , Transmisión de Enfermedad Infecciosa , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Infecciones por Herpesviridae/transmisión , Herpesvirus Humano 8/aislamiento & purificación , Trasplante de Riñón/efectos adversos , Sarcoma de Kaposi/etiología , Adulto , Anticuerpos Antivirales/sangre , Recuento de Células Sanguíneas , Médula Ósea/virología , Enfermedades de la Médula Ósea/sangre , Enfermedades de la Médula Ósea/virología , Resultado Fatal , Genoma Viral , Infecciones por Herpesviridae/etiología , Infecciones por Herpesviridae/virología , Herpesvirus Humano 8/genética , Herpesvirus Humano 8/inmunología , Humanos , Huésped Inmunocomprometido , Masculino , Persona de Mediana Edad , Sarcoma de Kaposi/virología , Viremia/etiología , Activación ViralRESUMEN
Fever, cutaneous rash, and hepatitis-for which an infectious cause was suspected-developed in an Italian patient with non-Hodgkin lymphoma after autologous peripheral blood stem cell (PBSC) transplantation. Polymerase chain reaction (PCR) with degenerate primers for the highly conserved DNA polymerase gene of herpesviruses detected herpesvirus sequences 100% identical to human herpesvirus-8 (HHV-8) in serial cell-free serum samples, collected immediately before or concomitant with the occurrence of clinical symptoms; no other common infections were documented. The presence of the HHV-8 genome (clade C) was confirmed by PCR with HHV-8-specific primers for orf 26 and orf-K1. HHV-8 viremia was undetectable either before transplantation or when the patient was clinically asymptomatic. Semiquantitative PCR analysis showed variations of the viral load correlating with the clinical status. Anti-HHV-8 antibodies were detected before and after transplantation by an immunofluorescence assay for lytic antigens. Active HHV-8 infection may be associated with nonmalignant illness after PBSC/bone marrow transplantation.
Asunto(s)
Linfoma de Burkitt/virología , Trasplante de Células Madre Hematopoyéticas , Herpesvirus Humano 8 , Sarcoma de Kaposi/diagnóstico , Adulto , Secuencia de Aminoácidos , Anticuerpos Antivirales/sangre , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Linfoma de Burkitt/tratamiento farmacológico , Linfoma de Burkitt/cirugía , ADN Viral/sangre , ADN Polimerasa Dirigida por ADN/química , ADN Polimerasa Dirigida por ADN/genética , Técnica del Anticuerpo Fluorescente , Herpesvirus Humano 8/enzimología , Herpesvirus Humano 8/genética , Herpesvirus Humano 8/inmunología , Humanos , Masculino , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Sarcoma de Kaposi/etiología , Sarcoma de Kaposi/virología , Trasplante Autólogo , Carga ViralAsunto(s)
Arsenicales/uso terapéutico , Síndromes Mielodisplásicos/tratamiento farmacológico , Óxidos/uso terapéutico , Enfermedad Aguda , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Apoptosis/efectos de los fármacos , Trióxido de Arsénico , Arsenicales/farmacología , Células de la Médula Ósea/efectos de los fármacos , Técnicas de Cultivo de Célula , Factor Estimulante de Colonias de Granulocitos y Macrófagos/farmacología , Inhibidores de Crecimiento/farmacología , Inhibidores de Crecimiento/uso terapéutico , Humanos , Leucemia Mieloide/sangre , Leucemia Mieloide/tratamiento farmacológico , Leucemia Mieloide/patología , Leucocitos Mononucleares/efectos de los fármacos , Síndromes Mielodisplásicos/sangre , Síndromes Mielodisplásicos/patología , Óxidos/farmacologíaRESUMEN
