curcumin has been researched along with Osteosarcoma* in 47 studies
3 review(s) available for curcumin and Osteosarcoma
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Targeting Signaling Pathway by Curcumin in Osteosarcoma.
The most prevalent primary bone malignancy among children and adolescents is osteosarcoma. The high mortality rate of osteosarcoma is due to lung metastasis. Despite the development of multi-agent chemotherapy and surgical resection, patients with osteosarcoma have a high metastasis rate and poor prognosis. Thus, it is necessary to identify novel therapeutic agents to improve the 5-year survival rate of these patients. Curcumin, a phytochemical compound derived from Curcuma longa, has been employed in treating several types of cancers through various mechanisms. Also, in vitro studies have demonstrated that curcumin could inhibit cell proliferation and induce apoptosis in osteosarcoma cells. Development in identifying signaling pathways involved in the pathogenesis of osteosarcoma has provided insight into finding new therapeutic targets for the treatment of this cancer. Targeting MAPK/ERK, PI3k/AKT, Wnt/β-catenin, Notch, and MircoRNA by curcumin has been evaluated to improve outcomes in patients with osteosarcoma. Although curcumin is a potent anti-cancer compound, it has rarely been studied in clinical settings due to its congenital properties such as hydrophobicity and poor bioavailability. In this review, we recapitulate and describe the effect of curcumin in regulating signaling pathways involved in osteosarcoma. Topics: Adolescent; Bone Neoplasms; Child; Curcumin; Humans; Osteosarcoma; Phosphatidylinositol 3-Kinases; Signal Transduction | 2023 |
Curcumin in human osteosarcoma: From analogs to carriers.
Osteosarcoma (osteogenic sarcoma), the most prevalent primary malignant bone tumor in adolescents, confers low survival rates in patients with metastatic disease. Dietary curcumin has a number of anticancer properties but has poor bioavailability. To improve the clinical applications of curcumin, several potential curcumin analogs and nanobased curcumin delivery systems have been developed. In this critical review, we address the biological and pharmacological characteristics of curcumin and its analogs, with an emphasis on strategies to improve the bioactivity and bioavailability of curcumin analogs that may increase their application in the treatment of potent human metastatic osteosarcoma. We highlight promising current multifunctional nanoformulations and three-dimensional printed scaffold systems utilized for the targeting and delivery of curcumin in human osteosarcoma cells. Our purpose is to drive further research on curcumin analogs and carriers to improve their bioavailability and anti-osteosarcoma bioactivity. Topics: Adolescent; Bone Neoplasms; Curcumin; Drug Carriers; Humans; Osteosarcoma | 2023 |
Curcumin and its Analogs and Carriers: Potential Therapeutic Strategies for Human Osteosarcoma.
Curcumin is a natural polyphenol phytochemical derived from turmeric with antioxidant, anti-inflammatory, and anticancer properties but is concerned about poor solubility in water, absorption, and metabolic stability. Potent metastatic osteosarcoma is the most common primary bone cancer in children, adolescents, and young adults. It is responsible for low survival rates because of its high rate of metastasis to the lungs. To improve poor bioavailability, numerous curcumin analogs were developed to possess anticancer characteristics through a variety of biological pathways involved in cytotoxicity, proliferation, autophagy, sensitizing chemotherapy, and metastases. This review provides an overview of their various pharmacological functions, molecular mechanisms, and therapeutic potential as a remedy for human osteosarcoma. To enhance therapeutic efficacy, several liposomal nanoparticles, nanocarriers, multifunctional micelles, and three-dimensional printed scaffolds have also been developed for the controlled delivery of curcumin targeting human osteosarcoma cells. Consequently, curcumin and several potential analogs and delivery formulations are optimistic candidates to improve the currently available strategy for human osteosarcoma. However, further insight into the mechanism of action of promising curcumin analogs and the development of carriers in clinical trials of osteosarcoma needs to be investigated to improve their overall potency and clinical utility, in particular the anti-metastatic effect. Topics: Adolescent; Bone Neoplasms; Child; Curcumin; Humans; Nanoparticles; Osteosarcoma; Solubility | 2023 |
44 other study(ies) available for curcumin and Osteosarcoma
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The lack of site-specific chemotherapeutic agents to treat bone malignancy throws a significant challenge in the design of a delivery vehicle. The major scientific question posed in this study is, can we utilize curcumin-loaded magnesium oxide (MgO) doped 3D printed tricalcium phosphate (TCP) bone grafts as a localized delivery system that improves early stage Topics: Animals; Bone Neoplasms; Curcumin; Magnesium Oxide; Osteosarcoma; Printing, Three-Dimensional; Rats; Staphylococcus aureus; Tissue Engineering; Tissue Scaffolds | 2023 |
Paradox: Curcumin, a Natural Antioxidant, Suppresses Osteosarcoma Cells via Excessive Reactive Oxygen Species.
Osteosarcoma (OS) is an aggressive tumor with a rare incidence. Extended surgical resections are the prevalent treatment for OS, which may cause critical-size bone defects. These bone defects lead to dysfunction, weakening the post-surgical quality of patients' life. Hence, an ideal therapeutic agent for OS should simultaneously possess anti-cancer and bone repair capacities. Curcumin (CUR) has been reported in OS therapy and bone regeneration. However, it is not clear how CUR suppresses OS development. Conventionally, CUR is considered a natural antioxidant in line with its capacity to promote the nuclear translocation of a nuclear transcription factor, nuclear factor erythroid 2 (NRF2). After nuclear translocation, NRF2 can activate the transcription of some antioxidases, thereby circumventing excess reactive oxygen species (ROS) that are deleterious to cells. Intriguingly, this research demonstrated that, in vitro, 10 and 20 μM CUR increased the intracellular ROS in MG-63 cells, damaged cells' DNA, and finally caused apoptosis of MG-63 cells, although increased NRF2 protein level and the expression of NRF2-regulated antioxidase genes were identified in those two groups. Topics: Antioxidants; Apoptosis; Bone Neoplasms; Curcumin; Humans; NF-E2-Related Factor 2; Osteosarcoma; Reactive Oxygen Species | 2023 |
Micelle encapsulated curcumin and piperine-laden 3D printed calcium phosphate scaffolds enhance in vitro biological properties.
Limitations in the current clinical management of critical-sized osseous defects have driven the need for multifunctional bone constructs. The ideal bone scaffold should possess advanced microarchitecture, well-defined pore interconnectivity, and supply biological signals, which actively guide and control tissue regeneration while simultaneously preventing post-implantation complications. Here, a natural medicine-based localized drug delivery from 3D printed scaffold is presented, which offers controlled release of curcumin, piperine from nano-sized polymeric micelles, and burst release of antibacterial carvacrol from the coating endowing the scaffold with their distinct, individual biological properties. This functionalized scaffold exhibits improved osteoblast (hFOB) cell attachment, 4-folds higher hFOB proliferation, and 73% increased hFOB differentiation while simultaneously providing cytotoxicity towards osteosarcoma cells with 61% lesser viability compared to control. In vitro, early tube formation (p < 0.001) indicates that the scaffolds can modulate the endothelial cellular network, critical for faster wound healing. The scaffold also exhibits 94% enhanced antibacterial efficacy (p < 0.001) against gram-positive Staphylococcus aureus, the main causative bacteria for osteomyelitis. Together, the multifunctional scaffolds provide controlled delivery of natural biomolecules from the nano-sized micelle-loaded 3D printed matrix for significant improvement in osteoblast proliferation, endothelial formation, osteosarcoma, and bacterial inhibition, guiding better bone regeneration for post-traumatic defect repair. Topics: Anti-Bacterial Agents; Bone Neoplasms; Bone Regeneration; Calcium Phosphates; Curcumin; Humans; Micelles; Osteogenesis; Osteosarcoma; Printing, Three-Dimensional; Tissue Engineering; Tissue Scaffolds | 2023 |
Hydroxyapatite coated titanium with curcumin and epigallocatechin gallate for orthopedic and dental applications.
Titanium and its alloy are clinically used as an implant material for load-bearing applications to treat bone defects. However, the lack of biological interaction between bone tissue and implant and the risk of infection are still critical challenges in clinical orthopedics. In the current work, we have developed a novel approach by first 1) modifying the implant surface using hydroxyapatite (HA) coating to enhance bioactivity and 2) integrating curcumin and epigallocatechin gallate (EGCG) in the coating that would induce chemopreventive and osteogenic potential and impart antibacterial properties to the implant. The study shows that curcumin and EGCG exhibit controlled and sustained release profiles in acidic and physiological environments. Curcumin and EGCG also show in vitro cytotoxicity toward osteosarcoma cells after 11 days, and the dual system shows a ~94 % reduction in bacterial growth, indicating their in vitro chemopreventive potential and antibacterial efficacy. The release of both curcumin and EGCG was found to be compatible with osteoblast cells and further promotes their growth. It shows a 3-fold enhancement in cellular viability in the dual drug-loaded implant compared to the untreated samples. These findings suggest that multifunctional HA-coated Ti6Al4V implants integrated with curcumin and EGCG could be a promising strategy for osteosarcoma inhibition and osteoblast cell growth while preventing infection. Topics: Anti-Bacterial Agents; Bone Neoplasms; Curcumin; Durapatite; Humans; Osteosarcoma; Titanium | 2023 |
Use of network pharmacology and molecular docking to explore the mechanism of action of curcuma in the treatment of osteosarcoma.
