PGA1-induced apoptosis involves specific activation of H-Ras and N-Ras in cellular endomembranes

B Anta et al.The cyclopentenone prostaglandin A(1) (PGA(1)) is an inducer of cell death in cancer cells. However, the mechanism that initiates this cytotoxic response remains elusive. Here we report that PGA(1) triggers apoptosis by a process that entails the specific activation of H-and N-Ras isoforms, leading to caspase activation. Cells without H- and N-Ras did not undergo apoptosis upon PGA(1) treatment; in these cells, the cellular demise was rescued by overexpression of either H-Ras or N-Ras. Consistently, the mutant H-Ras-C118-S, defective for binding PGA(1), did not produce cell death. Molecular analysis revealed a key role for the RAF-MEK-ERK signaling pathway in the apoptotic process through the induction of calpain activity and caspase-12 cleavage. We propose that PGA(1) evokes a specific physiological cell death program, through H- and N-Ras, but not K-Ras, activation at endomembranes. Our results highlight a novel mechanism that may be of potential interest for tumor treatment.APR, TG, and LMD were recipients of fellowships from the Comunidad de Madrid (APR), Ministerio de Educación y Ciencia (TG), and FIS-BEFI (LMD). Grant support was awarded to JMRC from Fondo de Investigaciones Sanitarias-Intrasalud (PI09/0562 and PI13/00703) and the Spanish Association Against Cancer. JLO received grants from the Fondo de Investigaciones Sanitarias (CP07/00141 and PI10/00815). AM received grants from Ministerio de Economía y Competitividad of Spain-Fondo Europeo de Desarrollo Regional (FEDER) to AM (SAF2013-43468-R), Comunidad de Madrid to AM (S2010/BMD-2344 Colomics2) and Instituto de Salud Carlos III-FEDER. JMS received grants from the Fondo de Investigaciones Sanitarias (PI070356) and ‘Ayuda Intramural de Incorporación al CSIC'. ES, AM, JMRC, and PC, respectively, received Grants RD06/0020/0000 and RD12/0036/0001, RD06/0020/0003 and RD12/0036/0021, and RD06/0020/0105 and RD12/0036/0033 from Instituto de San Carlos III-RETIC (Red Temática de Investigación Cooperativa en Cáncer).Peer Reviewe

PGA(1)-induced apoptosis involves specific activation of H-Ras and N-Ras in cellular endomembranes

The cyclopentenone prostaglandin A(1) (PGA(1)) is an inducer of cell death in cancer cells. However, the mechanism that initiates this cytotoxic response remains elusive. Here we report that PGA(1) triggers apoptosis by a process that entails the specific activation of H-and N-Ras isoforms, leading to caspase activation. Cells without H- and N-Ras did not undergo apoptosis upon PGA(1) treatment; in these cells, the cellular demise was rescued by overexpression of either H-Ras or N-Ras. Consistently, the mutant H-Ras-C118-S, defective for binding PGA(1), did not produce cell death. Molecular analysis revealed a key role for the RAF-MEK-ERK signaling pathway in the apoptotic process through the induction of calpain activity and caspase-12 cleavage. We propose that PGA(1) evokes a specific physiological cell death program, through H- and N-Ras, but not K-Ras, activation at endomembranes. Our results highlight a novel mechanism that may be of potential interest for tumor treatment.We thank T O'Boyle and D Perez-Sala for the critical reading of this manuscript. APR, TG, and LMD were recipients of fellowships from the Comunidad de Madrid (APR), Ministerio de Educacion y Ciencia (TG), and FIS-BEFI (LMD). Grant support was awarded to JMRC from Fondo de Investigaciones Sanitarias-Intrasalud (PI09/0562 and PI13/00703) and the Spanish Association Against Cancer. JLO received grants from the Fondo de Investigaciones Sanitarias (CP07/00141 and PI10/00815). AM received grants from Ministerio de Economia y Competitividad of Spain-Fondo Europeo de Desarrollo Regional (FEDER) to AM (SAF2013-43468-R), Comunidad de Madrid to AM (S2010/BMD-2344 Colomics2) and Instituto de Salud Carlos III-FEDER. JMS received grants from the Fondo de Investigaciones Sanitarias (PI070356) and `Ayuda Intramural de Incorporacion al CSIC'. ES, AM, JMRC, and PC, respectively, received Grants RD06/0020/0000 and RD12/0036/0001, RD06/0020/0003 and RD12/0036/0021, and RD06/0020/0105 and RD12/0036/0033 from Instituto de San Carlos III-RETIC (Red Tematica de Investigacion Cooperativa en Cancer).S

PGA(1)-induced apoptosis involves specific activation of H-Ras and N-Ras in cellular endomembranes

The cyclopentenone prostaglandin A1 (PGA1) is an inducer of cell death in cancer cells. However, the mechanism that initiates this cytotoxic response remains elusive. Here we report that PGA1 triggers apoptosis by a process that entails the specific activation of H- and N-Ras isoforms, leading to caspase activation. Cells without H- and N-Ras did not undergo apoptosis upon PGA1 treatment; in these cells, the cellular demise was rescued by overexpression of either H-Ras or N-Ras. Consistently, the mutant H-Ras-C118S, defective for binding PGA1, did not produce cell death. Molecular analysis revealed a key role for the RAF-MEK-ERK signaling pathway in the apoptotic process through the induction of calpain activity and caspase-12 cleavage. We propose that PGA1 evokes a specific physiological cell death program, through H- and N-Ras, but not K-Ras, activation at endomembranes. Our results highlight a novel mechanism that may be of potential interest for tumor treatment.status: publishe