Change in the localization of heat shock protein 27 (HSP 27) in BG-1 humanovarian cancer cells following treatment by the ether lipid ET-18-OCH3

We have demonstrated a higher nuclear protein content in the hypodiploid fr action of BG-1 human ovarian cancer cells following treatment with one of t he ether lipids, ET-18-OCH3. In this study, we have attempted to identify t he overexpressed nuclear protein induced in those dying or dead cells in th e hypodiploid fraction and its localization before and after ET-18-OCH3 tre atment. The pattern of nuclear proteins was analyzed by two-dimensional pol yacrylamide gel electrophoresis (2-D PAGE) before and after ET-18-OCH3 trea tment. The partial amino acid sequence of the most dominantly and consisten tly up-regulated protein spot after ET-18-OCH3 treatment was determined and it was found to be heat shock protein 27 (HSP27). Immunofluorescence stain ing disclosed that HSP27 localizes in the cytoplasm of the BG-1 cells befor e ET-18-OCH3 treatment. Condensation of HSP27 around the nuclei was observe d following treatment by ET-18-OCH3. Ultimately the nuclei of the cells in the hypodiploid fraction were stained by immunofluorescent HSP27. These res ults indicate that change of the localization of HSP27 may play an importan t role as a component of the signal transduction pathways affected by ether lipids.