Curcuma has been used as an adjuvant treatment for osteosarcoma (OS) due to its anticancer compounds. However, the underlying mechanism remains unclear. Therefore, this study aimed to explore the mechanism of action of curcuma in the treatment of OS using network pharmacology and molecular docking. In this study, anticancer compounds were obtained from relevant literature, and curcuma-related targets and OS treatment targets were obtained from public databases. Protein‒protein interaction networks were constructed to screen out the hub genes using the STRING database and Cytoscape software. Cluster analysis of the protein modules was then performed using the Cytoscape MCODE plugin. Furthermore, Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses were performed for common targets among curcuma targets and OS-related targets using the DAVID database. Finally, molecular docking was performed, and the results were verified by Auto dock Tool and PyMOL software. Our research identified 11 potential active compounds, 141 potential therapeutic targets and 14 hub genes for curcuma. AKT1, TNF, STAT3, EGFR, and HSP90AA1 were the key targets closely related to the PI3K/Akt signaling pathways, HIF-1 signaling pathways, ErbB signaling pathways, and FOXO signaling pathways, which are involved in angiogenesis, cancer cell proliferation, metastasis, invasion, and chemotherapy resistance in the microenvironment of OS. Molecular docking suggested that the core compound had a strong affinity for key targets, with a binding energy of less than - 5 kJ/mol. The study showed that curcuma-mediated treatment of OS was a complex process involving multiple compounds, targets, and pathways. This study will enhance the understanding of how curcuma affects the proliferation and invasion of OS cells and reveal the potential molecular mechanism underlying the effect of curcuma on OS lung metastasis and chemotherapy resistance. Topics: Bone Neoplasms; Curcuma; Molecular Docking Simulation; Network Pharmacology; Osteosarcoma; Phosphatidylinositol 3-Kinases; Tumor Microenvironment | 2023 |
Curcumin-Loaded Nanoparticles Impair the Pro-Tumor Activity of Acid-Stressed MSC in an In Vitro Model of Osteosarcoma.
In the tumor microenvironment, mesenchymal stromal cells (MSCs) are key modulators of cancer cell behavior in response to several stimuli. Intratumoral acidosis is a metabolic trait of fast-growing tumors that can induce a pro-tumorigenic phenotype in MSCs through the activation of the NF-κB-mediated inflammatory pathway, driving tumor clonogenicity, invasion, and chemoresistance. Recent studies have indicated that curcumin, a natural ingredient extracted from Topics: Anti-Inflammatory Agents; Cell Line, Tumor; Curcumin; Cytokines; Humans; I-kappa B Proteins; Mesenchymal Stem Cells; Nanoparticles; NF-kappa B; Osteosarcoma; Tumor Microenvironment | 2021 |
Curcumin-Microsphere/IR820 Hybrid Bifunctional Hydrogels for In Situ Osteosarcoma Chemo-
Topics: Bone Neoplasms; Bone Regeneration; Cell Line, Tumor; Cell Membrane Permeability; Combined Modality Therapy; Curcumin; Humans; Hydrogels; Hyperthermia, Induced; Indocyanine Green; Microspheres; Osteosarcoma | 2021 |
The role of miR-21/RECK in the inhibition of osteosarcoma by curcumin.
Osteosarcoma is a malignant tumor in bones that is common in children and adolescents. MicroRNAs (miRs) are small non-coding RNAs that are associated with various kinds of tumors. miR-21 is one of the most frequently overexpressed microRNAs in osteosarcoma. Curcumin is a naturally occurring phenolic compound that has antitumor properties. Curcumin significantly inhibits osteosarcoma. However, the role of miR-21 and its target gene, reversion-inducing cysteine-rich protein with kazal motifs (RECK), in the anticancer activity of curcumin against osteosarcoma remains unclear. The aim of this study is to investigate the effect(s) of curcumin on osteosarcoma cell proliferation and elucidate its molecular mechanism. Cell counting kit-8, colony formation and flow cytometry assays were performed to study cell proliferation and apoptosis. Real time-polymerase chain reaction was used to determine the expression of miR-21 and RECK. Wnt/β-catenin signaling pathway proteins were detected by Western Blot. We hereby show that curcumin upregulated the expression of RECK via miR-21, thereby subsequently regulating Wnt/β-catenin signaling leading to the inhibition of osteosarcoma. Topics: Antineoplastic Agents; Apoptosis; Bone Neoplasms; Cell Line, Tumor; Cell Proliferation; Curcumin; Gene Expression Regulation, Neoplastic; GPI-Linked Proteins; Humans; MicroRNAs; Osteosarcoma; Real-Time Polymerase Chain Reaction; Up-Regulation; Wnt Signaling Pathway | 2020 |
Doxorubicin and CD‑CUR inclusion complex co‑loaded in thermosensitive hydrogel PLGA‑PEG‑PLGA localized administration for osteosarcoma.
Combination therapy is a promising and prevalent strategy for osteosarcoma treatment. Curcumin (CUR), as a chemosensitizer, improves the antitumor effect of first‑line chemotherapy drugs. However, due to its poor solubility and instability in physiological conditions, the bioavailability of CUR is limited. In order to improve the physicochemical properties of natural CUR, β‑cyclodextrin was adopted to generate a β‑cyclodextrin curcumin (CD‑CUR) inclusion complex. A thermosensitive hydrogel, poly(D,L‑lactide‑co‑glycolide)-poly(ethylene‑glycol)‑poly(D,L‑lactide‑co‑glycolide), was selected and synthesized to co‑deliver doxorubicin (DOX) and CD‑CUR to tumor sites. The dual‑drug delivery system (gel+DOX+CD‑CUR) was prepared by mixing drugs with hydrogels and had a perfect sol‑gel phase transition temperature (18.3˚C for 20% concentration). Both DOX and CUR were released from hydrogels in a sustained manner in PBS (pH 7.4) medium. The combination therapy based on DOX+CD‑CUR exhibited higher antitumor activity than monotherapies in vitro. Combined CD‑CUR therapy significantly downregulated Bcl‑2 expression and upregulated caspase‑3 expression, suggesting that DOX combined with CD‑CUR treatment has a higher apoptosis‑inducing efficiency. The antitumor efficiency of the gel+DOX+CD‑CUR strategy was evaluated in K‑7 tumor‑bearing mice, and this localized combination therapy demonstrated a higher antitumor efficiency compared with free DOX+CD‑CUR or single‑drug strategies. There were no significant differences in body weight and histological changes of major organs in each group. Therefore, the present combination treatment based on hydrogel may be a feasible approach to co‑deliver DOX and CD‑CUR to osteosarcoma tumor sites in clinical practice. Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; beta-Cyclodextrins; Bone Neoplasms; Cell Line, Tumor; Curcumin; Disease Models, Animal; Doxorubicin; Drug Carriers; Drug Compounding; Feasibility Studies; Female; Humans; Hydrogels; Injections, Intralesional; Mice; Nanoparticles; Osteosarcoma; Polyesters; Polyethylene Glycols | 2020 |
Curcumin Analogue L48H37 Suppresses Human Osteosarcoma U2OS and MG-63 Cells' Migration and Invasion in Culture by Inhibition of uPA via the JAK/STAT Signaling Pathway.
Osteosarcoma, the most prevalent malignant bone tumor in the pediatric age group, is responsible for the great majority of cancer-associated deaths owing to its highly metastatic potential. The anti-metastatic effects of the new curcumin analogue L48H37 in human osteosarcoma are still unknown; hence, we investigated whether L48H37 represses human osteosarcoma cells' biological behavior of migratory potential and invasive activities and attempted to delve into its underlying mechanisms. L48H37 up to 5 μM inhibited, without cytotoxicity, the motility, migration, and invasion of human osteosarcoma U2OS and MG-63 cells. In U2OS cells, the human protease array revealed an obvious decrease in urokinase plasminogen activator (uPA) expression after L48H37 treatment, and L48H37 actually reduced the level, protein and mRNA expression, and promoter activity of uPA dose-dependently. L48H37 decreased the phosphorylation of STAT3, JAK1, JAK2, and JAK3 in U2OS cells, but did not affect the phosphorylation of ERK, JNK, p38, and Akt. Using colivelin, an activator of STAT3, the L48H37-induced decrease in uPA and migratory potential could be countered as expected. Collectively, L48H37 represses the invasion and migration capabilities of U2OS and MG-63 cells by the suppression of uPA expression and the inhibition of JAK/STAT signaling. These results suggest that L48H37 may be a potential candidate for anti-metastatic treatment of human osteosarcoma. Topics: Antineoplastic Agents; Apoptosis; Biomarkers, Tumor; Bone Neoplasms; Cell Movement; Cell Proliferation; Curcumin; Gene Expression Regulation, Neoplastic; Humans; Janus Kinase 1; Neoplasm Invasiveness; Osteosarcoma; Phosphorylation; Signal Transduction; STAT3 Transcription Factor; Tumor Cells, Cultured; Urokinase-Type Plasminogen Activator | 2020 |
Dual targeting curcumin loaded alendronate-hyaluronan- octadecanoic acid micelles for improving osteosarcoma therapy.
