Affiliations: Division of Molecular Medicine, Rudjer Boskovic
Institute, Zagreb, Croatia | University Clinic of Traumatology, University of Graz,
Graz, Austria
Note: [] Address for correspondence: Suzana Borovic Sunjic, Division of
Molecular Medicine, Rudjer Boskovic Institute, Bijenicka 54, 10000 Zagreb,
Croatia. Tel.: +385 1 4571213; Fax: +385 1 4561010; E-mail: borovic@irb.hr
Abstract: 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
μM HNE, while apoptosis was induced with supraphysiological as well as by
the physiological amount of the aldehyde (1 μM). Necrosis appeared when
cells were treated with 10 or 100 μM, but not with 1 μM HNE. The
proportion of cells in mitosis gradually declined with increased HNE
concentration. Multiple exposures of HOS cells to 10 μM 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.
Keywords: 4-Hydroxy-2-nonenal, human osteosarcoma, bone cells, proliferation, differentiation, apoptosis, growth regulation
Journal: BioFactors, vol. 24, no. 1-4, pp. 141-148, 2005
