title: Cell-surface receptor for complement component C1q (gC1qR) is a key regulator for lamellipodia formation and cancer metastasis.
abstract: We previously demonstrated that the receptor for the complement component C1q (gC1qR) is a lipid raft protein that is indispensable for adipogenesis and insulin signaling. Here, we provide the first report that gC1qR is an essential component of lamellipodia in human lung carcinoma A549 cells. Cell-surface gC1qR was concentrated in the lamellipodia along with CD44, monosialoganglioside, actin, and phosphorylated focal adhesion kinase in cells stimulated with insulin, IGF-1, EGF, or serum. The growth factor-induced lamellipodia formation and cell migration were significantly decreased in gC1qR-depleted cells, with a concomitant blunt activation of the focal adhesion kinase and the respective receptor tyrosine kinases. Moreover, the gC1qR-depleted cells exhibited a reduced proliferation rate in culture as well as diminished tumorigenic and metastatic activities in grafted mice. We therefore conclude that cell-surface gC1qR regulates lamellipodia formation and metastasis via receptor tyrosine kinase activation.
authors.affiliation: College of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Korea.
authors.forename: Ki-Bum
authors.initials: KB
authors.lastname: Kim
authors.forename: Jae-Sung
authors.initials: JS
authors.lastname: Yi
authors.forename: Nga
authors.initials: N
authors.lastname: Nguyen
authors.forename: Joo-Hyung
authors.initials: JH
authors.lastname: Lee
authors.forename: Young-Chan
authors.initials: YC
authors.lastname: Kwon
authors.forename: Byung-Yoon
authors.initials: BY
authors.lastname: Ahn
authors.forename: Hana
authors.initials: H
authors.lastname: Cho
authors.forename: Yoon Ki
authors.initials: YK
authors.lastname: Kim
authors.forename: Hee-Jung
authors.initials: HJ
authors.lastname: Yoo
authors.forename: Jae-Seon
authors.initials: JS
authors.lastname: Lee
authors.forename: Young-Gyu
authors.initials: YG
authors.lastname: Ko
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects / Q000235:genetics; D005260:Female; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000494:pharmacology; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism*; D009362:Neoplasm Metastasis; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D009368:Neoplasm Transplantation; D011554:Pseudopodia / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D014183:Transplantation, Heterologous
chemical_list: C087299:C1QBP protein, human; D002352:Carrier Proteins; D036341:Intercellular Signaling Peptides and Proteins; D024101:Mitochondrial Proteins; D009363:Neoplasm Proteins; D051416:Focal Adhesion Protein-Tyrosine Kinases