The biological relevance of two lipid peroxidation intermediates, the monohydroxy-isomers of stearic acid (9- and 10-HSA) has been previously shown (I ). Relevant differences in the total endogenous content and a different behaviour against exogenous administration were found in tumor as compared to normal cells. In tumor cells, HSA acted as a strong inhibitor of proliferation, producing cytostatic and cytotoxic effects. In human colon adeno-carcinoma HT29 cell line, the administration of 20 uM to 100 fa M of the compound induced dose- and time-dependent inhibition of cell growth ( IC,(I = 50 |oM at 48 h of treatment). Arrest in GO-G1 phases and a dose- and time-related inhibition of the histone HI kinase activity were also observed (2). To test whether apoptosis and/or necrosis were related to the HSA effects observed, multiparameter flow citoinetry, DNA agarose gel electrophoresis and UV microscopy investigations were carried out. To discriminate the two events. 20 uM-100 uM HSA-treated cells were analyzed by dividing them in two distinct morphological sub-populations (i.e. flattening and floating cells). Evaluation of cell DNA content showed a dose- and time-dependent induction of apoptosis, which mainly resulted in the appearence of the sub-GI cytometric peaks only in floating cells. After double-staining by Hoechst 33342 and propidium iodide, floating cells showed apoptotic features which were increasing along with HSA doses. Moreover, this sub-population exibited both chromatin condensation and the typical DNA ladder of 180-to 200-bp oligomers. By contrast, flattening cells, that have received the inducing HSA, did not exhibit any morphological and biological change of apoptosis and had no cleaved DNA. In this sub-population we then examined the effects of HSA on the activation of cellular protein kinases and phosphatases. Treatment with 50-100 joM HSA resulted in a twofold increase of MAPK, while the phosphorylase phosphatase activity was not activated.
Gesmundo N., Casali E., Boga C., Farruggia G., Novello M., Zanna S., et al. (1996). Apoptosis induced by 9-, 10-oh stearic acids in human HT29 adenocarcinoma cells. BIOCHEMICAL SOCIETY TRANSACTIONS, 24(4), 531S-531S [10.1042/bst024531sc].
Apoptosis induced by 9-, 10-oh stearic acids in human HT29 adenocarcinoma cells
Gesmundo N.;Boga C.;Farruggia G.;Novello M.;Zanna S.;Masotti L.
1996
Abstract
The biological relevance of two lipid peroxidation intermediates, the monohydroxy-isomers of stearic acid (9- and 10-HSA) has been previously shown (I ). Relevant differences in the total endogenous content and a different behaviour against exogenous administration were found in tumor as compared to normal cells. In tumor cells, HSA acted as a strong inhibitor of proliferation, producing cytostatic and cytotoxic effects. In human colon adeno-carcinoma HT29 cell line, the administration of 20 uM to 100 fa M of the compound induced dose- and time-dependent inhibition of cell growth ( IC,(I = 50 |oM at 48 h of treatment). Arrest in GO-G1 phases and a dose- and time-related inhibition of the histone HI kinase activity were also observed (2). To test whether apoptosis and/or necrosis were related to the HSA effects observed, multiparameter flow citoinetry, DNA agarose gel electrophoresis and UV microscopy investigations were carried out. To discriminate the two events. 20 uM-100 uM HSA-treated cells were analyzed by dividing them in two distinct morphological sub-populations (i.e. flattening and floating cells). Evaluation of cell DNA content showed a dose- and time-dependent induction of apoptosis, which mainly resulted in the appearence of the sub-GI cytometric peaks only in floating cells. After double-staining by Hoechst 33342 and propidium iodide, floating cells showed apoptotic features which were increasing along with HSA doses. Moreover, this sub-population exibited both chromatin condensation and the typical DNA ladder of 180-to 200-bp oligomers. By contrast, flattening cells, that have received the inducing HSA, did not exhibit any morphological and biological change of apoptosis and had no cleaved DNA. In this sub-population we then examined the effects of HSA on the activation of cellular protein kinases and phosphatases. Treatment with 50-100 joM HSA resulted in a twofold increase of MAPK, while the phosphorylase phosphatase activity was not activated.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