Curcumin (CUR) is a general ingredient of traditional Chinese medicine, which has potential antitumor effects. However, its use clinically has been limited due to its low aqueous solubility and bioavailability. In order to improve the therapeutic effect of CUR on osteosarcoma (i.e., bone cancer), a multifunctional micelle was developed here by combining active bone accumulating ability with tumor CD44 targeting capacity.. The CUR loaded micelles were self-assembled by using alendronate-hyaluronic acid-octadecanoic acid (ALN-HA-C18) as an amphiphilic material. The obtained micelles were characterized for size and drug loading. In addition, the in vitro release behavior of CUR was investigated under PBS (pH 5.7) medium containing 1% Tween 80 at 37℃. Furthermore, an hydroxyapatite (the major inorganic component of bone) affinity experiment was studied. In vitro antitumor activity was evaluated. Finally, the anti-tumor efficiency was studied.. The size and drug loading of the CUR loaded ALN-HA-C18 micelles were about 118 ± 3.6 nm and 6 ± 1.2%, respectively. CUR was released from the ALN-HA-C18 micelles in a sustained manner after 12 h. The hydroxyapatite affinity experiment indicated that CUR loaded ALN-HA-C18 micelles exhibited a high affinity to bone. CUR loaded ALN-HA-C18 micelles exhibited much higher cytotoxic activity against MG-63 cells compared to free CUR. Finally, CUR loaded ALN-HA-C18 micelles effectively delayed anti-tumor growth properties in osteosarcoma bearing mice as compared with free CUR.. The present study suggested that ALN-HA-C18 is a novel promising micelle for osteosarcoma targeting and delivery of the hydrophobic anticancer drug CUR. Topics: Alendronate; Animals; Antineoplastic Agents; Bone Neoplasms; Cell Line, Tumor; Curcumin; Drug Carriers; Drug Delivery Systems; Drug Liberation; Humans; Hyaluronic Acid; Male; Mice, Nude; Micelles; Osteosarcoma; Particle Size; Polymers; Proton Magnetic Resonance Spectroscopy; Stearic Acids | 2019 |
Liposome-Encapsulated Curcumin-Loaded 3D Printed Scaffold for Bone Tissue Engineering.
Curcumin, the active constituent for turmeric, is known for its antioxidant, anti-inflammatory, anticancer, and osteogenic activities. However, it shows extremely poor bioavailability, rapid metabolism, and rapid systemic elimination. In this study, we have increased the bioavailability of curcumin by encapsulating it in a liposome, followed by the incorporation onto 3D printed (3DP) calcium phosphate (CaP) scaffolds with designed porosity. 3DP scaffolds with a designed shape and interconnected porosity allow for the fabrication of patient-specific implants, providing new tissue ingrowth by mechanical interlocking between the surrounding host tissue and the scaffold. Upon successful encapsulation of curcumin into the liposomes, we have investigated the effect of liposomal curcumin released from the 3DP scaffolds on both human fetal osteoblast cells (hFOB) and human osteosarcoma (MG-63) cells. Interestingly, liposomal curcumin released from the 3DP scaffold showed significant cytotoxicity toward in vitro osteosarcoma (bone cancer) cells, whereas it promoted osteoblast (healthy bone cell) cell viability and proliferation. These results reveal a novel approach toward the fabrication of tissue engineering scaffolds, which couples the advanced additive manufacturing technology with the wisdom of alternative medicine. These bifunctional scaffolds eradicate the osteosarcoma cells and also promote osteoblast proliferation, offering new opportunities to treat bone defects after tumor resection. Topics: Bone and Bones; Bone Development; Cell Proliferation; Cell Survival; Curcumin; Humans; Liposomes; Osteoblasts; Osteogenesis; Osteosarcoma; Porosity; Printing, Three-Dimensional; Tissue Engineering; Tissue Scaffolds | 2019 |
Curcumin Analog DK1 Induces Apoptosis in Human Osteosarcoma Cells In Vitro through Mitochondria-Dependent Signaling Pathway.
Topics: Antineoplastic Agents; Apoptosis; Apoptosis Regulatory Proteins; Bone Neoplasms; Cell Line, Tumor; Cell Proliferation; Cell Survival; Curcumin; Drug Screening Assays, Antitumor; Gene Expression; Humans; Inhibitory Concentration 50; Membrane Potential, Mitochondrial; Mitochondria; Osteosarcoma; Signal Transduction | 2018 |
The Curcumin Analog CH-5 Exerts Anticancer Effects in Human Osteosarcoma Cells via Modulation of Transcription Factors p53/Sp1.
Curcumin is a potential anticancer drug with poor bioavailability, which limits its clinical use as a therapeutic agent. The aim of this study was a preliminary evaluation of the curcumin analogue CH-5 as a cytotoxic agent in human osteosarcoma cell lines U2OS, MG-63, and Saos-2. CH-5 inhibited cell viability at lower concentrations than curcumin, leading to the induction of apoptosis. The cellular levels of the transcription factors p53 and Sp1 affect the expression of cellular pathways that lead to apoptosis. CH-5 increased p53 protein levels in U2OS cells and reduced Sp1 levels, with a consequent effect on the expression of their target genes DNA methyltransferase 1 ( Topics: Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Proliferation; Cell Survival; Curcumin; HCT116 Cells; Humans; Inhibitory Concentration 50; Osteosarcoma; Sp1 Transcription Factor; Tumor Suppressor Protein p53 | 2018 |
Curcumin Promotes Osteosarcoma Cell Death by Activating miR-125a/ERRα Signal Pathway.
Curcumin has demonstrated valuable therapeutic potential against a variety of human cancers including osteosarcoma. However, the molecular mechanisms underlying its anti-tumor effect remain to be poorly understood. By RNA sequence profiling, we found that curcumin significantly down-regulates the expression of estrogen-related receptor alpha (ERRα) in osteosarcoma cells. Overexpression of ERRα diminished curcumin-activated apoptotic cell death and scavenged curcumin-induced reactive oxygen species (ROS), while ERRα silencing sensitized osteosarcoma cells to curcumin, resulting in increased inhibition of cell proliferation. In addition, we found that curcumin suppressed the ERRα gene expression through upregulation of miR-125a. Data from this study revealed a novel mechanism for curcumin-mediated apoptotic cell death, which involves tumor cell killing via activating miR-125a/ERRα pathway. Our studies also provide further support for osteosarcoma therapy by targeting ERRα alone or in combination with curcumin. J. Cell. Biochem. 118: 74-81, 2017. © 2016 Wiley Periodicals, Inc. Topics: Apoptosis; Bone Neoplasms; Cell Line, Tumor; Curcumin; ERRalpha Estrogen-Related Receptor; Humans; MicroRNAs; Neoplasm Proteins; Osteosarcoma; Receptors, Estrogen; RNA, Neoplasm; Signal Transduction | 2017 |
Curcumin inhibits hypoxia-induced proliferation and invasion of MG-63 osteosarcoma cells via downregulating Notch1.
Curcumin is a biologically active ingredient abundantly present in the ground rhizomes of Curcuma longa with a wide range of bioactive properties, including antitumor effects. Hypoxia is a common characteristic of solid tumors, including osteosarcoma. However, whether curcumin has antitumor effects on osteosarcoma under hypoxic conditions, and its underlying molecular mechanisms, remain unclear. The present study demonstrated that the MG‑63 osteosarcoma cell line exhibited increased proliferation and enhanced invasiveness upon exposure to hypoxic conditions. However, these effects were prevented by curcumin treatment. Further investigation revealed that curcumin may inhibit Notch1 upregulation induced by hypoxia. Overexpression of Notch1 via Notch1 cDNA transfection ameliorated curcumin‑inhibited MG‑63 cell growth under hypoxic conditions. Taken together, these data revealed that curcumin may suppress the growth of osteosarcoma cells in hypoxia via inhibiting Notch1 signaling. Topics: Cell Hypoxia; Cell Proliferation; Curcumin; Down-Regulation; Humans; Neoplasm Invasiveness; Osteosarcoma; Receptor, Notch1; Signal Transduction; Up-Regulation | 2017 |
Cellular effects of a turmeric root and rosemary leaf extract on canine neoplastic cell lines.
The use of nutraceuticals is gaining in popularity in human and canine oncology with a relatively limited understanding of the effects in the vastly different tumor types seen in canine oncology. We have previously shown that turmeric root (TE) and rosemary leaf (RE) extracts can work synergistically to reduce neoplastic cell growth, but the mechanisms are poorly understood and require further elucidation.. The use of RE in combination with TE induces a synergistic response to induce apoptosis which is better than either extract alone. This appears to be related to a variable increased TE uptake in cells and activation of pathways involved in the apoptotic response. Topics: Animals; Bone Neoplasms; Cell Line, Tumor; Curcuma; Dog Diseases; Dogs; Female; Mammary Neoplasms, Animal; Mastocytoma; Osteosarcoma; Phytotherapy; Plant Extracts; Plant Leaves; Rosmarinus | 2017 |
The effective combination therapy against human osteosarcoma: doxorubicin plus curcumin co-encapsulated lipid-coated polymeric nanoparticulate drug delivery system.
To overcome both the dose-limiting side effects of conventional chemotherapeutic agents and the therapeutic failure incurred from multidrug resistant (MDR) in osteosarcoma (OS), biodegradable lipid-coated polymeric nanoparticles (LPNs) were explored for the loading of doxorubicin (DOX) and curcumin (CUR).. DOX plus CUR co-encapsulated LPNs (DOX + CUR LPNs) of mixed lipid monolayer shell and biodegradable polymer core were prepared. The cytotoxicity effect of DOX + CUR LPNs, single drug loaded LPNs, and free drug solutions were evaluated on human OS cell line KHOS cells and mice KHOS cells xenograft in vivo.. DOX + CUR LPNs displayed a curative effect on OS cell lines than the free drug counterparts. Also, best anti-OS effects were observed on the animal model compared with other groups tested.. This promising dual drugs co-encapsulated lipid-coated polymeric nanoparticulate drug delivery system enhanced the cell delivery and activity of drugs against human OS cancer cell lines and in cancer bearing mice. This research may offer new options for the treatment of OS. Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Cell Line, Tumor; Curcumin; Doxorubicin; Drug Carriers; Drug Delivery Systems; Drug Resistance, Multiple; Drug Resistance, Neoplasm; Humans; Lipids; Mice; Mice, Inbred BALB C; Nanoparticles; Osteosarcoma; Polymers | 2016 |
Inhibition of the JAK2/STAT3 signaling pathway exerts a therapeutic effect on osteosarcoma.
