Ouabain Induces Apoptotic Cell Death Through Caspase- and Mitochondria-dependent Pathways in Human Osteosarcoma U-2 OS Cells.

BACKGROUND/AIM: Ouabain, a plant-derived product/substance with Na+/K+-ATPase inhibiting properties, has been shown to exert anti-cancer activity on human cancer cells. This is the first study to investigate the effect of ouabain on apoptotic cell death of human osteosarcoma-derived U-2 OS cells. MATERIALS AND METHODS: Flow cytometry was used to examine cell viability, cell cycle, and reactive oxygen species (ROS), Ca2+, mitochondrial membrane potential (MMP) and caspase activity. Morphological changes were examined by contrast-phase microscopy, while apoptosis-associated protein levels were analyzed by western blot. RESULTS: Ouabain, at concentrations of 5-60 µM, significantly decreased the total viable cells and induced cell morphological changes in a time-dependent manner. It also time-dependently decreased G0/G1 phase and increased S and G2/M phase in U-2 OS cells. The production of ROS and the levels of MMPs (ΔΨm) were inhibited, while Ca2+ production in U-2 OS cells was increased. Regarding cell apoptosis, flow cytometry assay revealed increased caspase-3, -8, and -9 activities in U-2 OS cells. Moreover, western blot results showed that ouabain increased the expression of pro-apoptotic protein Bax and decreased the expression of anti-apoptotic protein Bcl-2 in U-2 OS cells. Furthermore, results also showed that ouabain increased cytochrome c release, apoptosis-inducing factor (AIF) and endonuclease (Endo) G that is associated with apoptosis through caspase-dependent and -independent pathway in U-2 OS cells. CONCLUSION: Our findings provide important insight into the cytotoxic effects of ouabain on U-2 OS cells, in vitro, which are mediated at least partly via cell apoptosis induction.

Ouabain impairs cell migration, and invasion and alters gene expression of human osteosarcoma U-2 OS cells.

Ouabain, the specific Na+ /K+ -ATPase blocker, has biological activity including anti-proliferative and anti-metastasis effects in cancer cell. There is no study to show ouabain inhibiting cell migration and invasion in human osteosarcoma U-2 OS cells. Thus, we investigated the effect of ouabain on the cell migration and invasion of human osteosarcoma U-2 OS cells. Results indicated that ouabain significantly decreased the percentage of viable cells at 2.5-5.0 µM, thus, we selected 0.25-1.0 µM for inhibiting studies. Ouabain inhibited cell migration, invasion and the enzymatic activities of MMP-2, and also affected the expression of metastasis-associated protein in U-2 OS cells. The cDNA microarray assay indicated that CDH1, TGFBR3, SHC3 and MAP2K6 metastasis-related genes were increased, but CCND1, JUN, CDKN1A, TGFB1, 2 and 3, SMAD4, MMP13, MMP2 and FN1 genes were decreased. These findings provide more information regarding ouabain inhibited cell migration and invasion and associated gene expressions in U-2 OS cells after exposed to ouabain.

Bufalin Induces Apoptosis of Human Osteosarcoma U-2 OS Cells through Endoplasmic Reticulum Stress, Caspase- and Mitochondria-Dependent Signaling Pathways.

Bone cancer is one of the cancer-related diseases, and there are increased numbers of patients with bone cancer worldwide. Therefore the efficacy of treatment of bone cancer is considered extremely vital. Bufalin has been showed to have biological activities including anticancer activities in vitro and in vivo. However, the exact associated mechanisms for bufalin induced apoptosis in human bone cancer cells are still unclear. In the present study, we investigated the effect of bufalin on the cytotoxic effects in U-2 OS human osteosarcoma cells. For examining apoptotic cell deaths, we used flow cytometry assay, Annexin V/PI double staining, and TUNNEL assay. Reactive oxygen species (ROS), Ca2+, mitochondrial membrane potential (ΔΨm), and caspase-8, -9 and -3 activities were measured by flow cytometry assay. Furthermore, western blotting and a confocal laser microscopy examination were used for measuring the alterations of apoptotic associated protein expression and translocation, respectively. The results indicated that bufalin induced cell morphological changes, decreased the viable cell number, induced apoptotic cell death, and increased the apoptotic cell number, and affected apoptotic associated protein expression in U-2 OS cells. Bufalin increased apoptotic proteins such as Bak, and decreased anti-apoptotic proteins such as Bcl-2 and Bcl-x in U-2 OS cells. Furthermore, bufalin increased the protein levels of cytochrome c (Cyto c), AIF (Apoptosis inducing factor) and Endo G (Endonuclease G) in cytoplasm that were also confirmed by confocal microscopy examination. Based on those findings, bufalin induced apoptotic cell death in U-2 OS cells may be via endoplasmic reticulum (ER) stress, caspase-, and mitochondria-dependent pathways; thus, we may suggest that bufalin could be used as an anti-cancer agent for the treatment of osteosarcoma in the future, and further in vivo studies are needed.

Curcumin causes DNA damage and affects associated protein expression in HeLa human cervical cancer cells.

