vitamin-k-semiquinone-radical and Bone-Neoplasms

Topics: 1-Carboxyglutamic Acid; Adult; Bone and Bones; Bone Diseases; Bone Neoplasms; Calcium-Binding Proteins; Chronic Kidney Disease-Mineral and Bone Disorder; Female; Humans; Hyperparathyroidism; Male; Osteitis Deformans; Osteocalcin; Radioimmunoassay; Vitamin K

Vitamin K (VK) is a group of fat‑soluble vitamins, which serve important roles in blood coagulation and bone metabolism. A recent study reported that several VK subtypes possess antitumor properties, however the antitumor effects of VK in osteosarcoma are unknown. The present study aimed to identify the antitumor effects of VK in osteosarcoma and the possible underlying mechanism of action. The effect of VK4 on cell viability was determined using a 3‑(4,5‑dimethylthiazol‑2‑yl)‑2,5‑diphenyltetrazolium bromide (MTT) assay. Cellular and nuclear morphological changes were observed by phase contrast microscopy. Cell cycle analysis, apoptotic rate, mitochondrial membrane potential and levels of reactive oxygen species (ROS) were detected by flow cytometry. In vitro cancer cell migration activities were evaluated using a Wound healing assay and Transwell microplates. The results demonstrated that VK4 arrested the cells in S phase and induced apoptosis. Additional mechanistic studies indicated that the induction of apoptosis by VK4 was associated with the increased production of reactive oxygen species, dissipation of the mitochondrial membrane potential, decreased Bcl‑2 family protein expression levels and activation of caspase‑3. In conclusion, the results suggest that the sensitivity of U2OS osteosarcoma cells to VK4 may be as a result of mitochondrial dysfunction. As it is readily available for human consumption, VK4 may therefore present a novel therapeutic candidate for the treatment of patients with osteosarcoma.

Topics: Antineoplastic Agents; Apoptosis; Bone Neoplasms; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Cell Survival; Humans; Membrane Potential, Mitochondrial; Mitochondria; Osteosarcoma; Vitamin K; Vitamins

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

Fifty-four subjects were studied: 36 advanced prostatic adenocarcinoma patients in stage D and 18 normal age-matched male controls. Serum alkaline phosphatase, serum acid phosphatase, plasma osteocalcin, 24-h urinary hydroxyproline excretion, and 24-h whole-body retention of [99mTc]-methylene diphosphonate were measured in all subjects before and 3, 6, and 9 weeks after the start of treatment. Skeletal metastases were identified by radiography and/or [99mTc]-methylene diphosphonate bone scan. The results confirm that acid phosphatase is a significant marker in prostatic cancer; serum alkaline phosphatase may be useful in the evaluation and monitoring of bone metastases but it is not always specific; urinary excretion of hydroxyproline is an index of osteoclastic activity; serum osteocalcin may be considered more specific in the evaluation and monitoring of osteoblastic bone metastases in prostatic cancer.

Topics: 1-Carboxyglutamic Acid; Acid Phosphatase; Aged; Aged, 80 and over; Alkaline Phosphatase; Biomarkers, Tumor; Bone and Bones; Bone Neoplasms; Calcium-Binding Proteins; Humans; Hydroxyproline; Male; Middle Aged; Neoplasms, Hormone-Dependent; Osteocalcin; Prostatic Neoplasms; Radionuclide Imaging; Vitamin K

Bone Gla protein (BGP) was measured in the plasma by radioimmunoassay (RIA) during treatment of 59 patients with bone diseases including Paget's disease (N = 9), primary hyperparathyroidism (N = 25), chronic renal failure (N = 20), and cancer involving bone (N = 5). Plasma BGP was increased above normal in all patients. BGP decreased in the patients with Paget's disease following the acute and chronic administration of salmon calcitonin. Plasma BGP was higher in women then in men with primary hyperparathyroidism. Following parathyroidectomy, BGP decreased in both sexes but the decrease was significant in women only. Plasma BGP was increased in patients with renal osteodystrophy and did not change after hemodialysis. In the patients with bone cancer, plasma BGP decreased during treatment of the attendant hypercalcemia with salmon calcitonin. Although plasma BGP and serum alkaline phosphatase (AP) levels were generally correlated in these studies, there were examples of dissociation between the two. The measurement of plasma BGP appears to provide a specific index of bone metabolism that may in some circumstances be more sensitive than serum alkaline phosphatase measurement. However, further studies are necessary to establish the clinical value of plasma BGP measurement by RIA in the management of patients with bone diseases.

Topics: Alkaline Phosphatase; Bone and Bones; Bone Diseases; Bone Neoplasms; Calcitonin; Calcium-Binding Proteins; Chronic Kidney Disease-Mineral and Bone Disorder; Female; Humans; Hyperparathyroidism; Male; Osteitis Deformans; Osteocalcin; Parathyroid Glands; Radioimmunoassay; Renal Dialysis; Vitamin K