New therapeutic measure are needed to improve the outcome for patients with oral squamous cell carcinoma(OSCC) because OSCC continues to portend a relatively unfavorable prognosis. Recently RNA interference(RNAi) has emerged as an effective method to target specific genes for silencing. Although overexpression of urokinase-type plasminogen activator receptor(uPAR) has been implicated in progression and metastasis of OSCC, the transfection effect of RNAi- uPAR on OSCC has been rarely reported. The purpose of this study were to examine the efficient and specific inhibition of uPAR mRNA and protein expression by siRNA targeting of uPAR through RT-PCR and immunoslot blotting, and to study cell proliferation activity, adhesion, invasion and migration in vitro compared to the controls. In MTT assay, siRNA-uPAR transfected cells showed about 70-80% cell proliferation compared to OSCC cell lines after 2 days. In adhesion assay, siRNA-uPAR transfected cells showed about 20-30% adhesion activity compared to OSCC cell lines, but similar features to those of BSA coated wells. In migration assay, siRNA-uPAR transfected cells showed about 60% migration activity compared to OSCC cell lines, but higher 3.5 folds to those of BSA coated wells. In invasion assay, siRNA-uPAR transfected cells showed about 55% invasive activity compared to parental cell lines. mRNA expression of siRNA-uPAR transfected cells showed about 10-15 % compared to parental cell lines by RT-PCR. Protein expression of siRNA-uPAR transfected cells showed about 25% compared to parental cell lines by ELISA assay. It suggested that RNAi-uPAR tranfection might be used as a potent and specific therapeutic tool for the treatment of oral squamous cell carcinoma, especially in inhibiting invasion and metastasis.

Ⅰ. INTRODUCTION
 Ⅱ. MATERIALS and METHODS
  1. Preparation of siRNA Plasmid for uPAR
  2. Cell Culture and Transfections
  3. MTT(3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) Assay for CellProliferation
  4. Cell Adhesion Assay
  5. Cell Migration Assay
  6. Cell Invasion Assay
  7. RT-PCR
  8. ELISAs Analysis
 Ⅲ. RESULTS
 Ⅳ. DISCUSSION
 Ⅴ. REFERENCES

• 유철환(Department of Oral Pathology, The Oral Aging Research Center, College of Dentistry, Dankook University) | Chul Hwan Ryu
• 이종헌(Department of Oral Pathology, The Oral Aging Research Center, College of Dentistry, Dankook University) | Chong Heon Lee