title: Lasp1 gene disruption is linked to enhanced cell migration and tumor formation.
abstract: Lasp1 is an actin-binding, signaling pathway-regulated phosphoprotein that is overexpressed in several cancers. siRNA knockdown in cell lines retards cell migration, suggesting the possibility that Lasp1 upregulation influences cancer metastasis. Herein, we utilized a recently developed gene knockout model to assess the role of Lasp1 in modulating nontransformed cell functions. Wound healing and tumor initiation progressed more rapidly in Lasp1(-/-) mice compared with Lasp1(+/+) controls. Embryonic fibroblasts (MEFs) derived from Lasp1(-/-) mice also migrated more rapidly in vitro. These MEFs characteristically possessed increased focal adhesion numbers and displayed more rapid attachment compared with wild-type MEFs. Differential microarray analyses revealed alterations in message expression for proteins implicated in cell migration, adhesion, and cytoskeletal organization. Notably, the focal adhesion protein, lipoma preferred partner (LPP), a zyxin family member and putative Lasp1 binding protein, was increased about twofold. Because LPP gene disruption reduces cell migration, we hypothesize that LPP plays a role in enhancing the migratory capacity of Lasp1(-/-) MEFs, perhaps by modifying the subcellular localization of other motility-associated proteins. The striking contrast in the functional effects of loss of Lasp1 in innate cells compared with cell lines reveals distinct differences in mechanisms of motility and attachment in these models.
authors.affiliation: Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, Georgia, USA.
authors.forename: Han
authors.initials: H
authors.lastname: Zhang
authors.forename: Xunsheng
authors.initials: X
authors.lastname: Chen
authors.forename: Wendy B
authors.initials: WB
authors.lastname: Bollag
authors.forename: Roni J
authors.initials: RJ
authors.lastname: Bollag
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Sheehan
authors.forename: Catherine S
authors.initials: CS
authors.lastname: Chew
mesh_terms: D015127:9,10-Dimethyl-1,2-benzanthracene; D000818:Animals; D015153:Blotting, Western; D002448:Cell Adhesion; D002465:Cell Movement / Q000502:physiology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D022001:Focal Adhesions / Q000378:metabolism; D020869:Gene Expression Profiling; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D060588:LIM Domain Proteins; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018613:Microscopy, Confocal; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D009374:Neoplasms, Experimental / Q000139:chemically induced / Q000235:genetics / Q000473:pathology*; D020411:Oligonucleotide Array Sequence Analysis; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D003598:Cytoskeletal Proteins; D018398:Homeodomain Proteins; D060588:LIM Domain Proteins; C103594:LPP protein, human; C490692:Lasp1 protein, mouse; D009363:Neoplasm Proteins; D015127:9,10-Dimethyl-1,2-benzanthracene