RESUMEN
An apolar extract of the traditional medicinal plant Neurolaena lobata inhibited the expression of the NPM/ALK chimera, which is causal for the majority of anaplastic large cell lymphomas (ALCLs). Therefore, an active principle of the extract, the furanoheliangolide sesquiterpene lactone lobatin B, was isolated and tested regarding the inhibition of ALCL expansion and tumour cell intravasation through the lymphendothelium. ALCL cell lines, HL-60 cells and PBMCs were treated with plant compounds and the ALK inhibitor TAE-684 to measure mitochondrial activity, proliferation and cell cycle progression and to correlate the results with protein- and mRNA-expression of selected gene products. Several endpoints indicative for cell death were analysed after lobatin B treatment. Tumour cell intravasation through lymphendothelial monolayers was measured and potential causal mechanisms were investigated analysing NF-κB- and cytochrome P450 activity, and 12(S)-HETE production. Lobatin B inhibited the expression of NPM/ALK, JunB and PDGF-Rß, and attenuated proliferation of ALCL cells by arresting them in late M phase. Mitochondrial activity remained largely unaffected upon lobatin B treatment. Nevertheless, caspase 3 became activated in ALCL cells. Also HL-60 cell proliferation was attenuated whereas PBMCs of healthy donors were not affected by lobatin B. Additionally, tumour cell intravasation, which partly depends on NF-κB, was significantly suppressed by lobatin B most likely due to its NF-κB-inhibitory property. Lobatin B, which was isolated from a plant used in ethnomedicine, targets malignant cells by at least two properties: I) inhibition of NPM/ALK, thereby providing high specificity in combating this most prevalent fusion protein occurring in ALCL; II) inhibition of NF-κB, thereby not affecting normal cells with low constitutive NF-κB activity. This property also inhibits tumour cell intravasation into the lymphatic system and may provide an option to manage this early step of metastatic progression.
Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Asteraceae/química , Endotelio Linfático/efectos de los fármacos , Linfoma Anaplásico de Células Grandes/tratamiento farmacológico , Linfoma Anaplásico de Células Grandes/patología , FN-kappa B/antagonistas & inhibidores , Extractos Vegetales/farmacología , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Sesquiterpenos/farmacología , Apoptosis/efectos de los fármacos , Western Blotting , Caspasas/genética , Caspasas/metabolismo , Ciclo Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Endotelio Linfático/patología , Humanos , Leucocitos Mononucleares/efectos de los fármacos , Leucocitos Mononucleares/metabolismo , Leucocitos Mononucleares/patología , Linfoma Anaplásico de Células Grandes/metabolismo , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Mitocondrias/patología , FN-kappa B/genética , FN-kappa B/metabolismo , Invasividad Neoplásica , Proteínas Tirosina Quinasas/genética , Proteínas Tirosina Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-jun/genética , Proteínas Proto-Oncogénicas c-jun/metabolismo , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células Tumorales CultivadasRESUMEN
Phytocannabinoids are potential candidates for neurodegenerative disease treatment. Nonetheless, the exact mode of action of major phytocannabinoids has to be elucidated, but both, receptor and non-receptor mediated effects are discussed. Focusing on the often presumed structure-affinity-relationship, Ki values of phytocannabinoids cannabidiol (CBD), cannabidivarin (CBDV), cannabichromene (CBC), cannabigerol (CBG), cannabinol (CBN), THC acid (THCA) and THC to human CB1 and CB2 receptors were detected by using competitive inhibition between radioligand [(3)H]CP-55,940 and the phytocannabinoids. The resulting Ki values to CB1 range from 23.5 nM (THCA) to 14711 nM (CBDV), whereas Ki values to CB2 range from 8.5 nM (THC) to 574.2 nM (CBDV). To study the relationship between binding affinity and effects on neurons, we investigated possible CB1 related cytotoxic properties in murine mesencephalic primary cell cultures and N18TG2 neuroblastoma cell line. Most of the phytocannabinoids did not affect the number of dopaminergic neurons in primary cultures, whereas propidium iodide and resazurin formation assays revealed cytotoxic properties of CBN, CBDV and CBG. However, THC showed positive effects on N18TG2 cell viability at a concentration of 10 µM, whereas CBC and THCA also displayed slightly positive activities. These findings are not linked to the receptor binding affinity therewith pointing to another mechanism than a receptor mediated one. [Corrected]
Asunto(s)
Agonistas de Receptores de Cannabinoides/farmacología , Cannabinoides/farmacología , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Receptores de Cannabinoides/metabolismo , Animales , Agonistas de Receptores de Cannabinoides/metabolismo , Cannabinoides/metabolismo , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Neuronas Dopaminérgicas/efectos de los fármacos , Neuronas Dopaminérgicas/metabolismo , Glutatión/análisis , Humanos , Ratones , Neuroblastoma , Tirosina 3-Monooxigenasa/metabolismoRESUMEN
Penicillium marneffei is an important human immunodeficiency virus-associated opportunistic infection endemic in Southeast Asia. Central nervous system infection has not been described. We report the first case series of 21 human immunodeficiency virus-infected patients who presented with a syndrome consistent with acute central nervous system infection and who had Penicillium marneffei isolated from cerebrospinal fluid.