Abstract: Objective To study the effect of down-regulation of PTTG on the proliferation and migration of cutaneous squamous cell carcinoma cell line SCL-1 and its related mechanism. Methods SCL-1 cells were transfected with control siRNA or PTTG-targeting siRNA （PTTG-siRNA）, or remained untransfected. After additional culture, the proliferation of SCL-1 cells as observed with cell counting kit-8 （CCK-8）, and cell migration with Boyden chamber. Real-time PCR and Western blot were performed to detect the expression of matrix metalloproteinase 2 （MMP-2）, MMP-9 and PTTG. Results The proliferation of SCL-1 cells transfected with PTTG-siRNA was markedly deccelarated in comparision with that of untransfected cells and those transfected with control siRNA （both P < 0.05）. Real-time PCR and Western blot disclosed a significant decrease in the mRNA and protein expression of MMP-2, MMP-9 and PTTG in PTTG-siRNA-transfected SCL-1 cells compared with the other two groups of cells. As real-time PCR showed, the expressions of MMP-2, MMP-9 and PTTG in PTTG-siRNA-transfected SCL-1 cells were 0.8%, 23.2% and 21.3% of those in untransfected cells, respectively. Further more, the number of SCL-1 cells migrating through microporous membrane in the Boyden chamber was significantly smaller in PTTG-siRNA-transfected group than in untransfected group and control siRNA-transfected group （51.38 ± 4.71 vs 131.33 ± 6.12 and 127.72 ± 5.20, both P < 0.05）. Conclusion The down-regulation of PTTG may deccelarate the proliferation and migration of SCL-1 cells and inhibit the expression of MMP-2 and MMP-9 in SCL-1 cells.

Key words: Pituitary tumor-transforming gene, cell proliferation