Human β-defensin (hBD) 2 is an epithelial antimicrobial peptide. We studied single-nucleotide polymorphisms in the gene of hBD-2 in a Japanese population, and estimated the effect of a polymorphism in the promoter/enhancer region on the transcriptional activity. By sequencing the hBD-2 gene of 50 unrelated individuals, we detected one SNP in exon 2 and nine SNPs in the promoter/enhancer region. The SNP in the coding region at the +1765 position is synonymous [CCC (Pre)→CCT (Pre)]. One SNP in the promoter region (-1029) is located at the consensus sequence for NF-IL6 binding. By luciferase reporter assay and electrophoretic mobility shift assay, the wild-type (G) of -1029 showed significantly lower transcriptional activity than did the variant-type (A). The SNP at position -1029 may influence the hBD-2 expression and cause genetic variations in susceptibility to infectious diseases.

We report the in vitro establishment of a highly stable green fluorescent protein (GFP) -expressing transfectant of a highly-invasive human tongue squamous cell carcinoma (HTSCC) cell line, SAS-H1. The fluorescent cells permitted the visualization of tumor growth, local invasion, micrometastasis and cervical lymph node metastasis after submucosal injection into the tongues of nude mice. SAS-H1 cells were transfected with the pEGFP-N1 expression vector containing the GFP and neomycin resistance genes. Stable SAS-H1 clones expressing high levels of GFP were selected stepwise in vitro in levels of geneticin (G418) of up to 3,500 μg/ml. Subsequent early stages of local invasion and micrometastasis were visualized by GFP fluorescence in a primary tumor of the tongue. Furthermore, lymph node metastasis was confirmed for all of the orthotopic transplants in mice. However, no distant metastases, including those of lung and liver, were observed. Thus, this model should be useful for studying the metastatic process and for evaluating anti-metastasis agents in pre-clinical trials.

Human β-defensin (hBD) 2 is an epithelial antimicrobial peptide. We studied single-nucleotide polymorphisms in the gene of hBD-2 in a Japanese population, and estimated the effect of a polymorphism in the promoter/enhancer region on the transcriptional activity. By sequencing the hBD-2 gene of 50 unrelated individuals, we detected one SNP in exon 2 and nine SNPs in the promoter/enhancer region. The SNP in the coding region at the +1765 position is synonymous [CCC (Pre)→CCT (Pre)]. One SNP in the promoter region (-1029) is located at the consensus sequence for NF-IL6 binding. By luciferase reporter assay and electrophoretic mobility shift assay, the wild-type (G) of -1029 showed significantly lower transcriptional activity than did the variant-type (A). The SNP at position -1029 may influence the hBD-2 expression and cause genetic variations in susceptibility to infectious diseases.