Expression profile of drosomycin-like defensin in oral epithelium and oral carcinoma cell lines.
OBJECTIVE
Drosomycin-like defensin (DLD) is a recently discovered antimicrobial peptide mainly active against filamentous fungi. The present study investigated the expression profile of DLD in oral epithelium and oral squamous cell carcinoma (SCC) cell lines.


METHODS
Tissue sections of human oral mucosa, keratinocytes derived from oral mucosa (NOK) and eight kinds of SCC cell lines were used. In situ hybridization was performed on tissue sections of oral mucosa. Expression levels of DLD in the cells were observed by reverse transcription polymerase chain reaction (RT-PCR) and real-time RT-PCR assays. The cells were treated with IL-1β, IL-8 and TNF-α, and agonists for TLR2, TLR4 and β-glucan. DLD expression in cells was increased and decreased by the DLD gene and its siRNA transfection, respectively. The proliferation rates were assessed by cell counting.


RESULTS
By means of in situ hybridization, DLD mRNA positive staining was detected in the epithelial layer of the oral mucosa. An RT-PCR assay confirmed the expression of DLD mRNA in keratinocytes derived from oral epithelium. Expression of DLD in two out of eight cell lines was significantly lower than in NOK cells. The expression levels of DLD mRNA were not significantly changed in the cells stimulated with any cytokines or agonists. The cell proliferation rate where there was decreased expression of DLD was significantly lower than in the control.


CONCLUSIONS
DLD may be partially involved in the defence against filamentous fungal infection in the oral mucosa, and may also serve other functions, such as contribution to cell growth.
Division of Oral Medicine and Pathology, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido 061-0293, Japan.
Jun
J
Sato
Michiko
M
Nishimura
Mami
M
Yamazaki
Kouki
K
Yoshida
Yoshihito
Y
Kurashige
Masato
M
Saitoh
Yoshihiro
Y
Abiko
D000935:Antifungal Agents / Q000032:analysis*; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D002452:Cell Count; D002460:Cell Line; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D023082:Defensins / Q000032:analysis* / Q000235:genetics; D029721:Drosophila Proteins / Q000235:genetics; D004848:Epithelium / Q000473:pathology; D006801:Humans; D017403:In Situ Hybridization; D053583:Interleukin-1beta / Q000494:pharmacology; D016209:Interleukin-8 / Q000494:pharmacology; D015603:Keratinocytes / Q000473:pathology; D009061:Mouth Mucosa / Q000473:pathology*; D009062:Mouth Neoplasms / Q000473:pathology*; D034741:RNA, Small Interfering / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D040681:Structural Homology, Protein; D051195:Toll-Like Receptor 2 / Q000819:agonists; D051197:Toll-Like Receptor 4 / Q000819:agonists; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D047071:beta-Glucans / Q000819:agonists / Q000494:pharmacology
D000935:Antifungal Agents; D023082:Defensins; D029721:Drosophila Proteins; D053583:Interleukin-1beta; D016209:Interleukin-8; D034741:RNA, Small Interfering; C495342:TLR2 protein, human; C495345:TLR4 protein, human; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha; D047071:beta-Glucans; C091227:DRS protein, Drosophila