Oncogenesis, mechanisms

The importance of pathways and networks was revealed by the study of the mechanisms of action of hormones, as well as by numerous studies on the mechanisms of oncogenesis and development. Biology articles and books... 

Reznichenko, P.N. (1980). The Transformation and Change of Functional Mechanisms in Oncogenesis of Lower Vertebrates (In Russian). Nauka, Moscow, 216 pp. 

Much of the earlier literature of purines was concerned with attack by nucleophiles but more recently there has been a marked increase in studies of electrophile attack. This is no doubt encouraged in part by work concerned with the mechanism of oncogenesis which involve arylation or alkylation of purines usually at C-8. 

The same authors have examined the free radical methylation of several "nucleosides in the presence of r-butyl peracetate and shown that C-methylation occurs at pH 1-4 but at pH 4-10 there is increasing iV-methylation (80JOC2373) as the electron availability on these atoms builds up. C-Methylation is proposed to proceed via an addition mechanism and iV-methylation via a radical extraction of hydrogen from NH followed by reaction with a methyl radical. Implications of these reactions in radical oncogenesis are discussed. 

This paper has examined the theoretical and experimental basis for the existence of different mechanisms of carcinogenic activity of chemicals within the context of the basic definition of what constitutes a carcinogenic hazard. Examined in this way, the mechanism of carcinogenic action of a chemical may encompass exposure, cell dynamics and gene activation as interrelated parts of the process of oncogenesis. The balance of these effects, or segments, of the mechanistic process define the potential carcinogenic activity of a chemical. Yet, as complex and incompletely understood in toto as this... 

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