RESUMEN
Centrosome amplification (CA) and resultant chromosomal instability have long been associated with tumorigenesis. However, exacerbation of CA and relentless centrosome declustering engender robust spindle multipolarity (SM) during mitosis and may induce cell death. Recently, we demonstrated that a noscapinoid member, reduced bromonoscapine, (S)-3-(R)-9-bromo-5-(4,5-dimethoxy-1,3-dihydroisobenzofuran-1-yl)-4-methoxy-6-methyl-5,6,7,8-tetrahydro-[1,3]dioxolo-[4,5-g]isoquinoline (Red-Br-nos), induces reactive oxygen species (ROS)-mediated autophagy and caspase-independent death in prostate cancer PC-3 cells. Herein, we show that Red-Br-nos induces ROS-dependent DNA damage that resulted in high-grade CA and SM in PC-3 cells. Unlike doxorubicin, which causes double-stranded DNA breaks and chronic G2 arrest accompanied by 'templated' CA, Red-Br-nos-mediated DNA damage elicits de novo CA during a transient S/G2 stall, followed by checkpoint abrogation and mitotic entry to form aberrant mitotic figures with supernumerary spindle poles. Attenuation of multipolar phenotype in the presence of tiron, a ROS inhibitor, indicated that ROS-mediated DNA damage was partly responsible for driving CA and SM. Although a few cells (â¼5%) yielded to aberrant cytokinesis following an 'anaphase catastrophe', most mitotically arrested cells (â¼70%) succumbed to 'metaphase catastrophe,' which was caspase-independent. This report is the first documentation of rapid de novo centrosome formation in the presence of parent centrosome by a noscapinoid family member, which triggers death-inducing SM via a unique mechanism that distinguishes it from other ROS-inducers, conventional DNA-damaging agents, as well as other microtubule-binding drugs.
Asunto(s)
Centrosoma/metabolismo , Noscapina/análogos & derivados , Huso Acromático/metabolismo , Apoptosis/efectos de los fármacos , Autofagia/efectos de los fármacos , Caspasas/metabolismo , Línea Celular Tumoral , Roturas del ADN de Doble Cadena/efectos de los fármacos , Doxorrubicina/farmacología , Puntos de Control de la Fase G2 del Ciclo Celular/efectos de los fármacos , Humanos , Masculino , Metafase , Mitosis , Noscapina/farmacología , Especies Reactivas de Oxígeno/metabolismoRESUMEN
The data from this study showed that the excretion of three major metabolites of phenylalanine in patients with PKU approach normal values at blood phenylalanine levels less than 5.0 mg/dl. The MANOVA showed statistically significant differences in phenyllactate excretion when blood phenylalanine was greater than 10.0 mg/dl. The PL and total metabolite excretion were significantly correlated to blood phenylalanine in multiple samples taken from two individual subjects. Using data obtained from single patient observations may serve as a means for individualizing the PKU diet to insure low levels of phenylalanine metabolites and thus insure optimal development for patients with PKU.