HIFα as a target for different oncoproteins during carcinogenesis

The basic characteristics of tumours are ability for invasiveness and metastasis. These properties are realized due to destruction of intercellular matrix caused with acidification of intercellular area stimulated with transition from tissue respiration to glycolysis. The transition to glycolysis in tumor cells is observed not only during hypoxic state how is realized in normal cells but also during oxygenation (Warburg effect). It is accepted that by any carcinogenic action the activation of oncogenes or inactivation of genes – supressors occurs. As a result it is permanent expression of oncoproteins and stimulation of tumour development. Different oncoproteins operate in different regulation systems at that they cause the same effect – tumour development.It is assumed that oncoproteins are not the ultimate factor in tumour development but there are existed some common element which is activated by different oncoproteins. In this review it is assumed that common element is HIFα (hypoxia-inducible factor α) transcription factor and it is discussed the mechanisms its activation by oncoproteins takes place in different signal systems.

APPROACHES TO TOXICOLOGICAL AND HYGIENE ASSESSMENT OF UNSTABLE METAL-ORGANIC COMPOUNDS ON THE EXAMPLE OF MAGNESOCENE (CP2MG) (BIS (CYCLOPENTADIENYL) MAGNESIUM)

Approaches to the evaluation of toxicity and hazard of unstable substance bis(cyclopentadienyl) magnesium MAGNESOCENE (Cp2Mg)) are presented . The toxicity of the substance is determined by its main transformation products -magnesium oxide, magnesium hydroxide and cyclopentadiene. Due to the instability of the substance (it exists only in an inert environment) it is not possible to conduct studies on its sensitizing effect ,its reprotoxic, teratogenic, mutagenic and carcinogenic action on the organism. Control of the unstable compound bis (cyclopentadienyl) magnesium in the air of the working area and human habitat should be based on its transformation products: magnesium oxide and cyclopentadiene.

Ochratoxin A in foods of animal origin

Ochratoxin A (OTA) is a mycotoxin produced by the fungi Aspergillus ochraceus καιPénicillium verrucosum. OTA shows a nephrotoxic, teratogenic, immunotoxic and carcinogenic action against animals and humans. In humans, OTA is implicated in the aetiology of Balkan endemic nephropathy. OTA can be mainly found in foods of animal origin as a result of indirect transmission from animals exposed to naturally contaminated feed. Results from research works in various countries showed that the pork meat was the most important source of human contamination with OTA, as compared to other products of animal origin. Sausages containing blood or pork kidney presented the highest amounts of OTA among other food products of animal origin. The presence of OTA in cow's milk was rather low, since the bacteria in the rumen of ruminants are capable of splitting OTA to ochratoxin a, which is generally accepted as no toxic metabolite. The European Union has not yet set limits of ochratoxin in foods of animal origin, in contrast to these of limits in foods of plant origin.