Myosin II co-chaperone general cell UNC-45 overexpression is associated with ovarian cancer, rapid proliferation, and motility

Am J Pathol. 2007 Nov;171(5):1640-9. doi: 10.2353/ajpath.2007.070325. Epub 2007 Sep 14.


Both tumor cell proliferation and metastasis are dependent on myosin II. Because UNC-45 is required to chaperone the assembly of a functional myosin II motor, we examined the expression of the general cell (GC) UNC-45 isoform in ovarian tumors. Serous carcinoma expressed elevated levels of GC UNC-45 compared with normal ovarian surface epithelium and benign cystadenoma. High-stage exhibited greater GC UNC-45 expression than low-stage serous carcinoma. Similarly, GC UNC-45 transcripts and protein levels were higher in ovarian cell lines than in immortalized ovarian surface epithelial cells. Elevation of GC UNC-45 levels by ectopic expression enhanced the rate of ovarian cancer cell proliferation, whereas siRNA knockdown of GC UNC-45 suppressed proliferation without altering myosin II levels. GC UNC-45 and myosin II were diffuse within the cytoplasm of confluent interphase cells, but both accumulated together at the cleavage furrow during cytokinesis. GC UNC-45 and myosin II also trafficked to the leading edges of ovarian cancer cells induced to move in a scratch assay. Knockdown of GC UNC-45 reduced the spreading ability of ovarian cancer cells whereas it was enhanced by GC UNC-45 overexpression. In sum, these findings implicate elevated GC UNC-45 protein expression in ovarian carcinoma proliferation and metastasis.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Cell Line, Transformed
  • Cell Line, Tumor
  • Cell Movement
  • Cell Proliferation
  • Female
  • Humans
  • Intracellular Signaling Peptides and Proteins / physiology*
  • Molecular Chaperones / physiology*
  • Myosin Type II / physiology*
  • Ovarian Neoplasms / metabolism*
  • Ovarian Neoplasms / pathology
  • Protein Isoforms / physiology
  • Rabbits


  • Intracellular Signaling Peptides and Proteins
  • Molecular Chaperones
  • Protein Isoforms
  • UNC45A protein, human
  • Myosin Type II