Epidermal growth factor receptor and proliferating cell nuclear antigen in astrocytomas.
OBJECTIVE
The involvement of various growth factors, growth factor receptors and proliferative markers in the molecular pathogenesis of astrocytic neoplasms are being studied extensively. Epidermal Growth Factor Receptor (EGFR) gene overexpression occurs in nearly 50% of cases of glioblastoma. Since EGFR and proliferating cell nuclear antigen (PCNA) are involved in mitogenic signal transduction and cellular proliferation pathway, we have studied the correlation between the expression of EGFR and PCNA labeling index in astrocytic tumors.


METHODS
We investigated the immunohistochemical expression of EGFR and PCNA using the appropriate monoclonal antibodies in 40 cases of astrocytic tumors of which 21 cases were glioblastoma, eight cases were Grade III or anaplastic astrocytomas and six cases were Grade II or diffuse astrocytomas and five cases were Grade I or pilocytic astrocytomas.


RESULTS
Both the EGFR expression and PCNA labeling index increase with increasing grades of astrocytomas with a significantly high percentage of cells showing positive staining for both EGFR and PCNA in GBM and Grade III astrocytomas compared to Grade II astrocytomas. The expression levels of both EGFR and PCNA were low in Grade I or pilocytic astrocytomas.


CONCLUSIONS
A significant correlation was found between EGFR overexpression and PCNA labeling index in Grade III and Grade II astrocytomas and glioblastoma. These suggest that the tumor proliferation, at least in higher grades of astrocytomas is dependent in some measure on EGF and EGFR-related signaling pathways.
Maiti
Arpan K
AK
Department of Pathology, Institute of Post Graduate Medical Education and Research, 244, A J C Bose Road, Kolkatta, India.
Ghosh
Keya
K
Chatterjee
Uttara
U
Chakrobarti
Sasanka
S
Chatterjee
Sandip
S
Basu
Samik
S
D000328:Adult; D000368:Aged; D001254:Astrocytoma / Q000235:genetics / Q000378:metabolism*; D001932:Brain Neoplasms / Q000235:genetics / Q000378:metabolism*; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D018809:Proliferating Cell Nuclear Antigen / Q000235:genetics / Q000378:metabolism*
D018809:Proliferating Cell Nuclear Antigen; D066246:ErbB Receptors