Osteosarcoma (OS) is the most common type of malignant bone tumor. Despite aggressive multimodal treatments, including surgical resection, chemotherapy and adjunctive immunotherapies, patients with OS with high-grade malignancy have a poor five-year survival rate that has remained unchanged over the past two decades, highlighting the urgent requirement for novel therapeutic approaches. Signal transducers and activators of transcription 3 (STAT3) has been implicated as an oncogene and therapeutic target in a variety of neoplastic diseases. The aim of the present study was to determine whether inhibition of the janus kinase 2 (JAK2)/STAT3 pathway by FLLL32, a specific JAK2/STAT3 inhibitor, is able to provide a potential therapy for OS. FLLL32 inhibited OS cell growth in vitro and delayed OS growth in an OS xenograft nude mouse model. STAT3 knockdown by short hairpin RNA delayed OS formation in vivo. Thus, the JAK2/STAT3 pathway is important in OS formation. Efficacy of the FLLL32 pharmacological inhibitor in delaying OS growth suggests that targeting JAK2/STAT3 may be a potential therapeutic strategy for patients with OS. Topics: Animals; Apoptosis; Bone Neoplasms; Cell Line, Tumor; Cell Proliferation; Curcumin; Gene Expression Regulation, Neoplastic; Humans; Janus Kinase 2; Mice; Osteosarcoma; Signal Transduction; STAT3 Transcription Factor; Xenograft Model Antitumor Assays | 2015 |
Selective inhibition of MG-63 osteosarcoma cell proliferation induced by curcumin-loaded self-assembled arginine-rich-RGD nanospheres.
Osteosarcoma is the most frequent primary malignant form of bone cancer, comprising 30% of all bone cancer cases. The objective of this in vitro study was to develop a treatment against osteosarcoma with higher selectivity toward osteosarcoma cells and lower cytotoxicity toward normal healthy osteoblast cells. Curcumin (or diferuloylmethane) has been found to have antioxidant and anticancer effects by multiple cellular pathways. However, it has lower water solubility and a higher degradation rate in alkaline conditions. In this study, the amphiphilic peptide C18GR7RGDS was used as a curcumin carrier in aqueous solution. This peptide contains a hydrophobic aliphatic tail group leading to their self-assembly by hydrophobic interactions, as well as a hydrophilic head group composed of an arginine-rich and an arginine-glycine-aspartic acid structure. Through characterization by transmission electron microscopy, self-assembled structures of spherical amphiphilic nanoparticles (APNPs) with diameters of 10-20 nm in water and phosphate-buffered saline were observed, but this structure dissociated when the pH value was reduced to 4. Using a method of codissolution with acetic acid and dialysis tubing, the solubility of curcumin was enhanced and a homogeneous solution was formed in the presence of APNPs. Successful encapsulation of curcumin in APNPs was then confirmed by Fourier transform infrared and X-ray diffraction analyses. The cytotoxicity and cellular uptake of the APNP/curcumin complexes on both osteosarcoma and normal osteoblast cell lines were also evaluated by methyl-thiazolyl-tetrazolium assays and confocal fluorescence microscopy. The results showed that the curcumin-loaded APNPs had significant selective cytotoxicity against MG-63 osteosarcoma cells when compared with normal osteoblasts. We have demonstrated for the first time that APNPs can encapsulate hydrophobic curcumin in their hydrophobic cores, and curcumin-loaded APNPs could be an innovative treatment for the selective inhibition of osteosarcoma cells. Topics: Antineoplastic Agents; Arginine; Bone Neoplasms; Cell Line, Tumor; Cell Proliferation; Curcumin; Drug Carriers; Humans; Hydrophobic and Hydrophilic Interactions; Microscopy, Electron, Transmission; Nanospheres; Oligopeptides; Osteoblasts; Osteosarcoma; Solubility; Spectroscopy, Fourier Transform Infrared; X-Ray Diffraction | 2015 |
Curcumin inhibits the proliferation and invasion of human osteosarcoma cell line MG-63 by regulating miR-138.
In this study, we screened the different human osteosarcoma cell line MG-63 miRNAs after the treatment of curcumin and explored the effects of curcumin on MG-63 cells and its mechanism.. Affemitrix miRNA chip was used to detect the changes of miRNA expression profile in MG-63 cells before and after curcumin treatment, and screen different expression of miRNAs. The target gene of miRNA was analyzed by bioinformatics. The expression levels of miRNA-138 target genes Smad4, NFκB p65 and cyclin D3 were detected. MTT and Transwell Cell invasion assays were used to observe the effects of curcumin on MG-63 cells.. Curcumin could significantly inhibit the proliferation of MG-63 cells and the expression levels of miRNA-138 target genes Smad4, NFκB p65 and cyclin D3 in MG-63 cells (P<0.05); overexpression of hsa-miR-138 down-regulated the expression levels of Smad4, NFκB p65 and cyclin D3 compared with the treatment of curcumin, while inhibition of hsa-miR-138 up-regulated the expression levels of Smad4, NFκB p65 and cyclin D3.. Curcumin could increase the expression of hsa-miR-138, hsa-miR-138 inhibited cell proliferation and invasive ability by inhibition of its target genes. Topics: Antineoplastic Agents; Blotting, Western; Bone Neoplasms; Cell Line, Tumor; Cell Movement; Cell Proliferation; Curcumin; Gene Expression Regulation, Neoplastic; Humans; MicroRNAs; Oligonucleotide Array Sequence Analysis; Osteosarcoma; Real-Time Polymerase Chain Reaction; Transfection | 2015 |
Curcumin induces osteosarcoma MG63 cells apoptosis via ROS/Cyto-C/Caspase-3 pathway.
The antitumor effects of curcumin have attracted widespread attention worldwide. One of its major functions is to induce the apoptosis of tumor cells, but the antitumor mechanism is currently unclear. In the present study, we found that cell mortality and curcumin concentration were dose dependent. Curcumin of low concentrations (10 μΜ) could reduce the level of reactive oxygen species (ROS) in tumor cells, while curcumin of high concentrations (80 μΜ) was able to significantly increase the content of ROS. In addition, Western blotting detection suggested that curcumin of high concentrations can induce the release of Cyto-C and the activation of Caspase-3, and that ROS scavenger NAC apparently inhibits apoptosis protein release and activation, consequently slowing the curcumin-induced apoptosis. Taken together, curcumin further activates the mitochondrial apoptotic pathway by inducing cells to generate ROS and ultimately promotes the apoptosis of tumor cells. Topics: Apoptosis; Bone Neoplasms; Caspase 3; Cell Line, Tumor; Cell Proliferation; Curcumin; Cytochromes c; Humans; Osteosarcoma; Reactive Oxygen Species; Signal Transduction | 2014 |
Curcumin-loaded nanoparticles enhance apoptotic cell death of U2OS human osteosarcoma cells through the Akt-Bad signaling pathway.
Curcumin has potential anticancer activity and has been shown to be involved in several signaling pathways including differentiation and apoptosis. Our previous study showed that water-soluble PLGA curcumin nanoparticles (Cur-NPs) triggered apoptotic cell death through regulation of the function of MDR1 and the production of reactive oxygen species (ROS) in cisplatin-resistant human oral cancer CAR cells. In this study, we investigated the anti-proliferative effects of Cur-NPs on human osteosarcoma U2OS cells. The morphology of Cur-NPs showed spherical shape by TEM analysis. The encapsulation efficiency of curcumin in Cur-NPs prepared by single emulsion was 90.5 ± 3.0%. Our results demonstrated that the curcumin fragments on the mass spectrum of Cur-NPs and the peaks of curcumin standard could be found on the Cur-NPs spectrum by 1H-NMR spectra analysis. Cur-NPs induced anti-proliferative effects and apoptosis in U2OS cells. Compared to the untreated U2OS cells, more detectable amount of Cur-NPs was found inside the treated U2OS cells. Cur-NPs induced DNA fragmentation and apoptotic bodies in U2OS cells. Both the activity and the expression levels of caspases-3/-7 and caspase-9 were elevated in the treated U2OS cells. Cur-NPs upregulated the protein expression levels of cleaved caspase-3/caspase-9, cytochrome c, Apaf-1 and Bad and downregulated the protein expression level of p-Akt in U2OS cells. These results suggest Cur-NPs are effective in enhancing apoptosis in human osteosarcoma cells and thus could provide potential for cancer therapeutics. Topics: Apoptosis; bcl-Associated Death Protein; Cell Line, Tumor; Curcumin; Gene Expression Regulation, Neoplastic; Humans; Nanoparticles; Oncogene Protein v-akt; Osteosarcoma; Reactive Oxygen Species; Signal Transduction | 2014 |
Functionalized curcumin analogs as potent modulators of the Wnt/β-catenin signaling pathway.
