RESUMEN
BACKGROUND: Neuroblastic tumors (NBT) derive from neural crest stem cells (NCSC). Histologically, NBT are composed by neuroblasts and Schwannian cells. In culture, neuroblastic (N-), substrate-adherent (S-) and intermediate phenotype (I-) cell subtypes arise spontaneously. METHODS: Here, neuroblastoma (NB) cell line subtypes were characterized according to embryonic peripheral nervous system development markers (GAP43, Phox2b, Sox10, c-kit, GD2, NF68, vimentin, S100beta, calcyclin and ABCG2), morphological features, gene expression and differentiation potential. I-type cells were investigated as a bipotential (neuronal and glial) differentiation stage. RESULTS: Positive immunostaining of NCSC (GAP43, c-kit, NF68, vimentin and Phox2b) and undifferentiated cell (ABCG2) markers was observed in all NB subtypes. N- and I-type cells displayed cytoplasmic membrane GD2 staining, while nuclear calcyclin was restricted to S-type. N- and I-type cells showed similar phenotype and immunoreactivity pattern. Differential gene expression was associated with each cell subtype. N- and I-type cells displayed similar differentiation capacity towards neuronal and glial lineage fates. S-type cells, upon induction, did not show a neuronal-like phenotype, despite gene expression changes. CONCLUSION: Results suggest that N- and I-type NB cell subtypes represent an immature bilineage stage, able to progress towards neuronal and glial fates upon induction of differentiation. S-type cells appear irreversibly committed to a glial lineage fate.
Asunto(s)
Linaje de la Célula/fisiología , Cresta Neural/citología , Neuroblastoma/metabolismo , Neuroblastoma/patología , Células Madre/citología , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2 , Transportadoras de Casetes de Unión a ATP/metabolismo , Bromodesoxiuridina/farmacología , Proteínas de Ciclo Celular/genética , Diferenciación Celular/efectos de los fármacos , Línea Celular Tumoral , Linaje de la Célula/genética , Proteína GAP-43/metabolismo , Proteínas de Homeodominio/metabolismo , Humanos , Inmunohistoquímica , N-Acetilgalactosaminiltransferasas/genética , Proteínas de Neoplasias/metabolismo , Proteínas de Neurofilamentos/metabolismo , Proteínas Proto-Oncogénicas c-kit/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Proteína A6 de Unión a Calcio de la Familia S100 , Proteínas S100/genética , Factores de Transcripción SOXE/genética , Células Madre/metabolismo , Factores de Transcripción/metabolismo , Tretinoina/farmacología , Vimentina/metabolismoRESUMEN
BACKGROUND: Potassium channels are important in pulmonary circulation because they have been closely related to hypoxic pulmonary vasoconstriction (HPV). The objective of the study was to determine whether structural changes in pulmonary arteries (PA), such as those observed in patients with chronic obstructive pulmonary disease (COPD), might be associated with changes in the mRNA expression of both BK(Ca) and K(V) channels and their potential relationship with HPV. METHODS: PA (about 1.5 mm in diameter) were obtained from 16 patients who underwent resective lung surgery. Intimal thickening was evaluated morphometrically. mRNA expression of BK(Ca), K(V)1.2, K(V)1.5, K(V)2.1 and K(V)3.1 was evaluated by RT-PCR in PA homogenates. Endothelial function and HPV were assessed in vitro in isolated PA using an organ bath. RESULTS: Intimal enlargement was closely associated with an increase in the expression of BK(Ca) channel (r=0.57, p<0.05). Pulmonary arteries incubated with charybdotoxin, a BK(Ca) channel blocking agent, showed lower response to endothelium-dependent vasodilators indicating its contribution to reduce vascular tone. Pulmonary arteries with more pronounced responses to hypoxia were those with greater gene expression of BK(Ca) channels, suggesting a potential role in attenuating HPV (r=0.52, p<0.05). No changes in the expression of K(V) channels were found in remodeled arteries. CONCLUSIONS: Structural changes of PA in COPD could alter the response to hypoxia due to changes in BK(Ca) potassium channel distribution. Since BK(Ca) channels contribute to diminish vascular tone, their increased expression in remodeled PA might play a role in attenuating HPV.
Asunto(s)
Endotelio Vascular/fisiopatología , Canales de Potasio Calcio-Activados/fisiología , Arteria Pulmonar/fisiopatología , Vasoconstricción/fisiología , Anciano , Western Blotting , Caribdotoxina/farmacología , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/metabolismo , Histamina/farmacología , Humanos , Hipoxia/fisiopatología , Inmunoquímica , Técnicas In Vitro , Masculino , Persona de Mediana Edad , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patología , Norepinefrina/farmacología , Canales de Potasio Calcio-Activados/genética , Canales de Potasio Calcio-Activados/metabolismo , Cloruro de Potasio/farmacología , Arteria Pulmonar/metabolismo , Arteria Pulmonar/patología , Enfermedad Pulmonar Obstructiva Crónica/genética , Enfermedad Pulmonar Obstructiva Crónica/metabolismo , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Túnica Íntima/metabolismo , Túnica Íntima/patología , Vasoconstricción/efectos de los fármacosRESUMEN
TGFbeta acts as a tumor suppressor in normal epithelial cells and early-stage tumors and becomes an oncogenic factor in advanced tumors. The molecular mechanisms involved in the malignant function of TGFbeta are not fully elucidated. We demonstrate that high TGFbeta-Smad activity is present in aggressive, highly proliferative gliomas and confers poor prognosis in patients with glioma. We discern the mechanisms and molecular determinants of the TGFbeta oncogenic response with a transcriptomic approach and by analyzing primary cultured patient-derived gliomas and human glioma biopsies. The TGFbeta-Smad pathway promotes proliferation through the induction of PDGF-B in gliomas with an unmethylated PDGF-B gene. The epigenetic regulation of the PDGF-B gene dictates whether TGFbeta acts as an oncogenic factor inducing PDGF-B and proliferation in human glioma.
