The roles of human sucrose nonfermenting protein 2 homologue in the tumor-promoting functions of Rsf-1

Cancer Res. 2008 Jun 1;68(11):4050-7. doi: 10.1158/0008-5472.CAN-07-3240.

Abstract

Rsf-1 interacts with human sucrose nonfermenting protein 2 homologue (hSNF2H) to form a chromatin remodeling complex that participates in several biological processes. We have previously shown that Rsf-1 gene amplification was associated with the most aggressive type of ovarian cancer and cancer cells with Rsf-1 overexpression depended on Rsf-1 to survive. In this report, we determine if formation of the Rsf-1/hSNF2H complex could be one of the mechanisms contributing to tumor cell survival and growth in ovarian carcinomas. Based on immunohistochemistry, we found that Rsf-1 and hSNF2H were co-upregulated in ovarian cancer tissues. Ectopic expression of Rsf-1 in SKOV3 ovarian cancer cells with undetectable endogenous Rsf-1 expression enhanced hSNF2H protein levels and promoted SKOV3 tumor growth in a mouse xenograft model. Our studies also indicated that induction of Rsf-1 expression affected the molecular partnership of hSNF2H and translocated hSNF2H into nuclei where it colocalized with Rsf-1. Furthermore, analysis of Rsf-1 deletion mutants showed that the Rsf-D4 fragment contained the hSNF2H binding site based on coimmunoprecipitation and in vitro competition assays. As compared with other truncated mutants, expression of Rsf-D4 resulted in remarkable growth inhibition in ovarian cancer cells with Rsf-1 gene amplification and overexpression, but not in those without detectable Rsf-1 expression. The above findings suggest that interaction between Rsf-1 and hSNF2H may define a survival signal in those tumors overexpressing Rsf-1.

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

  • Adenosine Triphosphatases / metabolism
  • Adenosine Triphosphatases / physiology*
  • Animals
  • Apoptosis
  • Cell Division
  • Cell Line
  • Chromatin / physiology
  • Chromosomal Proteins, Non-Histone / metabolism
  • Chromosomal Proteins, Non-Histone / physiology*
  • Female
  • Fluorescent Antibody Technique
  • Humans
  • Immunoprecipitation
  • Mice
  • Mice, Nude
  • Nuclear Proteins / metabolism
  • Nuclear Proteins / physiology*
  • Ovarian Neoplasms / pathology
  • Polymerase Chain Reaction
  • Protein Binding
  • Trans-Activators / metabolism
  • Trans-Activators / physiology*

Substances

  • Chromatin
  • Chromosomal Proteins, Non-Histone
  • Nuclear Proteins
  • RSF1 protein, human
  • Trans-Activators
  • Adenosine Triphosphatases
  • SMARCA5 protein, human