Proteases are important molecules that are involved in many physiological and
pathological processes of the human body, such as growth, apoptosis and
metastasis cancer cells. They are potential targets in
cancer diagnosis and
biotherapy. In this study, we analyzed the salivary
protease spectrum of patients with
oral squamous cell carcinoma (OSCC), oral benign masses and
chronic periodontitis, as well as that of health, using human
protease array kits,
enzyme-linked
immunosorbent assay, western blot and immunofluorescence. The salivary
protease spectrum was found to be associated with oral diseases. For example, the saliva of patients with OSCC contained increased numbers of
proteases than those of other oral diseases and health. The levels of
matrix metalloproteinase (MMP)-1, MMP-2, MMP-10, MMP-12, A
disintegrin and
metalloprotease (ADAM)9, A
disintegrin and
metalloprotease with
thrombospondin type 13 motifs (ADAMST13),
cathepsin V and
kallikrein 5 in the saliva of patients with OSCC were significantly increased compared with those of other groups. Taking MMP-1,
cathepsin V,
kallikrein 5 and ADAM9 as
biomarkers of OSCC, cutoff values were199, 11.34, 9.29 and 202.55 pg·mL-1, respectively. From the area under the curve, sensitivity and specificity, the combination of
cathepsin V/kallikrein5/ADAM9 was an optimal
biomarker for diagnosing OSCC. Thus, analysis of the salivary
protease spectrum may be an innovative and cost-efficient approach to evaluating the health status of the oral cavity. Specifically, increases in
cathepsin V,
kallikrein 5 and ADAM9 may be useful
biomarkers in the screening and diagnosis of OSCC.