Neural tumour

The study of catecholamines and their metabolites has grown enormously in recent years since the advent of HPLC coupled to highly sensitive detection systems. The catecholamines play a major role in the function of the body s nervous system. Dopamine and noradrenaline exert a marked influence on the vascular system, whilst adrenaline, synthesized largely in the adrenal medulla, affects the rate of many metabolic processes, particularly carbohydrate metabolism. The major metabolic pathways of catecholamine inactivation are shown in Figure 1. Abnormal levels of these amines and their metabolites have been associated with a number of disease states, notably Parkinson s disease [1], neural tumours such as phaeochromocytoma[2] and hypertension [3]. 

The diagnosis of neural tumours such as phaeochromocytoma and neuroblastoma is heavily dependent on the laboratory measurement of urinary levels of methylated catecholamines and of their two acidic catabolites, 4-hydroxy-3-methoxymandelic acid (VMA) and 4-hydroxy-3-methoxyphenyl acetic acid (HVA). 

Yu JJ, Sun X, Yuan X, Lee JW, Snyder EY, Yu JS (2006) Immunomodulatory neural stem cells for brain tumour therapy. Expert Opin Biol Ther 6 1255-1262... 

On a more cautionary note, the EPO receptor is expressed not only by specific erythrocyte precursor cells, but also by endothelial, neural, and myeloma cells. Concern has been expressed that EPO, therefore, might actually stimulate growth of some tumour types, particularly those derived from such cells. To date, no evidence (in vitro or in vivo) has been obtained to support this hypothesis. 

Ball, G., Mian, S., Holding, R, Allibone, R.O., Lowe, J., Ali, S., Li, G., McCardle, S., Ellis, I.O., Creaser, C., and Rees, R.C., An integrated approach utilizing neural networks and SELDI mass spectrometry for classification of human tumours and rapid identification of potential biomarkers. Bioinformatics, 18, 395 04, 2002. 

Another method of removing fast growing fibroblasts is to prepare primary cultures from a tumour and after a short time return them to an animal where they will reform a tumour. By repeated alternation of growth in vivo and in vitro it was hoped to select for tumour cells and this has proved successful in isolating differentiated cell lines from adrenal, pituitary and neural tissue (Buonassisi et al., 1962 Augusti-Tocco and Sato, 1969). 

As reviewed here, cannabinoids may lead to opposite effects on the cell sur-vival/death decision. For example, in the case of neural cells, cannabinoids may kill tumour cells and protect their non-transformed counterparts from death (Guzman 2003) (Fig. 1). It is conceivable that different experimental factors may account for this yin-yang action, for example (1) cannabinoid neuroprotection is usually more evident in whole-animal than in cultured-neuron models, which may result from their aforementioned impact on various brain cell types (neurons, astroglia, oligodendroglia, microglia, vascular endothelium) (2) cannabinoids may exert... 

Pearson JM, Harris M, Eyden BP, et al. Divergent differentiation in small round-cell tumours of the soft tissues with neural features—an analysis of 10 cases. Histopathology. 1993 23 1-9. 

An improperly balanced diet may cause mutations and chromosomal aberrations. For the development of methods to counteract such changes, it is vital to determine the possible correlations between the dietary components and DNA changes. Folic acid and vitamin B12 are crucial elements in the methy-lation of DNA, proteins and neurotransmitiers. The development of neural tube defects associated with folic acid deficiency is related to methylation dysfunction and a malfunctioning expression of the genes responsible for the tube formation. Furthermore, it is believed that DNA hypermethylation causes mutations related to tumor initiation or development. Previous observations have shown that diets supplemented with the B group vitamins for 15 years were correlated with a significant reduction in the development of tumour diseases (Fenech 2001). 

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