Osteosarcoma is a primary bone malignancy with aggressive metastatic potential and poor prognosis rates. In our earlier work we have investigated the therapeutic potential of curcumin as an anti-invasive agent in osteosarcoma by its ability to regulate the Wnt/β-catenin signaling pathway. However, the clinical use of curcumin is limited owing to its low potency and poor pharmacokinetic profile. In this study, an attempt was made to achieve more potent Wnt inhibitory activity in osteosarcoma cells by carrying out synthetic chemical modifications of curcumin. We synthesized a total of five series consisting of 43 curcumin analogs and screened in HEK293T cells for inhibition of β-catenin transcriptional activity. Six promising analogs, which were 6.5- to 60-fold more potent than curcumin in inhibiting Wnt activity, were further assessed for their anti-invasive activity and Wnt inhibitory mechanisms. Western blot analysis showed disruption of β-catenin protein nuclear translocation following treatment with analogs 2f, 3c and 4f. Using transwell assays, we also found that these compounds were more potent than 1a (curcumin) in impeding the invasion of osteosarcoma cells, possibly through suppressing MMP-9 activity. Structure-activity-relationship studies revealed that Wnt inhibitory effects could be enhanced by shortening and restraining the flexibility of the 7-carbon linker moiety connecting the terminal aromatic rings of curcumin and substituting both rings with appropriate substituents. Our results demonstrate that the synthesized curcumin analogs are more potent Wnt inhibitors in osteosarcoma cell lines as compared to parental curcumin and are good lead compounds for further development. Future in vivo tests with these compounds will define their therapeutic potentials as promising drug candidates for clinical treatment of osteosarcoma. Topics: Antineoplastic Agents; beta Catenin; Bone Neoplasms; Cell Line, Tumor; Curcumin; HEK293 Cells; Humans; Neoplasm Invasiveness; Osteosarcoma; Wnt Signaling Pathway | 2014 |
The combined effect of encapsulating curcumin and C6 ceramide in liposomal nanoparticles against osteosarcoma.
This study examines the antitumor potential of curcumin and C6 ceramide (C6) against osteosarcoma (OS) cell lines when both are encapsulated in the bilayer of liposomal nanoparticles. Three liposomal formulations were prepared: curcumin liposomes, C6 liposomes and C6-curcumin liposomes. Curcumin in combination with C6 showed 1.5 times enhanced cytotoxic effect in the case of MG-63 and KHOS OS cell lines, in comparison with curcumin liposomes alone. Importantly, C6-curcumin liposomes were found to be less toxic on untransformed primary human cells (human mesenchymal stem cells) in comparison to OS cell lines. In addition, cell cycle assays on a KHOS cell line after treatment revealed that curcumin only liposomes induced G2/M arrest by upregulation of cyclin B1, while C6 only liposomes induced G1 arrest by downregulation of cyclin D1. C6-curcumin liposomes induced G2/M arrest and showed a combined effect in the expression levels of cyclin D1 and cyclin B1. The efficiency of the preparations was tested in vivo using a human osteosarcoma xenograft assay. Using pegylated liposomes to increase the plasma half-life and tagging with folate (FA) for targeted delivery in vivo, a significant reduction in tumor size was observed with C6-curcumin-FA liposomes. The encapsulation of two water insoluble drugs, curcumin and C6, in the lipid bilayer of liposomes enhances the cytotoxic effect and validates the potential of combined drug therapy. Topics: Animals; Apoptosis; Blotting, Western; Cell Line, Tumor; Cell Proliferation; Ceramides; Curcumin; Drug Delivery Systems; Flow Cytometry; Humans; Inhibitory Concentration 50; Liposomes; Mice; Microscopy, Electron, Transmission; Molecular Structure; Nanoparticles; Osteosarcoma | 2014 |
Short communication: selective cytotoxicity of curcumin on osteosarcoma cells compared to healthy osteoblasts.
Curcumin is a natural phenolic compound extracted from the plant Curcuma longa L. In previous studies, curcumin has been shown to have anticancer, antioxidant, and anti-inflammatory effects. In this study, the cytotoxicity of different concentrations (5, 10, 25, 50, 75, and 100 μM) of curcumin dissolved in dimethyl sulfoxide was compared between MG-63 osteosarcoma and healthy human osteoblast cells. Consequently, the viability of osteosarcoma cells was less than 50% at a concentration of 10 μM compared to the control sample without curcumin, but healthy osteoblast cells had at least 80% viability throughout all the concentrations tested. The results demonstrated that MG-63 osteosarcoma cells were much more sensitive in terms of cytotoxicity to curcumin, while the healthy human osteoblasts exhibited a higher healthy viability after 24 hours of curcumin treatment. Therefore, this study showed that at the right concentrations (5 μM to 25 μM), curcumin, along with a proper nanoparticle drug delivery carrier, may selectively kill bone cancer cells over healthy bone cells. Topics: Apoptosis; Cell Line, Tumor; Cell Survival; Curcumin; Dose-Response Relationship, Drug; Humans; Osteoblasts; Osteosarcoma | 2014 |
Induction of apoptosis by diphenyldifluoroketone in osteogenic sarcoma cells is associated with activation of caspases.
The aim of the present study was to investigate and compare the effects of diferuloylmethane (curcumin) and diphenyldifluoroketone (EF-24) on cell growth and apoptosis induction in human osteogenic sarcoma cells. This was examined by MTT assay, nuclear DAPI staining, caspase-activation assay, flow cytometry analysis and immunoblotting in Saos2 human osteogenic sarcoma cells. Curcumin and EF-24 inhibited the growth of Saos2 cells in a dose-dependent manner. The apparent potency of EF-24 was more than 3-fold higher that of curcumin. Treatment with curcumin or EF-24 resulted in nuclear condensation and fragmentation in the cells. The caspase-3/-7 activities were detected in living cells treated with curcumin or EF-24. Flow cytometry showed that the rate of apoptosis was increased by curcumin and EF-24 compared to the control. Curcumin and EF-24 promoted the proteolytic cleavages of procaspase-3/-7/-8/-9 with increases in the amount of cleaved caspase-3/-7/-8/-9. The curcumin- or EF-24-induced apoptosis in the Saos2 cells was mediated by the expression of Fas and activation of caspase-8, caspase-3 and poly(ADP-ribose) polymerase. Immunoblotting revealed the Bid and Bcl-2 proteins to be downregulated, and truncated-Bid, Bax and p53 proteins to be upregulated by curcumin and EF-24. Curcumin and EF-24 increased the Bax/Bcl-2 ratio significantly. These results suggest that the curcumin and EF-24 inhibit cell proliferation and induce apoptotic cell death in Saos2 human osteogenic sarcoma cells via both the mitochondria-mediated intrinsic pathway and the death receptor-mediated extrinsic pathway, and may have potential properties for anti-osteosarcoma drug discovery. Topics: Antineoplastic Agents; Apoptosis; bcl-2-Associated X Protein; Benzylidene Compounds; BH3 Interacting Domain Death Agonist Protein; Bone Neoplasms; Caspase 3; Caspase 7; Caspase 8; Caspase 9; Cell Line, Tumor; Cell Proliferation; Curcumin; Enzyme Activation; Fas-Associated Death Domain Protein; Humans; Osteosarcoma; Piperidones; Poly(ADP-ribose) Polymerases; Tumor Suppressor Protein p53 | 2014 |
Cytotoxic effects of curcumin in osteosarcoma cells.
Topics: Apoptosis; Curcumin; Humans; Osteoblasts; Osteosarcoma | 2014 |
Reversion effects of curcumin on multidrug resistance of MNNG/HOS human osteosarcoma cells in vitro and in vivo through regulation of P-glycoprotein.
P-glycoprotein (P-gp) encoded by ATP-binding cassette sub-family B member 1 (ABCB1) gene is a kind of ATP-dependent drug transporter, which plays important roles in multidrug resistance (MDR) of human cancers, such as osteosarcoma. Curcumin is a natural phenolic coloring compound originating from the rhizomes of Curcuma longa, which is proved to possess antitumor biological activities including reversion of MDR. However, the effect and molecular mechanisms of curcumin to osteosarcoma MDR remain unclear.. We established a human osteosarcoma drug-resistant cell line MNNG/HOS/MTX by pulse exposure to methotrexate (MTX) and verified that the new cell lines were cross-resistant to other anticancer agents. Then, according to the cytotoxicity assay, we reversed MDR of MNNG/HOS/MTX by 30 µmol/L curcumin, and detected the mechanisms of curcumin reversing MDR through Real-time PCR, Western blotting assay, and Rhodamine123 (Rh123) transport test. Finally, we evaluated the effect of curcumin reversing MDR in vivo by MNNG/HOS/MTX cells xenograft-nude mice model.. MNNG/HOS/MTX was proved to be a human osteosarcoma MDR cell line. MTT tumor chemosensitivity test indicates that 30 µmol/L curcumin attenuates the half maximal inhibitory concentration (IC50) and resistance index (RI) to MTX, diamminedichloroplatinum (DDP), adriamycin (ADM), ifosfamide (IFO), and epirubicin (EPI) in MNNG/HOS/MTX cells (P < 0.05). Real-time PCR and Western blotting assays demonstrated that curcumin down-regulated P-gp expression of MNNG/HOS/MTX cells. Rh123 transport test showed that curcumin inhibited the transport function of P-gp in vitro. In vivo studies showed that curcumin displayed the features of sensitizing antitumor drugs and inhibiting the proliferation, invasion, and metastasis of osteosarcoma MDR cells.. Down-regulation of P-gp and inhibition of the function of P-gp efflux pump may contribute to MDR reversion induced by curcumin in vitro and in vivo. Topics: Animals; Antineoplastic Agents; ATP Binding Cassette Transporter, Subfamily B, Member 1; Cell Line, Tumor; Curcumin; Drug Resistance, Multiple; Drug Resistance, Neoplasm; Humans; Male; Methotrexate; Mice; Mice, Inbred BALB C; Mice, Nude; Osteosarcoma | 2013 |
Small molecules, LLL12 and FLLL32, inhibit STAT3 and exhibit potent growth suppressive activity in osteosarcoma cells and tumor growth in mice.
