Background & objective: Up-regulation of a disintegrin and metalloprotease 8 (ADAM8) is correlated with genesis, progression, invasion, and metastasis of tumors. However, the expression of ADAM8, especially its correlation to epidermal growth factor receptor (EGFR), has seldom been reported in non-small cell lung cancer (NSCLC). This study was to investigate expressions of ADAM8 and EGFR in NSCLC, and to analyze their correlations.
Methods: Expressions of ADAM8 and EGFR in 49 specimens of NSCLC, 28 specimens of adjacent lung tissues and 13 specimens of benign lung tissues were detected using tissue microarray (TMA) and immunohistochemistry (IHC). The interrelationship between the two factors and their correlations to clinicopathologic features of NSCLC were analyzed.
Results: ADAM8 and EGFR were mainly expressed in the cytoplasm and on the cell membrane. The positive rates of ADAM8 and EGFR were significantly higher in NSCLC than in adjacent lung tissues and benign lung tissues (73.5% vs. 10.7% and 15.4%, 69.4% vs. 14.2% and 23.1%, P<0.01). The positive rates of ADAM8 and EGFR were slightly lower in squamous cell carcinoma than in adenocarcinoma (73.1% vs. 80.0%, 65.4% vs. 75.0%, P>0.05), while were significantly higher in stage N1-N3 NSCLC than in stage N0 (85.7% vs. 42.8%, 82.8 vs. 35.7%, P<0.01) and significantly higher in stage III-IV NSCLC than in stage I-II (90.0% vs. 62.1%, 90.0% vs. 65.5%, P<0.05). The expression of ADAM8 was positively correlated to EGFR (r=0.589, P<0.01), with a kappa value of 0.522.
Conclusion: ADAM8 and EGFR are overexpressed in NSCLC, and their expressions are consistent.