Identification of Novel
Regulatory Elements of Human Stem Cell Factor Gene in MCF Cell
TAN Wen-Bin, NIE Yi-Ling, LUO Sai-Qun, GUO Xiao-Shan,ZHU
Min,CHENG Guang-Jie,PENG Xing-Hua*
( Molecular Biology Research Center, Hunan Medical University, Changsha 410078,
China )
Abstract Human stem
cell factor(hSCF)is a pluripotent growth factor that regulates proliferation,
differentiation and migration of certain mammalian stem cells, such as
primordial germ cells etc. It is shown that hSCF and its receptor are
commonly co-expressed in human breast cancer cells. Up to now, the definite
regulatory mechanism of hSCF gene in breast cancer cells is unclear,
except that its 5′flanking sequence contains essential elements for regulating
transcription. To localize the regulatory elements responsible for the
regulation of the hSCF gene, we performed transient transfection study
in MCF cells, with a series of luciferase reporter gene constructs, containing
different 5′end deletions of hSCF gene. This study indicates that the
region of -1190～-853 significantly enhanced the luc
gene expression, while the region of -339～-162 inhibited the expression.
Eletrophoretic mobility shift assay confirmed that MCF nuclear extract proteins
bound to both -1190～-853 and -339～-273 regions, forming specific
DNA-protein complexes, indicating that there were nuclear protein binding sites
in these regions. The results suggest that both -1190～-853 and -339～-273 DNA fragments of the hSCF
5′flanking sequence may be novel regulatory elements, and may play a role in
the regulation of hSCF gene expression in MCF cells.
Key words human stem cell factor gene；gene expression and regulation；regulatory element；MCF cell line
*Corresponding author：Tel,86-731-4805449；Fax,86-731-4481180；e-mail,[email protected]