4-hydroxy-2-nonenal and Osteosarcoma

4-Hydroxynonenal (HNE) is a major aldehydic product of lipid peroxidation known to exert several biological effects. Normal and malignant cells of the same origin express different sensitivity to HNE. We used human osteosarcoma cells (HOS) in different stages of differentiation in vitro, showing differences in mitosis, DNA synthesis, and alkaline phosphatase (ALP) staining. Differentiated HOS cells showed decreased proliferation (

Topics: Aldehydes; Alkaline Phosphatase; Apoptosis; Cell Differentiation; Cell Line, Tumor; Cell Proliferation; Cell Survival; Glutathione; Glutathione Transferase; Humans; Lipid Peroxidation; Necrosis; Osteosarcoma; Proteasome Endopeptidase Complex

The onset of lipid peroxidation within cellular membranes is associated with changes in their physiochemical properties and enzymatic dysfunction of the membrane environment. There are increasing bodies of evidence indicating that aldehydic molecules generated endogenously during the process of lipid peroxidation are causally involved in most of the pathophysiological effects associated with oxidative stress in cells and tissues. 4-Hydroxy-2-nonenal (4-HNE), among them, is believed to be largely responsible for cytopathological effects observed during oxidative stress in vivo and has achieved the status of one of the best recognized and most studied of the cytotoxic products of lipid peroxidation. Here, we reported that 4-HNE treatment may induce cell death in MG63 human osteosarcoma cells. The 4-HNE treatment could activate caspase-3 and alter the Bax/Bcl-2 apoptotic signaling. All these changes are due to the inhibition of AKT activity by 4-HNE treatment, and we also found that the p70S6K activity, downstream factors of AKT, was also blocked by 4-HNE. Our results revealed the molecular mechanism of how 4-HNE induces cell death in MG63 human osteosarcoma cells, which contributes to the clinical treatment of cancer therapy.

Topics: Aldehydes; Antineoplastic Agents; Apoptosis; bcl-2-Associated X Protein; Bone Neoplasms; Caspase 3; Cell Death; Cell Line, Tumor; Cysteine Proteinase Inhibitors; Humans; Osteosarcoma; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-bcl-2; Signal Transduction

Normal and malignant cells of various origin differ in their sensitivity to oxidative stress. Therefore, we used normal and malignant mesenchymal cells--human osteosarcoma cells (HOS and 143B), human fibroblasts (WI38) and two primary cultures of normal human osteoblasts to test sensitivity to reactive aldehyde 4-hydroxynonenal (HNE), known as a second messenger of free radicals and a signaling molecule. Upon HNE-treatment, decrease in cell viability (by Trypan-blue), apoptosis induction (by TiterTACS TUNEL assay), HNE-protein binding (by HNE-His ELISA) were higher in malignant than in normal cells, while glutathione content was higher in normal cells. These results indicate that HNE affects the growth of malignant mesenchymal cells more than normal and that this effect was mainly related to lower glutathione concentration and higher binding of HNE to the cellular proteins. We thus assume that HNE and GSH homeostasis play an important role in the growth regulation of normal and malignant mesenchymal cells.

Topics: Aldehydes; Apoptosis; Bone Neoplasms; Cell Line, Tumor; Cell Survival; Fibroblasts; Humans; Mesoderm; Neoplasm Proteins; Osteosarcoma; Proteins; Reference Values

The product of lipid peroxidation, 4-hydroxy-2-nonenal (HNE) is known to cause cell death at high concentrations, while at lower concentrations it can influence cell proliferation and differentiation. In our experiments we used human osteosarcoma cells (HOS), to test the influence of HNE on cell proliferation, differentiation and induction of apoptosis. Apoptosis induction was estimated by TiterTACS TUNEL test. The cells were in parallel counted and the DAPI staining method was used to distinguish between apoptotic and necrotic cells as well as to define the proportion of cells in mitosis. To test the influence of HNE on HOS cell differentiation, cells were treated every second day with HNE. After 10 days, the cells were stained for alkaline phosphatase, a marker for osteoblast differentiation. Cell growth inhibition was caused by supraphysiological concentrations of 10 or 100 microM HNE, while apoptosis was induced with supraphysiological as well as by the physiological amount of the aldehyde (1 microM). Necrosis appeared when cells were treated with 10 or 100 microM, but not with 1 microM HNE. The proportion of cells in mitosis gradually declined with increased HNE concentration. Multiple exposures of HOS cells to 10 microM HNE prevented HOS cell differentiation. These results indicated that HNE inhibits proliferation and differentiation of HOS cells in the same concentration dependent manner as it causes apoptosis. We thus assume that HNE might be one of the important signaling molecules regulating the growth of the human osteosarcoma cells.

Topics: Aldehydes; Apoptosis; Cell Differentiation; Cell Division; Cell Line, Tumor; Humans; Mitosis; Osteosarcoma

Several studies point to the existence of an inverse correlation between cellular lipid peroxidation and both cell proliferation and neoplastic transformation. Furthermore, numerous results demonstrate that lipid peroxidation products affect central biochemical pathways and intracellular signalling at physiological concentrations. 4-Hydroxynonenal (HNE) is one of the most active products of lipid peroxidation. This work has focused on the evaluation of HNE nuclear content, so far never directly measured, by electrospray-ionization-mass-spectrometry (ESI/MS) and on the correlation between its concentration and the induced effects after exogenous administration. In a human osteosarcoma cell line (SaOS2), HNE exhibited an early cytotoxic effect characterized by apoptosis, cytostatic and differentiating effects characterized by slow growth, increase in alkaline phosphatase (ALP), and alpha5 integrin subunit content with decrease in tumorigenicity.

Topics: Aldehydes; Antigens, CD; Apoptosis; Cell Differentiation; Cell Division; Cell Line; Cell Nucleus; Chromatin; Chromatography, High Pressure Liquid; Cysteine Proteinase Inhibitors; Cytoskeleton; Humans; Integrin alpha5; Kinetics; Lipid Peroxidation; Microscopy, Confocal; Osteosarcoma; Oxidative Stress; Spectrometry, Mass, Electrospray Ionization; Time Factors; Tumor Cells, Cultured