Modulation of tumor cell migration, invasion and cell-matrix adhesion by human monopolar spindle-one-binder 2.

Human monopolar spindle-one-binder 2 (hMOB2) is a member of the hMOB family of proteins, and it has been reported to regulate the nuclear-Dbf2-related kinase (NDR) activation. However, the function of hMOB2 expression in tumor cell adhesion and motility has not been addressed. Herein, the lentiviral-mediated overexpression and the knockdown of hMOB2 in HepG2 and SMMC-7721 cells was established. It was demonstrated that overexpression of hMOB2 significantly reduced the cell motility and enhanced the cell-matrix adhesion, while the hMOB2 knockdown decreased not only the cell motility, but also the cell-matrix adhesion. Immunofluorescence results showed that both hMOB2 overexpression and knockdown altered assembly of the focal adhesions and the actin cytoskeleton rearrangement. Furthermore, the focal adhesion kinase (FAK)-Src-paxillin signal pathway activated by hMOB2 was confirmed to be involved in controlling the cell motility and the cell-matrix adhesion. These results demonstrated that the altered cell-matrix adhesion and cell motility induced by hMOB2 expression was caused by the assembly of focal adhesions as well as the actin cytoskeleton rearrangement through the activation of the FAK-Src-paxillin signal pathway, unveiling a novel mechanism of cell motility and cell-matrix adhesion regulation induced by hMOB2 expression.