rifampin and Osteosarcoma

To investigate induction of cell death in Osteosarcoma (OS) using the anti-tuberculosis drug, rifampicin, loaded into exosomes.. BMSC-exosomes were isolated by ultracentrifugation and loaded ultrasonically with rifampicin. Nanoparticle exosome-rifampicin (EXO-RIF) was added to the OS cell-lines, 143B and MG63, in vitro, to observe the growth inhibitory effect. In vivo experiments were conducted by injecting fluorescently labeled EXO-RIF through the tail vein of 143B cell xenograft nude mice and tracking distribution. Therapeutic and toxic side-effects were analyzed systemically.. Sonication resulted in encapsulation of rifampicin into exosomes. Exosome treatment accelerated the entry of rifampicin into OS cells and enhanced the actions of rifampicin in inhibiting OS proliferation, migration and invasion. Cell cycle arrest at the G2/M phase was observed. Dynamin-related protein 1 (Drp1) was activated by EXO-RIF and caused mitochondrial lysis and apoptosis. Exosome treatment targeted rifampicin to the site of OS, causing OS apoptosis and improving mouse survival in vivo.. The potent Drp1 agonist, rifampicin, induced OS apoptosis and exosome loading, improving OS targeting and mouse survival rates. EXO-RIF is a promising strategy for the treatment of diverse malignancies.

Topics: Animals; Apoptosis; Bone Neoplasms; Dynamins; Exosomes; Humans; Mice; Mice, Nude; Nanoparticles; Osteosarcoma; Rifampin

BACKGROUND Oxycodone is a semisynthetic opioid receptor agonist, and is frequently used for pain control in patients with cancer. Most oxycodone is metabolized by N-demethylation to noroxycodone by CYP3A. Rifampin is a strong inducer of several drug-metabolizing enzymes, including CYP3A. Hence, rifampin-induced CYP3A activity may decrease the effect of oxycodone. CASE REPORT Osteosarcoma is a highly aggressive primary bone tumor of childhood and adolescence. Here, we report a 30-year-old male with osteosarcoma of the femur with lung metastases in the upper lobe. The lung also contained small, scattered nodular lesions that were identified as tuberculosis. Multi-drug therapy, including rifampin, was administered. The upper-lobe metastatic lesion extended to the brachial plexus and caused severe pain. Over 1000 mg per day of oxycodone was ineffective for pain control. However, morphine was able to control his pain at about one-third the equivalent dose. CONCLUSIONS Our patient demonstrated oxycodone resistance due to rifampin. Chemotherapy may have compromised the patient's immune system, thus theoretically increasing the risk of tuberculosis. Recognition of the interactions between rifampin and oxycodone is important in this and other cancers. Notably, for patients using high doses of oxycodone to manage severe pain, stopping rifampin may lead to oxycodone overdose.

Topics: Adult; Analgesics, Opioid; Antibiotics, Antitubercular; Bone Neoplasms; Cancer Pain; Drug Resistance; Humans; Lung Neoplasms; Male; Osteosarcoma; Oxycodone; Rifampin; Tuberculosis, Pulmonary

The effect of the proinflammatory cytokine interleukin (IL)-1beta on the cellular proliferation of human osteoblastic cells (SaM-1) and osteosarcoma-derived cells (SaOS-2, HOS, and MG-63) was examined. IL-1beta stimulated the proliferation of SaM-1 and MG-63 cells, but had no effect on that of SaOS-2 or HOS cells. Using reverse transcription-polymerase chain reaction (RT-PCR) analysis, the mRNA expression of IL-1 receptor type I (IL-1R1) was detected in SaM-1 and MG-63 cells consistently, but not in SaOS-2 or HOS cells in the proliferative stage. Neither the decoy inhibitory IL-1 receptor type II (IL-1R2) nor IL-1R antagonist mRNA was detected in any of the cell lines, suggesting that IL-1beta stimulated proliferation via IL-1R1. The IL-1beta -stimulated proliferation was inhibited by the MAPK kinase (MEK) inhibitor PD98059 but not by the p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580 or the cyclooxygenase-2 specific inhibitor NS-398, suggesting that IL-1beta stimulated proliferation via MEK, without affecting prostaglandin E(2) synthesis. IL-1beta stimulated cellular proliferation but inhibited the synthesis of osteocalcin containing gamma-carboxylated glutamic acid (Gla-OSCAL). Both the increased proliferation and decreased Gla-OSCAL synthesis were suppressed by vitamin K(2) (VK(2)), which is a cofactor for gamma-carboxylase. Furthermore, the inhibitory effect of VK(2) on IL-1beta -stimulated proliferation was suppressed by warfarin. However, rifampicin the nuclear receptor steroid and xenobiotic receptor (SXR) ligand had no effect of IL-beta, suggesting that IL-1beta is involved in VK(2) dependent gamma-calboxylation but not SXR-activation. These results suggest that IL-1beta stimulated cellular proliferation via MEK and inhibited Gla-OSCAL synthesis, which were both inhibited by VK(2) via gamma-carboxylation.

