Suppression of cell motility and metastasis by transfection with human motility-related protein (MRP-1/CD9) DNA

J Exp Med. 1993 May 1;177(5):1231-7. doi: 10.1084/jem.177.5.1231.


Previously we showed that motility-related protein (MRP-1) is an antigen recognized by monoclonal antibody (mAb) M31-15 inhibiting cell motility and that the sequence of MRP-1 coincides with that of CD9. In the present study, plasmid was constructed in which human MRP-1/CD9 cDNA is expressed under the control of the Abelson murine leukemia virus promoter sequence. The expression plasmid for MRP-1/CD9 was introduced into Chinese hamster ovary cells, human lung adenocarcinoma cell line MAC10 (MRP-1 positive), and human myeloma cell line ARH77 (MRP-1 negative). All of the MRP-1/CD9 (over)expressing clones obtained from these transfected cells showed suppressed cell motility (penetration and phagokinetic track assays) depending on the degree of expression of MRP-1/CD9. Overexpression of MRP-1/CD9 by MAC10 cells resulted in the suppression of cell motility (maximally 73%) associated with considerable inhibition of the cell growth (maximally 48%). However, the inhibition of the growth of MAC10 cells by mAb M31-15 was < 17% at an antibody concentration of 1-5 micrograms/ml, which inhibits cell motility by > 90%. These results suggest that MRP-1/CD9 directly regulates cell motility and may also affect cell growth. Effects on metastasis by the expression of MRP-1 CD9 were investigated with mouse melanoma BL6 cells-BALB/c nu/nu mouse system. Metastatic potential of all transformants expressing MRP-1/CD9 was lower than that of parent BL6 cells.

MeSH terms

  • Animals
  • Antigens, CD / genetics
  • Antigens, CD / physiology*
  • CHO Cells
  • Cell Adhesion
  • Cell Division
  • Cell Movement / genetics
  • Cell Movement / physiology*
  • Cricetinae
  • DNA
  • Humans
  • Membrane Glycoproteins*
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • Neoplasm Metastasis* / genetics
  • Plasmids
  • Tetraspanin 29
  • Transfection
  • Tumor Cells, Cultured


  • Antigens, CD
  • CD9 protein, human
  • Cd9 protein, mouse
  • Membrane Glycoproteins
  • Tetraspanin 29
  • DNA