title: CXCR4/SDF1 mediate hypoxia induced chondrosarcoma cell invasion through ERK signaling and increased MMP1 expression.
abstract: BACKGROUND
  Chondrosarcoma is a disease that does not respond to conventional cytotoxic chemotherapy and expression of MMP1 is a marker for a poor prognosis. The mechanism of increased MMP1 expression in chondrosarcoma is not completely known. Our goal is to identify molecular pathways that could serve as therapeutic targets. Chondrosarcoma become hypoxic as they grow, are capable of eliciting an angiogenic response, and typically metastasize to the lungs. The present study determined the effect of hypoxia and specifically HIF-1a on expression of CXCR4 and MMP1 and their role in chondrosarcoma cell invasion.
  
  
  RESULTS
  CXCR4 and its ligand, SDF1, are upregulated in primary chondrosarcoma tumors compared to normal articular cartilage, and CXCR4 was upregulated in chondrosarcoma cell line JJ compared to normal chondrocytes. Hypoxia and specifically HIF-1a increased CXCR4 and MMP1 expression in JJ cell line and chondrosarcoma invasion in vitro. The hypoxia mediated increase in MMP1 expression and chondrosarcoma invasion could be inhibited by siRNA directed at HIF-1a or CXCR4, the CXCR4 inhibitor AMD3100, as well as with ERK inhibitor U0126 and ERK siRNA.
  
  
  CONCLUSIONS
  Chondrosarcoma cell invasion is increased by hypoxia induced expression of CXCR4 and MMP1 and is mediated by HIF-1a and ERK. Both invasion and MMP1 can be inhibited with CXCR4 blockade, suggesting that CXCR4/SDF1 signaling may be a therapeutic target for chondrosarcoma.
authors.affiliation: Department of Orthopaedics, Warren Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI, USA.
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Sun
authors.forename: Lei
authors.initials: L
authors.lastname: Wei
authors.forename: Qian
authors.initials: Q
authors.lastname: Chen
authors.forename: Richard M
authors.initials: RM
authors.lastname: Terek
mesh_terms: D015687:Cell Hypoxia / Q000187:drug effects / Q000235:genetics; D054377:Chemokine CXCL12 / Q000235:genetics / Q000378:metabolism*; D002813:Chondrosarcoma / Q000201:enzymology* / Q000235:genetics / Q000473:pathology*; D004789:Enzyme Activation / Q000187:drug effects; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D055785:Gene Knockdown Techniques; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000187:drug effects; D020781:Matrix Metalloproteinase 1 / Q000235:genetics / Q000378:metabolism*; D009361:Neoplasm Invasiveness; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D019718:Receptors, CXCR4 / Q000235:genetics / Q000378:metabolism*; D014407:Tumor Cells, Cultured
chemical_list: D054377:Chemokine CXCL12; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D047428:Protein Kinase Inhibitors; D012333:RNA, Messenger; D019718:Receptors, CXCR4; D048049:Extracellular Signal-Regulated MAP Kinases; C522360:MMP1 protein, human; D020781:Matrix Metalloproteinase 1