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Ymittos Athens, Greece

Rigopoulos D.N.,401 General Army Hospital | Tsiambas E.,National and Kapodistrian University of Athens | Lazaris A.C.,National and Kapodistrian University of Athens | Kavantzas N.,National and Kapodistrian University of Athens | And 8 more authors.
Journal of B.U.ON. | Year: 2010

Purpose: Overexpression of epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) in colon adenocarcinoma (CA) is a frequent event, whereas specific deregulation mechanisms in the corresponding signaling pathways remain under investigation. Our aim was to co-evaluate their expression correlated to the hypoxia inducible factor 1alpha (HIF-1a), which activates the transcription of VEGF gene. Methods: 60 paraffin-embedded primary CAs were cored at 1.5 mm diameter and transferred to the microarrcty block Immunohistochemistry (IHC) was performed using anti-EGFR, -VEGF, and -HIF 1a monoclonal antibodies. Concerning EGFR, quantitative evaluation was based on a semi-automated analysis system. Chromogenic in situ hybridization (CISH) was performed using EGFR gene and chromosome 7 centromeric probes. Results: Protein overexpression was observed in 13/60 (21.6%), 45/60 (75%) and 7/60 (11.6%) cases regarding EGFR, VEGF, and HIF 1a, respectively. CISH analysis detected 4/60 (6.6%) EGFR gene amplified cases, whereas chromosome 7 aneuploidy was identified in 11/60 (18.3%) cases. Significant associations raised correlating stage to chromosome 7 (p=0.024), HIF 1a expression to tumor anatomical location (p=0.019) and also VEGF to HIF 1a expression (p=0.001), whereas EGFR expression was not associated to EGFR gene copies. Conclusion: According to our results, chromosome 7 instability is correlated to advanced disease, whereas a significant subset of CAs demonstrates an alternative, non- HIF 1a depended mechanism of VEGF overexpression. Furthermore, EGFR protein overexpression does not predict a specific gene deregulation mechanism. © 2010 Zerbinis Medical Publications. Printed in Greece.

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