Expression of Critical Genes Involved in EGFR-Signaling Pathway in HNSCC
Alexis Bousamra, Haihong Zhang, Steve A Schichman, Chunyang Fan. Univ Arkansas for Med Sciences, Little Rock, AR; Central Arkansas Veterans Healthcare System, Little Rock, AR
Background: The Epidermal Growth Factor Receptor (EGFR) signaling pathway appears critically important in the pathogenesis of head and neck squamous cell carcinomas (HNSCC).Therefore, there has been immense interest in exploring targeted therapies aiming at EGFR, using either EGFR tyrosine kinase inhibitors (EGFR-TKI) or anti-EGFR monoclonal antibodies (EGFR-mab) for HNSCC. Because only a subset of HNSCC patients shows favorable responses to EGFR targeted therapy, correct selection of patient population who is destined to benefit from EGFR targeted therapy is important to improve the efficacy and efficiency of EGFR-targeted therapy in HNSCC.
Design: Total RNA samples were extracted from 8 cultured HNSCC cell lines and 1 immortalized normal keratinocyte cell lines, followed by real-time RNA analyses for the following genes involved in the EGFR signaling pathway: EGFR, E-cadherin, PTEN and SCOS1.
Results: EGFR and PTEN genes are overexpressed in 7 out 8 (87%) HNSCC lines with an average increase of 5.8 and 2.5 folds respectively when compared to normal keratinocytes. E-Cadherin gene is down regulated in 6 out of 8 (75%) HNSCC lines with an average decrease by 61% when compared to normal keratinocytes. The average SOCS1 expression in HNSCC lines is slightly higher in 5 out of 8 (62%) an average increase of 1.2 folds when compared to normal keratinocytes.
Conclusions: Overexpression of EGFR, PTEN and SOCS1 and downregulation of E-cadherin are common in HNSCC and a distinct EGFR signaling pathway gene expression pattern may be used to select for a subset of HNSCC responsive to EGFR-targeted therapies.
Category: Head & Neck
Wednesday, March 21, 2012 9:30 AM
Poster Session V # 183, Wednesday Morning