ABSTRACT
This study was aimed to investigate the biological behavior of annonaceous acetogenin mimic AA005 in various kinds of leukemia cells and further elaborated its possible mechanisms in acute promyelocytic leukemia (APL) cell line NB4. The proliferative inhibition of leukemia cells was measured by CCK-8 method. Cell death was determined by trypan blue. Cell morphological features of NB4 treated with AA005 were examined by microscopy after Wright's staining. The form of cell death was measured by flow cytometry. Proteins PARP-1 and caspase-3 were detected by Western blot. Flow cytometry was used to detect the cell cycle arrest induced by AA005 of low concentration. The results showed that AA005 (> 200 nmol/L) significantly inhibited proliferation of all tested leukemia cell lines in a concentration-dependent manner. The vast majority of cells went to die after leukemia cell lines of NB4, U937 and K562 were treated with different concentration of AA005 for 48 h. Typical morphologic changes significantly appeared in NB4 cells after AA005 treatment. AA005 almost simultaneously induced early apoptosis and late apoptosis. The little cleavage of PARP-1 and activation of caspase-3 happened in AA005-induced cell death, and caspase-3 inhibitor Z-VAD-fmk could not block the cell death. The non-toxic concentrations of AA005 (< 200 nmol/L) caused NB4 cells G(2)/M-phase arrest. It is concluded that annonaceous acetogenin mimic AA005 induces significant proliferative inhibition of various leukemia cell lines in a concentration-dependent manner, which may be associated with cell death and G(2)/M-phase arrest induced by AA005.
Subject(s)
Humans , Acetogenins , Pharmacology , Apoptosis , Caspase 3 , Metabolism , Cell Cycle Checkpoints , Cell Proliferation , Fatty Alcohols , Pharmacology , HL-60 Cells , K562 Cells , Lactones , Pharmacology , Poly (ADP-Ribose) Polymerase-1 , Poly(ADP-ribose) Polymerases , MetabolismABSTRACT
<p><b>BACKGROUND</b>Trans-arachidonic acids (TAAs), newly discovered markers of nitrative stress and the major products of nitrogen dioxide (NO2(·))-mediated isomerization of arachidonic acid (AA), represent a new mechanism of NO2(·)-induced toxicity. It has been reported that TAAs were generated in oxygen-induced microvascular degeneration model and TAAs were also generated in a diabetic retinopathy (DR) model. In this study, we examined high glucose-induced nitrative stress damage and TAAs levels and explored the possible mechanisms for DR caused by reactive nitrogen species.</p><p><b>METHODS</b>Diabetic rats were induced by intraperitoneal injection of streptozotocin (STZ) at 60 mg/kg. Bovine retinal capillary endothelial cells (BRECs) were selectively cultured and incubated with normal or high glucose. The serum TAAs and AA in diabetic rats were measured by the gas chromatography and mass spectrometry (GC/MS) method. The ratio of peak area of TAAs to AA with selected ion of 79 was estimated by a group t-test. Thrombospondin-1 (TSP-1) in the rat retinas and BRECs extracts were examined by Western blotting. The phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) protein was examined by Western blotting in BRECs incubated with high glucose.</p><p><b>RESULTS</b>The TAAs to AA ratio (TAAs/AA) was significantly increased in the serum at 8, 12 and 16 weeks after STZ injection (P < 0.05), with no noticeable change found at 2 or 4 weeks (P > 0.05). Expression of TSP-1 in the retina of diabetic rats was progressively elevated according to the duration of diabetes. TSP-1 expression was increased in BRECs incubated with high glucose at 48 hours. Moreover, high glucose also increased ERK1/2 expression, which peaked at 30 minutes and then decreased in the following 48 hours.</p><p><b>CONCLUSION</b>An elevation of TAAs/AA is associated with high glucose-induced nitrative stress, which probably involves upregulation of TSP-1 through activating ERK1/2.</p>