Objective    To investigate the effect of small interfering RNA (siRNA)-expressing plasmid targeting connective tissue growth factor (CTGF) on the expressions of its mRNA and protein in cultured human keloid fibroblasts (hKFs).     Methods    Constructed siRNA-expressing plasmids targeting CTGF were transfected into hKFs by Dosper package. Then the transfected cells were treated with transforming growth factor 1 (TGF-β

1

10 ng/ml). Normal hKFs cells and those with TGF-β

1

treatment served as normal control and control groups respectively.

The expression level of CTGF mRNA and protein were detected by real-time fluorescent quantitative PCR (RQ-PCR) and Western blotting respectively.     Results    The expression level of CTGF mRNA was only 56.6% of that of the normal control(

P

<

0.05)

and the level of CTGF protein was close to that of the normal control(

P

<

0.05).     Conclusion    Our constructed CTGF siRNA plasmid suppresses the mRNA and protein expressions of the target gene in cultured hKFs

even in the cells after TGF-β

1

stimulation. This approach may be used as a novel method to treat keloid by gene therapy.