The newly identified MMP-28 has been shown to be expressed in several types of
carcinomas, however, none of its functional role in transformation events is known. This study was to assess
whether this proteinase plays a role in oral tumor malignancy. By using RT-PCR, we found that incidence of
MMP-28 was significantly higher in 92 oral squamous cell carcinomas (OSCCs) (52/92, 56.5%) than in 7
oral premalignant lesions (OPMLs) (0/7, 0%) (P = 0.004). No statistically significant correlation was found
between MMP-28 expression and tumor stage, thickness, size, and metastasis. Both mRNA and protein of
MMP-28 were preferentially concentrated in OSCC specimens than in neighboring tissues as analyzed by
semi-quantitative RT-PCR (P = 0.015) and immunohistochemistry, respectively. Transfection of an OSCC
and an esophageal carcinoma cell lines with MMP-28 antisense oligodeoxynucleotide (AODN) resulted in
the reduced secretion of MMP-28 protein and the ability of colony formation in soft agar without affecting cell
growth. Our findings show the close correlation between MMP-28 and OSCC, and support a role for MMP-
28 in the anchorage-independent growth of both OSCC and esophageal carcinomas.
