Increased expression of focal adhesion kinase correlates with cellular proliferation and apoptosis during 4-nitroquinoline-1-oxide-induced rat tongue carcinogenesis.
BACKGROUND
Oral carcinogenesis is a multistep process and requires accumulation and interplay of a series of molecular genetic events. Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase that plays an important role in signalling pathways that are initiated at sites of integrin-mediated cell adhesions and by growth factor receptors. Overexpression of FAK has been linked to oral squamous cell carcinoma (OSCC). So, it is hypothesized that FAK expression might contribute to oral carcinogenesis.


METHODS
During 4-nitroquinoline-1-oxide-induced rat tongue carcinogenesis, FAK protein expression, proliferating cell nuclear antigen (PCNA) and apoptotic nuclei (TUNEL assay) were examined by means of immunohistochemistry.


RESULTS
Along with the progress of multistage carcinogenesis, FAK expression increased significantly among different histopathological groups with normal mucosa, mild-dysplastic epithelia, moderate-dysplastic epithelia, severe-dysplastic epithelia and in turn OSCC. Furthermore, FAK immunohistochemical index and PCNA-labelling index displayed positive correlation (r = 0.946, P < 0.05), while negative associations were revealed between apoptotic index and final FAK index (r = -0.959, P < 0.05).


CONCLUSIONS
Our results implicated a role for FAK in oral carcinogenesis. Inhibition of FAK might be a potential novel treatment strategy in this disease.
Xia
Juan
J
Department of Oral Medicine, Guanghua School of Stomatology and Institute of Stomatological Research, Sun Yat-Sen University, Guangdong, China.
Lv
Na
N
Hong
Yun
Y
Li
Chunyang
C
Tao
Xiaoan
X
Chen
Xiaohua
X
Cheng
Bin
B
D015112:4-Nitroquinoline-1-oxide / Q000009:adverse effects*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D014408:Biomarkers, Tumor / Q000032:analysis; D002273:Carcinogens; D002294:Carcinoma, Squamous Cell / Q000139:chemically induced / Q000201:enzymology / Q000473:pathology; D002467:Cell Nucleus / Q000201:enzymology / Q000473:pathology; D049109:Cell Proliferation / Q000187:drug effects; D004848:Epithelium / Q000201:enzymology / Q000473:pathology; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000032:analysis*; D015971:Gene Expression Regulation, Enzymologic; D020287:In Situ Nick-End Labeling; D007972:Leukoplakia, Oral / Q000139:chemically induced / Q000201:enzymology / Q000473:pathology; D008297:Male; D009061:Mouth Mucosa / Q000201:enzymology / Q000473:pathology; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D014062:Tongue Neoplasms / Q000139:chemically induced / Q000201:enzymology* / Q000473:pathology
D014408:Biomarkers, Tumor; D002273:Carcinogens; D018809:Proliferating Cell Nuclear Antigen; D015112:4-Nitroquinoline-1-oxide; D051416:Focal Adhesion Protein-Tyrosine Kinases