title: Expression of a novel factor in human breast cancer cells with metastatic potential.
abstract: Clinical and experimental evidence suggests that tumor cells shed into the circulation from solid cancers are ineffective in forming distant metastasis unless the cells are able to respond to growth conditions offered by the secondary organs. To identify the phenotypic properties that are specific for such growth response, we injected carcinoma cells, which had been recovered from bone marrow micrometastases in a breast cancer patient who was clinically devoid of overt metastatic disease and established in culture, into the systemic circulation of immunodeficient rats. The animals developed metastases in the central nervous system, and metastatic tumor cells were isolated with immunomagnetic beads coated with an antibody that was reactive with human cells. The segregated cell population was compared with the injected cells by means of differential display analysis, and two candidate fragments were identified as up-regulated in the fully metastatic cells. The first was an intracellular effector molecule involved in tyrosine kinase signaling, known to mediate nerve growth factor-dependent promotion of cell survival. The second was a novel gene product (termed candidate of metastasis-1), presumably encoding a DNA-binding protein of helix-turn-helix type. Constitutive expression of candidate of metastasis-1 seemed to distinguish breast cancer cells with metastatic potential from cells without metastatic potential. Hence, our experimental approach identified factors that may mediate the growth response of tumor cells upon establishment in a secondary organ and, thereby, contribute to the metastatic phenotype.
authors.affiliation: Department of Tumor Biology, Norwegian Radium Hospital, Oslo. a.h.ree@dnr.uio.no
authors.forename: A H
authors.initials: AH
authors.lastname: Ree
authors.forename: M
authors.initials: M
authors.lastname: Tvermyr
authors.forename: O
authors.initials: O
authors.lastname: Engebraaten
authors.forename: M
authors.initials: M
authors.lastname: Rooman
authors.forename: O
authors.initials: O
authors.lastname: Røsok
authors.forename: E
authors.initials: E
authors.lastname: Hovig
authors.forename: L A
authors.initials: LA
authors.lastname: Meza-Zepeda
authors.forename: O S
authors.initials: OS
authors.lastname: Bruland
authors.forename: O
authors.initials: O
authors.lastname: Fodstad
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D051792:Basic Helix-Loop-Helix Proteins; D001853:Bone Marrow / Q000473:pathology*; D001943:Breast Neoplasms / Q000235:genetics / Q000473:pathology*; D018275:Carcinoma, Lobular / Q000235:genetics / Q000473:pathology*; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins; D005260:Female; D006801:Humans; D018189:Immunomagnetic Separation; D008969:Molecular Sequence Data; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D009363:Neoplasm Proteins / Q000235:genetics*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D011923:Rats, Nude; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D014158:Transcription, Genetic; D014183:Transplantation, Heterologous; D014407:Tumor Cells, Cultured
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D004268:DNA-Binding Proteins; D009363:Neoplasm Proteins; D011505:Protein-Tyrosine Kinases; D012333:RNA, Messenger; C491643:NUPR1 protein, human; C109741:Nupr1 protein, rat