Association of fragile site-associated (FSA) gene expression with epithelial differentiation and tumor development

M. Tien Kuo, Yingjie Wei, Xinlin Yang, Shigeru Tatebe, Jinsong Liu, Patricia Troncoso, Aysegul Sahin, Jae Ro, Stanly R. Hamilton, Niramol Savaraj

Research output: Contribution to journalArticlepeer-review

4 Scopus citations


A novel gene designated as fragile site-associated (FSA) gene was recently identified by positional cloning from the CHO 1q31 fragile site which plays an important role in regulating amplification of multidrug resistance (mdr1) gene in multidrug-resistant cells. FSA produces a message of ∼16 kb which encodes an open-reading frame of 5005 amino acids. FSA shares sequence similarity with that in Caenorhabditis elegans lpd-3, a lipid storage gene. Using immunohistochemical staining and RNA in situ hybridization we report here that expression of FSA is associated with developmental programs of spermatogenesis and mammary gland in mice. Real-time RT-PCR results also support the upregulation of FSA expression in mammary gland development. Expression of FSA in many tissues including colon, skin, ovary, prostate, and bladder is mainly in the postmitotic, well-differentiated compartments. Moreover, levels of FSA expression are downregulated in tumors of these tissue origins. These results suggest that FSA also plays important roles in regulating mammalian epithelial growth and differentiation and tumor development.

Original languageEnglish (US)
Pages (from-to)887-893
Number of pages7
JournalBiochemical and Biophysical Research Communications
Issue number3
StatePublished - Feb 17 2006


  • Epithelial cell differentiation
  • Fragile site
  • Immunohistochemistry
  • RNA in situ hybridization
  • Tumor development

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology


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