BACKGROUND AND OBJECTIVE: Acute promyelocytic leukemia is characterized by the chromosomal translocation t(15;17) which yields the fusion product PML/RARa. All-trans retinoic acid probably induces differentiation of atypical promyelocytes and clinical remission in APL patients by binding to the ligand binding domain (LBD) of the RARa portion of the PML-RARa chimeric protein. Structural alterations of the LBD of the PML/RARa have been revealed in ATRA-resistant APL cell lines and in a few APL patients with acquired clinical resistance to ATRA therapy. Two APL relapsed patients with clinical resistance to ATRA therapy were evaluated for the presence of nucleotide mutations in the LBD of PML/RARa gene and then treated with arsenic trioxide (As2O3). DESIGN AND METHODS: DNA fragments from the LBD of the PML/RARa chimeric transcript were obtained by reverse-transcribed polymerase chain reaction. Direct sequencing was performed by an unambiguous bi-directional automatic analysis. Samples representative of APL onset and relapse were analyzed from both patients. RESULTS: In both patients, at the ATRA-resistant relapse, a missense point mutation in the LBD of the PML/RARa gene was found. The mutations, absent at APL onset, led to an Arg272Gln and to an Arg276Trp amino acid substitution, according to the sequence of the RARa protein. Both patients had complete clinical and hematologic remission after treatment with As2O3. INTERPRETATION AND CONCLUSIONS: LBD missense mutations appear to be a significant mechanism of acquired ATRA-resistance in vivo, closely related to clinical APL relapse. The two cases reported here provide the first in vivo evidence of APL relapsed patients, who have become ATRA-resistant for molecular reasons, being sensitive to arsenic trioxide.
Asunto(s)
Resistencia a Antineoplásicos/genética , Leucemia Promielocítica Aguda/genética , Proteínas de Neoplasias/genética , Proteínas de Fusión Oncogénica/genética , Adulto , Antineoplásicos , Trióxido de Arsénico , Arsenicales/farmacología , Sitios de Unión/genética , Médula Ósea/química , Proteínas Portadoras/genética , Humanos , Leucemia Promielocítica Aguda/terapia , Ligandos , Masculino , Persona de Mediana Edad , Mutación Missense , Óxidos/farmacología , Mutación Puntual , Estructura Terciaria de Proteína/genética , ARN Mensajero/química , Recurrencia , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Tretinoina/farmacologíaRESUMEN
We have studied the in vivo tropism of human herpesvirus 6 (HHV-6) for hemopoietic cells in patients with latent HHV-6 infection. Having used a variety of cell purification, molecular, cytogenetic, and immunocytochemical procedures, we report the first evidence that HHV-6 latently infects early bone marrow progenitor cells and that HHV-6 may be transmitted longitudinally to cells which differentiate along the committed pathways.
Asunto(s)
Células de la Médula Ósea/virología , Células Madre Hematopoyéticas/virología , Infecciones por Herpesviridae/virología , Herpesvirus Humano 6/fisiología , Latencia del Virus , Antígenos CD34/análisis , ADN Viral/análisis , Humanos , Reacción en Cadena de la PolimerasaRESUMEN
The purpose was to verify the 5-year results of the MOPPEBVCAD chemotherapy regimen with limited radiotherapy in relation to the promising preliminary data. Mechlorethamine, vincristine, procarbazine, prednisone, epidoxorubicin, bleomycin, vinblastine, lomustine, melphalan, and vindesine were delivered according to a schedule derived through hybridization, intensification, and shortening of the corresponding alternating CAD/MOPP/ABV regimen. Radiotherapy was restricted to sites of bulky involvement or to areas that responded incompletely to chemotherapy. This multicenter, controlled, nonrandomized trial involved 145 eligible patients. Radiotherapy was administered to 47 patients, 46 of whom were in complete remission after chemotherapy. Remissions were complete in 137 patients (94%), partial in 4 (3%), and null in the remaining 4. Tumor-specific, overall, relapse-free, and failure-free survival at 5 years were 0.89, 0.86, 0.82, and 0.78, respectively. Hematologic toxicity was considerable, whereas nonhematologic side effects were fully acceptable. Most of the unfavorable prognostic factors lost their clinical weight. Only age and lymphocyte depletion histologic type were statistically correlated with major follow-up endpoints; performance status and bone marrow involvement were subordinate to age. Seven patients developed a second cancer (including 3 myelodysplasias). MOPPEBVCAD with selected radiotherapy is a highly effective regimen in advanced Hodgkin's disease. Early and late toxicity are no more severe than what would be expected with other alternating or hybrid regimens. A comparison with ABVD, which is currently considered the standard regimen for advanced Hodgkin's disease, is needed.