Cervical cancer is one of the most common cancers in women worldwide and it is a prominent cause of cancer mortality. Curcumin is one of the major compounds from Turmeric and has been shown to induce cytotoxic cell death in human cervical cancer cells. However, there is no study to show curcumin induced DNA damage action via the effect on the DNA damage and repair protein in cervical cancer cells in detail. In this study, we investigated whether or not curcumin induced cell death via DNA damage, chromatin condensation in human cervical cancer HeLa cells by using comet assay and DAPI staining, respectively, we found that curcumin induced cell death through the induction of DNA damage, and chromatin condensation. Western blotting and confocal laser microscopy examination were used to examine the effects of curcumin on protein expression associated with DNA damage, repair and translocation of proteins. We found that curcumin at 13 µM increased the protein levels associated with DNA damage and repair, such as O6-methylguanine-DNA methyltransferase, early-onset breast cancer 1 (BRCA1), mediator of DNA damage checkpoint 1, p-p53 and p-H2A.XSer140 in HeLa cells. Results from confocal laser systems microscopy indicated that curcumin increased the translocation of p-p53 and p-H2A.XSer140 from cytosol to nuclei in HeLa cells. In conclusion, curcumin induced cell death in HeLa cells via induction of DNA damage, and chromatin condensation in vitro.

Deguelin inhibits the migration and invasion of U-2 OS human osteosarcoma cells via the inhibition of matrix metalloproteinase-2/-9 in vitro.

Osteosarcoma is the most common malignant primary bone tumor in children and young adults and lung metastasis is the main cause of death in those patients. Deguelin, a naturally occurring rotenoid, is known to be an Akt inhibitor and to exhibit cytotoxic effects, including antiproliferative and anticarcinogenic activities, in several cancers. In the present study, we determined if deguelin would inhibit migration and invasion in U-2 OS human osteosarcoma cells. Deguelin significantly inhibited migration and invasion of U-2 OS human osteosarcoma cells which was associated with a reduction of activities of matrix metalloproteinases-2 (MMP-2) and matrix metalloproteinases-9 (MMP-9). Furthermore, results from western blotting indicated that deguelin decreased the cell proliferation and cell growth-associated protein levels, such as SOS1, PKC, Ras, PI3K, p-AKT(Ser473), IRE-1α, MEKK3, iNOS, COX2, p-ERK1/2, p-JNK1/2, p-p38; the cell motility and focal adhesion-associated protein levels, such as Rho A, FAK, ROCK-1; the invasion-associated protein levels, such as TIMP1, uPA, MMP-2. MMP-9, MMP-13, MMP-1 and VEGF in U-2 OS cells. Confocal microscopy revealed that deguelin reduced NF-κB p65, Rho A and ROCK-1 protein levels in cytosol. MMP-7, MMP-9 and Rho A mRNA levels were suppressed by deguelin. These in vitro results provide evidence that deguelin may have potential as a novel anti-cancer agent for the treatment of osteosarcoma and provides the rationale for in vivo studies in animal models.

Toxicological evaluation of Antrodia cinnamomea in BALB/c mice.

Antrodia cinnamomea is a natural component of some herbal medicines used for treatment of abdominal pain, hypertension and hepatocellular carcinoma in Taiwan and other countries. Subchronic oral toxicity studies of A. cinnamomea extracts in male and female BALB/c mice were performed to evaluate its safety. Three different concentrations of A. cinnamomea (16.67, 833.3 and 1666.67 mg/kg/day) were given orally to groups of mice (10 mice/dose) for 90 consecutive days. All animals survived to the end of the study, and there were no significant differences in body weight among the control and treatment groups. No significant differences were found in hematological and serum biochemical parameters among the control and treatment groups. No abnormalities of internal organs were observed in the treated groups.

Mosaicplasty for osteochondral lesions of the talus: a report of two cases.

Two women (24 and 27 years old) noted pain in the affected ankle of several years' duration. Radiography and magnetic resonance imaging revealed osteochondral lesions of the talus in both patients. The lesion sites measured 1.3 × 1.0 × 0.4 cm (0.52 cm(3)) and 2.0 × 1.9 × 0.5 cm (1.9 cm(3)). Each patient received a medial malleolar osteotomy with mosaicplasty. Donor plugs were obtained from the ipsilateral knee in both patients. Surgery was performed successfully in both patients without complications. At 2-year follow-up, both patients had recovered good ankle function, with no donor site morbidity. American Orthopedic Foot and Ankle Society ankle/hindfoot scores improved in the affected ankles from 16 to 84 in case 1 and from 43 to 87 in case 2. Mosaicplasty is effective in treating stage III or IV osteochondral lesions of the talus and results in good-to-excellent recovery of function.

Comparison of clinical results of surgical treatment for unstable distal clavicle fractures by transacromial pins with and without tension band wire.

BACKGROUND: An unstable distal clavicle fracture (Neer type II) is an indication that surgical intervention is required. Numerous treatment options have been introduced, but there is no gold standard. METHODS: We report on our experience of 29 consecutive cases, between 2002 and 2008, of acute unstable distal clavicle fracture (Neer type II) and operative treatment using transacromial pins with tension band wire, and compare the use of this treatment with that of traditional transacromial Kirschner wire fixation. All patients were given postoperative radiological and clinical evaluations at 4, 8 and 12 weeks, and then the final clinical outcome, based on the University of California at Los Angeles shoulder rating, was recorded. RESULTS: The fractures in both groups were clinically united at a mean follow-up of 8.62 weeks (range, 6-20 weeks). Six of the 14 patients (43%) with traditional transacromial Kirschner wire fixation suffered from pin migration and discomfort of skin erosion, 3 had residual displacement, and 1 had a recurrent fracture. In contrast, only 1 patient (7%) in the tension band wire group had residual displacement and pin migration causing skin tenting, and this was made comfortable by pin removal. The complication rate and the University of California at Los Angeles shoulder rating were significantly different between the 2 groups. CONCLUSION: Transacromial pins with tension band wire provide superior fixation for a type 2 fracture of the distal clavicle, compared with traditional transacromial Kirschner wire fixation.