Induction of cell killing and autophagy by amphiphilic pyrrolidine derivatives on human pancreatic cancer cells

57 p.-9 fig.-2 tab.+Graph. Abst.+Suppl.mat. Bello, Claudia et al.We have synthesized a wide array of structurally related amphiphilic compounds, containing a functionalized pyrrolidine polar group coupled to different ether-linked hydrocarbon chains, to generate novel structures with antitumor activity. These newly synthesized amphiphilic pyrrolidine-derived compounds were classified in three different sub-libraries regarding the number of hydroxyl groups substituting the pyrrolidine moiety at C3 and C4. Pyrrolidine compounds with one or none hydroxyl groups showed a potent cell killing activity against pancreatic cancer cells, but they lacked selectivity for tumor cells. Pyrrolidine compounds with two hydroxyl groups induced cell death in a wide variety of pancreatic cancer cell lines, and they were somewhat less cytotoxic to normal non-tumor cells. Among these latter compounds, the diol-derived pyrrolidine 20 ((2R,3R,4S)-2-{(9Z)-hexadec-9-en-1-yloxy] methyl}pyrrolidine-3,4-diol) induced autophagy and a potent apoptotic response in pancreatic ductal adenocarcinoma cells, which was inhibited by Bcl-XL overexpression and by caspase inhibition, in a way similar to that of the amphiphilic ether lipid edelfosine, with which it was compared. Pharmacological and genetic inhibition of autophagy potentiated 20-mediated apoptosis. These structure-activity relationship studies point out the importance of the diol polar group and aliphatic side chain of 20 in promoting apoptosis against pancreatic cancer cells in a rather controlled way, and some additional subtle modifications were found to be potential modulators of the cytotoxic activity.This work was supported by the European Community's Seventh Framework Programme FP7-2007-2013 (grant HEALTH-F2-2011-256986, PANACREAS), the Swiss National Science Foundation,the EPFL for a Innogrant to C.B., the Associazione Italiana per la ricerca sul cancro (AIRC), Ministerio de Ciencia e Innovación of Spain CTQ2012-31247, Spanish Ministerio de Economia y Competitividad (SAF2014-59716-R, SAF2017-89672-R and CTQ2016-77270-R), and Red Temática de Investigación Cooperativa en Cáncer, Instituto de Salud Carlos III, co-funded by the Fondo Europeo de Desarrollo Regional of the European Union (RD12/ 0036/0065).Peer reviewe