RESUMEN
Phosphoinositide-phospholipase C (PI-PLC) beta1 can be considered a specific target for demethylating therapy in high-risk myelodysplastic syndrome (MDS) patients, as azacitidine treatment has been associated with a PI-PLCbeta1-specific promoter demethylation, and induction of PI-PLCbeta1 gene and protein expression. However, little is known about the molecular effect of azacitidine in low-risk MDS or the functional mechanisms linked with azacitidine effect on PI-PLCbeta1 promoter. In the present study, we further investigated the role of epigenetic regulation of PI-PLCbeta1, mainly focusing on the structure of the PI-PLCbeta1 promoter. We first examined the effect of azacitidine on PI-PLCbeta1 promoter methylation and gene expression in low-risk MDS. Moreover, we studied the expression of key molecules associated with the nuclear inositide signaling pathways, such as cyclin D3. By applying a chromatin immunoprecipitation method, we also studied the correlation between the demethylating effect of azacitidine and the degree of recruitment to PI-PLCbeta1 promoter of some transcription factors implicated in hematopoietic stem cell proliferation and differentiation, as well as of the methyl-CpG-binding domain proteins, which specifically interact with methylated DNA. Taken together, our results hint at a specific involvement of PI-PLCbeta1 in epigenetic mechanisms, and are particularly consistent with the hypothesis of a role for PI-PLCbeta1 in azacitidine-induced myeloid differentiation.
Asunto(s)
Antimetabolitos Antineoplásicos/uso terapéutico , Azacitidina/uso terapéutico , Epigénesis Genética , Síndromes Mielodisplásicos/tratamiento farmacológico , Fosfatidilinositoles/metabolismo , Fosfolipasa C beta/metabolismo , Transducción de Señal , Anciano , Anciano de 80 o más Años , Secuencia de Bases , Metilación de ADN , Cartilla de ADN , Femenino , Humanos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Síndromes Mielodisplásicos/enzimología , Síndromes Mielodisplásicos/patología , Fosfolipasa C beta/genética , Regiones Promotoras GenéticasRESUMEN
A number of cancers possess constitutive activity of the dsRNA-dependent kinase, PKR. Inhibition of PKR in these cancers leads to tumor cell death. We recently reported the increased presence of PKR phosphorylated on Thr451 (p-T451 PKR) in clinical samples from myelodysplastic syndrome (MDS) patients and acute leukemia cell lines. Whereas p-T451 PKR in low-risk patient samples or PTEN-positive acute leukemia cell lines was mostly cytoplasmic, in high-risk patient samples and acute leukemia cell lines deficient in PTEN, p-T451 PKR was mainly nuclear. As nuclear activity of PKR has not been previously characterized, we examined the status of nuclear PKR in acute leukemia cell lines. Using antibodies to N-terminus, C-terminus and the kinase domain in conjunction with a proteomics approach, we found that PKR exists in diverse molecular weight forms in the nucleus. Analysis of PKR transcripts by reverse transcriptase-PCR, and PKR-derived peptides by MS/MS revealed that these forms were the result of post-translational modifications (PTMs). Biochemical analysis demonstrated that nuclear PKR is an active kinase that can respond to stress. Given the association of PKR with PTEN and the Fanconi complex, these results indicate that PKR likely has other previously unrecognized roles in nuclear signaling that may contribute to leukemic development.
Asunto(s)
Núcleo Celular/enzimología , Leucemia/patología , Estrés Fisiológico , eIF-2 Quinasa/análisis , Enfermedad Aguda , Secuencia de Aminoácidos , Línea Celular Tumoral , Daño del ADN , Humanos , Leucemia/enzimología , Mitomicina/farmacología , Peso Molecular , Procesamiento Proteico-Postraduccional , Transducción de Señal , eIF-2 Quinasa/fisiologíaRESUMEN
PURPOSE: To analyze tear protein variations in patients suffering from dry eye symptoms in the presence of tear film instability but without epithelial defects. METHODS: Five microlitres of non-stimulated tears from 60 patients, suffering from evaporative dry eye (EDE) with a break-up time (BUT) <10 s, and from 30 healthy subjects as control (no symptoms, BUT >10 s) were collected. Tear proteins were separated by mono and bi-dimensional SDS-PAGE electrophoresis and characterized by immunoblotting and enzymatic digestion. Digested peptides were analyzed by liquid chromatography coupled to electrospray ionization quadrupole-time of flight mass spectrometry followed by comparative data analysis into Swiss-Prot human protein database using Mascot. Statistical analysis were performed by applying a t-test for independent data and a Mann-Whitney test for unpaired data (P<0.05). RESULTS: In EDE patients vscontrols, a significant decrease in levels of lactoferrin (data in %+/-SD): 20.15+/-2.64 vs 24.56+/-3.46 (P=0.001), lipocalin-1: 14.98+/-2.70 vs 17.73+/-2.96 (P=0.0001), and lipophilin A-C: 2.89+/-1.06 vs 3.63+/-1.37 (P=0.006) was revealed, while a significant increase was observed for serum albumin: 9.45+/-1.87 vs 3.46+/-1.87 (P=0.0001). No changes for lysozyme and zinc alpha-2 glycoprotein (P=0.07 and 0.7, respectively) were shown. Proteomic analysis showed a downregulation of lipophilin A and C and lipocalin-1 in patients, which is suggested to be associated with post-translational modifications. CONCLUSIONS: Data show that tear protein changes anticipate the onset of more extensive clinical signs in early stage dry eye disease.
