title: Death-receptor O-glycosylation controls tumor-cell sensitivity to the proapoptotic ligand Apo2L/TRAIL.
abstract: Apo2L/TRAIL stimulates cancer cell death through the proapoptotic receptors DR4 and DR5, but the determinants of tumor susceptibility to this ligand are not fully defined. mRNA expression of the peptidyl O-glycosyltransferase GALNT14 correlated with Apo2L/TRAIL sensitivity in pancreatic carcinoma, non-small-cell lung carcinoma and melanoma cell lines, and up to 30% of samples from various human malignancies showed GALNT14 overexpression. RNA interference of GALNT14 reduced cellular Apo2L/TRAIL sensitivity, whereas overexpression increased responsiveness. Biochemical analysis of DR5 identified several ectodomain O-(N-acetyl galactosamine-galactose-sialic acid) structures. Sequence comparison predicted conserved extracellular DR4 and DR5 O-glycosylation sites; progressive mutation of the DR5 sites attenuated apoptotic signaling. O-glycosylation promoted ligand-stimulated clustering of DR4 and DR5, which mediated recruitment and activation of the apoptosis-initiating protease caspase-8. These results uncover a new link between death-receptor O-glycosylation and apoptotic signaling, providing potential predictive biomarkers for Apo2L/TRAIL-based cancer therapy.
authors.affiliation: Department of Molecular Diagnostics, Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, USA.
authors.forename: Klaus W
authors.initials: KW
authors.lastname: Wagner
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Punnoose
authors.forename: Thomas
authors.initials: T
authors.lastname: Januario
authors.forename: David A
authors.initials: DA
authors.lastname: Lawrence
authors.forename: Robert M
authors.initials: RM
authors.lastname: Pitti
authors.forename: Kate
authors.initials: K
authors.lastname: Lancaster
authors.forename: Dori
authors.initials: D
authors.lastname: Lee
authors.forename: Melissa
authors.initials: M
authors.lastname: von Goetz
authors.forename: Sharon Fong
authors.initials: SF
authors.lastname: Yee
authors.forename: Klara
authors.initials: K
authors.lastname: Totpal
authors.forename: Ling
authors.initials: L
authors.lastname: Huw
authors.forename: Viswanatham
authors.initials: V
authors.lastname: Katta
authors.forename: Guy
authors.initials: G
authors.lastname: Cavet
authors.forename: Sarah G
authors.initials: SG
authors.lastname: Hymowitz
authors.forename: Lukas
authors.initials: L
authors.lastname: Amler
authors.forename: Avi
authors.initials: A
authors.lastname: Ashkenazi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis; D002289:Carcinoma, Non-Small-Cell Lung; D045744:Cell Line, Tumor; D002470:Cell Survival; D020022:Genetic Predisposition to Disease; D006031:Glycosylation; D006801:Humans; D008175:Lung Neoplasms; D008545:Melanoma; D051379:Mice; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D010190:Pancreatic Neoplasms; D012333:RNA, Messenger / Q000235:genetics; D053218:Receptors, Death Domain / Q000502:physiology*; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand / Q000235:genetics / Q000378:metabolism; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000502:physiology*; D014183:Transplantation, Heterologous
chemical_list: D012333:RNA, Messenger; D053218:Receptors, Death Domain; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human