[1314] Expression of Fas and FasL in Ameloblastoma and Its Different Subtypes

Fatemeh Mashhadi Abbas, Sepideh Mokhtari, Hakimeh Ghorbani. Shahid Beheshti University of Medical Sciences, Tehran, Islamic Republic of Iran

Background: Ameloblastoma originates from dental follicle or other sources of odontogenic epithelium. It is the most important odontogenic neoplasm due to its local aggressive behavior. Fas and FasL are critical factors in apoptosis and their altered expression has been detected in many neoplasms. To clarify the possible role of these factors in progression and invasive behavior of ameloblastoma, we examined the expression of Fas and FasL in dental follicle and different types of ameloblastoma.
Design: We analyzed immunohistochemical expression of Fas and FasL antibodies in 11 dental follicles and 56 specimens of ameloblastoma (35 conventional-type, 15 unicystic-type and 6 ameloblastic carcinoma). Intensity of stain (Intensity Score) and proportion of stained cells (Proportional Score) for each tumor were evaluated and the sum was described as Total Score. Data were analyzed by Non-parametric Kruskal-Wallis and Mann-Whitney tests.
Results: Fas expression was not seen in dental follicles. 44.6% and 100% of ameloblastomas expressed Fas and FasL markers, respectively. Expression of Fas and FasL was significantly higher in ameloblastoma than dental follicle (P value: Fas=0.01, FasL=0.0001). The proportional score of FasL expression was significantly higher in conventional ameloblastoma than other types(p=0.003). Except this observation, no other important difference of Fas or FasL expression was seen between different types of ameloblastoma.




Conclusions: Increased expression of Fas/FasL in ameloblastoma implies that they have critical role in progression and invasion of this tumor. Coexpression of these factors may be due to the presence of an autocrine mechanism of Fas/FasL pathway in ameloblastoma. It seems that Fas/FasL expression is not significantly different in various types of Ameloblastoma. FasL was more expressed than Fas in ameloblastoma specimens; so, it may be more related to its progression and invasive behavior.
Category: Head & Neck

Tuesday, March 20, 2012 1:00 PM

Poster Session IV # 168, Tuesday Afternoon

 

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