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Enfermedad de Hodgkin/tratamiento farmacológico , Enfermedad de Hodgkin/fisiopatología , Enfermedad de Hodgkin/radioterapia , Adolescente , Adulto , Anciano , Terapia Combinada , Supervivencia sin Enfermedad , Esquema de Medicación , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Inducción de Remisión , Resultado del TratamientoRESUMEN
A woman with t(15;17) and PML/RAR alpha positive acute promyelocytic leukemia (APL-M3v) achieved a complete remission (CR) with cytogenetic and molecular conversion, after one-month ATRA plus idarubicin treatment. During CR, less than one-month after consolidation therapy with topoisomerase II inhibitors, a novel t(11;19) (q13;q13.3) was detected in peripheral blood stem cells and later in harvest bone marrow cells. Persisting CR and the negativity for BCL1 and PRAD1 genes rearrangement, the autotransplantation was performed, with good outcome. The patient is still in CR eighteen months post-transplant, in spite of the persistence of a small t(11;19) clone in BM cells. The emergence of a novel chromosomal change during CR of acute leukemia is a rare phenomenon. This is the first t(11;19)(q13;q13.3) described in APL. This finding raises the issue of whether the abnormal karyotypes at remission might represent a risk of tumor recurrence. The meaning of this genomic instability is yet unknown.
Asunto(s)
Cromosomas Humanos Par 11 , Cromosomas Humanos Par 19 , Antineoplásicos/uso terapéutico , Bandeo Cromosómico , Femenino , Humanos , Idarrubicina/uso terapéutico , Hibridación Fluorescente in Situ , Leucemia Promielocítica Aguda , Persona de Mediana Edad , Translocación Genética , Tretinoina/uso terapéuticoRESUMEN
PURPOSE: Optimal tissue oxygenation, as obtained by hyperbaric oxygen therapy, potentiates or restores the host's bactericidal mechanisms and wound healing activity in patients afflicted by serious synergeic aerobic and anaerobic infections of the cutaneous and subcutaneous tissues. Furthermore, hyperbaric oxygen therapy has a direct toxic effect on anaerobic bacteria. We describe our experience with hyperbaric oxygen therapy in the treatment of 11 patients with Fournier's syndrome. MATERIALS AND METHODS: The average age of our patients was 59.5 years; the most common predisponsing condition was diabetes. All patients were treated with antibiotic therapy and hyperbaric oxygen therapy (minimum 5 and maximum 24 cycles, consisting of 90 minutes 2.5 atmosphere absolute pressure). Furthermore, 6 of these patients underwent surgical débridement of the wounds and 3 patients underwent delayed reconstructive surgery. RESULTS: The results we obtained with hyperbaric oxygen therapy as an adjunctive measure for the treatment of these infections were excellent; our mortality rate for Fournier's disease was 0. Moreover, no complications whatsoever were observed. Furthermore, the 3 patients who underwent delayed corrective surgery presented with well healed tissues and their operations were not complicated by infections or other pathological conditions. CONCLUSIONS: We believe that our findings, although limited in number, underline the excellent results that can be obtained with hyperbaric oxygen therapy as an adjunct treatment in Fournier's disease.
