title: L1CAM-integrin interaction induces constitutive NF-kappaB activation in pancreatic adenocarcinoma cells by enhancing IL-1beta expression.
abstract: L1 cell adhesion molecule (L1CAM) overexpression is often associated with bad prognosis in various human carcinomas. Recent studies also suggest a role of L1CAM in pancreatic ductal adenocarcinomas (PDAC). To further address its contribution, we expressed functional domains of L1CAM in PT45-P1 PDAC cells. We found that L1CAM that is full length (L1-FL), but neither the soluble ectodomain (L1ecto) nor the cytoplasmic part (L1cyt), could enhance cell proliferation or tumour growth in mice. Expression of L1-FL resulted in constitutive activation of NF-kappaB, which was abolished by L1CAM knockdown. We showed that the expression of IL-1beta was selectively upregulated by L1-FL, and increased IL-1beta levels were instrumental for sustained NF-kappaB activation. IL-1beta production and NF-kappaB activation were abolished by knockdown of alpha5-integrin and integrin-linked kinase, but insensitive to depletion of L1CAM cleavage proteinases. Supporting these data, PT45-P1 cells transduced with an L1CAM mutant deficient in integrin binding (L1-RGE) did not support the described L1-FL functions. Our results suggest that membranous L1CAM interacts with RGD-binding integrins, leading to sustained NF-kappaB activation by IL-1beta production and autocrine/paracrine signalling. The unravelling of this novel mechanism sheds new light on the important role of L1CAM expression in PDAC cells.
authors.affiliation: Translational Immunology, German Cancer Research Center, Heidelberg, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Kiefel
authors.forename: S
authors.initials: S
authors.lastname: Bondong
authors.forename: N
authors.initials: N
authors.lastname: Erbe-Hoffmann
authors.forename: J
authors.initials: J
authors.lastname: Hazin
authors.forename: S
authors.initials: S
authors.lastname: Riedle
authors.forename: J
authors.initials: J
authors.lastname: Wolf
authors.forename: M
authors.initials: M
authors.lastname: Pfeifer
authors.forename: A
authors.initials: A
authors.lastname: Arlt
authors.forename: H
authors.initials: H
authors.lastname: Schäfer
authors.forename: S Sebens
authors.initials: SS
authors.lastname: Müerköster
authors.forename: P
authors.initials: P
authors.lastname: Altevogt
mesh_terms: D000818:Animals; D021441:Carcinoma, Pancreatic Ductal / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D002448:Cell Adhesion / Q000502:physiology; D048708:Cell Growth Processes / Q000502:physiology; D045744:Cell Line, Tumor; D019008:Drug Resistance, Neoplasm; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D055785:Gene Knockdown Techniques; D006801:Humans; D053583:Interleukin-1beta / Q000096:biosynthesis*; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D039842:Neural Cell Adhesion Molecule L1 / Q000235:genetics / Q000378:metabolism*; D010190:Pancreatic Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D015398:Signal Transduction; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014162:Transfection
chemical_list: D053583:Interleukin-1beta; D016328:NF-kappa B; D039842:Neural Cell Adhesion Molecule L1; D013755:Tetradecanoylphorbol Acetate