EGFR and c-Jun exhibit the same pattern of expression and increase gradually during the progress of oral oncogenesis.
BACKGROUND
Epidermal growth factor receptor (EGFR) and c-Jun oncogenes are implicated in the same pathway of signal transduction affecting cell differentiation. In order to investigate their possible correlation with sequential histological stages of OSCC formation, we established an experimental model of induced oral carcinogenesis in Syrian golden hamsters.


METHODS
Thirty-seven animals were divided into one control group (n=7) and three experimental groups (n = 10 each), which were treated with a carcinogen and sacrificed at 10, 14 and 19 weeks after treatment. Tumour sections were studied using monoclonal antibodies against EGFR and c-Jun proteins.


RESULTS
The same pattern of expression was observed for both oncogenes, with a significant gradual increase of positively stained cells throughout oral carcinogenesis.


CONCLUSIONS
Since EGFR and c-Jun are implicated in the same molecular pathway of signal transduction, it may be assumed that an increase in EGFR levels leads to increased activation of phospholipase Cy signal transduction cascade, which in turn activates c-Jun protein. Therefore, c-Jun expression in oral cancer seems to be increased through the EGFR-PLCy-Raf-MEK-ERK pathway and not the H-ras-Raf-MEK-ERK/JNK pathway.
Vairaktaris
Eleftherios
E
Department of Oral and Maxillofacial Surgery, University of Athens Medical School, Athens 11521, Greece. lvairakt@med.uoa.gr
Loukeri
Sofia
S
Vassiliou
Stavros
S
Nkenke
Emeka
E
Spyridonidou
Sofia
S
Vylliotis
Antonis
A
Papakosta
Veronica
V
Lazaris
Andreas
A
Agrogiannis
Giorgos
G
Yapijakis
Christos
C
Perrea
Despina
D
Patsouris
Efstratios
E
D000818:Animals; D001706:Biopsy; D002471:Cell Transformation, Neoplastic / Q000378:metabolism* / Q000473:pathology*; D006224:Cricetinae; D018450:Disease Progression; D066246:ErbB Receptors / Q000378:metabolism*; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism*; D008297:Male; D009062:Mouth Neoplasms / Q000378:metabolism* / Q000473:pathology*; D011230:Precancerous Conditions / Q000378:metabolism / Q000473:pathology
D066246:ErbB Receptors; D048031:JNK Mitogen-Activated Protein Kinases