Constitutive activation of Signal Transducers and Activators of Transcription 3 (STAT3) is frequently detected in osteosarcoma, and hence, may serve as a therapeutic target. In order to target STAT3, we tested two new STAT3 inhibitors, LLL12 and FLLL32. LLL12 and FLLL32 inhibit STAT3 phosphorylation and STAT3 downstream targets. LLL12 and FLLL32 also inhibit IL-6 induced STAT3 phosphorylation. The inhibition of STAT3 by LLL12 and FLLL32 resulted in the induction of apoptosis, reduction of plating efficiency, and migration in osteosarcoma cells. Furthermore, LLL12 and FLLL32 inhibited SJSA osteosarcoma cells and OS-33 tumor growth in murine xenografts. These results provide evidence that constitutive STAT3 signaling is required for osteosarcoma survival and migration in vitro and tumor growth in vivo. Blocking persistent STAT3 signaling by LLL12 and FLLL32 may be a novel therapeutic approach for osteosarcoma. Topics: Animals; Anthraquinones; Antineoplastic Agents; Apoptosis; Bone Neoplasms; Cell Line; Cell Line, Tumor; Cell Movement; Cell Proliferation; Curcumin; Female; Humans; Interleukin-6; Mice; Mice, Nude; Osteosarcoma; Phosphorylation; STAT3 Transcription Factor; Sulfonamides; Tumor Burden; Xenograft Model Antitumor Assays | 2012 |
Curcumin-loaded γ-cyclodextrin liposomal nanoparticles as delivery vehicles for osteosarcoma.
The delivery of curcumin, a broad-spectrum anticancer drug, has been explored in the form of liposomal nanoparticles to treat osteosarcoma (OS). Curcumin is water insoluble and an effective delivery route is through encapsulation in cyclodextrins followed by a second encapsulation in liposomes. Liposomal curcumin's potential was evaluated against cancer models of mesenchymal (OS) and epithelial origin (breast cancer). The resulting 2-Hydroxypropyl-γ-cyclodextrin/curcumin - liposome complex shows promising anticancer potential both in vitro and in vivo against KHOS OS cell line and MCF-7 breast cancer cell line. An interesting aspect is that liposomal curcumin initiates the caspase cascade that leads to apoptotic cell death in vitro in comparison with DMSO-curcumin induced autophagic cell death. In addition, the efficiency of the liposomal curcumin formulation was confirmed in vivo using a xenograft OS model. Curcumin-loaded γ-cyclodextrin liposomes indicate significant potential as delivery vehicles for the treatment of cancers of different tissue origin.. Curcumin-loaded γ-cyclodextrin liposomes were demonstrated in vitro to have significant potential as delivery vehicles for the treatment of cancers of mesenchymal and epithelial origin. Differences between mechanisms of cell death were also evaluated. Topics: Animals; Antineoplastic Agents; Apoptosis; Breast Neoplasms; Caspases; Cell Line, Tumor; Curcumin; Female; gamma-Cyclodextrins; Humans; Liposomes; Mice; Mice, Nude; Neoplasm Proteins; Neoplasm Transplantation; Osteosarcoma; Transplantation, Heterologous; Xenograft Model Antitumor Assays | 2012 |
Curcumin inhibits proliferation and invasion of osteosarcoma cells through inactivation of Notch-1 signaling.
The Notch signaling pathway plays critical roles in human cancers, including osteosarcoma, suggesting that the discovery of specific agents targeting Notch would be extremely valuable for osteosarcoma. Curcumin, a naturally occurring phenolic compound found in curcuma longa, has been shown to inhibit proliferation and induce apoptosis of osteosarcoma cells in vitro and tumor growth in xenotransplant or orthotransplant models. However, the precise molecular mechanisms by which curcumin exerts its antitumor activity remain unclear. Here we used multiple molecular approaches, such as the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, the invasion assay, gene transfection, real-time RT-PCR, western blot and gelatin zymography, to investigate whether the downregulation of Notch-1 contributes to curcumin-induced inhibition of proliferation and invasion in osteosarcoma cells. The results showed that curcumin caused marked inhibition of osteosarcoma cell growth and G2/M phase cell cycle arrest. This was associated with concomitant attenuation of Notch-1 and downregulation of its downstream genes, such as matrix metalloproteinases, resulting in the inhibition of osteosarcoma cell invasion through Matrigel. We also found that specific downregulation of Notch-1 via small-interfering RNA prior to curcumin treatment resulted in enhanced inhibition of cell growth and invasion. These results suggest that antitumor activity of curcumin is mediated through a novel mechanism involving inactivation of the Notch-1 signaling pathway. Our data provide the first evidence that the downregulation of Notch-1 by curcumin may be an effective approach for the treatment of osteosarcoma. Topics: Blotting, Western; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Curcumin; Flow Cytometry; Humans; Osteosarcoma; Receptor, Notch1; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction | 2012 |
[Empirical study of reverse effect on mediated multidrug resistance of U-2OS/ADM cells with curcumin in vitro].
To investigate the reversion of P-gp mediated multidrug resistance of U-2OS/ADM cells with curcumin in vitro.. With doxorubicin as induction drugs, human osteosarcoma cell line U-2OS was induced object, multi-drug resistant of human osteosarcoma cell line model (U-2OS/ADM) were established by high-dose method, The before and after reversal efficacy of curcumin for U-2OS/ADM cells to chemotherapeutic drugs were measured by MTT assay. The effects of curcumin on Rh-123 uptake and efflux were analyzed by flow cytometer.. (1) MTT demonstrates curcumin (20 micromol/L) can increase the cytotoxicity of Adriamycin to U-2OS/ADM cells. (2) The result of FCM shows that Curcumin can increase the accumulation of Rh-123 and increase the cytotoxicity of Adriamycin to U-2OS/ADM cells in a dose-dependent manner.. The reversal mechanism of curcumin was blocked the function of P-gp in U-2OS/ADM cellular membrane. Topics: Antineoplastic Agents; Bone Neoplasms; Cell Line, Tumor; Curcumin; Doxorubicin; Drug Resistance, Multiple; Drug Resistance, Neoplasm; Humans; Osteosarcoma | 2011 |
The novel curcumin analog FLLL32 decreases STAT3 DNA binding activity and expression, and induces apoptosis in osteosarcoma cell lines.
Curcumin is a naturally occurring phenolic compound shown to have a wide variety of antitumor activities; however, it does not attain sufficient blood levels to do so when ingested. Using structure-based design, a novel compound, FLLL32, was generated from curcumin. FLLL32 possesses superior biochemical properties and more specifically targets STAT3, a transcription factor important in tumor cell survival, proliferation, metastasis, and chemotherapy resistance. In our previous work, we found that several canine and human osteosarcoma (OSA) cell lines, but not normal osteoblasts, exhibit constitutive phosphorylation of STAT3. Compared to curcumin, we hypothesized that FLLL32 would be more efficient at inhibiting STAT3 function in OSA cells and that this would result in enhanced downregulation of STAT3 transcriptional targets and subsequent death of OSA cells.. Human and canine OSA cells were treated with vehicle, curcumin, or FLLL32 and the effects on proliferation (CyQUANT®), apoptosis (SensoLyte® Homogeneous AMC Caspase- 3/7 Assay kit, western blotting), STAT3 DNA binding (EMSA), and vascular endothelial growth factor (VEGF), survivin, and matrix metalloproteinase-2 (MMP2) expression (RT-PCR, western blotting) were measured. STAT3 expression was measured by RT-PCR, qRT- PCR, and western blotting.. Our data showed that FLLL32 decreased STAT3 DNA binding by EMSA. FLLL32 promoted loss of cell proliferation at lower concentrations than curcumin leading to caspase-3- dependent apoptosis, as evidenced by PARP cleavage and increased caspase 3/7 activity; this could be inhibited by treatment with the pan-caspase inhibitor Z-VAD-FMK. Treatment of OSA cells with FLLL32 decreased expression of survivin, VEGF, and MMP2 at both mRNA and protein levels with concurrent decreases in phosphorylated and total STAT3; this loss of total STAT3 occurred, in part, via the ubiquitin-proteasome pathway.. These data demonstrate that the novel curcumin analog FLLL32 has biologic activity against OSA cell lines through inhibition of STAT3 function and expression. Future work with FLLL32 will define the therapeutic potential of this compound in vivo. Topics: Animals; Apoptosis; Bone Neoplasms; Cell Line, Tumor; Curcumin; DNA; Dog Diseases; Dogs; Drug Evaluation, Preclinical; Gene Expression Regulation, Neoplastic; Humans; Osteosarcoma; Protein Binding; STAT3 Transcription Factor | 2011 |
Selective cytotoxicity against human osteosarcoma cells by a novel synthetic C-1 analogue of 7-deoxypancratistatin is potentiated by curcumin.