Asunto(s)
Síndromes de Ojo Seco , Proteínas del Ojo/análisis , Lágrimas/química , Adipoquinas , Adulto , Anciano , Albúminas/análisis , Proteínas Portadoras/análisis , Estudios de Casos y Controles , Electroforesis en Gel de Poliacrilamida , Proteínas del Ojo/genética , Femenino , Glicoproteínas/análisis , Humanos , Lactoferrina/análisis , Lipocalinas/análisis , Lipocalinas/genética , Masculino , Persona de Mediana Edad , Muramidasa/análisis , Proteínas de la Mielina/análisis , Proteínas de la Mielina/genética , Proteolípidos/análisis , Proteolípidos/genética , Proteómica , Secretoglobinas , Uteroglobina/análisis , Uteroglobina/genéticaRESUMEN
Biochemical modulation is one of the most interesting fields in cancer chemotherapy. Interferon-alpha (IFNalpha) is a cytokine that is able to influence the pharmacodynamics of 5-fluorouracil (5FU) through a number of mechanisms. With the aim of confirming some data emerging from the literature, we initiated a multicentric randomized study comparing the combination of 5FU and IFNalpha-2a with 5FU alone in the treatment of advanced or metastatic colon cancer. A group of 205 colon cancer patients (104 in the 5FU arm and 101 in the 5FU + IFNapha-2a arm) were included in the final intention-to-treat analysis. Rectal cancers were not considered eligible. All patients had measurable disease, were aged 75 years or less, had a Karnofsky index of at least 60 and had good bone marrow, renal, liver and cardiac functions. No previous chemo-immunotherapy was allowed. The treatment was 750 mg/m2 5FU (4 h i.v. infusion) on days 1 5 and then i.v. bolus weekly, starting from day 12, with or without IFNalpha-2a given s.c. three times weekly (starting dose 3 x 10(6) IU rising to 9 x 10(6) IU, if tolerated). Patients were treated until progression or, if responsive, for a maximum of 48 weeks and then observed for a period of 2 years. The primary end-point of the study was objective clinical response (OR); secondary parameters were time to progression, overall survival, and time to death after progression. WHO criteria were used for both clinical response and toxicity measurements. Dose reduction was planned a priori in the event of significant toxicity due to 5FU, IFNalpha-2a or both. Association between primary and secondary end-points and treatment was studied by univariate and multivariate analysis. Altogether, 47 patients achieved a documented response. A 25% OR was observed in the combination arm while a 21% OR was seen in the 5FU arm; this difference is not statistically significant (P = 0.6). Patients with a small tumour burden (below 5 cm2) showed a higher probability of response in both arms. Patients in the experimental arm had a higher but not statistically significant cumulative progression-free probability. Median survival was 47.1 weeks overall, while it was 43.7 and 48.5 weeks in the control and experimental arms, respectively. The combination was clearly more toxic than 5FU alone, leukopenia being the most frequent side-effect in the experimental arm and nausea and vomiting in the control arm. In conclusion these results are quite disappointing and 5FU + IFNalpha-2a can not be considered a standard treatment for advanced colon cancer.
Asunto(s)
Antimetabolitos Antineoplásicos/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias del Colon/tratamiento farmacológico , Fluorouracilo/uso terapéutico , Anciano , Antimetabolitos Antineoplásicos/administración & dosificación , Antimetabolitos Antineoplásicos/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Femenino , Fluorouracilo/administración & dosificación , Fluorouracilo/efectos adversos , Humanos , Interferón alfa-2 , Interferón-alfa/administración & dosificación , Interferón-alfa/efectos adversos , Masculino , Persona de Mediana Edad , Proteínas RecombinantesRESUMEN
The authors report 4 cases of patients with AIDS and harbouring oral lesions of Kaposi's sarcoma. They describe the macroscopic appearance and clinical signs in relation to epidemic Kaposi's systemic ones. Because of the anamnestic or coexistence of oral mycosis (Candida), in every case the authors suppose that it may precede Kaposi's manifestations, with a very severe prognosis, correlated to progressive and deadly course of this illness.
