High concentration of beta-defensin-2 in oral squamous cell carcinoma.

We have previously reported the presence of human beta-defensin-2 (HBD-2), a peptide with antimicrobial and cytotoxic properties, in oral squamous cell carcinomas. The aim of the present study was to measure the concentration of HBD-2 in abnormal tissues such as oral squamous cell carcinomas. HBD-2 was extracted from tissue samples in the presence of retinoic acid and subjected to reversed-phase HPLC. The fraction representing peak 17 (P17) was obtained by elution using a linear gradient of acetonitrile. Amino acid sequencing and homology studies were subsequently performed, and the molecular weight of P17 was calculated to be 432702 daltons. This molecular weight was consistent with HBD-2. The concentration of HBD-2 in the oral squamous cell carcinoma samples was 3.85+/-1.87 microg/mg which was much higher than in normal oral epithelium (0.04+/-0.02 microg/mg).