Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0029463 (osteosarcoma)
 16,637 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Glioblastomas are high-risk primary brain tumors that are generally unresponsive or only weakly responsive to the currently available antineoplastic agents. Thus novel therapeutic strategies and agents are urgently needed to treat these incurable cancers. Oleanolic acid and ursolic acid are naturally occurring triterpenoids that have been used in traditional Asian medicine as anti-inflammatory and anti-cancer agents. Recently, synthetic oleanolic acid triterpenoid 2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oic acid (CDDO) and its C-28 methyl ester (CDDO-Me) and C-28 imidazole (CDDO-Im) derivatives have been shown to exhibit potent antitumor activity against diverse types of tumor cell lines, including leukemia, multiple myeloma, osteosarcoma, breast, lung, and pancreatic cancer cell lines; however, the anticancer activity of these agents for brain tumors has not been reported. In the present study, we investigated the apoptosis-inducing activity of CDDOs in glioblastoma (U87MG, U251MG) and neuroblastoma (SK-N-MC) cell lines. Cell growth/viability (MTS) and cytotoxicity (LDH release) assays demonstrated that glioblastoma cell lines are least sensitive to CDDO, but are highly sensitive to CDDO-Me and CDDO-Im at concentrations of 2.5-10 muM. CDDO-Im and CDDO-Me were equipotenent in their growth inhibitory activity. The primary mode of tumor cell destruction was apoptosis as demonstrated by significant increase in the number of hypo-diploid (sub-G0) cells and annexin V-FITC binding. Induction of apoptosis was associated with the activation of procaspases-3, -8, and -9, mitochondrial depolarization and the release of cytochrome c from mitochondria. Furthermore, CDDO-Me inhibited the levels of anti-apoptotic and prosurvival p-Akt, NF-kappaB (p65) and Notch1 signaling molecules. These studies provide rationale for clinical evaluation of these novel agents for the management of lethal brain neoplasms.
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PMID:Synthetic triterpenoids inhibit growth and induce apoptosis in human glioblastoma and neuroblastoma cells through inhibition of prosurvival Akt, NF-kappaB and Notch1 signaling. 1736 29

This study was undertaken to investigate the inhibitory effects of triterpenoid compound oleanolic acid and its synthetic derivatives on osteosarcoma cells in order to identify new therapeutic candidates for the treatment of this disease. We used the 3-(4,5-dimethyl-2 thiazolyl)-2,5-diphenyl tetrazolium bromide assay to assess the effect of oleanolic acid compounds on the proliferation of osteosarcoma cells. The effect of dextrose-oleanolic acid (the most potent oleanolic acid derivative) on apoptosis of osteosarcoma cells was evaluated using the Annexin-V method. The cell cycle of dextrose-oleanolic acid-treated cells was examined by flow cytometry, and the in vivo effects of dextrose-oleanolic acid were evaluated in a mouse osteosarcoma model. Oleanolic acid compounds had an overall inhibitory effect on the proliferation of osteosarcoma cells. Our in vitro data showed that the dextrose-oleanolic acid derivative brought about maximal inhibition of proliferation of osteosarcoma cells while inducing apoptosis. It could also inhibit the growth of osteosarcoma and decreased the rate of lung metastasis in vivo. Of the oleanolic acid derivatives, dextrose-oleanolic acid exhibited the most potent anti-osteosarcoma activity; it may represent a new frontier in the treatment of osteosarcoma.
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PMID:Oleanolic acid derivative Dex-OA has potent anti-tumor and anti-metastatic activity on osteosarcoma cells in vitro and in vivo. 1994 81

Oleanolic acid (OA), a pentacyclic triterpenoid exhibits potent anti-tumor activity against many tumor cell lines. But the mechanisms through which OA inhibits osteosarcoma cells are not known. The mammalian target of rapamycin (mTOR) serves as a central regulator of cell growth, proliferation, survival, and metabolism by integrating intracellular and extracellular signals. In this study, we examined effects of OA on proliferation, cell cycle progression, apoptosis in osteosarcoma cells, and involvement of mTOR signaling in this process. OA inhibited cell proliferation and colony formation, induced G1 arrest in osteosarcoma MG63 and Saos-2 cells dose and time dependently. The protein level of cyclin D1, which plays critical role in G1 to S phase transition and servers as a downstream target of mTOR complex 1 (mTORC1) was down-regulated by OA. Phosphorylation of p70 ribosomal S6 kinase 1 (p70 S6K1) (T389) and S6 (S235/236), mediators of mTORC1 signaling in controlling protein translation and cell growth, was also inhibited by OA. Furthermore, OA inhibited phosphorylation of Akt, a pro-survival factor and substrate for mTORC2. Inactivation of Akt correlated with pro-apoptotic role of OA in osteosarcoma cells, as manifested by an increase in annexin V-FITC binding, cleavage of poly (ADP-ribose) polymerase (PARP) and activation of caspases 3. Our results suggest that OA is a promising agent for treatment of osteosarcoma and mTOR signaling may contribute to its anti-tumor effects on osteosarcoma cells.
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PMID:Inhibition of mTOR signaling by oleanolic acid contributes to its anti-tumor activity in osteosarcoma cells. 2124 13

Oleanolic acid (OA), a naturally occurring triterpenoid, exhibits potential antitumor activity in several tumor cell lines. Although the inhibition effects of OA on proliferation and survival in human cancers have been confirmed, the potential mechanism underlying OA-induced osteosarcoma cell death has not yet been fully elucidated. Our results in this study showed that OA inhibits proliferation and viability of osteosarcoma cells in a dose-dependent manner. Flow cytometry assays revealed that apoptosis in osteosarcoma cells was significantly induced by OA treatment, while this induction was blocked by Jagged1-mediated activation of Notch signaling. Western blot analysis and a mitochondrial membrane potential assay demonstrated that OA functions through the mitochondrial apoptosis pathway. More importantly, our data revealed that OA treatment interrupted the balance between pro-apoptotic factors and anti-apoptotic factors in osteosarcoma cells by inhibition of the Notch signaling pathway. These data suggest that OA induces osteosarcoma cell apoptosis by targeting mitochondria in a Notch signaling-dependent manner. Thus, OA may be a promising drug for adjuvant chemotherapy in osteosarcoma.
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PMID:Oleanolic acid induces osteosarcoma cell apoptosis by inhibition of Notch signaling. 2956 82