X-linked Gene Expression Profiles by RNAi-Mediated BRCA1 Knockdown in MCF7 Cells.
- Author:
Min Ae SONG
1
;
Jung Hoon PARK
;
Hee Jeong AHN
;
Jung Jae KO
;
Suman LEE
Author Information
1. Functional Genomics Lab, Bundang Campus, Pochon CHA University College of Medicine, Sungnam-Si, Gyeonggi-Do 463-836, Korea.
- Publication Type:Original Article
- MeSH:
Breast;
Breast Neoplasms;
Cell Line;
Female;
Gene Expression;
Genes, BRCA1;
Genes, X-Linked*;
Germ-Line Mutation;
Humans;
MCF-7 Cells*;
Oligonucleotide Array Sequence Analysis;
Ovarian Neoplasms;
RNA Interference;
X Chromosome;
X Chromosome Inactivation
- From:Genomics & Informatics
2005;3(4):154-158
- CountryRepublic of Korea
- Language:English
-
Abstract:
Germ-line mutations of the BRCA1 gene confer an increased risk for breast and ovarian cancers. BRCA1 in female cells is directly related with the maintenance of the inactive X chromosome (Xi). The effect by the loss of the BRCA1 function on the X chromosome gene expression remains unclear in cancer cells. We attempted to investigate the expression pattern of the X-linked genes by performing BRCA1 knockdown via RNA interference in the MCF 7 breast cancer cell line. The transcriptional and translational levels of BRCA1 were decreased over 95% in the MCF 7 cells after BRCA1 knockdown. The expression patterns of one hundred ninety X-linked genes were profiled by the X chromosome-specific cDNA arrays. A total of seven percent of the X-linked genes (14/190) were aberrantly expressed by over 2-fold in the MCF7-BRCA1 knockdown cells, which contained two up-regulated genes (2/190, 1%) and 12 downregulated genes (12/190, 6.3%). It is interesting that 72% of the aberrantly expressed X-linked genes were located on the Xq (10/14,) region. Our data suggests that BRCA1 may not be important to maintain X chromosome inactivation in cancer because the BRCA1 knockdown did increase the expression of the only one percent of X-linked genes in the human breast cancer cells.
