title: p8 expression controls pancreatic cancer cell migration, invasion, adhesion, and tumorigenesis.
abstract: p8 is a stress gene whose activity is necessary for tumor development and progression. The acquisition of invasive properties by transformed cells is a key event in tumor development. In order to establish whether p8 is involved or not in this phenomenon, we assessed the capacity of p8 at influencing cell adhesion, migration, invasion, and tumorigenesis of pancreatic cancer cells. p8 expression was knocked down by a small interfering RNA (siRNA) in pancreatic cancer-derived Panc-1 and MiaPaCa-2 cells and subsequent changes in cell adhesion, migration, invasion, and tumorigenesis were assessed. Influence of p8 silencing on gene expression was analyzed using cDNA microarrays. The influence of inhibiting CDC42, one of the genes most over-expressed in p8-silenced cells, on the changes observed in p8-silenced cells was also evaluated. Finally, the tumorigenic capacities of Panc-1 cells transfected with control siRNA or p8 siRNA were compared by assessing their ability to form colonies in soft agar and to grow as xenografts in nude mice. Knocking-down p8 in pancreatic cancer cells in vitro decreased migration and invasion while increasing cell adhesion; over-expression produced the opposite effect. Knocking down CDC42 reversed almost completely the effects of silencing p8 in vitro. Finally, cells transfected with p8 siRNA were almost unable to form colonies in soft agar. In addition, p8-deficient Panc-1 cells did not develop tumors when injected subcutaneously in nude mice. In conclusion, p8 expression controls pancreatic cancer cell migration, invasion and adhesion, three processes required for metastasis, at least in part, through CDC42, a major regulator of cytoskeleton organization.
authors.affiliation: INSERM U624, Stress Cellulaire, Parc Scientifique et Technologique de Luminy, Marseille, France.
authors.forename: Maria Jose
authors.initials: MJ
authors.lastname: Sandi
authors.forename: Tewfik
authors.initials: T
authors.lastname: Hamidi
authors.forename: Cédric
authors.initials: C
authors.lastname: Malicet
authors.forename: Carla
authors.initials: C
authors.lastname: Cano
authors.forename: Céline
authors.initials: C
authors.lastname: Loncle
authors.forename: Anne
authors.initials: A
authors.lastname: Pierres
authors.forename: Jean Charles
authors.initials: JC
authors.lastname: Dagorn
authors.forename: Juan L
authors.initials: JL
authors.lastname: Iovanna
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism*; D002448:Cell Adhesion; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002633:Chemotaxis; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D051379:Mice; D008819:Mice, Nude; D009361:Neoplasm Invasiveness; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D034622:RNA Interference; D013997:Time Factors; D014162:Transfection; D047368:Tumor Burden; D014410:Tumor Stem Cell Assay; D020764:cdc42 GTP-Binding Protein / Q000235:genetics / Q000378:metabolism
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D009363:Neoplasm Proteins; D020764:cdc42 GTP-Binding Protein; C491643:NUPR1 protein, human