title: Granulysin induces apoptotic cell death and cleavage of the autophagy regulator Atg5 in human hematological tumors.
abstract: Granulysin is a protein present in the granules of human CTL and NK cells, with cytolytic activity against microbes and tumors. Previous work demonstrated that granulysin caused cell death through mitochondrial damage with release of AIF and cytochrome c. However, the molecular mechanism and, especially, the type of cell death were still not well defined. In the present work we show that granulysin-induced cell death is apoptotic, with phosphatidylserine exposure preceding membrane breakdown and with caspase 3 activation. Granulysin-induced apoptosis is prevented in Jurkat cells over-expressing Bcl-xL or Bcl2, or lacking Bak and Bax or Bim expression, suggesting a central role of the mitochondrial apoptotic pathway. This apoptotic process is initiated by intracellular Ca(2+) increase and mitochondrial ROS generation. We have tested granulysin against other hematological tumor cells such as multiple myeloma cell lines, and cells from B cell chronic lymphocytic leukemia (B-CLL) patients, finding different degrees of sensitivity. We also show that granulysin induces the cleavage of Atg5 in the complex formed with Atg12, without affecting autophagy. In conclusion, granulysin induces apoptosis on hematological tumor cells and on cells from B-CLL patients, opening the door to research on its use as a new anti-tumoral treatment.
authors.affiliation: Apoptosis, Immunity & Cancer Group, Dept. Biochemistry and Molecular and Cell Biology, University of Zaragoza and Aragón Health Research Institute (IIS Aragón), Zaragoza, Spain. Electronic address: aaporta@unizar.es.
authors.forename: Adriana
authors.initials: A
authors.lastname: Aporta
authors.affiliation: Apoptosis, Immunity & Cancer Group, Dept. Biochemistry and Molecular and Cell Biology, University of Zaragoza and Aragón Health Research Institute (IIS Aragón), Zaragoza, Spain. Electronic address: elenagelsa@hotmail.com.
authors.forename: Elena
authors.initials: E
authors.lastname: Catalán
authors.affiliation: Apoptosis, Immunity & Cancer Group, Dept. Biochemistry and Molecular and Cell Biology, University of Zaragoza and Aragón Health Research Institute (IIS Aragón), Zaragoza, Spain. Electronic address: pgalan@unizar.es.
authors.forename: Patricia
authors.initials: P
authors.lastname: Galán-Malo
authors.affiliation: Apoptosis, Immunity & Cancer Group, Dept. Biochemistry and Molecular and Cell Biology, University of Zaragoza and Aragón Health Research Institute (IIS Aragón), Zaragoza, Spain. Electronic address: 606735@unizar.es.
authors.forename: Ariel
authors.initials: A
authors.lastname: Ramírez-Labrada
authors.affiliation: Immune Effector Cells Group, IIS Aragón, Biomedical Research Centre of Aragón (CIBA), Nanoscience Institute of Aragon (INA), Zaragoza, Spain. Electronic address: martaperez@gmail.com.
authors.forename: Marta
authors.initials: M
authors.lastname: Pérez
authors.affiliation: Hematology Service, Clinical Hospital "Lozano Blesa", Zaragoza, Spain. Electronic address: gemma@azaceta.net.
authors.forename: Gemma
authors.initials: G
authors.lastname: Azaceta
authors.affiliation: Hematology Service, Clinical Hospital "Lozano Blesa", Zaragoza, Spain. Electronic address: lpalomera@salud.aragon.es.
authors.forename: Luis
authors.initials: L
authors.lastname: Palomera
authors.affiliation: Apoptosis, Immunity & Cancer Group, Dept. Biochemistry and Molecular and Cell Biology, University of Zaragoza and Aragón Health Research Institute (IIS Aragón), Zaragoza, Spain. Electronic address: jnaval@unizar.es.
authors.forename: Javier
authors.initials: J
authors.lastname: Naval
authors.affiliation: Apoptosis, Immunity & Cancer Group, Dept. Biochemistry and Molecular and Cell Biology, University of Zaragoza and Aragón Health Research Institute (IIS Aragón), Zaragoza, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Marzo
authors.affiliation: Immune Effector Cells Group, IIS Aragón, Biomedical Research Centre of Aragón (CIBA), Nanoscience Institute of Aragon (INA), Zaragoza, Spain; Aragón I+D Foundation (ARAID), Zaragoza, Spain. Electronic address: pardojim@unizar.es.
authors.forename: Julián
authors.initials: J
authors.lastname: Pardo
authors.affiliation: Apoptosis, Immunity & Cancer Group, Dept. Biochemistry and Molecular and Cell Biology, University of Zaragoza and Aragón Health Research Institute (IIS Aragón), Zaragoza, Spain. Electronic address: anel@unizar.es.
authors.forename: Alberto
authors.initials: A
authors.lastname: Anel
mesh_terms: D000945:Antigens, Differentiation, T-Lymphocyte / Q000235:genetics / Q000378:metabolism*; D017209:Apoptosis / Q000502:physiology*; D000071187:Autophagy-Related Protein 5; D002118:Calcium / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology*; D006801:Humans; D019169:Jurkat Cells; D015448:Leukemia, B-Cell / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism; D017382:Reactive Oxygen Species
chemical_list: C502778:ATG5 protein, human; D000945:Antigens, Differentiation, T-Lymphocyte; D000071187:Autophagy-Related Protein 5; C075005:GNLY protein, human; D008869:Microtubule-Associated Proteins; D017382:Reactive Oxygen Species; D002118:Calcium
keywords: AIF; Apoptosis; B-CLL; B-cell chronic lymphocytic leukemia; Leukemia; Mitochondria; Multiple myeloma; PS; ROS; apoptosis-inducing factor; phosphatidylserine; reactive oxygen species; sh; small hairpin