Plasminogen activators(PA) such as urokinase(uPA) and tissue type plasminogen activators(tPA), physiologically catalyze the conversion of the plasminogen to the wide spectrum proteinase plasmin. Because uPA and tPA are involved in cell growth, differentiation and migration of oral cancer, oral epithelial carcinogenesis including transformation of precancerous lesion into oral squamous cell carcinoma with PA is very interesting. It is important to prevent precancerous condition from transfoming into oral squamous cell carcinoma by the inhibitory effect of various drug. It is well known that cyclosporine A(CsA) as immunosuppressive properties exerts anti-cancer effects. Recently it is widely accepted that cultured immortalized oral keratinocyte (IHOK) is considered as an intermediate stage of oral carcinogenesis and used as precancerous condition in vitro. Thus it was thought that it might be interesting to investigate CsA effect on PA expression of IHOK. IHOK was cultured under KBM bullet kit at 37℃ under 95% CO2 incubator. Subconfluent IHOK cells was treated at different CsA concentration. uPA and tPA protein expression from cultured IHOK cell line has been detected by ELISA analysis in the CsA-treated samples. uPA expression of IHOK was higher than that of NHOK, while tPA was similar to that of NHOK. After CsA treatment, CsA might not effect the expression of uPA of IHOK, while showed a little effect on tPA of IHOK. It suggested that CsA had no effect in uPA expression of IHOK although uPA could be used as a marker for precancerous lesion.

This study was conducted to isolate and characterize a novel feather-degrading bacterium producing keratinase activity. A strain K9 was isolated from soil at poultry farm and identified as Xanthomonas sp. K9 by phenotypic characters and 16S rRNA gene analysis. The cultural conditions for the keratinase production were 0.3% fructose, 0.1% gelatin, 0.04% K2HPO4, 0.06% KH2PO4, 0.05% NaCl and 0.01% FeSO4 with an initial pH 8.0 at 30℃ and 200 rpm. In an optimized medium containing 0.1% chicken feather, production yield of keratinase was approximately 8-fold higher than the yield in basal medium. The strain K9 effectively degraded chicken feather meal (67%) and duck feather (54%), whereas human nail and human hair showed relatively low degradation rates (13-22%). Total free amino acid concentration in the cell-free supernatant was about 25.799 mg/l. Feather hydrolysate produced by the strain K9 stimulated growth of red pepper, indicating Xanthomonas sp. K9 could be not only used to increase the nutritional value of chicken feather but also a potential candidate for the development of natural fertilizer applicable to crop plant soil.