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Osteosarcoma is the most common primary bone tumor that occurs in children and adolescents. Osteosarcoma has a poor prognosis and is often unresponsive to chemotherapy. Therefore, it remains a challenge to identify a novel strategy to effectively treat osteosarcoma. The present study demonstrated a novel opportunity in osteosarcoma treatment using the natural compound plumbagin. Plumbagin reduced cell viability in osteosarcoma cells but not normal bone cells, as determined by MTT assay and colony formation assay. Plumbagin induced cell apoptosis by mitochondrial dysfunction, which in turn promoted Ca2+ release and endoplasmic reticulum (ER)‑stress, as determined by DAPI staining assay, DNA fragmentation assay, flow cytometry and western blotting analysis. In addition, plumbagin improved reactive oxygen species (ROS) generation, as determined by flow cytometry. Finally, these apoptotic cascades activated caspase‑3 and caspase‑9 to elicit apoptosis response. Our results demonstrated the anticancer effect of plumbagin by inducing cell apoptosis in osteosarcoma cells. In conclusion, plumbagin activated the apoptosis signaling pathway through eliciting ROS, ER stress, mitochondria dysfunction, and finally causing caspase activation. These results indicated that plumbagin may serve as potential antitumor drug by its multifunctional effects in osteosarcoma. [ABSTRACT FROM AUTHOR]

The aim of the present study was to explore the effect of silencing wild‑type p53‑induced phosphatase 1 (Wip1) on apoptosis of human ovarian cancer SKOV3 cells. SKOV3 cells cultured in vitro were divided into three groups: untreated cells, cells transfected with control small interfering RNA (siRNA) and cells transfected with siRNA targeting Wip1. Flow cytometry analysis was used to detect cell apoptosis. Western blot analysis was performed to determine expression of tumor protein 53 (p53), cleaved caspase‑3, caspase‑3, BCL2 associated X (Bax), BCL2 apoptosis regulator (Bcl‑2), p38 mitogen‑activated protein kinase (p38 MAPK) and phosphorylated (p)‑p38 MAPK. Reverse transcription‑quantitative polymerase chain reaction was used to detect expression of p53, Bax, Bcl‑2 and caspase‑3 mRNAs. Compared with control, apoptosis of SKOV3 cell was significantly increased following Wip1 siRNA silencing. Wip1 silencing also resulted in a significant increase of p53 and p‑p38 MAPK expression, as well as increased cleaved caspase‑3/caspase‑3 and Bax/Bcl‑2 protein ratios. No significant differences were observed in apoptosis and apoptosis‑related protein expression in the control siRNA transfected cells. The present study demonstrated that Wip1 silencing promotes apoptosis of human ovarian cancer SKOV3 cells by activation of the p38 MAPK signaling pathways and through subsequent upregulation of p53, and cleaved caspase‑3/caspase‑3 and Bax/Bcl‑2 protein ratios. Overall, the findings of the present study suggest that targeting Wip1 may be a potential therapeutic avenue for the treatment of human ovarian cancer in the future. [ABSTRACT FROM AUTHOR]

The toxicities of conventional chemotherapeutic agents to normal cells restrict their dosage and clinical efficacy in acute leukemia; therefore, it is important to develop novel chemotherapeutics, including natural products, which selectively target cancer-specific pathways. The present study aimed to explore the effect of the chemopreventive agent asiatic acid (AA) on the proliferation and apoptotic rate of the leukemia cell line HL-60 and investigated the mechanisms underlying its anti-tumor activity. The effect of AA on the proliferation of HL-60 cells was evaluated using the MTT assay. Annexin V-fluorescein isothiocyanate/propidium iodide double staining followed by flow cytometric analysis as well as Hoechst 33258 staining were used to analyze the apoptotic rate of the cells. Furthermore, changes of survivin, B-cell lymphoma 2 (Bcl-2), myeloid cell leukemia 1 (Mcl-1), extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 expressions were detected by western blot analysis. AA blocked the growth of HL-60 cells in a dose- and time-dependent manner. The IC50-value of AA on HL-60 cells was 46.67±5.08 µmol/l for 24 h. AA induced apoptosis in a dose-dependent manner, which was inhibited in the presence of Z-DEVD-FMK, a specific inhibitor of caspase. The anti-apoptotic proteins Bcl-2, Mcl-1 and survivin were downregulated by AA in a dose-dependent manner. Concurrently, AA inhibited ERK and p38 phosphorylation in a dose-dependent manner, while JNK phosphorylation was not affected. In conclusion, the present study indicated that the p38 and ERK pathways, as well as modulation of Bcl-2 family and survivin proteins were key regulators of apoptosis induced in HL-60 cells in response to AA. [ABSTRACT FROM AUTHOR]

The pathogenesis of atherosclerosis is multi factorial. The proliferation and migration of vascular smooth muscle cells (VSMCs) are significant in the genesis and development of atherosclerosis plaques, and the degradation of VSMCs plays a crucial role in the process. Mimecan is a member of the Keratan sulfate family of proteoglycans, which are leucine-rich proteoglycans. It has been demonstrated that mimecan is associated with arteriogenesis and atherosclerosis. In the present study, the effect of mimecan on the characteristics of cultured human aortic smooth muscle cells (HASMCs) was investigated. In vitro, human mimecan was stably overexpressed in HASMCs using a lentiviral system. It was observed that the proliferation rate of HASMCs transduced with mimecan was lower compared with that of control cells; overexpression of mimecan induced HASMC apoptosis. To determine the effect of mimecan on HASMC migration, a Transwell cell culture chamber and sterile cloning cylinder assays were used, and it was noted that mimecan enhanced the migration of HASMCs horizontally and vertically. These data indicated that mimecan may be involved in the pathogenesis of atherosclerosis by regulating the proliferation, apoptosis and migration of VSMCs. [ABSTRACT FROM AUTHOR]

