Synthesis of a novel adamantyl nitroxide derivative with potent anti-hepatoma activity in vitro and in vivo.

In this study, a novel adamantyl nitroxide derivative was synthesized and its antitumor activities in vitro and in vivo were investigated. The adamantyl nitroxide derivative 4 displayed a potent anticancer activity against all the tested human hepatoma cells, especially with IC50 of 68.1 µM in Bel-7404 cells, compared to the positive control 5-FU (IC50=607.7 µM). The significant inhibition of cell growth was also observed in xenograft mouse model, with low toxicity. Compound 4 suppressed the cell migration and invasion, induced the G2/M phase arrest. Further mechanistic studies revealed that compound 4 induced cell death, which was accompanied with damaging mitochondria, increasing the generation of intracellular reactive oxygen species, cleavages of caspase-9 and caspase-3, as well as activations of Bax and Bcl-2. These results confirmed that adamantyl nitroxide derivative exhibited selective antitumor activities via mitochondrial apoptosis pathway in Bel-7404 cells, and would be a potential anticancer agent for liver cancer.

[Effects of nuclear factor of activated T cells on the promoter activity of constitutively activated SV40].

AIM: To check if the common used constitutively promoters, such as CMV, TK and SV40 could be responded to the nuclear factor of activated T cell (NFAT), and to explore the strategies to choose rational internal control in the dual luciferase reporter assay. METHODS: pCMV-luc vector, in which luciferase activity is driven by CMV promoter, was cloned by amplifying the CMV promoter fragment from the pCDNA3.1 vector and then inserting the CMV promoter region into the pGL3-basic vector using the standard protocol. pTK-Luc reporter was similarly constructed, with the TK promoter from the pRL-TK vector. The constructed pCMV-Luc or pTK-Luc was co-transfected with pBIND or pRL-TK respectively, together with NFAT or constitutively active form named NFATCA. Relative luciferase activity was calculated as instructed by the manual instruction. RESULTS: Both pCMV-Luc and pTK-Luc vectors were successfully constructed. Luciferase activity assay revealed that SV40 promoter responded to active NFAT. CONCLUSION: The common used internal control promoter SV40 could respond to active NFAT, which should be kept in mind for selection of the rational internal control vector in the dual luciferase reporter assay. In addition, our study here also provides a practical strategy for rational selection of the internal control.