DNA amplification and expression of FADD in oral squamous cell carcinoma.
BACKGROUND
The Fas-associated death domain-containing protein, FADD, is an adaptor for relaying apoptotic signals. However, recent studies have shown that FADD also plays an important role in the growth and regulation of the cell cycle. The purpose of this study was to elucidate the role of FADD in oral squamous cell carcinoma (SCC).


METHODS
The DNA amplification of FADD from 30 samples of tongue SCC was analyzed using real-time PCR and the protein expression of FADD from 60 samples of tongue SCC was analyzed using immunohistochemistry.


RESULTS
The DNA amplifications of FADD were observed in 13 cases (44.3%) and were significantly correlated with the histopathological differentiation grade of SCCs (P = 0.009). FADD expression levels compared with the matched adjacent epithelium increased significantly (P = 0.000). Additionally, the positive expressions of FADD were significantly correlated with lymph node metastasis of SCCs (P = 0.029) and the 5-year disease-specific survival rates (P = 0.049). A positive association between FADD expression level and the histopathological differentiation grade was found to be limited to T1 SCCs (P = 0.019). DNA amplification was moderately correlated (correlation coefficient = 0.406, P = 0.026) with expression of FADD in 30 samples of tongue SCC.


CONCLUSIONS
In tongue SCCs, the expression of FADD was higher when compared with that of adjacent areas, which might be determined via genomic amplification in 11q13.3. Thus, SCC cells with the expression of FADD are possibly more likely to become metastatic and to worsen survival rates.
Prapinjumrune
Chanwit
C
Oral and Maxillofacial Surgery, Department of Oral Restitution, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
Morita
Kei-ichi
K
Kuribayashi
Yuri
Y
Hanabata
Yasuko
Y
Shi
Qi
Q
Nakajima
Yusuke
Y
Inazawa
Johji
J
Omura
Ken
K
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017209:Apoptosis / Q000235:genetics; D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000473:pathology; D002453:Cell Cycle / Q000235:genetics; D045744:Cell Line, Tumor; D002880:Chromosomes, Human, Pair 11 / Q000235:genetics; D004848:Epithelium / Q000473:pathology; D053200:Fas-Associated Death Domain Protein / Q000235:genetics*; D005260:Female; D005784:Gene Amplification / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis / Q000235:genetics / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D016133:Polymerase Chain Reaction / Q000379:methods; D015996:Survival Rate; D014059:Tongue / Q000473:pathology; D014062:Tongue Neoplasms / Q000235:genetics* / Q000473:pathology
D014408:Biomarkers, Tumor; C505533:FADD protein, human; D053200:Fas-Associated Death Domain Protein