Asunto(s)
Neoplasias de la Boca/diagnóstico , Sarcoma de Kaposi/diagnóstico , Complejo Relacionado con el SIDA/complicaciones , Complejo Relacionado con el SIDA/diagnóstico , Síndrome de Inmunodeficiencia Adquirida/complicaciones , Síndrome de Inmunodeficiencia Adquirida/diagnóstico , Adulto , Candidiasis Bucal/complicaciones , Candidiasis Bucal/diagnóstico , Seropositividad para VIH/complicaciones , Seropositividad para VIH/diagnóstico , Humanos , Masculino , Neoplasias de la Boca/etiología , Infecciones Oportunistas/complicaciones , Infecciones Oportunistas/diagnóstico , Pronóstico , Sarcoma de Kaposi/etiologíaRESUMEN
Oral complications of cancer chemotherapy have been studied in a group of 50 adult patients. A number of 25 patients was treated by means of oral hygiene and prophylactic measures: drugs and topical agents, while the other group of 25 patients had not received stomatological prevention. The goal of the research has showed that prevention measures and elimination of existing or potential sources of infection reduce and minimize mucositis, infection etc.
Asunto(s)
Antineoplásicos/efectos adversos , Estomatitis/prevención & control , Anciano , Clorhexidina , Femenino , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Humanos , Masculino , Persona de Mediana Edad , Mucosa Bucal/patología , Antisépticos Bucales , Estomatitis/inducido químicamente , VitaminasRESUMEN
The effectiveness of an 8-week, 125 mg/day intravenous course of methylprednisolone sodium succinate (MPSS) for improving quality of life in patients with preterminal cancer was investigated in a double-blind, placebo-controlled, multicenter study. Quality of life was assessed using the Nurses' Observational Scale for Inpatient Evaluation (NOSIE), the Linear Analog Self-Assessment Scale (LASA), and the Physicians' Global Evaluation. A total of 403 patients were enrolled: 207 were treated with MPSS and 196 were treated with placebo. MPSS was significantly more effective than placebo in improving quality of life as judged by the changes from baseline in the NOSIE and LASA total scores. (P less than 0.05) and by the Physicians' Global Evaluation (P less than 0.001). The mortality rate was similar between MPSS-treated males (40.2%), placebo-treated males (35.5%), and MPSS-treated females (40.0%). However, the mortality rate of 27.7% for female placebo-treated females was significantly lower than for their MPSS-treated counterparts. The reason for lower mortality among placebo-treated females is unknown and warrants further study.
Asunto(s)
Hemisuccinato de Metilprednisolona/uso terapéutico , Metilprednisolona/análogos & derivados , Neoplasias/tratamiento farmacológico , Calidad de Vida , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Método Doble Ciego , Femenino , Humanos , Masculino , Hemisuccinato de Metilprednisolona/efectos adversos , Persona de Mediana Edad , Estudios Multicéntricos como Asunto , Neoplasias/mortalidad , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
Thalamic masses are generally considered inoperable; little is known of the precise nature of these lesions. Stereotactic biopsy was performed in 44 patients, with no mortality and low morbidity (only 1 case of transitory hemiparesis). The stereotactic biopsy (minimum 5 specimens taken along the major axis of the lesion) showed that the majority of the young patients (less than 40 years) had low-grade glial neoplasms (grade I-II astrocytomas or oligodendrogliomas), while in older patients highly malignant tumors prevailed. Beside the neoplasms in the children and adults, we found granulomas, abscesses, infarcts, hemorrhages and glioses. Present neuroradiological methods cannot establish a final correct diagnosis in thalamic lesions, so stereotactic biopsy is recommended. A follow-up of 1-6 years is presented for 7 patients who underwent stereotactic 125I brachytherapy.
Asunto(s)
Neoplasias Encefálicas/patología , Técnicas Estereotáxicas , Enfermedades Talámicas/patología , Adolescente , Adulto , Biopsia/métodos , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/cirugía , Niño , Preescolar , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Enfermedades Talámicas/radioterapia , Enfermedades Talámicas/cirugía , Tomografía Computarizada por Rayos XRESUMEN
The authors report their series of 45 patients harboring inoperable, low-grade cerebral neoplasms, treated in the past 6 years with 125I stereotactic brachytherapy. The majority of these tumors were grade I and II astrocytomas and oligodendrogliomas (82.2%). A 2.6- to 6-year follow-up shows good results in 65.6% with reduction or disappearance of the lesions on CT images and good social reentry. Nine patients (23.7%) died prior to follow-up. Young patients (less than 40 years) responded well to interstitial radiotherapy, while patients over 40 with the same histological findings of low-grade tumors responded poorly to this type of treatment. Diffuse infiltrating cortico-subcortical tumors, optochiasmatic gliomas, hypothalamic and lower brainstem neoplasms do not respond satisfactorily to 125I radioisotope implantations.
Asunto(s)
Braquiterapia , Neoplasias Encefálicas/radioterapia , Radioisótopos de Yodo/uso terapéutico , Técnicas Estereotáxicas , Neoplasias Encefálicas/diagnóstico por imagen , Humanos , Tomografía Computarizada por Rayos XRESUMEN
The opportunity of stereotactic biopsy for the histological diagnosis of brain tumors, the radiobiologic bases, clinical implications and technical possibilities of interstitial radiation therapy are discussed. The results of 9 cases, out of 14 treated to-date over 20 months, with a minimum follow-up of 4 months, are presented.