The present study aimed to investigate the effects of the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway on the Wnt/β-catenin signaling pathway in rats with focal cerebral ischemia-reperfusion injury. A total of 96 rat focal cerebral ischemia-reperfusion models, established according to a modified version of Longa's method, were randomly divided into four groups: Sham-operated (S), cerebral ischemia-reperfusion injury (I), cerebral ischemia-reperfusion + basic fibroblast growth factor (bFGF) post-processing and, finally, cerebral ischemia-reperfusion + bFGF post-processing + PI3K inhibitor LY294002 (LY). Each group consisted of 24 rats and each group was divided into four subgroups according to the indicated reperfusion times of 12, 24, 48 and 72 h. The morphological changes of the cortical tissue and the cellular apoptosis were determined using hematoxylin and eosin staining and the terminal deoxynucleotidyl transferase dUTP nick end labeling method, respectively. The expression levels of phosphorylated (p-)Akt, glycogen synthase kinase-3β (GSK-3β) mRNA and β-catenin in the cortical tissue were detected at different time-points. The number of apoptotic cells and the expression levels of p-Akt, GSK-3β mRNA and β-catenin in the I and LY groups were significantly higher compared with those in the S group (P<0.05). In the bFGF group, the number of apoptotic cells and the mRNA expression levels of GSK-3β were significantly decreased, whereas the expression levels of p-Akt and β-catenin were significantly increased compared with those in the I and LY groups (P<0.05). In cerebral ischemia-reperfusion injury, the PI3K/Akt signaling pathway regulated β-catenin, the main member of the Wnt signaling pathway, via GSK-3β, providing information to assist in further investigation of the mechanism of β-catenin in ischemia-reperfusion injury. [ABSTRACT FROM AUTHOR]

Puerarin, a predominant isoflavonoid compound extracted from the Chinese medicinal herb Radix Puerariae, is considered to exhibit an antitumor effect. In the present study, the effects of puerarin on SMMC-7721 human hepatocellular carcinoma cells were investigated. Cell viability was assessed by MTT assay. Apoptosis was detected by flow cytometry with Annexin V-fluorescein isothiocyante staining and morphological observation of nuclear changes by Hoechst staining. The mitochondrial membrane potential (MMP) was monitored using rhodamine 123. The generation of reactive oxygen species (ROS) was quantified using dichloro-dihydro-fluorescein diacetate. Polymerase chain reaction and western blot analysis were used to detect the expression levels of apoptosis-associated genes. The results revealed that high concentrations of puerarin (500, 1,000 and 1,500 μg/ml) significantly inhibited the proliferation of SMMC-7721 cells in a time- and dose-dependent manner. Simultaneously, apoptotic rates were increased and cell morphology was changed following puerarin treatment. Furthermore, puerarin-induced apoptosis of SMMC-7721 cells was associated with loss of MMP and generation of ROS. Puerarin treatment increased caspase-3,8,9 and apoptosis-inducing factor (AIF) mRNA expression levels in SMMC-7721 cells, while the phosphorylation levels of P38, extracellular signal-regulated kinase (ERK1) and c-Jun N-terminal kinase were also increased. Furthermore, caspase-9 and AIF protein expression was upregulated. In conclusion, puerarin inhibited proliferation and induced apoptosis in SMMC-7721 cells via the mitochondria-dependent pathway; however, the specific mechanisms require further investigation. [ABSTRACT FROM AUTHOR]

The sporoderm-broken spores of Ganoderma lucidum (G. lucidum) polysaccharide (BSGLP) have been demonstrated to inhibit carcinogenesis in several types of cancer. However, to the best of our knowledge, the anticancer effects of polysaccharides extracted from the newly developed sporoderm-removed spores of G. lucidum (RSGLP) have not been assessed. The present study first compared the anticancer effects of RSGLP and BSGLP in three gastric cancer cell lines and it was found that RSGLP was more potent than BSGLP in decreasing gastric cancer cell viability. RSGLP significantly induced apoptosis in AGS cells, accompanied by downregulation of Bcl-2 and pro-caspase-3 expression levels, and upregulation of cleaved-PARP. Furthermore, RSGLP increased LC3-II and p62 expression, indicative of induction of autophagy and disruption of autophagic flux in AGS cells. These results were further verified by combined treatment of AGS cells with the late-stage autophagy inhibitor chloroquine, or early-stage autophagy inducer rapamycin. Adenoviral transfection with mRFP-GFP-LC3 further confirmed that autophagic flux was inhibited by RSGLP in AGS cells. Finally, the present study demonstrated that the RSGLP-induced autophagy and disruption of autophagic flux disruption was, at least in part, responsible for RSGLP-induced apoptosis in AGS cells. The results of the present study demonstrated for the first time that RSGLP is more effective than BSGLP in inhibiting gastric cancer cell viability, and RSGLP may serve as a promising autophagy inhibitor in the management of gastric cancer. [ABSTRACT FROM AUTHOR]