Perlecan-rich epithelial linings as a background of proliferative potentials of keratocystic odontogenic tumor.
BACKGROUND
The intraepithelial deposit of perlecan, a basement membrane-type heparan sulfate (HS) proteoglycan, has been demonstrated in neoplastic conditions such as salivary gland tumors, odontogenic tumors, and oral carcinoma in situ. Our aim was to determine whether perlecan turnover was enhanced in the lining cells of keratocystic odontogenic tumor (KCOT), which had been recently renamed from odontogenic keratocyst because of its accumulated evidence of neoplasm, as a possible background for neoplastic proliferation.


METHODS
Ten surgical specimens from each of KCOT, dentigerous cyst, and radicular cyst were examined for the expressions of perlecan core protein, HS chains, heparanase, and Ki-67 by immunohistochemistry and in situ hybridization.


RESULTS
In KCOT, perlecan core protein and HS chains were localized on the cell border from the parabasal to subkeratinized layers of the lining epithelium. Heparanase was localized in a similar fashion to those for perlecan and HS chains but was within the cytoplasm. mRNA signals for perlecan core protein and heparanase were mostly compatible with their protein signals. Ki-67-positive cells were localized mainly in the second basal cell layers with definitely higher labeling indices (approximately 31.3%, second layer). In contrast to KCOT, dentigerous cysts and radicular cysts had no perlecan, HS chains, and heparanase deposition in their linings with extremely lower Ki-67 indices (0.4-0.8%).


CONCLUSIONS
The result suggests that the characteristic intra-lining-epithelial deposit of perlecan in KCOT, which has never been seen in other cystic jaw lesions, is a new evidence supporting the neoplastic nature of KCOT.
Tsuneki
Masayuki
M
Division of Oral Pathology, Department of Tissue Regeneration and Reconstruction, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
Cheng
Jun
J
Maruyama
Satoshi
S
Ida-Yonemochi
Hiroko
H
Nakajima
Motowo
M
Saku
Takashi
T
D014408:Biomarkers, Tumor / Q000032:analysis* / Q000096:biosynthesis / Q000235:genetics; D049109:Cell Proliferation; D004847:Epithelial Cells / Q000737:chemistry; D015870:Gene Expression; D005966:Glucuronidase / Q000032:analysis; D019812:Heparan Sulfate Proteoglycans / Q000032:analysis* / Q000096:biosynthesis / Q000235:genetics; D006497:Heparan Sulfate / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007573:Jaw Neoplasms / Q000737:chemistry* / Q000145:classification / Q000378:metabolism / Q000473:pathology; D019394:Ki-67 Antigen / Q000032:analysis; D009807:Odontogenic Cysts / Q000737:chemistry* / Q000378:metabolism; D009808:Odontogenic Tumors / Q000737:chemistry* / Q000145:classification / Q000378:metabolism / Q000473:pathology; D016133:Polymerase Chain Reaction; D000099175:Heparanase
D014408:Biomarkers, Tumor; D005966:Glucuronidase; D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate; D019394:Ki-67 Antigen; D000099175:Heparanase; C071927:perlecan