The natural compound pancratistatin (PST) is a non-genotoxic inducer of apoptosis in a variety of cancers. It exhibits cancer selectivity as non-cancerous cells are markedly less sensitive to PST. Nonetheless, PST is not readily synthesized and is present in very low quantities in its natural source to be applied clinically. We have previously synthesized and evaluated several synthetic analogues of 7-deoxypancratistatin, and found that JC-TH-acetate-4 (JCTH-4), a C-1 acetoxymethyl analogue, possessed similar apoptosis inducing activity compared to PST. In this study, notoriously chemoresistant osteosarcoma (OS) cells (Saos-2, U-2 OS) were substantially susceptible to JCTH-4-induced apoptosis through mitochondrial targeting; JCTH-4 induced collapse of mitochondrial membrane potential (MMP), increased reactive oxygen species (ROS) production in isolated mitochondria, and caused release of apoptosis inducing factor (AIF) and endonuclease G (EndoG) from isolated mitochondria. Furthermore, JCTH-4 selectively induced autophagy in OS cells. Additionally, we investigated the combinatory effect of JCTH-4 with the natural compound curcumin (CC), a compound found in turmeric spice, previously shown to possess antiproliferative properties. CC alone had no observable effect on Saos-2 and U-2 OS cells. However, when present with JCTH-4, CC was able to enhance the cytotoxicity of JCTH-4 selectively in OS cells. Such cytotoxicity by JCTH-4 alone and in combination with CC was not observed in normal human osteoblasts (HOb) and normal human fetal fibroblasts (NFF). Therefore, this report illustrates a new window in combination therapy, utilizing a novel synthetic analogue of PST with the natural compound CC, for the treatment of OS. Topics: Amaryllidaceae Alkaloids; Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Curcumin; Dose-Response Relationship, Drug; Drug Synergism; Humans; Isoquinolines; Mitochondria; Osteosarcoma | 2011 |
Antitumor activity of natural compounds, curcumin and PKF118-310, as Wnt/β-catenin antagonists against human osteosarcoma cells.
Aberrant activation of the Wnt/β-catenin signaling pathway promotes osteosarcoma tumorigenesis and metastasis. In this study, we tested the hypothesis that osteosarcoma progression may be delayed by disrupting the Wnt/β-catenin pathway using small molecule inhibitors such as curcumin and PKF118-310. Effective inhibitions of the Wnt/β-catenin pathway by curcumin and PKF118-310 in osteosarcoma cells were shown by the suppression of both intrinsic and activated β-catenin/Tcf transcriptional activities using luciferase reporter assays. Western blot analysis revealed that there was no change in the amount of cytosolic β-catenin, although nuclear β-catenin was markedly reduced by treatment with either compounds. We next performed wound healing and Matrigel invasion assays and observed a dose-dependent decrease in osteosarcoma cell migration and invasion with curcumin and PKF118-310 treatment. Overexpression of the wild-type β-catenin plasmid in osteosarcoma cells resulted in enhanced cell invasiveness but this effect was significantly overcome by curcumin. Gelatin zymography and Western blotting showed that reduced cell invasion with curcumin and PKF118-310 treatment correlated with the activity and protein level of matrix metalloproteinase-9 under conditions of intrinsic or extrinsic Wnt/β-catenin activation. Using cell apoptosis assay and cell cycle analysis, we further showed that the anti-proliferative effect of PKF118-310 is attributed to PKF118-310-induced apoptosis and G2/M phase arrest. Lastly, we observed that these anti-cancer effects correlated with the decreased expression of cyclin D1, c-Myc and survivin. Our findings strongly suggest that curcumin and PKF118-310 have great therapeutic potential for the treatment of osteosarcoma. Topics: Antineoplastic Agents; beta Catenin; Biological Products; Cell Cycle; Cell Death; Cell Line, Tumor; Cell Movement; Cell Nucleus; Cell Proliferation; Cell Survival; Curcumin; Drug Screening Assays, Antitumor; Gene Expression Regulation, Neoplastic; Humans; Matrix Metalloproteinase 9; Neoplasm Invasiveness; Osteosarcoma; Pyrimidinones; Signal Transduction; Triazines; Wnt Proteins | 2010 |
Safety and pharmacokinetics of a solid lipid curcumin particle formulation in osteosarcoma patients and healthy volunteers.
Curcumin is the lipid-soluble antioxidant compound obtained from the rhizome of Curcuma longa Linn, also known as turmeric. Curcumin targets multiple chemotherapeutic and inflammatory pathways and has demonstrated safety and tolerability in humans, supporting its potential as a therapeutic agent; however, the clinical literature lacks conclusive evidence supporting its use as a therapeutic agent due to its low bioavailability in humans. The purpose of this study was to quantify plasma levels of free curcumin after dosing of a solid lipid curcumin particle (SLCP) formulation versus unformulated curcumin in healthy volunteers and to determine its tolerability and dose-plasma concentration relationship in late-stage osteosarcoma patients. Doses of 2, 3, and 4 g of SLCP were evaluated in 11 patients with osteosarcoma. Plasma curcumin levels were measured using a validated high-performance liquid chromatography method. The limit of detection of the assay was 1 ng/mL of curcumin. In healthy subjects, the mean peak concentration of curcumin achieved from dosing 650 mg of SLCP was 22.43 ng/mL, whereas plasma curcumin from dosing an equal quantity of unformulated 95% curcuminoids extract was not detected. In both healthy individuals and osteosarcoma patients, high interindividual variability in pharmacokinetics and nonlinear dose dependency was observed, suggesting potentially complex absorption kinetics. Overall, good tolerability was noted in both healthy and osteosarcoma groups. Topics: Adolescent; Adult; Antineoplastic Agents; Bone Neoplasms; Chemistry, Pharmaceutical; Child; Chromatography, High Pressure Liquid; Curcuma; Curcumin; Drug Tolerance; Female; Humans; Male; Osteosarcoma; Reference Values; Safety; Young Adult | 2010 |
The aberrant expressions of nuclear matrix proteins during the apoptosis of human osteosarcoma cells.
The objective of this study was to investigate altered expressions of nuclear matrix proteins (NMPs) of human osteosarcoma (OS) MG-63 cells during curcumin-induced apoptosis of human OS MG-63 cells. MG-63 cells were cultured with curcumin (7.5 mg/L) for 72 hr. Morphological alterations of cells were captured using light microscopy and transmission electron microscopy, and cell cycle distribution was estimated by flow cytometry. NMPs were selectively extracted and subjected to two-dimensional gel electrophoresis (2-DE) analysis. Western blots were performed to determine changes in the expression levels of specific NMPs. The results demonstrated that typical characteristics of apoptosis were observed. Cellular chromatin agglutinated, cell nuclei condensed, and apoptotic bodies were formed after treatment with curcumin. The 2-DE results displayed 27 NMPs, 21 of which were identified to have change in expression levels significantly during apoptosis. The altered expressions of three of these NMPs (nucleophosmin, prohibitin, and vimentin) were further confirmed by immunoblotting. These findings indicated that the apoptosis of MG-63 cells was accompanied by the expression alteration of NMPs. Our results might help to reveal the relationship between NMPs and the regulation of gene expression in the process of apoptosis, as well as provide the basic concepts for future studies on the mechanisms of apoptosis and the therapy for bone diseases. Topics: Antineoplastic Agents; Apoptosis; Blotting, Western; Bone Neoplasms; Cell Line, Tumor; Cell Nucleus; Chromatin; Curcumin; Electrophoresis, Gel, Two-Dimensional; Flow Cytometry; Gene Expression Regulation, Neoplastic; Humans; Microscopy, Electron, Transmission; Nuclear Matrix-Associated Proteins; Nuclear Proteins; Nucleophosmin; Osteosarcoma; Prohibitins; Repressor Proteins; Vimentin | 2010 |
Curcumin induces cell cycle arrest and apoptosis in human osteosarcoma (HOS) cells.
Curcumin is a major component of Curcuma longa rhizome and has been used as a traditional medicine for centuries. In this study, we showed that curcumin induced cell cycle arrest followed by antiproliferation and apoptosis in human osteosarcoma (HOS) cells.. Antiproliferative activity was measured with the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Nuclear fragmentation was observed with a fluorescence microscope. Flow cytometry was performed to observe cell cycle distribution and apoptotic body appearance. Changes in cell cycle regulatory and apoptosis-related proteins were investigated by Western blot analysis.. The IC(50) value of curcumin was approximately 4.0 microg/ml. Induction of apoptosis was evidenced by apoptotic body appearance and chromosomal DNA degradation. Flow-cytometric analysis indicated that curcumin induced successive G(1)/S and G(2)/M phase arrest followed by apoptosis in HOS cells. The G(1)/S and G(2)/S phase arrest was accompanied by down-regulation of cyclin D1, cdc2 and cyclin B1, respectively. Apoptosis was induced by capspase-3 activation and poly(ADP-ribosyl)polymerase (PARP) cleavage.. Our results demonstrated that curcumin caused death of HOS cells by blocking cells successively in G(1)/S and G(2)/M phases and activating the caspase-3 pathway. Topics: Antineoplastic Agents; Apoptosis; Blotting, Western; Bone Neoplasms; Caspase 3; Cell Cycle; Cell Proliferation; Curcumin; Enzyme Activation; Flow Cytometry; Humans; Osteosarcoma; Poly(ADP-ribose) Polymerases; Tumor Cells, Cultured | 2009 |
Apoptotic effects of curcumin on human osteosarcoma U2OS cells.