Asunto(s)
Gangrena de Fournier/terapia , Oxigenoterapia Hiperbárica , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Nonrandom translocations with breakpoint at band q21 on chromosome 18 might cause bcl-2 gene deregulation and might contribute to neoplastic transformation in human lymphomas. As the pattern of expression of bcl-2 in hematopoietic cells is still unclear, we have measured the level of the corresponding messenger RNA (mRNA) in a variety of myeloid and lymphoid cell malignancies not usually associated with the t(14;18) translocation. Molecular genetic analysis showed that bcl-2 was rearranged in only 2 of 77 patients: one was affected by hairy cell leukemia and one by diffuse small cleaved cell lymphoma with peripheral blood invasion. Although in rare cases of myeloid leukemia fairly high levels can be found, the expression of bcl-2 appears to be typical of certain lymphoid malignancies. High levels of bcl-2 mRNA had been found, previously, in established pre-B-cell lines. However, in fresh specimens, the peak level of bcl-2 expression shifts to a more differentiated cell type, represented by the long-living B lymphocytes that are found in most cases of chronic lymphocytic leukemia. bcl-2 gene product might have a role in prolonging cell survival and, even in the absence of translocations, might contribute to some of the biologic features that are typical of this disorder.
Asunto(s)
Médula Ósea/patología , Diferenciación Celular/fisiología , Cromosomas Humanos Par 18 , Células Madre Hematopoyéticas/fisiología , Leucemia/genética , Linfoma/genética , Trastornos Linfoproliferativos/genética , Proteínas Proto-Oncogénicas/genética , Proto-Oncogenes , Translocación Genética , Médula Ósea/fisiopatología , Linfoma de Burkitt/genética , Cromosomas Humanos Par 14 , Expresión Génica , Reordenamiento Génico , Células Madre Hematopoyéticas/patología , Humanos , Leucemia/sangre , Leucemia/patología , Leucemia de Células T/genética , Leucemia-Linfoma de Células T del Adulto/genética , Leucocitos/fisiología , Linfoma/sangre , Linfoma/patología , Trastornos Linfoproliferativos/sangre , Trastornos Linfoproliferativos/patología , Plasmacitoma/genética , Preleucemia/genética , Proteínas Tirosina Quinasas/genética , Proteínas Proto-Oncogénicas c-bcl-2 , ARN Mensajero/genética , ARN Mensajero/metabolismoRESUMEN
Molecular genetic analysis was exploited to determine the lineage of the neoplastic cells in nine patients affected by hairy cell leukemia (HCL). In all cases the B-lineage of the cells was confirmed at the molecular level. In four cases a relatively advanced maturation stage was suggested by the expression of lambda light chain genes. Surprisingly, in two patients lambda light chain gene rearrangement was observed in spite of a germ-line kappa light chain gene. In at least one case the rearrangement was productive, as a full length messenger RNA (mRNA) was shown by Northern blot analysis and lambda light chain-restricted surface immunoglobulins (sIg) were found. These data suggest that exceptions to the hierarchy that regulates light chain gene rearrangements are not uncommon in this type of leukemia and that molecular genetic analysis should include lambda gene locus to determine more precisely the lineage origin of some leukemic cell populations.
Asunto(s)
Linfocitos B/patología , Reordenamiento Génico de Cadena Ligera de Linfocito B , Cadenas lambda de Inmunoglobulina/genética , Leucemia de Células Pilosas/genética , Antígenos de Diferenciación/análisis , Diferenciación Celular , Células Clonales/patología , Reordenamiento Génico de Cadena Pesada de Linfocito B , Reordenamiento Génico de la Cadena beta de los Receptores de Antígenos de los Linfocitos T , Reordenamiento Génico de la Cadena gamma de los Receptores de Antígenos de los Linfocitos T , Humanos , Cadenas Pesadas de Inmunoglobulina/genética , Cadenas kappa de Inmunoglobulina/genética , ARN Mensajero/análisis , ARN Neoplásico/análisisRESUMEN
Forty-three patients were studied to determine whether light chain gene rearrangements may occur in hematopoietic cells not pertaining to the B-lineage. In only one patient, affected by T-cell lymphoblastic lymphoma, one kappa light chain allele was rearranged. Neither at the protein level nor at the RNA level the rearranged gene was expressed. These data confirm that, although rarely, kappa light chain gene rearrangements may occur in neoplastic T-cells. Furthermore, as in our patient Ig heavy chain genes retained a germline configuration, the present data demonstrate that kappa light chain gene rearrangements may occur regardless of Ig heavy chain gene arrangement.
