Overexpression of cFLIP in head and neck squamous cell carcinoma and its clinicopathologic correlations.
OBJECTIVE
The aim of this study was to determine the expression of cellular FLICE-like inhibitory protein (cFLIP) in head and neck squamous cell carcinoma (HNSCC) and revealed its possible correlation to Fas protein and tumour clinical parameters.


METHODS
The expression of cFLIP was analysed in 58 HNSCC samples and 30 morphologically normal tissues adjacent to the carcinomas using immunohistochemistry, reverse transcription-polymerase chain reaction (RT-PCR) and western blot analysis. Furthermore, its possible correlation to the expression of Fas protein and tumour clinicopathologic parameters were discussed.


RESULTS
Cellular FLICE-like inhibitory protein was demonstrated to be up regulated in most HNSCC than in normal tissues by immunohistochemistry (p<0.01). Although the mRNA levels of both isoforms of cFLIP, long form (cFLIP(L)) and short form (cFLIP(S)), in HNSCC were higher than those in normal tissues (p<0.01), only cFLIP(L) protein could be detected by western blot. Furthermore, the expression of cFLIP(L) protein was significantly associated with tumour clinical stage (p<0.01) and lymph node metastasis (p=0.01). Since all of the tumours with Fas immunostaining also express cFLIP protein, there was no significant correlation between them (p>0.05).


CONCLUSIONS
Overexpression of cFLIP(L) is a frequent event in HNSCC and HNSCC cells in vivo may need it to evade apoptosis mediated by Fas or other receptors, which might contribute to tumour development and progression.
Li
Xiuguo
X
Department of Otolaryngology, Qilu Hospital of Shandong University, 107 Wenhua xi Road, Jinan, Shandong 250012, People's Republic of China.
Pan
Xinliang
X
Zhang
Hui
H
Lei
Dapeng
D
Liu
Dayu
D
Xu
Fenglei
F
Luan
Xinyong
X
D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D015153:Blotting, Western; D053446:CASP8 and FADD-Like Apoptosis Regulating Protein / Q000096:biosynthesis*; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D015870:Gene Expression; D006258:Head and Neck Neoplasms / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019014:fas Receptor / Q000096:biosynthesis
D014408:Biomarkers, Tumor; D053446:CASP8 and FADD-Like Apoptosis Regulating Protein; D019014:fas Receptor