RESUMEN
BACKGROUND: Polycomb group (PcG) proteins are histone modifiers known to transcriptionally silence key tumour suppressor genes in multiple human cancers. The chromobox proteins (CBX2, 4, 6, 7, and 8) are critical components of PcG-mediated repression. Four of them have been associated with tumour biology, but the role of CBX2 in cancer remains largely uncharacterised. METHODS: Addressing this issue, we conducted a comprehensive and unbiased genotranscriptomic meta-analysis of CBX2 in human cancers using the COSMIC and Oncomine databases. RESULTS: We discovered changes in gene expression that are suggestive of a widespread oncogenic role for CBX2. Our genetic analysis of 8013 tumours spanning 29 tissue types revealed no inactivating chromosomal aberrations and only 40 point mutations at the CBX2 locus. In contrast, the overall rate of CBX2 amplification averaged 10% in all combined neoplasms but exceeded 30% in ovarian, breast, and lung tumours. In addition, transcriptomic analyses revealed a strong tendency for increased CBX2 mRNA levels in many cancers compared with normal tissues, independently of CDKN2A/B silencing. Furthermore, CBX2 upregulation and amplification significantly correlated with metastatic progression and lower overall survival in many cancer types, particularly those of the breast. CONCLUSIONS: Overall, we report that the molecular profile of CBX2 is suggestive of an oncogenic role. As CBX2 has never been studied in human neoplasms, our results provide the rationale to further investigate the function of CBX2 in the context of cancer cells.
Asunto(s)
Neoplasias/genética , Oncogenes , Complejo Represivo Polycomb 1/genética , Transcriptoma , HumanosRESUMEN
The authors present the case of a patient who developed left bundle branch block with asynchrony of left ventricular contraction and, secondarily, a dilated hypokinetic cardiomyopathy. There were no signs of an ischaemic, toxic or inflammatory cause for the cardiomyopathy whereas cardiac resynchronisation by biventricular stimulation rapidly restored a normal left ventricular ejection fraction. This suggests that asynchrony of left ventricular contraction is not necessarily the consequence of a dilated hypokinetic cardiomyopathy but it may also be considered as a possible cause.
Asunto(s)
Bloqueo de Rama/etiología , Cardiomiopatía Dilatada/complicaciones , Anciano , Válvula Aórtica/fisiopatología , Cardiomiopatía Dilatada/fisiopatología , Cardiomiopatía Dilatada/terapia , Electrocardiografía , Ventrículos Cardíacos/fisiopatología , Humanos , Hipertensión/complicaciones , Masculino , Válvula Mitral/fisiopatologíaRESUMEN
An unusual case of transient electro-mechanical dissociation concomitant with myocardial reperfusion is reported. The patient had myocardial infarction caused by occlusion of the middle anterior interventricular artery relieved by injection of urokinase and plasminogen in situ. The dissociation could be documented by simultaneous ECG recording on 3 leads and direct intravascular recording of femoral arterial pressure, the patency of that artery, and its maintenance, being demonstrated by angiography. This clinical case can be added to the list of events which occur during reperfusion of the myocardium after prolonged ischaemia. Its mechanisms, so far, are purely conjectural.