Topics: Adult; Anticoagulants; Bone Neoplasms; Cell Line; Cell Proliferation; Cyclooxygenase 2; Cyclooxygenase Inhibitors; Dinoprostone; Enzyme Inhibitors; Flavonoids; Glutamic Acid; Humans; Imidazoles; Interleukin-1; Interleukin-1beta; Male; Mitogen-Activated Protein Kinase Kinases; Nitrobenzenes; Osteoblasts; Osteocalcin; Osteosarcoma; p38 Mitogen-Activated Protein Kinases; Pregnane X Receptor; Protein Kinase Inhibitors; Pyridines; Receptors, Steroid; Reverse Transcriptase Polymerase Chain Reaction; Rifampin; RNA, Messenger; Sulfonamides; Vitamin K; Vitamins; Warfarin; Young Adult

Approximately 30% to 40% of all patients with osteosarcomas ultimately experience recurrence. The study investigated the hypothesis that the resistance of osteosarcoma to chemotherapy may be related to the expression of a pregnane xenobiotic receptor (PXR) variant protein and its role as the major inducer of P450 3A4 in these tumors.. Polymerase chain reaction (PCR) and Western blot analysis were used to determine PXR mRNA and protein expression, respectively. Real-time PCR and CYP3A catalytic activity using 7-benzyl-trifluoromethyl coumarin (BFC) as the probe substrate were used to measure the induction of P450 3A4 or MDR1. siRNA transfections were performed for PXR and cytotoxicity determined by a colorimetric based assay or Annexin v-Fitc staining.. Differences were observed in the molecular size of the PXR protein expressed in sarcoma cell lines when compared with the wildtype PXR expressed in normal liver, kidney, or small intestine. A polyclonal PXR antibody raised against the N-terminus of the wildtype PXR did not detect PXR expressed in these sarcoma cell lines. In the osteosarcoma cell lines, etoposide and doxorubicin were better inducers of P450 3A4 and MDR1 than rifampin. siRNA against PXR down-regulated P450 3A4 expression only in the osteosarcoma cell line. Cytotoxicity assays showed that the resistance of the osteosarcoma cell lines to etoposide correlated with PXR protein expression levels and activation of P450 3A4 and could be prevented by ketoconazole.. The results suggest that PXR plays a critical role in the regulation of P450 3A4 expression in osteosarcoma and that its expression and activation in these tumors may influence the effect of chemotherapeutic agents on the induction of target genes implicated in drug resistance.

Topics: Antineoplastic Agents; ATP Binding Cassette Transporter, Subfamily B, Member 1; Blotting, Western; Cell Line, Tumor; Cytochrome P-450 CYP3A; Cytochrome P-450 Enzyme System; Doxorubicin; Drug Resistance, Neoplasm; Etoposide; Humans; Osteosarcoma; Pregnane X Receptor; Protein Isoforms; Receptors, Steroid; Reverse Transcriptase Polymerase Chain Reaction; Rifampin; RNA, Messenger; RNA, Small Interfering

Vitamin K2 is a critical nutrient required for blood clotting that also plays an important role in bone formation. Vitamin K2 supplementation up-regulates the expression of bone markers, increases bone density in vivo, and is used clinically in the management of osteoporosis. The mechanism of vitamin K2 action in bone formation was thought to involve its normal role as an essential cofactor for gamma-carboxylation of bone matrix proteins. However, there is evidence that suggests vitamin K2 also has a transcriptional regulatory function. Vitamin K2 bound to and activated the orphan nuclear receptor SXR and induced expression of the SXR target gene, CYP3A4, identifying it as a bona fide SXR ligand. Vitamin K2 treatment of osteosarcoma cells increased mRNA levels for the osteoblast markers bone alkaline phosphatase, osteoprotegerin, osteopontin, and matrix Gla protein. The known SXR activators rifampicin and hyperforin induced this panel of bone markers to an extent similar to vitamin K2. Vitamin K2 was able to induce bone markers in primary osteocytes isolated from wild-type murine calvaria but not in cells isolated from mice deficient in the SXR ortholog PXR. We infer that vitamin K2 is a transcriptional regulator of bone-specific genes that acts through SXR to favor the expression of osteoblastic markers. Thus, SXR has a novel role as a mediator of bone homeostasis in addition to its role as a xenobiotic sensor. An important implication of this work is that a subset of SXR activators may function as effective therapeutic agents for the management of osteoporosis.

Topics: Alkaline Phosphatase; Animals; Biomarkers; Bone and Bones; Bone Density; Bridged Bicyclo Compounds; COS Cells; Cytochrome P-450 CYP3A; Cytochrome P-450 Enzyme System; Gene Expression; Glycoproteins; HeLa Cells; Homeostasis; Humans; Mice; Mice, Knockout; Osteoblasts; Osteocalcin; Osteopontin; Osteoprotegerin; Osteosarcoma; Phloroglucinol; Pregnane X Receptor; Receptors, Cytoplasmic and Nuclear; Receptors, Steroid; Receptors, Tumor Necrosis Factor; Recombinant Proteins; Reverse Transcriptase Polymerase Chain Reaction; Rifampin; RNA, Messenger; Sialoglycoproteins; Terpenes; Transfection; Tumor Cells, Cultured; Vitamin K 2

Topics: Cell Division; Cell Line; Cell Survival; Cells, Cultured; Dose-Response Relationship, Drug; Doxorubicin; Drug Evaluation, Preclinical; Female; Fibroblasts; Humans; Melanoma; Neoplasms; Osteosarcoma; Rifampin; Urinary Bladder Neoplasms; Uterine Cervical Neoplasms