Apoptosis-related factors (TRAIL, DR4, DR5, DcR1, DcR2, apoptotic cells) and proliferative activity in ameloblastomas.
BACKGROUND
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a recently identified death factor that acts as a potent apoptosis inducer in ameloblastomas.


METHODS
The expression of TRAIL and its receptors (TRAIL-R), and the location of apoptotic cells were evaluated in 15 cases of ameloblastoma using immunohistochemistry and an in situ DNA nick-end labeling method. The proliferative activity of ameloblastomas was analyzed by determining the Ki-67 labeling index.


RESULTS
TRAIL and TRAIL-R were diffusely expressed in ameloblastomas, without clear correlation with the location of apoptotic cells. Apoptosis and proliferation were opposite in the peripheral and central components of the ameloblastomas. In some ameloblastoma variants, apoptosis and proliferation seemed to modify in the same direction.


CONCLUSIONS
TRAIL and its receptors might be involved in neoplastic transformation of odontogenic epithelium and might suggest some intrinsic regulation of neoplastic cell proliferation and death in ameloblastomas, thus explaining their slow growth and inability to metastasize.
Dipartimento di Patologia e Medicina Legale, Ospedale di Cattinara, Strada di Fiume 447, 34149 Trieste, Italy.
Clara
C
Rizzardi
Pietro
P
Leocata
Luca
L
Ventura
Marina
M
Zweyer
Alessandro
A
Brollo
Manuela
M
Schneider
Mauro
M
Melato
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000564:Ameloblastoma / Q000378:metabolism / Q000473:pathology*; D017209:Apoptosis; D049109:Cell Proliferation; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D020287:In Situ Nick-End Labeling; D008297:Male; D008875:Middle Aged; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand / Q000378:metabolism*; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism*; D053320:Receptors, Tumor Necrosis Factor, Member 10c / Q000378:metabolism*; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000378:metabolism*; D055815:Young Adult
D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor; D053320:Receptors, Tumor Necrosis Factor, Member 10c; D053221:TNF-Related Apoptosis-Inducing Ligand; C105190:TNFRSF10A protein, human; C505653:TNFSF10 protein, human