Analysis of CUL-5 expression in breast epithelial cells, breast cancer cell lines, normal tissues and tumor tissues.
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.
Fay
Michael J
MJ
Department of Pharmacology, Midwestern University, Chicago College of Osteopathic Medicine, 555 31st Street, Downers Grove, IL 60515, USA. mfayxx@midwestern.edu
Longo
Kenneth A
KA
Karathanasis
George A
GA
Shope
David M
DM
Mandernach
Craig J
CJ
Leong
Jason R
JR
Hicks
Alfred
A
Pherson
Kenneth
K
Husain
Amyna
A
D001940:Breast / Q000166:cytology* / Q000473:pathology*; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D045744:Cell Line, Tumor; D044842:Cullin Proteins / Q000096:biosynthesis*; D004847:Epithelial Cells / Q000737:chemistry* / Q000378:metabolism* / Q000473:pathology; D020869:Gene Expression Profiling / Q000379:methods; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D006801:Humans; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D009928:Organ Specificity / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis; D012334:RNA, Neoplasm / Q000096:biosynthesis; D017483:Receptors, Vasopressin / Q000096:biosynthesis*
C496871:CUL5 protein, human; D044842:Cullin Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D017483:Receptors, Vasopressin