AKAGI Takumi Okayama Univ. Dental Sch., Assistant, 歯学部, 教務員 (50192878)
INOUE Masahisa Okayama Univ. Dental Sch., Assistant prof., 歯学部, 助手 (20223274)
NAGATSUKA Hitoshi Okayama Univ. Dental Sch., Assistant prof., 歯学部, 助手 (70237535)
TAKESHITA Nobuyoshi Okayama Univ. Dental Sch., Associate prof., 歯学部, 助教授 (00118275)
|Budget Amount *help
¥1,800,000 (Direct Cost : ¥1,800,000)
Fiscal Year 1992 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1991 : ¥1,200,000 (Direct Cost : ¥1,200,000)
Cytokeratins, intermediate filaments characteristic of epithelial cells, are well known to be closely related to epithelial differentiation. That is, the differentiation specificity to expression of different composition of cytokeratins has been described in epithelial cell types. Along these approaches, the expression of cytokeratins has been observed in the odontogenic epithelium and analyzed with special reference to the relationship between tooth germs and odontogenic cysts and tumors. But the distribution of cytokeratins has been unlikely to explain satisfactorily the origin of odontogenic tumors, because of heterogenous expression of cytokeratins in odontogenic tumors.
1.Ameloblastoma ; Interestingly, they presented difference of cytokeratin distribution between follicular and plexiform types. In follicular ameloblastomas, the central portion showed immunoreactivity with all markers of cytokeratins, SE-K, NSE-K and K19. But the columnar cells arranged in the periphery were reacted
positively for K19, faintly reacted for NSE-K, and negatively responded for the marker of squamous cells, SE-K. In plexiform ameloblastoma both central and peripheral cells demonstrated the positive reaction with all markers, SE-K, NSE-K and K19.
2.Adenomatoid Odontogenic Tumors ; Adenomatoid odontogenic tumors demonstrated different distribution between central areas composed of columnar cells and peripheral areas of small round cells. Most areas of central cells, showing whorled structure or solid nests, demonstrated no expression for the marker of squamous cells, SE-K, however, only a few areas showed faint positivity. The immunoreactivity for NSE-K and K19 was so heterogenous that both immunoreactive and non-reactive areas were present within the central area. Ductal or tubular structures also showed no immunoreactivity for the marker of squamous cells (SE-K) with positive reaction for NSE-K and K19. The cells surrounding central whorled structures were smaller than central columnar cells and were proliferated without organizing pattern. These peripheral cells showed positive reaction for all markers of cytokeratins. Areas of reticular pattern composed of small round cells, which was frequently found in adenomatoid odontogenic tumors, also showed the same cytokeratin distribution with peripheral cells.
3.Enamel Organ ; Along the maturation to enamel organ from dental lamina, the immunoreaction for the marker of squamous differentiation, SE-K, was negatively reacted. NSE-K and K19 were well demonstrated in the enamel organ proper.