Asunto(s)
Reordenamiento Génico , Genes de Inmunoglobulinas , Cadenas kappa de Inmunoglobulina/genética , Linfoma de Células T/genética , Adulto , Genes myc , Humanos , Linfoma de Células T/inmunología , Masculino , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas c-bcl-2 , Proto-OncogenesRESUMEN
To gain some insight into the role of c-myb and c-fes in myeloid differentiation, the authors have analyzed the ability of HL60 cells to differentiate in response to several different inducers after inhibition of c-myb and c-fes function. This function has been inhibited almost completely by using deoxynucleotides complementary to two 18-nucleotide sequences of c-myb and c-fes encoding mRNA. After 5 days in culture, in several separate experiments with different oligomer preparations, more than 90% growth inhibition was observed in c-myb antisense-treated HL60 cells. At this time, independent of the differentiation inducer used, c-myb antisense-treated HL60 cells differentiate only along the monocytic pathway, whereas in sense oligomer-treated cultures, retinoic acid and dimethyl sulfoxide induced granulocytic differentiation. No perturbation of the HL60 cell growth was observed after 5 days of treatment with antisense c-fes oligomer. However, induction to granulocytic differentiation by retinoic acid and dimethyl sulfoxide resulted in progressive cell death, whereas monocytic differentiation by other differentiation inducers was only marginally affected. These results suggest that granulocytic, unlike monocytic, differentiation requires c-myb-conditioned proliferation and the activity of the protein encoded by c-fes.
Asunto(s)
Diferenciación Celular , Granulocitos/citología , Oligonucleótidos Antisentido/farmacología , Proteínas Tirosina Quinasas , Proteínas Proto-Oncogénicas/genética , Ciclo Celular , Diferenciación Celular/efectos de los fármacos , Leucemia Mieloide , Proteínas Proto-Oncogénicas c-fes , Proteínas Proto-Oncogénicas c-myb , Acetato de Tetradecanoilforbol/farmacología , Tretinoina/farmacología , Células Tumorales Cultivadas , Vitamina D/farmacologíaRESUMEN
The steady state levels of mRNAs codying for the ribosomal proteins S6, S11, and S14 have been evaluated in quiescent and proliferating human fibroblasts and in resting and proliferating human peripheral blood mononuclear cells. It was found that the amounts of ribosomal protein mRNA are very similar and are not increased by serum or mitogen stimulation. The constitutive expression of these genes appears to be coordinately regulated and it is not modified after protein synthesis inhibition by cycloheximide. The ribosomal protein mRNA was also assayed in 15 different populations of human leukemic blast cells. In these populations the abundance of each ribosomal protein mRNA is remarkably different from the other. The results of our present experiments indicate that the expression of the three ribosomal protein genes undergoes independent noncoordinated changes in the large majority of the leukemic populations studied.
Asunto(s)
Expresión Génica , Leucemia/genética , Proteínas Ribosómicas/genética , Crisis Blástica/genética , Diferenciación Celular , Fibroblastos/metabolismo , Humanos , Leucemia/patología , Leucocitos Mononucleares/metabolismo , ARN/análisis , Proteína S6 RibosómicaRESUMEN
The abundance of the mRNAs of two growth-related genes, vimentin and c-myc, and that of the corresponding proteins have been studied in unstimulated and phytohemagglutinin-stimulated lymphocytes as well as in 18 populations of leukemic blast cells. The quantitative assay was carried out by densitometric scanning of Northern and Western blots. In normal lymphocytes the mRNA and the protein of both genes were almost undetectable. The phytohemagglutinin stimulation led to a sharp increase of the mRNA and the proteins of vimentin and c-myc. The increase was followed by a progressive fall of the gene products. The rate of decrease of the two mRNAs was similar to that of the corresponding proteins. In some leukemic populations very similar amounts of the vimentin protein were accompanied by amounts of the mRNA differing at least 25 times. Not unlikely, very similar amounts of p62c-myc corresponded to mRNA abundances differing at least 16 times. The coordinated biogenesis of both messenger RNAs and proteins, which occurs in mitogen-stimulated lymphocytes, is substituted, in approximately 30% of the leukemic blast cell populations, by molecular events leading to the accumulation of an excess of mRNA.
