Evaluation of TGF-alpha and EGFR expression in oral leukoplakia and oral submucous fibrosis by quantitative immunohistochemistry.
OBJECTIVE
Oral leukoplakia (OL) and oral submucous fibrosis (OSMF) are clinically distinct preneoplastic states that precede the development of oral squamous cell carcinoma. Recently, attempts are being made to identify specific molecular event(s) as prognostic markers to identify oral precancerous lesions with higher malignant potential. The goal of the present study was to evaluate the expression of EGFR and its ligand TGF-alpha in OL with dysplasia and OSMF as intermediate markers of malignancy by quantitative immunohistochemistry.


METHODS
Oral tissues were stained with monoclonal antibodies to TGF-alpha and EGFR. The results were analyzed with Photoquant image analysis software.


RESULTS
The expression of TGF-alpha and EGFR was upregulated in OL, OSMF and oral squamous cell carcinomas relative to normal oral mucosa. The area and intensity of staining of TGF-alpha in the proliferative layers (stratum germinativum) increased linearly in OL with mild, moderate and severe dysplasia as compared to control mucosa (p < 0.05). EGFR levels increased linearly in the stratum spinosum in OL with increasing degrees of dysplasia (p < 0.05). In general, the expression of both proteins in OSMF was similar to that in OL with moderate dysplasia.


CONCLUSIONS
EGFR and TGF-alpha represent early markers of malignancy in OL with dysplasia. Quantitative measurement of these proteins may provide intermediate endpoints in prospective chemopreventive trials.
Srinivasan
M
M
Ragas Dental College and Hospital, Madras, India.
Jewell
S D
SD
D017668:Age of Onset; D000428:Alcohol Drinking; D001114:Areca; D066246:ErbB Receptors / Q000032:analysis*; D005260:Female; D006801:Humans; D007972:Leukoplakia, Oral / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000473:pathology; D009914:Oral Submucous Fibrosis / Q000473:pathology*; D012907:Smoking; D016211:Transforming Growth Factor alpha / Q000032:analysis*
D016211:Transforming Growth Factor alpha; D066246:ErbB Receptors