Asunto(s)
Proliferación Celular/efectos de los fármacos , Metilación de ADN , Glioma/patología , Proteínas Proto-Oncogénicas c-sis/genética , Proteína Smad2/metabolismo , Factor de Crecimiento Transformador beta/farmacología , Adolescente , Adulto , Anciano , Astrocitoma/metabolismo , Astrocitoma/patología , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patología , Niño , Preescolar , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Glioblastoma/metabolismo , Glioblastoma/patología , Glioma/metabolismo , Humanos , Lactante , Persona de Mediana Edad , Análisis de Secuencia por Matrices de Oligonucleótidos , Fosforilación , Pronóstico , Proteínas Proto-Oncogénicas c-sis/metabolismo , Receptores de Factores de Crecimiento Transformadores beta/metabolismo , Transducción de Señal , Proteína smad7/metabolismo , Tasa de Supervivencia , Células Tumorales CultivadasRESUMEN
BACKGROUND/AIM: Pro-inflammatory cytokines and chemokines, such as interleukin (IL) 8, are important mediators of hepatic injury and repair following an insult. The purpose of this work was to study the regulation of IL-8 by IL-10 and IL-4 in HepG2 cells treated with acetaldehyde (Ac). METHODS: HepG2 cells were pretreated with IL-10 or IL-4 before exposure to Ac, examining IL-8 expression by reverse transcription polymerase chain reaction and Western blot. RESULTS: Ac treatment produced an increment in IL-8 induction and secretion that was prevented by IL-4 pretreatment, while IL-10 pretreatment failed to decrease Ac-induced IL-8 production. Consistent with these findings Ac increased NF-kappa B and AP-1 activation that were prevented by IL-4 but not by IL-10, findings accompanied by greater I kappa B-alpha levels in IL-4 but not IL-10 pretreated cells. In contrast to the pro-inflammatory role of IL-10 in HepG2, IL-10 did not show any change in the activation of NF-kappa B by Ac in WRL-68 cells, a human fetal hepatic cell line. Moreover, IL-10 did not induce the degradation of I kappa B-alpha in cellular extract from rat primary cultured cells. CONCLUSIONS: While the present findings demonstrate the anti-inflammatory role of IL-4 in preventing the expression of IL-8 by Ac, the regulation of chemokines by anti-inflammatory cytokines is complex and depends on the cellular lineage.
Asunto(s)
Acetaldehído/farmacología , Carcinoma Hepatocelular/tratamiento farmacológico , Interleucina-10/farmacología , Interleucina-4/farmacología , Interleucina-8/metabolismo , Neoplasias Hepáticas/tratamiento farmacológico , Animales , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patología , Línea Celular Tumoral/efectos de los fármacos , Línea Celular Tumoral/patología , Combinación de Medicamentos , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Humanos , Proteínas I-kappa B/metabolismo , Interleucina-8/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patología , Masculino , Inhibidor NF-kappaB alfa , FN-kappa B/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor de Transcripción AP-1/metabolismoRESUMEN
Ganglioside GD3 (GD3) has emerged as a modulator of cell death pathways due to its ability to interact with mitochondria and disable survival pathways. Because NF-kappaB activation contributes to cancer therapy resistance, this study was undertaken to test whether GD3 modulates the response of human hepatoblastoma HepG2 cells to radio- and chemotherapy. NF-kappaB was activated in HepG2 cells shortly after therapeutic doses of ionizing radiation or daunorubicin treatment that translated into up-regulation of kappaB-dependent genes. These effects were accompanied by minimal killing of HepG2 cells by either ionizing radiation or daunorubicin. However, GD3 pretreatment blocked the nuclear translocation of active kappaB members, without effect on Akt phosphorylation, induced by either treatment. The suppression of kappaB-dependent gene induction by GD3 was accompanied by enhanced apoptotic cell death caused by these therapies. Furthermore, the combination of GD3 plus ionizing radiation stimulated the formation of reactive species followed by the mitochondrial release of cytochrome c and Smac/Diablo and caspase 3 activation. Pretreatment with cyclosporin A before radiotherapy protected HepG2 cells from the therapeutic combination of GD3 plus ionizing radiation. These findings underscore a key role of mitochondria in the response of tumor cells to cancer therapy and highlight the potential relevance of GD3 to overcome resistance to cancer therapy by combining its dual action as a mitochondria-interacting and NF-kappaB-inactivating agent.