Defferensial expression of Drosomycin-like Defensin in Human Oral Cells

Objective: Drosomycin-like defensin (DLD) recently found as a putative novel human defensin with high homology with drosomycin. It may be central in the defense against fungal infection. Expression of DLD in oral tissues has not been shown thus far. The present study investigated expression of DLD mRNA and the role of DLD in oral cells and tissues. Methods: Normal oral keratinocytes (NOK), six kinds of oral squamous cell carcinoma cell (SCC) lines (SCC-9, SAS, HSC-2, OSC-19, BSC-OF, Ca-9), salivary duct cell line (HSY) and human gingival fibroblasts were used. The cells except NOK were cultured in DMEM supplemented with 10% FBS. NOK were cultures in keratinocyte growth medium (KBM, Switzerland). Expression of DLD mRNA was observed by RT-PCR and quantitative RT-PCR using TaqMan probes (Applied Biosystem, CA). The relative expression of each mRNA was calculated as the ÄÄCt using the formula described by Saitoh et al.(Med.Mol.Morph 2007). The data was analyzed using student-t test. Cells stably expressing DLD were generated using the Flp-In™ System (Invitrogen, CA, USA).The proliferation of cells was observed by XTT assay (Roche Applied Science) Results: The expression of DLD mRNA was observed in the cells. The expression level of DLD in the Ca9-22 and HSy were significantly higher than that in the other cells. In the cells stably expressing DLD, the change in a dominant proliferation rate was seen .Conclusion: These results indicate that DLD may be constitutively expressed in oral cells and tissues.