Bufalin, a key active ingredient of the Chinese medicine Chan Su, inhibits breast cancer tumorigenesis in vitro and in vivo. Here, we found that the pan-caspase inhibitor zVAD-fmk failed to inhibit bufalin-induced cell death in MCF-7 and MDA-MB-231 human breast cancer cells, confirming that the cell death induced by bufalin is caspase-independent. Instead, bufalin increased the expression of the necroptosis mediators RIP1 and RIP3. Bufalin-induced cell death was prevented by small molecule inhibitors of RIP1 and poly (ADP-ribose) polymerase-1 (PARP-1) or genetic knockdown of RIP3 by shRNA transfection. In addition, ectopic RIP3 expression enhanced cell death by bufalin. We also found that bufalin increased intracellular reactive oxygen species levels; and cell death by bufalin was inhibited by the antioxidant NAC. In a mouse xenograft model of human breast cancer, bufalin induced PARP-1-dependent tumor cell death and inhibited tumor growth. These results demonstrated that bufalin inhibits human breast cancer tumorigenesis by inducing cell death through the reactive oxygen species-mediated RIP1/RIP3/PARP-1 pathways.
Abstract. The aim of the current study was to investigate the effects of resveratrol (Res) on vascular endothelial growth factor (VEGF) expression and cell proliferation in the human osteosarcoma cell line U20S. U20S cells were treated with Res at various concentrations (0, 10, 20 and 40 µmol/l) for various times (24, 48 and 72 h). The inhibitory effect of Res on U20S proliferation was observed using methyl thiazolyl tetrazolium (MTT) colorimetry. VEGF expression was determined using real-time polymerase chain reaction (RT-PCR) and western blot analysis. The inhibitory effect of Res on U20S proliferation increased as the concentration of Res increased. The inhibitory effect also increased with time. Res had an inhibitory effect on VEGF expression and significantly inhibited U20S cell proliferation. Res may exert an anti-osteosarcoma effect by inhibiting VEGF expression in tumor cells.
The work was to demonstrate a repaid, precise and accurate determination method for ten trace elements (Al, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Se and Zn) in periostracum serpentis (PS) and periostracum cicadae (PC) by inductively coupled plasma atomic emission spectrometry (ICP-AES). In order to evaluate the best digestion method, three different sample digestion methods including dry ashing, wet ashing and microwave digestion procedures were compared in this study. Method validation was carried out through the generation of calibration curves with multi-element standard solutions and a standard addition method by using standard reference material (GBW 07604-Poplar leaves). The results revealed the microwave digestion procedures were the best sample digestion method because of dry ashing and wet ashing procedures without any advantages in terms of digestion efficiency than the microwave digestion procedures. Trace element contents in PS and PC samples presented a wide variability from the test results, and ten trace element contents in PC were found to be higher than in PS. Determination of trace elements by ICP-AES after microwave digestion was more sensitive and precise, which can be used for quality control and analysis of pharmacological effect in various ecdyses of some animal samples.
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