Curcumin, an active ingredient derived from the rhizome of the plant, Curcuma longa, has antioxidant, anti-inflammatory and anti-cancer activities. The aims of this study were to examine whether curcumin can induce apoptosis in an osteosarcoma cell line.. Curcumin-induced apoptosis in human osteosarcoma U2OS cells was investigated using morphological analysis, marked nuclear condensation and fragmentation of chromatin, which were observed by Hoechst 33258 staining and DNA ladder formation. The U2OS cells were treated with or without curcumin. Cell viability was assessed by the 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium (MTT) method. Cell-cycle, apoptosis and apoptosis-related proteins in U2OS cells were evaluated by flow cytometry and western blotting.. Curcumin showed growth inhibitory effects on U2OS cells in a dose-and time-dependent manner, inducing significant G1 arrest and apoptosis in U2OS cells. This curcumin-induced apoptosis in U2OS cells was accompanied by up-regulation of Bax, Bak, and p-Bad and down-regulation of Bcl-2, but no effect on the levels of Bcl-X(L) or Bad proteins was noted. Moreover, curcumin treatment resulted in a significant reduction of mitochondrial membrane potential and increase in the concentrations of mitochondrial cytochrome C and caspase-3.. Multiple molecular pathways are involved in curcumin-induced apoptosis of human U2OS cells. These include pro-and anti-apoptotic Bcl-2 family proteins, mitochondrial membrane potential, mitochondrial cytochrome C and caspase-3. Topics: Antineoplastic Agents; Apoptosis; Biomarkers, Tumor; Blotting, Western; Bone Neoplasms; Cell Line, Tumor; Cell Survival; Curcumin; DNA, Neoplasm; Flow Cytometry; Humans; Osteosarcoma; Up-Regulation | 2009 |
[Changes of nuclear matrix proteins during apoptosis of human osteosarcoma MG-63 cells induced by curcumin].
Human osteosarcoma MG-63 cells were induced into apoptosis by curcumin (Cur). Its nuclear matrix proteins were selectively extracted, and subjected to two dimensional gel electrophoresis analysis. The resulted protein patterns were analyzed by Melanie software. There were 27 spots changed remarkably during the apoptosis induced by curcumin, 21 of which were identified. There were seven up-regulated proteins including DNA polymerase zeta and forteen down-regulated proteins including Prohibitin. This study suggests that the induced apoptosis of carcinoma cells is accompanied with changes of nuclear matrix proteins, and confirms the presence of some specific nuclear matrix proteins associated with carcinoma cell growth, apoptosis and the associated signal transduction pathways in induced apoptosis of carcinoma cells. It provides proofs and a new way to study the mechanisms of gene expression carcinogenesis which reveal the relationship between configuration and composition of nuclear matrix and cell apoptosis. Besides, this study provides several potential target proteins for cancer diagnosis and cancer therapy. Topics: Apoptosis; Cell Line, Tumor; Curcumin; Electrophoresis, Gel, Two-Dimensional; Humans; Microscopy, Electron, Transmission; Nuclear Matrix-Associated Proteins; Osteosarcoma | 2008 |
Cytotoxic effects of curcumin on osteosarcoma cell lines.
Curcumin (diferuloylmethane), one of the main components of the Indian spice turmeric, is known to possess potent anti-inflammatory and anti-oxidant properties. In addition, curcumin has also been shown to have in vitro and in vivo efficacy against a variety of malignancies. In the current study we examined the cytotoxic effect of curcumin on seven osteosarcoma (OS) cell lines with varying degrees of in vivo metastatic potential. Curcumin inhibited the growth of all OS cell lines tested with half-maximal inhibitory concentration values ranging from 14.4 to 24.6 microM. Growth inhibition was associated with a dose dependent increase in the number of apoptotic cells and accumulation of cells in the G(2)/M phase of the cell cycle. Curcumin treatment also resulted in cleavage of caspase-3 and poly adenosine diphosphate-ribose polymerase. Moreover, curcumin treatment was associated with an increase in cellular levels of the apoptotic B-cell leukemia/lymphoma 2 (Bcl-2)-associated X protein and a decrease in cellular content of the anti-apoptotic protein Bcl-2. In addition, curcumin treatment also inhibited the migration of OS cell lines. These data indicate that the potent cytotoxic activity of curcumin on OS cell lines is mediated by induction of apoptotic processes. Thus, curcumin has potential to be a novel OS chemotherapeutic agent. Topics: Antineoplastic Agents, Phytogenic; Apoptosis; bcl-2-Associated X Protein; Caspase 3; Cell Division; Cell Line, Tumor; Curcuma; Curcumin; G2 Phase; Humans; India; Inhibitory Concentration 50; Osteosarcoma; Poly(ADP-ribose) Polymerases; Proto-Oncogene Proteins c-bcl-2 | 2008 |
Signal transduction system for interleukin-6 and interleukin-11 synthesis stimulated by epinephrine in human osteoblasts and human osteogenic sarcoma cells.
Epinephrine increased gene- and protein-expression of interleukin-6 (IL-6) and interleukin-11 (IL-11), which are capable of stimulating the development of osteoclasts from their hematopoietic precursors, in human osteoblast (SaM-1) and human osteosarcoma (SaOS-2, HOS, and MG-63) cell lines. An increase in IL-6 and IL-11 synthesis in response to epinephrine appeared to be a common feature in osteoblastic cells, but the magnitude of expression was different in these cell lines. In HOS cells treated with epinephrine, increases of IL-6 and IL-11 synthesis were inhibited by timolol (a beta-blocker), H-89 (N-[2-((p-bromocinnamyl)amino)ethyl]-5-isoquinolinesulfonamide; an inhibitor of protein kinase A (PKA)) and SB203580 [4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-imidazole; an inhibitor of p38 mitogen-activated protein kinase (MAPK)], but not by phentolamine (an alpha-blocker), calphostin C [an inhibitor of protein kinase C (PKC)], or PD98059 (2'-amino-3'-methoxyflavone; an inhibitor of classic MAPK), suggesting a common pathway mediated by beta-adrenergic receptors in the PKA and p38 systems involved in the signal transduction of IL-6 and IL-11. Furthermore, expression of both genes was inhibited by curcumin [an inhibitor of activating protein-1 (AP-1) activation], but not by pyrrolidine dithiocarbamate (PDTC) [an inhibitor of nuclear factor (NF)-kappaB]. The pharmacological study suggested that coinduction of the two genes in response to epinephrine occurred via activation of AP-1. The findings of the present study suggest that coinduction of IL-6 and IL-11 in response to epinephrine probably occurs via the PKA and p38 MAPK systems, leading to the transcriptional activation of AP-1 in human osteoblastic cells. Topics: Adrenergic Agonists; Adrenergic alpha-Antagonists; Adrenergic beta-Antagonists; Antioxidants; Curcumin; Cyclic AMP-Dependent Protein Kinases; Drug Interactions; Enzyme Inhibitors; Enzyme-Linked Immunosorbent Assay; Epinephrine; Gene Expression; Humans; Interleukin-11; Interleukin-6; Mitogen-Activated Protein Kinases; NF-kappa B; Osteoblasts; Osteosarcoma; Protein Kinase C; Pyrrolidines; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Thiocarbamates; Transcription Factor AP-1; Tumor Cells, Cultured | 2001 |
Signal transduction system for interleukin-6 synthesis stimulated by lipopolysaccharide in human osteoblasts.
Lipopolysaccharide (LPS) is a bacterial cell component that plays multifunctional roles in inflammatory reactions, and one of the roles is as a powerful stimulator of bone resorption. LPS stimulated bone resorption via CD14 in mouse calvaria and was reported to function as a receptor for bacterial LPS complexed with serum proteins. Interleukin-6 (IL-6) is capable of stimulating the differentiation of osteoclasts from their hematopoietic precursors, and LPS elevates IL-6 synthesis in human osteoblastic cells. However, the signaling pathway of LPS-induced IL-6 synthesis in osteoblasts is unknown. In the present study, we could detect the existence of CD14 in human osteoblastic cells by RT-PCR analysis and show that LPS increased IL-6 mRNA and synthesis via CD14 in human osteoblastic cells. In human osteoblasts (SaM-1 cells) treated with 10 microg/ml LPS, increases in IL-6 mRNA and synthesis were inhibited by anti-CD14 antibody (MEM-18), PD98059 (an inhibitor of classic mitogen-activated protein kinase [MAPK]), or SB203580 (an inhibitor of p38 MAPK) but were not inhibited by H-89 (an inhibitor of protein kinase A [PKA]) and calphostin C (an inhibitor of protein kinase C [PKC]). Furthermore, LPS-induced IL-6 synthesis was inhibited by curcumin (an inhibitor of activating protein-1 [AP-1]) but not by pyrrolidine dithiocarbamate (PDTC) (an inhibitor of nuclear factor kappa B [NF-kappaB]). The findings of the present study suggest that the LPS receptor CD14, existent in human osteoblastic cells, and IL-6 synthesis in response to LPS probably occur via CD14, p38 MAPK, and MAP kinase/extracellular-regulated kinase kinase (MEK), leading to the transcriptional activation of AP-1 in human osteoblastic cells. Topics: Adult; Cell Line; Curcumin; Cyclic AMP-Dependent Protein Kinases; Enzyme Inhibitors; Humans; Interleukin-6; Kinetics; Lipopolysaccharide Receptors; Lipopolysaccharides; Male; MAP Kinase Signaling System; Mitogen-Activated Protein Kinase Kinases; Mitogen-Activated Protein Kinases; NF-kappa B; Osteoblasts; Osteosarcoma; p38 Mitogen-Activated Protein Kinases; Protein Kinase C; Pyrrolidines; RNA, Messenger; Thiocarbamates; Transcriptional Activation; Tumor Cells, Cultured | 2001 |