Analysis of CUL-5 expression in breast epithelial cells, breast cancer cell lines, normal tissues and tumor tissues

Mol Cancer. 2003 Nov 25;2:40. doi: 10.1186/1476-4598-2-40.


Background: The chromosomal location of CUL-5 (11q 22-23) is associated with LOH in breast cancer, suggesting that CUL-5 may be a tumor suppressor. The purpose of this research was to determine if there is differential expression of CUL-5 in breast epithelial cells versus breast cancer cell lines, and normal human tissues versus human tumors. The expression of CUL-5 in breast epithelial cells (HMEC, MCF-10A), and breast cancer cells (MCF-7, MDA-MB-231) was examined using RT-PCR, Northern blot analysis, and Western blot analysis. The expression of mRNA for other CUL family members (CUL-1, -2, -3, -4A, and -4B) in these cells was evaluated by RT-PCR. A normal human tissue expression array and a cancer profiling array were used to examine CUL-5 expression in normal human tissues and matched normal tissues versus tumor tissues, respectively.

Results: CUL-5 is expressed at the mRNA and protein levels by breast epithelial cells (HMEC, MCF-10A) and breast cancer cells (MCF-7, MDA-MB-231). These cells also express mRNA for other CUL family members. The normal human tissue expression array revealed that CUL-5 is widely expressed. The cancer profiling array revealed that 82% (41/50) of the breast cancers demonstrated a decrease in CUL-5 expression versus the matched normal tissue. For the 50 cases of matched breast tissue there was a statistically significant approximately 2.2 fold decreased expression of CUL-5 in tumor tissue versus normal tissue (P < 0.0001).

Conclusions: The data demonstrate no apparent decrease in CUL-5 expression in the breast cancer cell lines (MCF-7, MDA-MB-231) versus the breast epithelial cells (HMEC, MCF-10A). The decrease in CUL-5 expression in breast tumor tissue versus matched normal tissue supports the hypothesis that decreased expression of CUL-5 may play a role in breast tumorigenesis.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Breast / cytology*
  • Breast / pathology*
  • Breast Neoplasms / genetics*
  • Breast Neoplasms / pathology
  • Cell Line, Tumor
  • Cullin Proteins / biosynthesis*
  • Epithelial Cells / chemistry*
  • Epithelial Cells / metabolism*
  • Epithelial Cells / pathology
  • Gene Expression Profiling / methods
  • Gene Expression Regulation, Neoplastic / genetics
  • Humans
  • Oligonucleotide Array Sequence Analysis / methods
  • Organ Specificity / genetics
  • RNA, Messenger / biosynthesis
  • RNA, Neoplasm / biosynthesis
  • Receptors, Vasopressin / biosynthesis*


  • CUL5 protein, human
  • Cullin Proteins
  • RNA, Messenger
  • RNA, Neoplasm
  • Receptors, Vasopressin