Environmental exposure to cadmium in breast cancer - association with the Warburg effect and sensitivity to tamoxifen.

The association between cadmium and breast cancer remains unexplained due to inconsistent epidemiological data and unknown underlying mechanisms. This study aimed to assess the relationship between environmental exposure to cadmium and the Warburg effect in breast cancer and, thus, its possible interference with breast cancer treatment. The observational study in two groups of breast cancer patients indicated a positive correlation between urinary cadmium concentration and tumor expression of HIF1A (a master regulator of the Warburg effect). Further explanatory research in MCF-7 cells showed no impact of cadmium exposure on molecular and biochemical markers of the Warburg effect. However, long-term exposure to a low and environmentally relevant concentration of cadmium led to the accumulation of the metal in MCF-7 cells and decreased their sensitivity to tamoxifen. To conclude, the association between cadmium and the Warburg effect was suggested in the observational study, although not confirmed in vitro. Nevertheless, cadmium seems to interfere with tamoxifen treatment which deserves further investigation in terms of its possible implication in intrinsic resistance to hormone therapy.

Applications and Biological Activity of Nanoparticles of Manganese and Manganese Oxides in In Vitro and In Vivo Models.

The expanding applications of nanotechnology seem to be a response to many technological, environmental, and medical challenges. The unique properties of nanoparticles allow for developing new technologies and therapies. Among many investigated compounds is manganese and its oxides, which in the form of nanoparticles, could be a promising alternative for gadolinium-based contrast agents used in diagnostic imaging. Manganese, which is essential for living organisms as an enzyme cofactor, under excessive exposure-for example, due to water contamination or as an occupational hazard for welders-can lead to neurological disorders, including manganism-a condition similar to Parkinson's disease. This review attempts to summarise the available literature data on the potential applications of manganese and manganese oxide nanoparticles and their biological activity. Some of the published studies, both in vitro and in vivo, show negative effects of exposure to manganese, mainly on the nervous system, whereas other data suggest that it is possible to develop functionalised nanoparticles with negligible toxicity and novel promising properties.