Asunto(s)
Crisis Blástica/genética , Leucemia/genética , Proteínas Proto-Oncogénicas/genética , ARN Mensajero/genética , Vimentina/genética , Crisis Blástica/patología , Northern Blotting , Western Blotting , División Celular , Expresión Génica , Humanos , Leucemia/patología , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-myc , Vimentina/metabolismoRESUMEN
The Philadelphia (Ph1) chromosome is found in the majority of patients affected by chronic myelogenous leukemia (CML), being considered the hallmark of the disease, but around 5-8% of patients diagnosed as CML lack the Ph1 chromosome-negative (Ph-) CML has been discussed extensively in the literature because of its heterogeneity. However, it is now accepted that some of the Ph1-CML patients have a disease indistinguishable from Ph1-positive (Ph+) CML. It was investigated whether Ph- CML with clinical and morphological features indicating true CML would always have bcr rearrangements, as the relocation of c-abl from 9q34 into the breakpoint cluster region on 22q11 is considered a crucial event in the pathogenesis of CML. From molecular studies, it seemed that Ph- CML with features of true CML always have the bcr rearrangement, while Ph- patients, lacking such rearrangement, have atypical forms of CML. Here we describe 8 Ph- CML and myeloproliferative syndrome (MPS) patients of whom 6 were by all respects true CML cases. Nevertheless, bcr rearrangement and expression of the classic bcr/abl chimeric mRNA was found in only 1 of the 6 patients. More advanced molecular techniques will be needed to understand which molecular mechanisms underlie Ph-, bcr- CML, resulting in phenotypes sometimes indistinguishable from Ph+, bcr+ CML.
Asunto(s)
Proteínas de Fusión bcr-abl/genética , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Leucemia Mieloide Crónica Atípica BCR-ABL Negativa/genética , Adulto , Anciano , Northern Blotting , Southern Blotting , ADN de Neoplasias/sangre , ADN de Neoplasias/genética , ADN de Neoplasias/aislamiento & purificación , Femenino , Humanos , Masculino , Persona de Mediana Edad , ARN Neoplásico/genética , ARN Neoplásico/aislamiento & purificación , Mapeo RestrictivoRESUMEN
Northern blot analysis of four typical cases of acute promyelocytic leukemia showed that one of the cell population examined was characterized by a very high level of expression of the myeloperoxidase (MPO) gene. Western blot analysis confirms that the protein content of the cells corresponded to the levels of the MPO mRNA. Southern blot studies of the DNA of this cell population ruled out the presence of any genome amplification or rearrangement. Chromosome hybridization studies in situ confirmed that the MPO gene was translocated on the long arm of chromosome 15. The observation that a typical genomic pattern may or may not be associated with the MPO overexpression leads us to believe that so far it is impossible to reach any conclusion about the significance of the translocation in the genesis of MPO overexpression.
