Positive correlation between the expression of X-chromosome RBM genes (RBMX, RBM3, RBM10) and the proapoptotic Bax gene in human breast cancer

J Cell Biochem. 2006 Apr 15;97(6):1275-82. doi: 10.1002/jcb.20725.

Abstract

In a recent report, it has been postulated that the ubiquitous RBM proteins might constitute a novel family of apoptosis modulators. We measured the expression of the X-chromosome RBM genes (RBMX, RBM3, and RBM10) in 122 breast cancers by means of differential RT-PCR. Using the same method, we also studied the expression of the apoptosis-related genes Bcl-2 and Bax. Markers of hormone dependence (estrogen and progesterone receptors), proliferation (Ki67 and DNA-ploidy), angiogenesis (VEGF and CD105), as well as oncogene (c-erb-B2), and tumor suppressor gene (p53) expression were also analyzed. The expression of all X-chromosome RBM genes was significantly associated with the expression of the proapoptotic Bax gene (RBMX, P=0.039; RBM3, P<0.001; RBM10 large variant, P<0.001; RBM10 small variant, P<0.001). Furthermore, the expression of both RBM10 variants was significantly associated with the expression of the VEGF gene (large variant, P=0.004; small variant, P=0.003). We also found an association of borderline significance (P=0.05) between the expression of RBM3, the large variant of RBM10 and wild-type p53. Expression of the small RBM10 variant, finally, was associated with high proliferation of the tumors (Ki67>or=20%; P=0.037). The expression of both RBM10 variants seems to be interdependent to a significant degree (r=0.26, P=0.006). From these results, it seems that the X-chromosome, through its RBM genes, plays a formerly unknown role in the regulation of programmed cell death (apoptosis) in breast cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis*
  • Breast Neoplasms / genetics
  • Breast Neoplasms / metabolism*
  • Chromosomes, Human, X*
  • Female
  • Flow Cytometry
  • Gene Expression Regulation, Neoplastic*
  • Heterogeneous-Nuclear Ribonucleoproteins / genetics*
  • Heterogeneous-Nuclear Ribonucleoproteins / metabolism
  • Humans
  • RNA-Binding Proteins / genetics*
  • RNA-Binding Proteins / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • bcl-2-Associated X Protein / genetics*
  • bcl-2-Associated X Protein / metabolism

Substances

  • BAX protein, human
  • Heterogeneous-Nuclear Ribonucleoproteins
  • RBM10 protein, human
  • RBM3 protein, human
  • RBMX protein, human
  • RNA-Binding Proteins
  • bcl-2-Associated X Protein