piplartine and Osteosarcoma

The present study evaluated the functions of Piperlongumine (PL) in osteosarcoma (OS) cell growth and metastasis both in vitro and in vivo.. MTT assay was conducted to test the cytotoxic effects of PL on the human osteoblasts line HFOB1.19 and the human normal chondrocyte line C28/I2T. FITC-Annexin V and propidium iodide (PI) were used to examine cell apoptosis. The migration, invasion and relative epithelial-mesenchymal transition were examined by Transwell assay and Western blotting. Reverse transcription-quantitative PCR (RT-qPCR) was performed to analyze the cytokine signaling 3 (SOCS3) mRNA expression. TargetScan database was used to predict the target of SOCS3. The binding association between miR-30d-5p and SOCS3 in U2OS and MG63 cells was evaluated by the dual-luciferase reporter assay. A xenograft model was constructed to evaluate the effect of PL on OS cell growth in vivo.. The results revealed that PL inhibited the growth, migration, invasion, epithelial-mesenchymal transition, and promoted the apoptosis of OS cells dose-dependently. In addition, PL upregulated the protein levels of suppressor of SOCS3, while it inactivated the JAK2/STAT3 pathway, which was accompanied by a decreased level of microRNA (miR)-30d-5p. Furthermore, SOCS3was confirmed as a novel target of miR-30d-5p. Overexpression of miR-30d-5p not only led to decreased expression of SOCS3, but also dampened the antitumor effect of PL on OS.. The present data demonstrated that PL inhibited the progression of OS via downregulation of the SOCS3-mediated JAK2/STAT3 pathway by inhibiting miR-30d-5p.

Topics: Animals; Apoptosis; Cell Movement; Cell Proliferation; Dioxolanes; Disease Progression; Epithelial-Mesenchymal Transition; Female; Gene Expression Regulation, Neoplastic; Humans; Janus Kinase 2; Mice; Mice, Nude; MicroRNAs; Osteosarcoma; Signal Transduction; STAT3 Transcription Factor; Suppressor of Cytokine Signaling 3 Protein

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Cell Line, Tumor; Cell Survival; Dioxolanes; G2 Phase Cell Cycle Checkpoints; Humans; Osteosarcoma; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Reactive Oxygen Species; Signal Transduction

Elevation of reactive oxygen species (ROS) levels has been observed in many cancer cells relative to nontransformed cells, and recent reports have suggested that small-molecule enhancers of ROS may selectively kill cancer cells in various in vitro and in vivo models. We used a high-throughput screening approach to identify several hundred small-molecule enhancers of ROS in a human osteosarcoma cell line. A minority of these compounds diminished the viability of cancer cell lines, indicating that ROS elevation by small molecules is insufficient to induce death of cancer cell lines. Three chemical probes (BRD5459, BRD56491, BRD9092) are highlighted that most strongly elevate markers of oxidative stress without causing cell death and may be of use in a variety of cellular settings. For example, combining nontoxic ROS-enhancing probes with nontoxic doses of L-buthionine sulfoximine, an inhibitor of glutathione synthesis previously studied in cancer patients, led to potent cell death in more than 20 cases, suggesting that even nontoxic ROS-enhancing treatments may warrant exploration in combination strategies. Additionally, a few ROS-enhancing compounds that contain sites of electrophilicity, including piperlongumine, show selective toxicity for transformed cells over nontransformed cells in an engineered cell-line model of tumorigenesis. These studies suggest that cancer cell lines are more resilient to chemically induced increases in ROS levels than previously thought and highlight electrophilicity as a property that may be more closely associated with cancer-selective cell death than ROS elevation.

Topics: Antineoplastic Agents; Bone Neoplasms; Buthionine Sulfoximine; Cell Death; Cell Line, Transformed; Cell Line, Tumor; Cell Survival; Dioxolanes; Drug Screening Assays, Antitumor; High-Throughput Screening Assays; Humans; Molecular Probes; Osteosarcoma; Oxidative Stress; Reactive Oxygen Species; Small Molecule Libraries