Τομέας Κλινικοεργαστηριακός
Library of the School of Health Sciences

2013-03-08

2013

Ιακώβου Μαρία

Τσελένη-Μπαλαφούτα Σοφία, Χρυσομάλη Ευανθία, Βλαχοδημητρόπουλος Δημήτρης

Ανοσοϊστοχημική διερεύνηση του οστεολυτικού δυναμικού του αδαμαντινοβλαστώματος των γνάθων

Greek

Immunihistochemical evaluation of the osteolytic potential in ameloblastoma of the jaws

The aim of this study was to evaluate the immunohistochemical expression of
RANKL, OPG, TRAIL and Ki-67 in ameloblastomas of the jaws. Tissue sections from
40 cases of ameloblastoma (solid n=29, unicystic n=11) were
immunohistochemically stained using a streptavidine-biotin peroxidase method,
and antibodies against RANKL, OPG, TRAIL and Ki-67. Immunohistochemical
expression was evaluated by a semi-quantitative method according to the
staining intensity and extent of the immunoreactivity in the tumour. OPG was
expressed in ameloblastic epithelium in all cases, whereas no immunoreactivity
for RANKL and TRAIL was observed in 40% and 12,5% cases respectively. 52,5% of
the cases showed intense OPG immunoreactivity. 72,5% and 60% of cases showed
greater expression of OPG over RANKL and TRAIL respectively. 50% of cases
exhibited lower expression of RANKL than TRAIL. No significant differences were
found in the expression of TRAIL and RANKL with regards to age, sex, clinical
type or histological variant. No significant difference in the OPG expression
was found with regards to sex. OPG expression was significantly increased in
solid ameloblastomas and older patients. The OPG over-expression in solid
ameloblastomas reflects its possible role in inactivating TRAIL-induced
apoptosis of ameloblastic cells. It may also be related to the aggressive
behaviour of this type compared to the unicystic ameloblastoma. In cases that
OPG was overexpressed RANKL and TRAIL were positively associated (mainly low
RANKL and low TRAIL). Low RANKL concentrations may favor the binding of OPG to
TRAIL. Low proliferative activity was observed in 95% of the cases which may
reflect the slow growing and overall benign nature of this lesion. The intense
OPG expression indicates its possible role in ameloblastoma pathogenesis.
Prevalence of the OPG/TRAIL over the OPG/RANKL pathway with inhibition of
TRAIL-induced apoptosis of ameloblastic cells and subsequent infiltration of
the surrounding bone seems to be the pathogenetic mechanism that underlies the
locally aggressive behaviour of this tumour.

Ameloblastoma, OPG, RANKL, TRAIL, Ki-67

Yes

5-7

Yes

346

147

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https://pergamos.lib.uoa.gr/uoa/dl/object/1305730