The inhibitory effect of a novel phosphodiesterase 4 inhibitor ZL-n-91 on proliferation of osteosarcoma U20S cells / 中国药理学通报

Aim To explore the anti-cancer effects of ZL-n-91, a novel and highly selective phosphodiesterase 4 inhibitor, on the osteosarcoma U2OS cells.Methods CCK-8 assay was used to detect the inhibitory effect of ZL-n-91 with different concentrations(0, 20, 40, 80, 160, 240, 320, 400, 480 μmol·L-1)and different intervention time(0, 24, 48, 72, 96 h)on the proliferation of U2OS cells.Tablet clone forming experiment was used to detect the effect of ZL-n-91 on the clonality of U2OS cells.Flow cytometry was used to detect the cell apoptosis and cell cycle distribution.Western blot was employed to detect the expression of Bcl-2, CDK2, CDK4, CyclinD1, CyclinE1 protein.Results The inhibitory rate of ZL-n-91 on U2OS cells was concentration- and time-dependent(P<0.05), and its half inhibition rate IC50 was 174.1 μmol·L-1.ZL-n-91 significantly inhibited the clonality of U2OS cells(P<0.01).ZL-n-91 significantly induced cell apoptosis, and caused cell cycle arrest at G0/G1 phase in U2OS cells(P<0.01).The results of Western blot showed that ZL-n-91 significantly down-regulated the expression of Bcl-2, CDK2, CDK4, CyclinD1, CyclinE1 proteins in U2OS cells(P<0.05).Conclusions The novel selective phosphodiesterase 4 inhibitor, ZL-n-91, can significantly inhibit the proliferation of osteosarcoma U2OS cells with induction of cell cycle arrest and cell apoptosis, and may become a potential anti-cancer agent.

Expression of Gab2 in human osteosarcoma U2-OS cells / 中国病理生理杂志

AIM:To investigate the expression of Grb2-associated binding protein 2 (Gab2) in human osteo-sarcoma cells and its relationship with the invasion and metastases of human osteosarcoma cells.METHODS: The tech-nique of small RNA interference was used to transfect human osteosarcoma U2-OS cell lines.Western blotting and RT-PCR were used to detect the protein and mRNA expression of Gab2 in transfected U2-OS cells.After transfection, through chem-otaxis and invasion assays in vitro, the cell migration and invasion abilities were detected.RESULTS:After transfection, the expression of Gab2 at mRNA and protein levels in Gab2 siRNA transfected cells ( SiGab2/U2-OS) was lower than that in scrambled siRNA transfected cells ( Scr/U2-OS ) and U2-OS cells.After stimulation with epidermal growth factor ( EGF) at concentration of 10 μg/L, the migration SiGab2/U2-OS cells was significantly less than Scr/U2-OS cells and U2-OS cells ( P<0.01 ) .The number of invasion cells of SiGab2/U2-OS group was significantly lower than the other 2 control groups ( P<0.01) .CONCLUSION:Inhibition of Gab2 expression obviously attenuates the migration and invasion abilities of human osteosarcoma U2-OS cell line.

MK-2206, an inhibitor of Akt, induced cell apoptosis and autophagy in U2 OS cells / 中国病理生理杂志

AIM:To observe the effect of MK-2206, an inhibitor of Akt, on the cell apoptosis and autophagy of U2OS cells.METHODS:The cell viability was detected by MTT assay .The cell apoptosis was analyzed by TdT-media-ted dUTP nick end labeling assay .The expression of LC3-II was examined by Western blotting .RESULTS:MK-2206 in-hibited the cell viability in a dose-dependent manner .MK-2206 induced the cell apoptosis via activation of caspase-3, caspase-9 and PARP.MK-2206 treatment substantially induced the U 2OS cell autophagy by increasing in the levels of LC 3-II.Blockage of autophagy using chloroquine magnified MK-2206-induced cell death in U2OS cells.CONCLUSION:The Akt inhibitor MK-2206 induces cell apoptosis and autophagy .Blocking autophagy magnifies MK-2206-induced the inhibi-tion of the viability in U2OS cells.

In Vitro Inhibitory Effect of Wogonin on Human Osteosarcoma / 中国药房

OBJECTIVE:To study the inhibitory effect of wogonin on human osteosarcoma. METHODS:MTT chromatometry was employed to determine the the influence of wogonin to the activity of U2OS cell line and its time-dependent effect and dose-dependent effect against osteosarcoma cell line detected. The apoptosis of wogonin-treated U2OS cells was determined by flow cytometry together with morphological observation,meanwhile the cell cycle of U2OS cell line was analyzed. RESULTS:The growth of U2OS cells was inhibited and the apoptosis of which was promoted by wogonin in a time-dependent and dose-dependent manner. The U2OS cells were arrested at G0/G1 phase with conspicuous apoptotic peak,nuclear fragmentation and chromosome agglomeration. The IC50 against U2OS cells stood at (37.18?1.57) ?mol?mL-1. CONCLUSION:Wogonin can inhibit cell growth and promote apoptosis of U2OS cells.

Sec13 induces genomic instability in U2OS cells

Sec13p has been known as an endoplasmic reticulum-Golgi transport protein. Recently, it has also been shown to be required for the formation of septation in the fission yeast Schizosaccharomyces pombe. In the present study, we focused on the role of a human homolog of Saccharomyces cerevisiae SEC13, Sec13 protein during mitosis in U2OS cells. We found that the expression of Sec13 was constant throughout the cell cycle, and localized to the kinetochores at metaphase during mitosis. By using green fluorescent protein technology, we observed that Sec13 is required for evasion of mitotic arrest in response to spindle damage, leading to G1-like phase and apoptotic cell death. In addition, cells expressing exogenous Sec13 showed giant nuclei compared to endogenous ones in the absence of nocodazole. These results demonstrate that Sec13 is involved in the regulation of the metaphase/anaphase transition and may be functionally associated with mitotic machinery to maintain genomic stability during mitosis.