Asunto(s)
Leucemia Promielocítica Aguda/enzimología , Peroxidasa/genética , Southern Blotting , Western Blotting , Cromosomas Humanos Par 17 , Genotipo , Humanos , Leucemia Promielocítica Aguda/genética , Peroxidasa/análisis , ARN Mensajero/análisis , Translocación GenéticaRESUMEN
Using Northern-blot analysis we have studied the expression of T-cell receptor (TCR) alpha, beta and gamma chain genes in primary cells obtained from 36 leukaemic patients. Fifteen patients had myeloid leukaemias, two had T-cell leukaemias, and 19 leukaemias corresponding to various stages of B-lymphocyte differentiation. We observed that truncated TCR beta mRNAs were produced in B-cells at relatively high levels even in the absence of detectable gene rearrangements. Ti alpha mRNAs of abnormal size were also frequently found. Such transcripts were not detectable in total RNA extracted from leukaemic myeloid cells. Factors allowing Ti alpha and beta gene transcription must be active in leukaemic pre-B and B cells but not in myeloid cells. Neither B-lineage nor myeloid leukaemias expressed TCR gamma gene at detectable levels.
Asunto(s)
Linfocitos B , Genes , Leucemia/genética , ARN Mensajero/análisis , Receptores de Antígenos de Linfocitos T/genética , Linfocitos B/inmunología , Linfocitos B/metabolismo , Northern Blotting , Humanos , Leucemia/inmunología , Leucemia/metabolismo , Receptores de Antígenos de Linfocitos T/metabolismo , Transcripción GenéticaRESUMEN
The expression of the myeloperoxidase (MPO) gene was studied, by means of Northern blot analysis in 14 cases of acute myeloid leukemia (AML), 11 cases of chronic myeloid leukemia (CML), and 6 cases of CML blast crisis, and in HL60 cells before and after induction of terminal differentiation with retinoic acid (RA), phorbol esters (TPA), or vitamin D. The expression of a panel of cell cycle-related genes, namely C-MYC, histone H3, ornithine decarboxylase, P53, vimentin, and calcyclin, was also studied in the same cell populations. Our results indicate that: (a) MPO gene expression (steady state mRNA levels) is strictly confined to the first stages of myeloid differentiation, reaching its peak at the promyelocyte stage and becoming undetectable in mature granulocytes and monocytes; (b) cells devoid of any detectable MPO enzymatic activity such as leukemic basophils have a high content of MPO mRNA; and (c) MPO gene expression is not related to the growth activity of the cell population. Finally, our results show that the pattern of expression of growth-regulated genes in the neoplastic myeloid disorders AML, CML, and CML blast crisis is remarkably different.
Asunto(s)
Genes , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Leucemia Mieloide Aguda/genética , Peroxidasa/genética , Crisis Blástica/enzimología , Crisis Blástica/genética , Crisis Blástica/patología , Northern Blotting , Southern Blotting , Ciclo Celular , Diferenciación Celular , División Celular , Sondas de ADN , Histonas/genética , Humanos , Leucemia Mielógena Crónica BCR-ABL Positiva/enzimología , Leucemia Mielógena Crónica BCR-ABL Positiva/patología , Leucemia Mieloide Aguda/enzimología , Leucemia Mieloide Aguda/patología , Oncogenes , ARN Mensajero/análisis , Células Tumorales Cultivadas/análisis , Células Tumorales Cultivadas/patologíaRESUMEN
By using a cDNA clone of the myeloperoxidase (MPO) gene, we have studied, by Northern blot analysis, the level of MPO mRNA in eight cases of acute lymphoblastic leukemia (ALL). The blast cell populations studied were characterized by morphologic, cytochemical, immunochemical, and molecular criteria. With all the methods used the populations were found to be highly homogeneous and showed a typical lymphoid phenotype. In particular, the Ig heavy-chain gene rearrangement was largely prevalent, and the germ line configuration was almost absent. However, in three of eight cases, high levels of MPO mRNA were detected. The remarkable homogeneity of the cell populations examined suggests that the MPO mRNA observed was present in cellular elements certainly identified as lymphoid. The absence of contamination by myeloid cells was confirmed by the results of Western blot analysis of the proteins of the cell population studied: no MPO protein was detectable. The levels of mRNA observed were high enough to be comparable to those observed in a promyelocytic cell population.