Focal adhesion kinase serves as a marker of cervical lymph node metastasis and is a potential therapeutic target in tongue cancer.
OBJECTIVE
The aims of the present study were to examine whether focal adhesion kinase (FAK) expression is correlated with cervical lymph node metastasis of tongue cancer and to investigate the roles of FAK in the process of cancer cell migration, invasion and anoikis resistance using the human tongue cancer cell line, Tca8113.


METHODS
FAK expression was evaluated in 5 normal oral mucosa, 10 premalignant lesions, 80 primary tongue cancers and 41 lymph node metastases using anti-FAK immunohistochemistry. The migration, invasion and anoikis resistance of tongue cancer cells were evaluated using wound healing assays, invasion assays and anoikis induction. The effect of FAK inhibition was evaluated using RNA interference (RNAi).


RESULTS
In total, 55 of 80 primary tongue cancers (69%) showed high expression of FAK, and 25 of 80 tumors (31%) and all normal oral mucosa or premalignant lesions showed low expression of FAK. There was a significant correlation between FAK expression and the cervical lymph node metastasis of tongue cancer. Moreover, RNAi-mediated FAK reduction decreased tongue cancer cell migration, invasion and anoikis resistance.


CONCLUSIONS
These results suggest that FAK may serve as a marker of cervical lymph node metastasis of tongue cancer and that RNAi targeting FAK could serve as a potential therapeutic for the treatment of tongue cancer.
Jiang
Hongbing
H
Department of Oral and Maxillofacial Surgery, School of Stomatology, Nanjing Medical University, Nanjing, 210029, Jiangsu, People's Republic of China. jhbtooth@yahoo.com.cn
Liu
Laikui
L
Ye
Jinhai
J
Liu
Hualian
H
Xing
Shuzhong
S
Wu
Yunong
Y
D014408:Biomarkers, Tumor / Q000096:biosynthesis / Q000378:metabolism*; D045744:Cell Line, Tumor; D051417:Focal Adhesion Kinase 1 / Q000096:biosynthesis / Q000378:metabolism*; D020868:Gene Silencing; D006801:Humans; D007150:Immunohistochemistry; D008198:Lymph Nodes / Q000201:enzymology* / Q000378:metabolism / Q000473:pathology; D008207:Lymphatic Metastasis / Q000473:pathology; D009061:Mouth Mucosa / Q000166:cytology / Q000378:metabolism; D011230:Precancerous Conditions / Q000378:metabolism; D014062:Tongue Neoplasms / Q000188:drug therapy* / Q000201:enzymology* / Q000378:metabolism / Q000473:pathology
D014408:Biomarkers, Tumor; D051417:Focal Adhesion Kinase 1; C496050:PTK2 protein, human