Within the concentration range of 1-20 FM, orthovanadate (Na ! VO ") demonstrated a time and dose-dependent inhibition of autocrine growth of the human carcinoma cell lines A549 (lung), HTB44 (kidney) and DU145 (prostate), as compared to appropriate controls (without Na ! VO "). The investigation was conducted by two methods: staining with N-hexa-methylpararosaniline (crystal violet=CV) or bromide3-(4,5-dimethyltio-azo-2)-2,5-diphenyl-tetrazole (MTT). In 5, 10 and 20 FM of Na ! VO " in serum-free medium, the mean values of these two tests for A549 were approximately 40%, 45% or 65% as compared to the appropriate controls. HTB44 had the greatest opportunity (statistically insignificant) at lower vanadium concentrations (up to 10 FM), whereas at 20 FM growth inhibition of these cells was approximately 50% of the controls. DU145 showed approximately 33%, 65% and 98% growth inhibition for 5, 10 and 20 FM of Na ! VO " , respectively Additionally, hypothetical curves obtained by a MANOVA test based on the CV results after 72 h incubation with Na ! VO " in serum-free medium, and an example of a time-dependent effect of Na ! VO " on A549 cells, were also presented. Sodium orthovanadate was also examined for its cytotoxic capabilities, especially its ability to induce tumor cell apoptosis; the results were compared with the effect of paclitaxel. The target cells were dyed by differential staining (HOECHST33258 and propidium iodide) after 3 h and 24 h (DU145) or 3 h and 72 h (A549) of incubation with the vanadium compound. Contrary to the two cancer cell lines (viable, apoptotic or necrotic in experimental conditions), the renal HTB44 cells were insensitive up to 15 FM Na ! VO " concentrations. After 3 h incubation with Na ! VO " , both lung (A549) and prostate (DU145) cancer cells showed a slight but significant reduction in the percentage of viable cells, and an increased amount of apoptotic cells. In contrast to the lung cells, DU145 prostate cells after 24 h were more sensitive to paclitaxel than to sodium orthovanadate. In the case of lung cells, the time of incubation was prolonged (to 72 h) to allow for a study of the effect of orthovanadate in greater detail. After 72 h of incubation with Na ! VO " or paclitaxel, A549 showed a similar level of viable cells (25-32% of total cultured cells); however, the percentage of apoptotic cells was higher in the case of A549 cells ca 36% for both drugs, but the concentration of Na ! VO " was significantly greater than paclitaxel levels.

Silver nanoparticles (AgNPs) have many biological applications in biomedicine, biotechnology and other life sciences. Depending on the size, shape and the type of carrier, AgNPs demonstrate different physical and chemical properties. AgNPs have strong antimicrobial, antiviral and antifungal activity, thus they are used extensively in a range of medical settings, particularly in wound dressings but also in cosmetics. This study was undertaken to examine the potential toxic effects of 15 nm polyvinylpyrrolidone-coated AgNPs on primary normal human epidermal keratinocytes (NHEK). Cells were treated with different concentrations of AgNPs and then cell viability, metabolic activity and other biological and biochemical aspects of keratinocytes functioning were studied. We observed that AgNPs decrease keratinocyte viability, metabolism and also proliferatory and migratory potential of these cells. Moreover, longer exposure resulted in activation of caspase 3/7 and DNA damage. Our studies show for the first time, that AgNPs may present possible danger for primary keratinocytes, concerning activation of genotoxic and cytotoxic processes depending on the concentration.

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Abstract:It is well established that autocrine growth of human prostate cancer cell line DU145 is dependent on TGF (EGF)/EGFR loop. However, the participation of several other growth factors in proliferation of DU145 cells has been also proposed. We employed two selective tyrosine kinase inhibitors (tyrphostins): AG1024 (an IGFIR inhibitor) and SU1498 (a VEGFR2 inhibitor) for growth regulation of DU145 cells, cultured in chemically defined DMEM/F12 medium. Both the tested compounds inhibited autocrine growth of DU145 cells at similar concentration values (IC50 ≈2.5 μM). The tyrphostins arrested cell growth of DU145 in G1 phase, similarly as inhibitors of EGFR. However, in contrast to selective inhibitors of EGFR, neither AG1024, nor SU1498 (at concentration ≤10 μM) decreased the viability of the investigated cells. These results strongly suggest that autocrine growth of DU145 cells is stimulated by, at least, three autocrine loops: TGFα(EGF)/EGFR, IGFII/IGFIr and VEGF/VEGFR2(VEGFR1). These data support the hypothesis of multi-loops growth regulation of metastatic prostate cancer cell lines.

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It was found that middle-sized molecules obtained from dialysate of uremic patients caused suppression of PHA-induced lymphocyte transformation. This was expressed by the lowering of labeled leucine incorporation and by the suppression of lymphocyte transformation as morphologically assessed. In view of the presented data middle-sized molecules seem to be biologically active substances.