title: Formation of tissue factor-factor VIIa-factor Xa complex induces activation of the mTOR pathway which regulates migration of human breast cancer cells.
abstract: Tissue factor (TF) is a transmembrane glycoprotein that initiates blood coagulation when complexed with activated factor VII (FVIIa). TF is constitutively expressed in a variety of tumor cells and has been implicated in cellular signaling, angiogenesis, and tumor progression. Formation of TF-FVIIa complex and generation of downstream coagulation proteases, including activated factor X (FXa) and thrombin, initiate signaling by activation of protease-activated receptors (PARs). We have previously shown that TF-FVIIa-Xa complex formation promotes phosphorylation of p44/42 mitogen-activated protein kinase and Akt/protein kinase B in human breast cancer cells. In the present study, we show that formation of TF-FVIIa-FXa complex induces phosphorylation of mammalian target of rapamycin (mTOR) and p70 S6 kinase in a human breast cancer cell line, Adr-MCF-7. Activation of the mTOR pathway, which is probably mediated by PAR1 and/or PAR2, was associated with enhanced cell migration, a key step in the metastatic cascade. Inhibition of this pathway with the specific mTOR inhibitor, rapamycin, markedly decreased cell migration induced by formation of TF-FVIIa-FXa complex. These studies suggest that TF-FVIIa-mediated signaling modulates mTOR pathway activation, which regulates in part breast cancer cell migration. Targeting the TF-mediated cell signaling pathway might represent a novel strategy for the treatment of breast cancer.
authors.affiliation: Sol Sherry Thrombosis Research Center, Temple University School of Medicine, 3400 North Broad Street Room 300 OMS, Philadelphia, PA 19140, USA.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Jiang
authors.forename: Shimei
authors.initials: S
authors.lastname: Zhu
authors.forename: Tracee S
authors.initials: TS
authors.lastname: Panetti
authors.forename: Michael E
authors.initials: ME
authors.lastname: Bromberg
mesh_terms: D001943:Breast Neoplasms / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D002867:Chromones / Q000494:pharmacology; D015942:Factor VIIa / Q000378:metabolism*; D015951:Factor Xa / Q000378:metabolism*; D005260:Female; D006801:Humans; D009025:Morpholines / Q000494:pharmacology; D009361:Neoplasm Invasiveness; D010455:Peptides / Q000494:pharmacology; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011494:Protein Kinases / Q000187:drug effects / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000037:antagonists & inhibitors / Q000378:metabolism; D044463:Receptor, PAR-1 / Q000378:metabolism; D044464:Receptor, PAR-2 / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D038762:Ribosomal Protein S6 Kinases, 70-kDa / Q000378:metabolism; D020123:Sirolimus / Q000494:pharmacology; D058570:TOR Serine-Threonine Kinases; D013925:Thromboplastin / Q000378:metabolism*
chemical_list: D002867:Chromones; D009025:Morpholines; D010455:Peptides; D047428:Protein Kinase Inhibitors; D044463:Receptor, PAR-1; D044464:Receptor, PAR-2; D011994:Recombinant Proteins; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D013925:Thromboplastin; D011494:Protein Kinases; C546842:MTOR protein, human; D051057:Proto-Oncogene Proteins c-akt; D038762:Ribosomal Protein S6 Kinases, 70-kDa; D058570:TOR Serine-Threonine Kinases; C448901:ribosomal protein S6 kinase, 70kD, polypeptide 1; D015942:Factor VIIa; D015951:Factor Xa; D020123:Sirolimus