Role of protein kinase C-delta in hyperthermia-induced apoptosis in tongue squamous cell carcinoma Tca8113 cells / 华西口腔医学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To study the role of protein kinase C-delta (PKC-delta) in hyperthermia-induced apoptosis in human tongue squamous cell carcinoma Tca8113 cells.</p><p><b>METHODS</b>Tca8113 cells were treated at 43 degrees C in a heating water bath for 0, 40, 80, 120 min after pretreatment with Rottlerin, a specific inhibitor of PKC-delta, and equal volume dimethyl sulfoxide (DMSO) for 30 min, respectively. The cells were stained by propidium iodide (PI) and Rhodamine 123 to analysis apoptotic rate and the changes of mitochondrial transmembrane potential by flow cytometry (FCM). The total proteins were extracted for Western blotting analysis of activation and proteolysis of PKC-delta, and for colorimetric assay of relative activity of Caspase-3.</p><p><b>RESULTS</b>Hyperthermia could induce proteolysis and activation of PKC-delta, and this was attenuated by Rottlerin. Apoptotic rate, decreasing of mitochondrial transmembrane potential and activity of Caspase-3 which being induced by hyperthermia in Tca8113 cells were inhibited by PKC-delta specific inhibitor Rottlerin. There were significantly statistical differences in apoptosis rates, mitochondrial transmembrane potential and activity of Caspase-3 between Rottlerin- and non-Rottlerin-pretreated cells after hyperthermia for 40, 80, 120 min (P < 0.01).</p><p><b>CONCLUSION</b>Activated PKC-delta may facilitate hyperthermia-induced apoptosis in Tca8113 cells, and may be one of the mechanisms of apoptosis induced by hyperthermia.</p>